Download Immigrant background and orthodontic treatment need

School of Health Sciences, Jönköping University
Swedish Dental Journal, Supplement 207, 2010
Immigrant background and
orthodontic treatment need
Quantitative and qualitative studies in
Swedish adolescents
EVA JOSEFSSON
The Institute for Postgraduate
Dental Education, Jönköping
DISSERTATION SERIES NO. 10, 2010
JÖNKÖPING 2010
© Eva Josefsson, 2010
Publisher: School of Health Sciences
Print: Intellecta Infolog
ISSN 1654-3602, 0348-6672
ISBN 978-91-85835-09-6
To all the young people
who took part in these studies
“May God grant me
- the serenity to accept the things that cannot be changed,
- the courage to change the things that can
and
- the wisdom to know the difference.”
An Irish Prayer (Anonymous)
Contents
Abstract ....................................................................................... 5
Preface ......................................................................................... 7
Introduction and review of the literature ....................................... 8
Aims .......................................................................................... 19
Subjects ..................................................................................... 21
Methods .................................................................................... 25
Results ....................................................................................... 33
Discussion ................................................................................. 49
Key findings ............................................................................... 64
Conclusions ............................................................................... 66
Summary in Swedish .................................................................. 67
Svensk sammanfattning…………………………………………… . 67
Acknowledgements ..................................................................... 69
References .................................................................................. 71
Appendix ................................................................................... 84
Paper I-V
Abstract
During the last three decades there has been an increased influx of
refugees and immigrants into Scandinavia. The overall aim of this thesis
was primarily to improve our knowledge of malocclusion and
orthodontic treatment need, both normative and self-perceived, in
adolescents of varying geographic origin. A further aim was to determine
whether any differences with respect to perception of general appearance
and psychosocial well-being were related to geographic origin.
Papers I and II concerned self perceived and normative orthodontic
treatment need. About 500 12-13 year-old subjects, stratified into
different groups: A-Sweden, B-Eastern/Southeastern Europe, C-Asia and
D-other countries, answered a questionnaire and underwent clinical
examination by the author. In paper III the association between the two
variables in papers I and II was investigated. Paper IV was a follow up
study, at 18-19 years of age, of the relationship between geographic
origin and prevalence of malocclusion, self-perceived treatment need,
temporomandibular symptoms and psychosocial wellbeing. In Paper V a
qualitative study of 19-20 year old subjects was conducted, to identify
the strategies they had adopted to handle the issue of persisting poor
dental aesthetics.
The main findings were that at 12-13 years of age, immigrant subjects
had a lower perceived orthodontic treatment need than subjects of
Swedish background. Girls of Swedish background had the highest selfperceived treatment need, whilst girls of non-Swedish background were
most concerned that fixed appliance therapy would be painful. In a few
of the clinical variables measured at 12-13 years of age, the Swedish
group exhibited the greatest space deficiency and irregularity in both the
maxillary and mandibular anterior segments and greater overjet,
compared to the Eastern/Southeastern European and Asian groups. The
clinical implications were negligible. The orthodontic treatment need
according to “Index of Orthodontic Treatment Need - Dental Health
Component” (IOTN-DHC) grades 4 and 5, ranged from 30 to 40 per
cent, without any inter-group differences. There were strong associations
between subjects perceiving a need for orthodontic treatment and
5
IOTN-DHC grades 4 and 5, anterior crossbite and avoiding smiling
because they were self-conscious about their teeth. At the age of 18-19
years, the frequency of malocclusion was similar in all groups. Subjects of
Asian origin had a higher self-perceived orthodontic treatment need than
their Swedish counterparts and a higher frequency of headache than
those of Eastern/Southeastern European origin. Psychological wellbeing
was reduced in nearly one quarter of the sample, more frequently in girls
than boys. No association was found between self-perceived orthodontic
treatment need and psychological wellbeing.
The theory “Being under the pressure of social norms” was generated in
Paper V, and it can be applied to improve our understanding of young
adults who have adjusted to living with poor dental aesthetics and also
aid to identify those who are not as well-adjusted and would probably
benefit from treatment. Undisclosed dental fear is an important barrier
to acceptance of orthodontic treatment in early adolescence.
Despite demographic changes due to immigration, no major change in
the prevalence of malocclusion and normative orthodontic treatment
need has been disclosed. This does not apply to adolescents and adults
who immigrated at an older age.
6
Preface
This thesis is based on the following papers, which will be referred to in
the text by their Roman numerals.
I. Josefsson E, Bjerklin K, Halling A. Self-perceived orthodontic
treatment need and culturally related differences among adolescents in
Sweden. European Journal of Orthodontics 2005; 27: 140-147.
II. Josefsson E, Bjerklin K, Lindsten R. Malocclusion frequency in
Swedish and immigrant adolescents-influence of origin on orthodontic
treatment need. European Journal of Orthodontics 2007; 29: 79-87.
III. Josefsson E, Bjerklin K, Lindsten R. Factors determining perceived
orthodontic treatment need in adolescents of Swedish and immigrant
background. European Journal of Orthodontics 2009; 31: 95-102.
IV. Josefsson E, Bjerklin K, Lindsten R. Self-perceived orthodontic
treatment need and prevalence of malocclusion in 18- and 19-year-olds
in Sweden with different geographic origin. Swed Dent J 2010; 34: 95106.
V. Josefsson E, Lindsten R, Hallberg L R-M. A qualitative study of the
influence of poor dental aesthetics on the lives of young adults. Acta
Odont Scand 2010; 68:19-26.
The articles have been reprinted with the kind permission of the
publishers of the respective journals.
7
Introduction and review of the literature
Immigration
Immigration to Sweden is a post-war phenomenon. In recent years
immigration to Sweden has been immense (Figure 1) and continues to
be high. In 2008, Sweden accepted 101,171 immigrants, the greatest
annual number ever.
120 000
Immigration
100 000
Emigration
80 000
60 000
40 000
20 000
0
1850 ‐60
‐70 ‐80 ‐90 1900 ‐10 ‐20 ‐30 ‐40 ‐50 ‐60 ‐70 ‐80 ‐90 ‐00 2010
Figure 1. Immigration and emigration in Sweden during the years 1850 to 2008.
The most recent immigrants comprise mainly young people: in 2008 the
mean age was 27.8 years for men and 27.2 for women. The citizenship of
169 different countries was represented, but most were people with
Swedish citizenship, who had previously lived in Sweden (Figure 2). The
second largest group of immigrants was of Iraqi origin.
From World War II to 2008, 2.4 million people have moved to Sweden
and 1.4 million have left the country. Thus, in just over 50 years, the
number of foreign-born people in Sweden has increased by around 1
million. From having been almost unnoticeable in the overall
8
population, immigrants have become an inherent part of Swedish
society.
Migration from The Middle East has dominated immigration in recent
decades, together with the influx of refugees from the Balkans in the
1990’s. Since the beginning of the 1970s, immigration has taken on a
somewhat different character: refugees and the associated immigration of
their close relatives have becoming increasingly predominant. At the
same time, labour immigration has been minimal. The number of
asylum seekers depends partly on unrest in different parts of the world
and partly on Swedish immigration policies. One example of this is the
war in former Yugoslavia, which resulted in a substantial flow of asylum
seekers to Sweden in 1992 and 1993.1
Immigration according to citizenship
120000
100000
80000
60000
40000
20000
0
2000
2001
2002
2003
Eastern/Southeastern Europe
2004
Asia
2005
2006
Sweden
2007
2008
Total
Figure 2. Distribution of immigrants to Sweden of Eastern/Southeastern
European, Asian and Swedish origin in relation to total number of immigrants.
9
Definitions
An immigrant is a person who moves from one country to another and
intends to be a resident of the new country for a period of at least one
year.1 Statistical yearbook of Sweden2 has introduced the term “person of
foreign background” as a synonym for the term “immigrant”, to define a
person’s relationship to the country in which he or she lives. Today, the
Swedish authorities define people of foreign background as follows:
”People of foreign background are those born outside Sweden, or born in
Sweden, with two foreign-born parents”. In December 2003, the
definition of this term was adopted by the Swedish authorities to replace
the earlier description of people of ”immigrant background” which had
included those with at least one foreign-born parent.
Immigrants’ children who are born in Sweden are not by definition
immigrants, but are often referred to as ”second generation immigrants”.
Immigrant background – earlier description of people born outside
Sweden or born in Sweden with at least one foreign-born parent.
Foreign background – foreign-born people, or people born in Sweden
with both parents born outside Sweden.
Ethnicity – is a description for a number of attributes such as genetic
inheritance and ancestry, religion and culture (including diet, language,
dress and lifestyle). “Ethnicity” is defined in the UK as “a group with a
long-shared history and a distinct culture”.3 An ethnic group is a group
of humans whose members identify with each other, through a common
heritage that may be real or presumed.
Culture – refers to shared patterns, meanings and behaviors of a social
group. It generally refers to patterns of human activity and the symbolic
structures that give such activity significance.3 Cultures can differ in a
number of ways. These differences are based on combinations of values
and norms. Cultures are often based on some sort of religion or faith.
Cultural changes may occur, in response to the environment (including
education and socioeconomic status), to inventions and to contact with
other cultures.
10
Immigrants in Sweden
Data on the number of immigrants in Sweden vary, depending on how
the term "immigrant" is defined. At the end of 2008, there were
1,281,581 foreign-born persons in Sweden. The majority, about
176,000, were born in Finland, 109,000 in Iraq and 72,000 in Former
Yugoslavia. It is estimated that there are around 380,000 Swedish-born
people, both of whose parents were foreign-born. Around one seventh, or
16 per cent, of Sweden's population comprises people of foreign
background, such as foreign-born people, or people born in Sweden, but
both of whose parents are foreign-born. Moreover, almost 624,000, i.e.
about 7 per cent of the population are Swedish-born but with one
foreign-born and one Swedish-born parent.
In the year 2000, approximately 24 per cent of children and adolescents
(0-17 years) were of non-Swedish origin, i.e. he or she, or at least one of
their parents was born outside Sweden.4 Only eight years later, in 2008,
the corresponding frequency was 27.9 per cent.2
This demographic change has raised many issues related to integration of
refugees and immigrants from different cultural backgrounds into
Swedish society. One important issue is the provision of appropriate
education and healthcare for children with parents of foreign
background. A change towards a society of greater ethnic heterogeneity
per se does not necessarily imply an increase in health-related problems
among adolescents, but because of the rapid change which has occurred
in Sweden there may well be a change in the spectrum and a shift in the
relative frequency of such issues. The diversity of background among
adolescents needs to be recognized, not only by health professionals, but
also by policy-makers.
Two factors with important implications for planning of orthodontic
services are the frequency of malocclusion and orthodontic treatment
need. Whether the major demographic change described above is
influencing the frequency and type of malocclusion and orthodontic
treatment need in Swedish adolescents has not been determined.
11
Malocclusion frequency, orthodontic treatment need and
demand in Sweden
The prevalence of malocclusion in a population is a fundamental
determinant of appropriate levels of orthodontic services. From a
planning perspective, the importance of epidemiological studies to
provide current data on the prevalence of different types of malocclusions
and orthodontic treatment need in a population cannot be
overestimated.5
Thirty-five years ago, the frequency of malocclusion in the Swedish
population, i.e. deviations from normal dental arrangement (ideal
occlusion), was estimated to be about 75 per cent.6,7 Twenty years ago,
studies in Norway and Denmark reported that about 30-40 per cent of
children and adolescents underwent orthodontic treatment8-10 A recent
study stated that the frequency of treated children and adolescents in
Nordic countries varied between 11 and 35 per cent and in Swedish
children and adolescents, about 20 to 40 per cent, with a mean value of
27 per cent.11 However, there are no epidemiological studies describing
the current frequency of malocclusion in Sweden: early orthodontic
treatment has eliminated some types of malocclusion and thus it is no
longer possible to determine the exact prevalence.
Demand for orthodontic treatment is increasing in many countries, but
not all malocclusions need to be treated. In Sweden, orthodontic
treatment is provided under the auspices of the public dental services, as
part of the comprehensive provision of dental care for children,
adolescents and young adults up to the age of 20 years. Priority is based
on greatest need, i.e. highest priority is given to a malocclusion associated
with risk of tissue damage, functional disturbances or psychological
problems.12
In countries where orthodontic treatment is subsidized to some extent
by public funding, different indices are used to determine eligibility for
such treatment.13-16 These indices are based on professional assessment of
severity of malocclusion. Some indices also include assessment of
aesthetics. Indices may be classified according to their different purpose:
Diagnostic, Epidemiological, Treatment need, Treatment success and
Treatment complexity.17
12
Indices for estimation of treatment need are used to select patients for
treatment, but also to exclude patients with minor orthodontic
conditions from being eligible for treatment. Whether these indices select
the same patients or not, is an important question. A comparison of
three indices when a group of orthodontists set the gold standard
resulted in good agreement after adjusting the cut-off points for the
different indices.18 A recently published study from Stockholm, Sweden,
reported no agreement at all,19 when an index that has been debated, was
used.20 The cut-off point for eligibility for subsidized treatment is a
political rather than a clinical issue.
Over the years, numerous indices for estimating treatment need have
been introduced: Grainger introduced the Treatment Priority Index,
TPI,21 in 1967 the index from the Swedish National Board of Health,
Swe NBH was introduced,22,23 Indication Index, developed by
Lundström,24 the Orthodontic Indication Index according to Bergström25
and OMFI, Occlusal Morphology and Function Index.26
The Index of Orthodontic Treatment Need (IOTN) has facilitated more
objective assessment of treatment need, incorporating both a dental
health component (DHC)27 and an aesthetic component (AC).28 Details
of the DHC and representative photographs of the AC have been
published.27 The validity and reliability of the IOTN have been
established 29,30 but not without discussion and debate.31-33 Mohlin et al.33
has shown that IOTN-DHC is not adjustable for all ages and offers very
limited help when selecting patients in the middle of the range of severity
of malocclusion. Some authors have reported a more favourable patient
rating of the aesthetic component than the professional rating.34
Objective and subjective orthodontic treatment need was studied in 8 to
16-year-olds in different parts in the Stockholm area.35 The results
showed that objective treatment need ranged from 24 to 29 per cent and
subjective treatment need from 22 to 30 percent. The authors concluded
that neither the objective, nor the subjective need for orthodontic
treatment exhibited any tendency to decline.
When 19-year-olds leave the free Public Dental Service in Sweden, some
36,37
have persisting functional malocclusions or poor dental aesthetics.
One reason may be that in early adolescence, their malocclusion traits
had been assessed as mild deviations from the normal, for which no
13
treatment was offered. Another reason may be that at the time treatment
was offered, in early adolescence, the individual was not concerned about
the appearance and function of the dentition and declined the offer of
orthodontic treatment. A third reason may be relapse of earlier
treatment.
An earlier study of orthodontic care in three different counties in Sweden
showed that 28 to 42 per cent of all inhabitants up to 20 years of age
had undergone orthodontic treatment.38 Residual treatment need and
demand in these young people when they leave the Public Dental Service
have also been investigated. In several studies of Swedish 19-year-olds,
residual definite orthodontic treatment need is estimated at twenty per
cent 37,39 and subjective demand for treatment at about 8 per cent.37,40
Frequency of malocclusion, orthodontic treatment need
and demand in relation to geographic origin
Earlier studies have shown that occlusal characteristics and the prevalence
of occlusal anomalies vary in different populations and ethnic groups.
Thus orthodontic treatment need varies among children of different
foreign origin.41-46 Orthodontic treatment uptake is also influenced by
socioeconomic, ethnic and cultural factors.43 The prevalence of
malocclusion and treatment need in different populations have been
investigated in numerous studies (Table A).5,6,35,41,42,44-61 The reported
frequencies of malocclusion vary from 39 to 93 per cent.50,62 This wide
range may be attributable to differences in registration methods63,64
and/or differences in the ages of the populations examined, but may also
have a genetic basis.
In most countries, there is increasing demand for orthodontic treatment.
In this context, the importance of self-perceived orthodontic treatment
need should not be underestimated. The major factors determining a
patient’s perceived need for treatment may broadly be described as
aesthetic, functional, financial or social.65 While the orthodontist is
obliged to prioritize function and occlusion in objective assessment of
treatment need5,14,16,48,66,67 the patient might perceive other factors to be
just as important. A questionnaire study by Fox et al.68 found that
14
aesthetics were of greater concern to children seeking orthodontic
treatment than to other children.
Cultural or geographic origin can also influence self-perceived treatment
need and demand.35,69,70 Although family, cultural background and ethnic
origin are acknowledged as highly influential in shaping children’s
attitudes, the perspectives of refugee and immigrant children and
adolescents may be further modified as they adapt to life in a new
country and are exposed to the cultural values of their Swedish peers:
sometimes the influence of foreign origin may be only minor.69 The
extent to which the perspectives of refugee children and adolescents are
modified by this exposure is not known.
The relationship of gender to frequency of malocclusion has been
addressed in several investigations, with conflicting results. The majority
opinion seems to be that there are no major gender differences in
objective orthodontic treatment need,71 but some studies have reported
higher frequency and more severe malocclusion in males.7,72,73 A higher
normative treatment need in girls has also been shown.69 Sex differences
have been reported for some specific malocclusion traits: higher
frequency of anterior crossbite,5,74 maxillary overjet and spacing in males
and crowding in girls.5 O’Brien showed a strong association between
gender and uptake of orthodontic treatment:75 being female increases the
odds of receiving orthodontic treatment.49
In a study of Chinese schoolchildren, Wang et al.52 found a very high
orthodontic treatment need (Grades 4 and 5) in 37 per cent: about 27
per cent were keen to receive treatment. A definite relationship was
found between negative self-appraisal of dental appearance and demand
for orthodontic treatment.
Objective and subjective orthodontic treatment needs have been studied
in children and teenagers living in the Stockholm area. The highest
prevalence was found in areas with a large immigrant population. In all
the investigated areas, the subjective demand for treatment was 1-1.5 per
35
cent less than the objective need.
An American study reported a higher objective treatment need in white
children than in black, but the latter were less satisfied with their smile.
No gender differences emerged with respect to either objective or
15
subjective treatment need.76 Mandall et al.69 found no differences in selfperceived treatment need between Caucasian and Asians.
In this context, little is known about the attitudes of Swedish
adolescents. Are perceived need and attitudes to dental appearance and
orthodontic care among adolescents of foreign background different
from those of their Swedish-born cohorts? Are any differences in
attitudes among adolescents of immigrant background related to their
specific family backgrounds, e.g. do the attitudes of those of Middle
Eastern origin differ from those of eastern European origin?
Given that nearly 30 per cent of the Swedish population under 20 years
of age has at least one foreign-born parent and in nearly 20 per cent of
cases both parents are foreign-born, the answers to these questions may
have important implications with respect to policies for provision of
appropriate orthodontic services in Sweden. To date there are few such
studies which take these issues into account.
Malocclusion and psychological well-being
It has long been recognized that people seek and undergo orthodontic
treatment, not because of the anatomic irregularities per se or to prevent
the destruction of tissue within the oral cavity, but because of the
aesthetic impact of the malocclusion.77 During the past two decades, this
topic has been investigated intensively and specially with reference to the
association between malocclusion and oral health-related quality of
life.78-82 The relevant question in relation to aesthetics is whether
malocclusion contributes to psychological problems or dissatisfaction
with appearance. It appears that much orthodontic treatment was being
justified on psychological grounds for which there was little direct
evidence. Without objective evidence of a long-term positive effect of
orthodontic outcomes on psychological well-being, the issue cannot be
fully investigated and will not be resolved.83
In Sweden, psychological factors were highlighted as an indication for
orthodontic treatment in 199112 but internationally had warranted
attention even earlier.84,85 Orthodontic treatment should not be
motivated solely by reduced function.
16
In an evaluation of the short-term effects of orthodontic treatment,
Kenealy et al.86 concluded that there was little support for the hypothesis
that poor dentition has a negative effect on children’s psychological wellbeing. If this is so, then why is there such a high demand for orthodontic
treatment? This question raises issues to do with physical appearance and
attractiveness. The notion of perfect teeth is strongly related to a concept
of beauty that embodies the ideas of goodness, wealth and happiness.
Social expectations contribute to cultural definitions of beauty and the
literature on physical attractiveness suggests that appearance may be a
potent source of social stereotyping.
Opinions differ about the influence of orthodontics on psychological
well-being. In a study of children with Class II malocclusion, O’Brien87
found an increase in self-esteem in children who received early treatment,
compared to controls, at least in the short term. A review article by Liu et
al.88 drew the conclusion that there is an association between
malocclusion/orthodontic treatment need and poor health-related quality
of life and that they coexist in the same population.
In a follow-up study on 31-year-olds, Shaw et al.89 did not find any
differences concerning satisfaction with own dentition, between treated
and untreated, when pre-treatment self-esteem in 1981 was factored in.
Furthermore, Kenealy et al.83 found that when the current level of selfesteem was controlled for, it emerged that in patients with a prior need
for treatment, orthodontic treatment had had a significant effect on
dental status and dental attractiveness, as would be expected, but no
significant effect on psychological health, life satisfaction, quality of life
or health status. These findings are consistent with those of Albino90, that
dental-specific evaluations appear to be influenced by treatment, while
more general psychosocial responses are not. Visible malocclusion has no
discernible negative effect on social and psychological well-being, and
orthodontic treatment has no discernible positive effect.
Orthodontics cannot be justified on psychological grounds alone,
although there are minor psychological effects that contribute to an
individual’s perception of self-esteem. From a phenomenological
perspective, the dentition is important to the individual’s perception of
self during adolescence. However, by adulthood, other psychological and
17
social factors are of greater importance to general health and
psychological well-being.83
18
Aims
The present thesis is based on a six-year longitudinal study, from 2001 to
2007, of malocclusion and orthodontic treatment need and uptake in a
representative sample of Swedish subjects, initially aged 12-13 years.
The overall aim was to investigate the potential influence of specific
immigrant background on such issues as frequency of malocclusion,
treatment need and barriers to orthodontic treatment uptake in early
adolescence; and to identify, in late adolescence, differences between
native born and immigrants with respect to frequency of malocclusion
and self-perceived treatment need and to highlight the main concerns of
young adults with poor dental aesthetics.
Paper I
To compare 12- and 13-year-old boys and girls of Swedish and
immigrant backgrounds, with special reference to the following:
self-perceived need for and attitude to orthodontic treatment
attitude to own teeth and general appearance
behavioral pattern and psychosocial functioning
self-perceived need for orthodontic treatment in relation to psychosocial
functioning.
Paper II
To compare the frequency of malocclusion and orthodontic treatment
need in 12- and 13-year olds of Swedish and immigrant background.
Paper III
To investigate the association between self-perceived orthodontic
treatment need and malocclusion in 12-13 year-olds of Swedish and
immigrant background.
19
Paper IV
To record current orthodontic treatment need in a follow up study of
18-19 year-olds and to analyze any differences related to geographic
origin, with special reference to the following: frequency of malocclusion,
self-perceived treatment need, previous orthodontic treatment, current
interest in treatment, body esteem and psychological wellbeing and
prevalence of symptoms of temporomandibular disorders.
Paper V
To apply a grounded theory approach to generate a theory highlighting
the main concerns of young adults, 19-20 years of age, with poor dental
aesthetics and the measures they adopt to manage this condition in
everyday life.
20
Subjects
In this thesis the following nomenclature has been used:
Early adolescence – subjects 12-13 years of age
Late adolescence – subjects 18-19 years of age
Young adult – subjects 19-20 years of age
During the years in which the studies were conducted, the criteria
applied in Sweden to describe “a person of immigrant background” were
officially changed. To allow comparison of the results of early and later
studies, the earlier definition was retained throughout the studies, i.e. a
person of immigrant background is defined as someone with at least one
parent born abroad.
The initial population sample in papers I-III comprised 553 subjects: all
the 12-13 year olds (born 1988 and 1989), in six schools in Jönköping
and Motala. Jönköping, with 125,000 inhabitants, is one of the largest
ten cities in Sweden; Motala is smaller, with 42,000 inhabitants. The
uptake areas for these schools had a mixed socio-economic structure and
the immigrant frequency was higher than the Swedish national average.
In the present studies the term “immigrant” denotes a subject with at
least one parent born outside Sweden. On the days on which the
examinations were conducted, 37 subjects were absent from school due
to illness and some declined to participate: 8 in Paper I and 23 in Paper
II, respectively.
The remaining students were stratified into four groups according to
family origins,
A – Subject and both parents born in Sweden
Subject or at least one parent born in: B – Eastern/Southeastern Europe
(Albania, Bosnia-Herzegovina, Kosovo, Croatia, Hungary, Former
Yugoslav Republic of Macedonia, Poland, Romania, Serbia, mainly
former Yugoslavia), C – Asia (Cambodia, China, Lebanon, India, Iran,
Iraq, Pakistan, Syria, Turkey, Vietnam, mainly Middle East) and D –
other countries (Africa, America, Western Europe except Scandinavian
countries).
21
Two children were adopted and were included in group A in Paper I,
and stratified according to parents’ origin in papers II and III. In the case
of eight subjects, both parents were foreign-born, but were not from the
same geographic area (B,C,D): these subjects were grouped according to
the mother’s origin.
For 97 per cent of the subjects from Eastern/Southeastern Europe, 92
per cent from Asia and 44 per cent from other countries, both parents
were born outside Sweden. Of the 97 per cent of subjects in the
Eastern/Southeastern European group with both parents born outside
Sweden, the parents of 94 per cent had both been born in
Eastern/Southeastern Europe. In groups C and D, the parents of 86 per
cent in each group had both been born in the same region. In the
Eastern/Southeastern European group (B), no mothers and two fathers
were born in Sweden. In the Asian group (C), seven mothers and no
fathers were born in Sweden and in the other countries group (D), 16
mothers and 12 fathers were born in Sweden.
The sample in Paper III was selected from that in papers I and II, but
was restricted to subjects with both parents born in the same area. Three
groups were selected according to family origin:, A - Sweden, B Eastern/Southeastern Europe (Former Yugoslavia) and C - Middle East
(Lebanon, Iraq and Syria). The group “other countries” was excluded in
this paper because of its diversity.
Six years after the initial examination, a follow-up study, including reexamination, was conducted on the same sample. The subjects were now
aged 18-19 years (Paper IV). Of the initial study sample, 482 were still
living in one of the two town areas. There were 186 non-responders, but
53 of them were interviewed by telephone. The subjects were stratified as
in papers I and II. Group D, (other countries), was excluded as it was
inhomogeneous and the results from the questionnaire and clinical
examination did not differ substantially from the other groups.
In Paper V, 13 subjects, six males and seven females, aged 19 to 20 years,
were strategically selected from the sample in Paper IV. The selection was
based on gender, family origin (native born or immigrant) and persisting
poor dental aesthetics. With respect to origin, both the parents of seven
subjects were Swedish born and the parents of the remaining six had
both been born in either Asia or Former Yugoslavia. The following
22
inclusion criteria were applied: persisting poor dental aesthetics, defined
as overjet ≥6mm, overjet <-1 mm or contact point displacement >4mm
or contact point displacement 2-4 mm in combination with strained lip
closure.
Thus in the different studies (I-V), the number of subjects varied from
13 to 508. The distribution of subjects according to geographic origin,
gender and attrition is presented in Figure 3.
Ethical considerations and informed consent
The research design of all five studies was approved by the Research
Ethics Committee, Faculty of Health Sciences, Linköping University,
Sweden (Dnr 01-020, M5-07, T118-07). The requirements with respect
to informed consent and confidentiality were fulfilled.
For subjects aged 12 or 13 (papers I-III), an informed consent form was
sent to parents, to be signed before the initial examination. Before the
second examination (Paper IV), an informed consent form was sent to
students, to be signed before the examination. In Paper V, an informed
consent form was signed by the young adult before the interview started.
23
Paper I
553
45 dropouts
B – 61 C – 127
D – 50
60 dropouts
493 A – 263 B – 64 C – 118
D – 48
508
A – 270
253 males 255 females
Paper II
553
Paper III
379 A – 269 B – 56 C – 54
191 males
188 females
Paper IV
482
186 dropouts
344 296 (clinical exam) + 53 (interview by telephone)
5 (ongoing treatment)
28 (group D)
316
268 (clinical exam) + 48 (interview by telephone)
A – 178 B – 50 C – 88
150 males
166 females
6 males
7 females
Paper V
13
Figure 3. Distribution of number of subjects according to gender and
geographic origin in the separate studies.
A – Sweden, B – Eastern/Southeastern Europe, C – Asia, D – other countries
24
Methods
Paper I
A questionnaire study was conducted. The questionnaires were answered
in the classroom by the subjects attending school that day.
The responses to the questions were designed as a mix of fixed
statements, multiple choice, free answers and five-point scales,
(Appendix, Table B). The questionnaire comprised seven domains:
Demographic data: This domain contained 4 questions (1-4), about
sex, place of birth and parents’ geographic background. The responses
were designed as fixed statements and free answers.
Experience of orthodontic treatment: The responses to these two
questions (5-6) were fixed statements, giving information about any
previous orthodontic treatment.
Satisfaction with own teeth: The response to Question 7 was on a 5point ordinal scale, and to Question 8 on a 5-point scale which has
previously been used in modified form.69,85
Self perceived treatment need and attitude to orthodontic treatment:
This domain contained 3 questions (9-11): one question with a 5-point
ordinal scale and two questions with multiple choice responses.
Questions 9 and 10 have previously been used in modified form.85
Body esteem and general appearance: This domain contained six
questions. The responses were all 5-point ordinal scales, 12 a-e91 and 14.
Behavioural pattern: These two questions, 13 a-b, were constructed
with 5-point scale responses and have been used previously.85
Psychosocial functioning: The responses to questions about
psychosocial functioning (15 a-i) were pooled to an amalgamated index.
Summary score 9-45. A low value indicates good psychosocial
92
functioning.
Reliability
Reliability tests were conducted on 50 randomly selected 12- and 13 year
old subjects. They were presented with the same questionnaire after an
interval of four weeks. Their initial answers were included in the study.
25
Only questions with good and very good reliability were retained for
inclusion in the final questionnaire.
Paper II
The registrations in this paper included clinical examination,
examination of radiographs (panoramic and intraoral) and patient
records.
The clinical examination comprised extraoral inspection, including the
soft tissues and intraoral inspection of the teeth and classification of
occlusion. An assessment was also made according to the dental health
(DHC) and aesthetic components (AC) of the Index of Orthodontic
Treatment Need (IOTN)27 (Appendix, Table C, D, E). To determine the
normative treatment need, several variables were registered (Appendix,
Table E). The IOTN-DHC classification was made on completion of all
registrations.
The AC was estimated both by the examiner and the subject.
For subjects undergoing treatment with fixed or functional appliances,
(n=25 and n=14 respectively), registrations were made on pre-treatment
study models. No IOTN-AC classification was made for these subjects.
For the 30 subjects who had previously undergone treatment with
functional appliances, assessment was based on post-treatment status.
With respect to orthodontic treatment with other types of appliances,
mainly space-maintainers, lingual arch appliances and expansion-plates,
42 had previously undergone treatment and 22 were currently
undergoing treatment. The existing conditions were registered in these
subjects, but the soft tissue registrations were excluded in those with
ongoing treatment.
Reliability
To test reliability, 25 12-year-olds and 25 13-year-olds, selected at
random, were re-examined after an interval of four weeks under the same
conditions. Variables with good and very good reliability were retained
for inclusion in the final study, and also two variables with moderate
reliability (“Rotation” and “IOTN-AC subject”). The variables excluded
26
were “Short upper lip” and “Midline deviation”. The initial registrations
were used in the study.
Paper III
This study was based on parts of the questionnaire and registrations
previously used in papers I and II. The questionnaire was an abbreviated,
modified version of that used in Paper I (Appendix, Table F). Some
clinical variables were recorded to determine the presence of any
malocclusion with a potentially detrimental impact on aesthetics
(Appendix, Table G).
Radiographs (panoramic and intraoral) and patient records were
examined. The subjects were classified according to the Dental Health
Component of the Index of Orthodontic Treatment Need
(DHC-IOTN). 27
For subjects currently undergoing orthodontic treatment with fixed or
functional appliances, registrations were made on pre-treatment study
models and soft tissue registrations were excluded. In subjects who had
earlier undergone treatment with functional appliances, assessment was
based on post-treatment status. With respect to other appliance therapy,
mainly with space maintainers, lingual arch appliances and expansion
plates, existing conditions were registered in these subjects.
From the questionnaire, the answer to the question “Do you think that
you need a brace today?” was selected as representing individual, selfperceived orthodontic treatment need. The characteristics of the group of
subjects with a positive response to this question were compared with
those with a negative response, and then tested in relation to the clinical
variables, the demographic data, and to the other items in the
questionnaire.
The subjects currently undergoing orthodontic treatment with functional
or fixed appliances (n=27) were statistically tested in relation to selfperceived treatment need and their opinion of their own teeth in relation
to those of their peers, compared with the other subjects (questions 5 and
3, Table F).
27
Paper IV
This was a follow-up study, comprising a questionnaire and a clinical
examination.
Questionnaire study
The questionnaire was in many respects identical with that in Paper I.
The responses were designed as a mix of visual analogue scales (VAS),
multiple choice, five-point ordinal scales and fixed statements (Appendix,
Table H). It comprised the following seven domains:
Demographic data: This domain contained 3 questions (1-3), about
sex, place of birth and parents’ geographic origin. The responses were in
the form of fixed statements and free answers.
Experience of orthodontic treatment: This question (4), designed with
responses in the form of fixed statements, gave information about any
earlier treatment with appliances or extractions.
Self-perceived treatment need, attitude to orthodontic treatment:
The responses to these questions (10, 5) were multiple choice with 3
fixed statements.85
Satisfaction with, and importance of dental appearance: This domain
contained 2 questions (6, 9) designed as a 5-point ordinal scale.85
Question 7 was answered by “yes” or “no”: a “yes” response was further
analyzed on a VAS, with the end phrases “disappointed” and “much
disappointed”. Question 8 was assessed on a VAS, with the end phrases
“unlikely” and “likely”.
Temporomandibular symptoms: These 4 questions (11a-d) were
answered “yes” or ”no”.
Body esteem and general appearance: Responses to Questions 12-14
91
were on a 5-point ordinal scale. Question 12 has previously been
validated and found useful for patients referred for orthognathic
surgery.93
Psychological wellbeing: This domain contained 12 questions (15-26)
with 4-point scales, which are used by the Swedish National Institute of
Public Health (general health questionnaire) and have been validated and
described previously.94 The measure of wellbeing is calculated by a
summary index of the twelve questions. The first two choices of response
28
to each question are given a score of zero, and the third and fourth
choices are given a score of 1. The summary variable ranges between 0
and 12. A dichotomous variable is constructed. If the summary is lower
than 3, the index value is 0. If the summary is 3 or more, the index value
is 1. Subjects with an index value of 1 are denoted as having reduced
psychological wellbeing.
Clinical examination
The clinical examination was conducted in an orthodontic department.
The examination comprised intraoral inspection of the teeth and
occlusion and palpation of the temporomandibular joint (TMJ) and
muscles (Appendix, Table I).
Reliability and validity
Thirteen subjects, selected at random, answered the questionnaire a
second time, after an interval of four weeks. The association between the
first and second rounds of responses was calculated. Questions and
answers with a correlation of 0.6 to 1.0 were included in the study.
Question 9, with moderate reliability, was also included.
The reliability of the clinical examination of occlusion had been tested in
an earlier study, Paper II. Variables with good and very good reliability
were retained for inclusion in this study. The examiner (EJ) was
calibrated with an experienced specialist in stomatognathic physiology
with respect to muscle and TMJ palpation and tooth wear.
The validity of the questionnaire was verified by asking the participants if
they considered the questions and items to be relevant for describing
their perception of their teeth and their general appearance. The domain
94
“Psychological well-being” had been validated previously.
Paper V
Grounded theory
This investigation had a qualitative approach and was based on classic
grounded theory methods.95 Thus, we did not set out with a hypothesis
or a theory. Instead, we started with an area of interest: data were
29
collected and analysed. Sequential analysis and stratification eventually
disclosed a number of related problems which could be conceptualized.
From this concept, a theory could be developed.
Data collection
An interview in conversational style was conducted with each participant.
An interview guide was used. The interviews covered different topics
such as family situation, geographic origin, history of any earlier
orthodontic consultation and treatment, factors influencing the decision
to undergo or not to undergo treatment, consequences of the decision,
dental appearance, body image, interpersonal relationships and future
aspirations. The interviews were tape-recorded and transcribed by the
interviewer. Thus collection and analysis of data were a continuous
process (i.e. each interview was analyzed as soon as it had been
transcribed), closely related to process of theory-generation.
Data analysis
Each interview was analyzed line-by-line as soon as collected. Initial
codes, capturing the meaning of the data, were identified. Codes with
similar meaning were clustered to form more comprehensive categories.
The categories were then compared and further analyzed by identifying
their properties or dimensions, that is, subcategories were formed.
Thus by constantly comparing codes with each other and clustering
those of similar meaning into categories, which were also constantly
compared for similarities and differences, the data were conceptualized,
i.e. organized into a simplified form. In the analysis, the subjects’
descriptions were gradually raised to a more abstract level, in order to
highlight the basic pattern underlying the participants’ collective words.
During this process, we also asked questions about the data: What is this
all about? How can we define it? What is the main concern? How do the
informants manage this concern? The analytical process disclosed a core
category, which was central to the data and highlighted the participants’
main concern. The core could be related to all other categories and
subcategories. Then theoretical sampling was performed, with the
purpose of “saturating” each category with additional information from
new or existing data. Saturation implies that new data do not contribute
30
new information or that new data fit into existing categories. Memos
were made during the analytical process. These included pictures, short
reflections and assumptions based on the data.
Reliability and validity
The reliability of a qualitative study denotes the quality of the measuring
instruments. In this study the reliability was dependent on the quality of
the researcher: i.e. the ability to conduct interviews of high quality and
objectivity, the ability to follow the information and to be flexible.
Reliability is also described as good when the same information
repeatedly emerges from the data.
In a qualitative study, validity is often described in terms of credibility
and trustworthiness ensured by checking, questioning and theorizing.96
In the present study, the validity was tested during the process of data
collection and analysis, that the work was performed in a reliable way.
Good validity was declared when quotes from the interviews
corresponded well with the categories. Questions were asked continually:
what is being investigated and why?
Statistical analysis
Reliability (test- retest correlation)
Reliability (test-retest correlation) for each question in papers I and III
97
was tested by using the weighted Kappa statistic (Cohen’s Kappa, •). A
Kappa-value of 0.00-0.20 was denoted as slight agreement, 0.21-0.40
fair, 0.41-0.60 moderate, 0.61-0.80 substantial and 0.81-1.00 as almost
perfect agreement.98 Inclusion in the study was restricted to questions
and variables with Kappa values of 0.61-1.00, with the exception of one
variable of moderate reliability in Paper III (the question “Do you avoid
smiling because of your teeth?”), with a Kappa value of 0.53).
In Paper IV, the test-retest correlation for questions with both
ordinal/nominal scales and questions with continuous scales was
calculated by Spearman’s ranking correlation test (correlation coefficient
r).97 Questions and answers with a correlation r > 0.6 were included in
the study.
31
In the clinical examinations in papers II-IV, Kappa statistics were used
for intra-observer agreement, and also for the subject and orthodontist
AC-scores in Paper II. Variables with continuous scales were transformed
to ordinal scales. Variables with Kappa values of 0.61-1.00 were retained
for inclusion in the final studies.
Three variables of moderate reliability (Paper II: “Rotation” and “IOTNAC subject” with Kappa values of 0.55 and 0.54, respectively and
Question 9 in Paper IV) were also included. The reason for this was that
the information from these variables were assessed as important for the
studies. All Kappa scores were supplemented with percentage of
agreement.
Descriptive statistics
Descriptive statistics such as median value, mean value, standard
deviation and range were used (paper II-IV).
Intergroup differences
The non-parametric method Chi-square test was used to assess
differences in distribution between the groups, when categorical variables
were tested. When this method showed a difference in distribution or if
the method did not fulfill the requirements, the Mann-Whitney-U test
or the Kruskal-Wallis method was used (papers I, II, IV). Intergroup
differences in responses to question 15 in Paper I were tested by analysis
of variance (ANOVA).
In Paper II, the analysis of variance was followed by a post hoc test to
disclose details in the differences. For analysis of median and mean values
in the different groups the Kruskal-Wallis test was used in Paper II and
ANOVA in Paper IV.
In Paper III, the association between “self-perceived treatment need” and
the variables was analyzed by logistic regression using the odds ratio and
p-value. When more than one dependent variable was tested, multiple
regression analyses were used.
The Kruskal-Wallis test was used to compare the median values on VAS
scales for the three groups and between sexes (paper IV).
Significance was set at p<0.05.
32
Results
Reliability and validity
In Paper I, tests of the reliability of the answers disclosed variations in
Kappa values between 0.63-0.95 and a percentage agreement between
71-95%. When the reliability of the clinical examination and the
estimation of IOTN was tested in Paper II, variations in Kappa values
between 0.50-1.0 was disclosed and a percentage agreement between 50100%. In Paper III, the Kappa values for both the questionnaire and the
clinical variables varied between 0.53-1.0. The reliability for the
questionnaire in Paper IV, varied with a correlation rs 0.54 – 1.0. The
validity of the questionnaire in Paper IV was tested with two questions.
“Do you think that the questions you have answered allow you to express
your perception of your teeth?” This question was constructed as a VAS
(0-100) and the result showed an overall mean value of 76.3 and a
median value of 80. The median value was 77 for boys and 83 for girls,
p=0.050 for differences between sexes.
“Do you think the questions you have answered allow you to express
your perception of your general appearance”? This question was
constructed as a VAS and the result shows an overall mean value of 78.3
and a median value of 80. There was a significant difference between the
sexes: the median was 77 for boys and 84 for girls, (p=0.021).
Frequency of malocclusion
There were no significant inter-group differences with respect to
frequency of sagittal occlusion, crossbite, scissors bite, RP-IP difference,
deep bite with gingival contact, or proclination or retroclination of the
maxillary and mandibular incisors at 12-13 years of age (Paper II).
With respect to distribution of Class II and Class III malocclusions at
18-19 years of age, there were significant differences between subjects of
Swedish and Asian origin: Class II malocclusions were recorded in 21.6
per cent of subjects of Swedish origin and 32.3 per cent of those of Asian
33
origin (p=0.042). The corresponding values for Class III malocclusions
were 3.7 per cent and 10.8 per cent respectively (p=0.016), (Paper IV).
No significant differences were disclosed for the variables deep bite with
gingival contact, or posterior or anterior crossbite (Paper IV).
At 12 and 13 years of age, the mean value for overjet in groups A and D
was 4.3 mm and 3.9 and 3.6 mm in groups B and C, respectively, with a
significant difference between subjects of Swedish and Asian origin,
p=0.003 (Paper II). In the follow up study (Paper IV), the mean overjet
ranged from 3.0 to 3.6 millimeters, with no significant intergroup
differences. The mean value for overbite did not differ among the groups
(papers II, IV)
Alignment anomalies
Subjects of Swedish origin exhibited a higher number of rotated
maxillary incisors than those of Eastern/Southeastern European origin, at
the age of 12-13 years. Overall, rotation was more frequent for lateral
than for central incisors. Tipping of maxillary central incisors was similar
in the four groups, but tipping of maxillary lateral incisors was more
frequent in group A than in group B or C (Paper II).
Anterior available space and contact point displacement
In the initial study (Paper II), all groups showed a space deficiency in the
anterior segments of both jaws. In group A, lack of space in the maxillary
anterior segment was 2.1 mm, which was significantly different from
groups B and C (1.2 mm). The difference in anterior available space in
the mandible was less pronounced among the groups, but the difference
between groups A and B was significant (p=0.046).
At 12-13 years of age, the mean value for contact point displacement in
the maxilla was greater in subjects of Swedish origin (2.1 mm) than in
those of Eastern European (1.4 mm) and Asian origin (1.6 mm). The
contact point displacement in the mandible did not differ significantly
among the groups.
At 18-19 years of age, the mean anterior available space varied between
-0.1 to 0.1mm in the maxilla and -1.4 to -0.1 mm in the mandible. The
differences in contact point displacements were also minor. The mean
value for contact point displacement in the maxilla was 1.9 mm in the
34
subjects of Swedish origin, and 1.7 and 2.1 mm for those of
Eastern/Southeastern European and Asian origin, respectively. The mean
value for contact point displacement in the mandible varied between 1.8
and 2.0 mm. There were no significant inter-group differences with
respect to any of these variables (Paper IV).
Teeth and eruption anomalies
Tooth retention was found in 8.6 per cent in group A, 16.4 per cent in
group B, 9.4 per cent in group C and 2.1 per cent in group D, with a
significant difference between groups B and D (p<0.05). In the subjects
of Eastern/Southeastern European origin, (group B) the frequency of
hypodontia was 9.8 per cent. The corresponding values in groups A, C
and D were 5.5, 6.0 and 8.5 per cent respectively. The frequency of
ectopic eruption was 5.9 per cent for the subjects of Swedish origin,
(group A) and 3.3, 3.4 and 2.1 per cent respectively in groups B, C and
D (Paper II).
Orthodontic treatment
At the initial examination, when the subjects were 12-13 years of age
(Paper II), 46 per cent of all subjects had, at some time during their
childhood, had an orthodontic consultation: 15 per cent were currently
undergoing orthodontic treatment and 13 per cent had previously
undergone treatment, with no significant differences among groups A, B,
C and D. There were no inter-group differences with respect to the
number of subjects referred to an orthodontist, n= 57, or those currently
undergoing treatment, n=61.
At the second examination, (18-19 years of age), 44.4 per cent of all
subjects had undergone orthodontic treatment with fixed or removable
appliances or orthodontic extraction: 50.6 per cent of Group A, 38.0 per
cent of Group B and 35.6 per cent of Group C. The difference between
groups A and C was significant (p=0.047). There was no significant
difference between the sexes (Paper IV).
35
Extractions
At the age of 12-13 years, subjects of Swedish origin (A), had the lowest
frequency of extracted primary molars before 7.5 years of age, and also
the total number of extractions during childhood and adolescence,
significantly fewer than for subjects of Eastern/Southeastern European
(B) and Asian (C) origin. Compared with groups B and D, the subjects
of Asian origin (Group C) had undergone significantly more extractions
of primary molars before 7.5 years of age. With respect to extraction of
primary canines, there were no inter-group differences.
Although the overall number of extracted permanent molars was very
low, the frequency of extraction of first permanent molars was higher in
subjects of immigrant background than those of Swedish background,
p=0.040.
A positive correlation was found between extraction of any primary
molar before 7.5 years of age and retention of the permanent successor
(p=0.016). The correlation was even stronger for early extraction of two
or more primary molars (p=0.002).
Index of Orthodontic Treatment Need
According to the Dental Health Component of the Index of
Orthodontic Treatment Need (IOTN-DHC), in 37.0 per cent of all
subjects, a “real treatment need”, (grades 4 and 5) was registered; 35.5
per cent had “little or no treatment need” (grades 1 and 2), while
“borderline need” (grade 3) was registered in 27.5 per cent. There were
no significant inter-group differences.
The orthodontist’s assessment of the Aesthetic Component of the Index
of Orthodontic Treatment Need (IOTN-AC) showed no significant
inter-group differences (p=0.084). However, the mean value of the
orthodontist’s assessment was significantly higher than the subject’s selfassessment (p=0.000) in all four groups. The self-assessed treatment need
(IOTN-AC) was highest in group A and differed significantly from
groups B (p=0.027) and C (p=0.000) (Paper II).
36
Self-perceived orthodontic treatment need and attitude to
orthodontic treatment
At the age of 12-13 years, twenty per cent of the subjects considered that
they needed orthodontic treatment, more girls than boys (p=0.012), but
in groups C and D, self-perceived treatment need was greater among
boys than girls. The inter-group differences were statistically significant
(p=0.001) (Table 1).
girls
boys
p
girls + boys
A+B+C+D
23
17
*
20
A
B
C
D
31
17
15
9
15
22
18
9
19
14
24
**
12
A - Sweden, B – Eastern/Southeastern Europe, C- Asia, D - other
* - p<0.05, ** - p<0.01
Table 1. Self-perceived orthodontic treatment need in groups A-D (12-13 years old)
according to gender (%).
At the age of 18-19 years, the self-perceived need for treatment was 11.8
per cent for all subjects: 7.9 per cent in group A, 10.0 per cent in group
B and 20.5 per cent in group C, with a significant difference between
groups A and C (p= 0.016) and between girls and boys (p=0.050) (Table
2).
37
Variables
Groups
A
n
(%)
Girls
Boys
11 (11.2)
P
n.s
Girls+Boys
14 (7.9)
3
(3.9)
P
B
C
n
A+B+C
n
(%)
3
(12.5)
11 (25.0)
n.s
25 (15.1)
2
(7.7)
7 (15.9)
n.s
12 (8.2)
n.s
5
(%)
n
n.s
(10.0)
18 (20.5)
(%)
*
A≠C *
A – Sweden B – Eastern/Southeastern Europe C – Asia.
n.s non significant * p<0.05
Table 2. Self-perceived orthodontic treatment need in groups A-C (18-19 years
old), related to origin group and gender (%).
Approximately 66 per cent of the 12-13 year old participants subjects
answered that they would be prepared to undergo two years of fixed
appliance therapy if it was recommended by the dentist: 72 per cent in
group A, 63 per cent in group B, 54 per cent in group C and 61 per cent
in group D. There was no significant gender difference with respect to
willingness to undergo treatment.
To the question “Do you believe that orthodontic treatment with fixed
appliances is painful?”, half the subjects answered “Yes, somewhat” or
“Yes, very”. More girls than boys were concerned about treatment-related
pain (p=0.003). The highest percentage was found among the
Eastern/Southeastern European girls, 68 per cent, in comparison with
the other groups, (p=0.008).
At the age of 18-19 years, 37.9 per cent of the girls and 24.1 per cent of
the boys who had not previously received treatment with fixed appliances
would have accepted such treatment if offered today: 23.2 per cent in
Group A, 35.7 per cent in Group B and 46.5 per cent in Group C. The
difference between groups A and C was significant (p=0.022) (Paper IV).
38
Satisfaction with own teeth
At the initial examination, nineteen per cent of the 12-13 year olds
perceived their teeth to be worse than those of their peers. The subjects
of Swedish background were least satisfied with their teeth and subjects
of Eastern/Southeastern European background were the most satisfied.
With respect to gender and origin, girls of Swedish origin were the most
dissatisfied (Paper I).
At 18-19 years of age, eighteen per cent (17.9) of all subjects thought
that the appearance of their teeth was worse or much worse than that of
their peers. There were no significant differences among the groups or
between girls and boys (Paper IV).
In total 1 per cent of the 12-13 years olds reported being teased every
week or every day and 10 per cent reported that at some time they had
been teased about their teeth (Paper I).
The self-perceived attitudes to the four variables “tooth colour”,
“irregular teeth”, “increased overjet” and “spaced teeth” were examined at
the age of 18-19 years. “Tooth colour” was the variable that caused most
dissatisfaction (38.5%), significantly more in girls than boys (p=0.020).
However, there were no significant intergroup differences.
Thirty-four per cent (34.4) were dissatisfied with their irregular teeth,
25.0 per cent with their large overjet and 18.1 per cent with their spaced
teeth. There were no significant differences between the sexes or among
groups A, B and C in the responses to any of these questions (Paper IV).
In a VAS analysis, more boys of Eastern/Southeastern European origin
believed that straightened teeth would improve career prospects: median
value 50, compared to 22 for the boys of Swedish origin and 45 for the
boys of Asian origin. The difference between boys of Swedish and
Eastern/Southeastern European origin was significant (p=0.030). No
difference was found between boys and girls.
Sixty-three per cent (200) of the subjects considered their teeth to be
important or very important for self-esteem. The difference between girls
and boys (72.5 and 53.0 per cent respectively) was significant (p=0.002).
However, there were no significant intergroup differences (Paper IV).
39
General appearance
At the age of 12-13 years, more subjects from groups A and D
considered their own appearance to be generally less attractive than that
of their peers, 9 per cent and 12 per cent respectively. The subjects of
Asian origin were least dissatisfied, 6 per cent (p=0.012). None of the
girls of Eastern/Southeastern European origin (group B), was dissatisfied
(Paper I).
The corresponding values at the age of 18-19 years were: 11.9 per cent
in Group A, 8.0 per cent in Group B and 5.7 per cent in Group C. The
subjects in group A were significantly more dissatisfied with their general
appearance than the subjects of Asian origin, Group C (p=0.010).
In the 12-13 year olds, dissatisfaction with facial appearance was
significantly higher in girls than in boys, (p=0.002). At the age of 18-19
years, 7.4 per cent of the subjects of Swedish origin were dissatisfied,
compared with 0.0 and 1.6 per cent respectively among those of
Eastern/Southeastern European and Asian origin (p=0.05). There was no
difference between the sexes. Satisfaction with overall facial features
compared to overall physical appearance was higher: 80.0 per cent were
satisfied or very satisfied with their facial appearance, while only 68.7 per
cent expressed satisfaction with their overall physical appearance.
With respect to satisfaction with the appearance of hair, ears, eyes, nose,
cheeks, lips and mouth, there were no inter-group differences or sex
differences (Paper IV).
At the age of 12-13 years old, girls were significantly more dissatisfied
with their body height (p=0.009) and weight (p=0.005) than boys. The
subjects of Asian background (group C), were the most dissatisfied with
their height and weight.
In the follow up study (Paper IV), girls were significantly more
dissatisfied with their height than boys, 14.5 % compared to 4.1 %
(p=0.003). There was significantly greater dissatisfaction among boys of
Asian origin (12.5 per cent) than those of Eastern/Southeastern
European
(0.0 per cent) and Swedish origin (1.4 per cent), p=0.015. More girls
than boys were dissatisfied with their weight: 30.8 and 13.1 per cent
respectively, p<0.000.
40
The girls were more dissatisfied with their chin compared to the boys,
(11.6 and 2.5 per cent respectively), p=0.040. There were no inter-group
differences.
The girls in group A (16.1 per cent) were, with respect to overall physical
appearance, significantly more dissatisfied than the boys in group A (2.9
per cent), p=0.004. There were no significant sex differences in groups B
and C, but the overall sex difference (girls 15.8 and boys 5.7 per cent)
was significant, p=0.004.
Eighty-five per cent of the girls and 77.1 per cent of the boys considered
the general physical appearance to be important or very important for the
self-esteem. The gender difference was not significant, nor were the intergroup differences significant (Paper IV).
Association between self-perceived orthodontic treatment
need and malocclusion (Paper III)
Of 373 subjects, 22.3% (26.5% females, 18.1% males) answered “Yes”
to the question “Do you think that you need a brace today” and 55.5%
(48.6% females, 62.2% males) answered “No”. Twenty-two per cent
were uncertain.
There was a significant association between the response to the above
question and the presence of overjet, with positive responses from 49 per
cent of subjects with an overjet > 6 mm and 16 per cent with an overjet
of 1-6 mm.
Subjects with an anterior crossbite of one or more teeth answered “yes”
significantly more often to the question, (60 per cent), compared with
those without an anterior crossbite (17 per cent) (P=0.000 OR=7.0).
Maxillary contact point displacement > 4 mm and strained lip closure
were strongly associated with a self-perceived need for orthodontic
treatment (P=0.000 and P=0.005, respectively).
Subjects with IOTN-DHC grades 4 and 5 differed significantly from
those with grades 1 and 2: 44 and 7 per cent, respectively (P=0.000,
OR=13.0).
Among subjects of Middle Eastern origin, none of the occlusal anomalies
influenced the perceived “need for braces”. In the Eastern/Southeastern
European subjects, a positive response to the specific question was
41
significantly correlated with an overjet > 6 mm, maxillary contact point
displacement > 2-4 mm and IOTN-DHC grades 4 and 5. In the
Swedish group (Group A), a significantly higher proportion of positive
responses to the specific question was recorded in girls than in boys,
(P=0.002), in students with an overbite <5 mm (P=0.010), anterior
crossbite (P =0.000), maxillary contact point displacement >4 mm
(P=0.000) and >2 mm in the mandible (P= 0.015), strained lip closure
(P=0.012) and IOTN-DHC grades 4 and 5 (P=0.000).
Subjects in groups A and C who thought that they needed an
orthodontic appliance also thought that the appearance of their teeth was
somewhat worse or much worse than that of their peers (P= 0.000 and
P=0.005, respectively). There was also a positive association between
subjects of Swedish origin who thought they needed an orthodontic
appliance and avoided smiling because of their teeth (P=0.000). No
association was found in any of the groups between general appearance
and the need for braces.
The most important factors explaining a positive response to the
question “Do you think that you need a brace today” were the
morphological variables IOTN-DHC grades 4 and 5 and anterior
crossbite, (P=0.000 and P=0.021) (OR=7.7 and OR=3.5). Of the
subjective variables, the one most closely associated with a perceived need
for an orthodontic appliance was “My teeth look somewhat worse or
much worse than those of my peers”, P=0.000 (OR=26.8).
A positive response to the question “Do you avoid smiling because of
your teeth ?” was recorded in 34 per cent in group A, 9 per cent in group
B, and 31 per cent in group C. The most important factors explaining a
positive response to this question were the morphological variables
contact point displacement 2-4 mm in both the maxilla (P =0.013,
OR=2.3) and the mandible, (P=0.027, OR=2.1), and for the subjective
variable “My teeth look worse or much worse than those of my peers”
(P=0.000, OR=8.8).
Of all subjects with IOTN-DHC grades 4 and 5, 74.5 per cent (n=104)
were allocated to these grades on the basis of the occlusal variables overjet
>6 mm (n=55), maxillary contact point displacement >4 mm (n=43) or
anterior crossbite (n=34). Of all subjects with a positive response to the
42
question “Do you think that you need braces today?”, 73.4 per cent
showed IOTN-DHC grades 4 and 5 (Paper III).
Temporomandibular symptoms and signs (Paper IV)
Twenty-five per cent of all subjects, at 18-19 years of age, 32.5 per cent
of the girls and 14.2 per cent of the boys, suffered from headaches at least
once a week (p=0.000) (Table 3).
The distribution of weekly headaches in relation to geographic origin
and gender is shown in Table 3. The highest frequency was noted in the
girls of Asian origin. The difference between groups B and C was
statistically significant (p=0.019).
Variables
Groups
A
n
(%)
P
B
n
(%)
C
n
A+B+C
(%)
n
(%)
Girls
Boys
P
30 (30.6)
4 (16.7)
20 (45.4)
B#C *
54 (32.5)
11 (13.9)
2 (7.7)
8 (18.6)
n.s
21 (14.2)
**
n.s
**
Girls+Boys
B≠C *
***
A- Sweden, B – Eastern/Southeastern Europe, C – Asia.
n.s – non significant, * - p<0.05, ** - p<0.01, *** - <0.001
Table 3. Distribution of positive responses to the question “Do you suffer from
headaches at least once a week?”, in relation to origin group and gender in 18-19 year
old subjects.
43
TMJ signs were significantly more frequent in girls than in boys: 22.1
per cent and 5.7 per cent respectively (p=0.000). Tenderness to palpation
in the masseter and/or temporalis muscles was noted in 42.8 percent of
girls and 30.9 percent of boys, p=0.035. There were no significant intergroup differences.
The distribution of tooth wear into the dentin (grades 3-5) in the
maxillary and mandibular anterior teeth varied between 53.7 and 75.6
per cent among the three groups. There were no significant inter-group
differences, nor between the sexes (Paper IV).
Psychosocial functioning
At the age of 12-13 years, the psychosocial index for all subjects
(A+B+C+D), had a mean value of 21 (range 11-31, SD=3), where a low
value indicates good psychosocial functioning (range of scale 9-45). The
subjects of Eastern/Southeastern European origin showed a low value,
mean 20 (SD=2.8), and the other groups (A, C and D) mean
21(SD=2.8). The girls (A+B+C+D) had a significantly lower index value,
20 (SD=3.0), than the boys, 21(SD=2.9), p=0.007. The index value for
those subjects with a self-perceived orthodontic treatment need was 21.5,
half a unit higher than the mean value for all groups. There was no
difference between subjects with and without self-perceived treatment
need (Paper I).
In the follow up study (Paper IV), another questionnaire, more suitable
for subjects in the late adolescence, was used. At this age, the overall
result, showed reduced psychological wellbeing in 23.2 per cent of the
sample: 29.0 per cent of girls and 16.4 per cent of boys (p=0.019). The
highest frequency, 37.5%, was found among the girls of Asian origin
(group C). There were no differences among the groups A-C. The
examination did not disclose any significant association between reduced
psychological wellbeing and a positive response to the question about
self-perceived current orthodontic treatment need (Paper IV).
44
Paper V
In this qualitative paper, a core category and three conceptual categories
were generated and formed a theory explaining the main concerns of
young adults with poor dental aesthetics and how they deal with this
condition. The core category was labeled “Being under the pressure of
social norms”. This includes concerns that young people did not want to
be “culturally unacceptable” or perceive themselves as being “undesirably
different”. According to the data, at the same time as these young adults
are striving to conform with social norms, they also consider it very
important to express their own individual “style” or look. The subjects
considered that dental aesthetics were important for self-esteem but not
for a successful career. However, they thought that a pleasant appearance
was important for career prospects. This study did not disclose any
gender differences.
This core category is related to categories explaining three different ways
in which these young people accommodate the main concern related to
their malocclusion: that is Avoiding showing their teeth, Minimizing the
importance of one’s appearance and Seeking orthodontic treatment (Figure
4).
45
Being under the pressure
of social norms
A
B
C
Avoiding showing
Minimizing the importance
Seeking orthodontic
the teeth
of appearance
treatment
Hiding the teeth
Focusing on work and
Prioritizing function
Striving for overall health
Preventing oral disease
Increasing self-esteem
education
Figure 4. A substantive theory explaining the main concern of adolescents with poor dental aesthetics, that is “Being under the
pressure of social norms”, and their ways of coping this (Avoiding showing the teeth, Minimizing the importance of one’s appearance and
Seeking orthodontic treatment).
A. Avoiding showing their teeth
The participants using this strategy were very conscious of their poor
dental aesthetics: for them, it was important to not be considered
different from the norm.
The condition that bothered the informants most was increased overjet
or crowded incisors, with an associated incomplete lip closure.
Actually, the participants who avoided showing their teeth seemed
dissatisfied with their dental aesthetics, but they had dealt with the
problem in their own way. They would not have accepted orthodontic
treatment even if it had been offered. The main reasons for refusal were
anxiety about pain and that fixed appliances were ugly. All subjects using
this strategy were of immigrant background.
B. Minimizing the importance of one’s appearance
The second category Minimizing the importance of one’s appearance,
contains the subcategories Focusing on work and education, Prioritizing
function and Striving for overall health. The category describes how the
participants arrived at a decision to refuse or abandon orthodontic
treatment and accept the appearance of their teeth. While poor dental
aesthetics had previously been a problem, it was no longer a concern.
They considered it important to take good care of oneself and one’s
body. The main reason that these participants had not undergone
orthodontic treatment in their early teens was their perception at the
time that it was not necessary. This strategy was most often used by
subjects of Swedish background.
C. Seeking orthodontic treatment
A third way of dealing with the problem of poor dental aesthetics was to
seek orthodontic treatment. The participants using this strategy gave
various reasons for not undergoing orthodontic treatment earlier, such
as: the normative need was assessed as minor and the condition did not
47
fall into a category eligible for treatment. Two subcategories were
included in this category, preventing oral disease and increasing self-esteem.
48
Discussion
The overall aims of this series of studies were to investigate the potential
influence of specific immigrant background on such issues as frequency
of malocclusion, treatment need and barriers to orthodontic treatment
uptake in early adolescence; to identify, in late adolescence, differences
between native-born Swedes and those of immigrant background with
respect to frequency of malocclusion and self-perceived treatment need;
and to highlight the main concerns of young adults with poor dental
aesthetics. A further aim was to determine whether any differences with
respect to perception of general appearance and psychosocial well-being
were related to geographic origin.
The main finding was that compared to native-born Swedes, perceived
orthodontic treatment need was lower in adolescents of immigrant
background at 12-13 years of age, but higher at the age of 18-19 years.
There were no major differences in frequencies of malocclusion and
normative orthodontic treatment need between adolescents with and
without immigrant background.
Material and methodological considerations
The material for the study comprised a sample of adolescents of Swedish
and foreign origin. The subjects were selected from schools where the
uptake areas had higher proportions of immigrants and thus the
prevalence of adolescents of immigrant background was higher than for
the national average. The author examined, by a power analysis, the
possibility of stratifying the immigrant subjects into the following three
groups on the basis of their origin: Eastern/Southeastern Europe, Middle
East and Eastern/Southeastern Asia. After the initial questionnaire
examination (Paper I: self-perceived treatment need), four groups finally
emerged and comprised the subjects of papers I and II (Paper II:
frequency of malocclusion).
Primarily the intention was also to stratify the subjects according to
socioeconomic standard and ethnic or cultural background. This was
however not feasible, because 12-13 year-olds are unable to answer such
49
questions. The terms “ethnicity” and “cultural background” have broad
connotations and it was therefore impossible to use these terms for group
classification. The final classification, based on geographic origin, was
not ideal, as within such a group there may be pronounced cultural,
ethnic and socioeconomic differences, but this was found to be the most
appropriate stratification. While the groups A (Sweden) and B
(Eastern/Southeastern Europe) were very homogeneous, groups C (Asia)
and D (other) were quite disparate. The origin of 80% of subjects in
group C was The Middle East, but group D consisted of subjects
originating from all other countries and diversity was therefore
pronounced. Another option would have been to combine all
immigrants into a single group, but relevant information would then
have been lost, as most of the immigrants at the time of the study were
from these two areas, Former Yugoslavia and The Middle East.
Previous dental treatment constitutes a source of error in epidemiologic
malocclusion studies. Väkiparta et al.99 found that early orthodontic
intervention may result in a reduction in the treatment need between 8
and 12 years of age. In papers I and II, subjects with former or ongoing
orthodontic treatment were included. This is a confounding factor. In
many epidemiological studies such subjects are excluded. However, in
the present project, exclusion would have led to incorrect reporting of
the existing prevalence of malocclusion and orthodontic treatment need.
In an attempt to approach the true prevalence, the pre-treatment
condition of all subjects with ongoing fixed or functional appliances was
registered on the pre-treatment study-models. As the frequency of earlier
or ongoing orthodontic treatment was similar for all four groups in the
present studies, it is assumed that earlier orthodontic treatment would
not influence the results with respect to differences between the groups.
Most of the subjects in papers I - II had participated in the children’s
public dental health care program from the age of 3 years, and for these
children, comprehensive treatment records were available. The
interceptive treatment may have resulted in a reduction in the frequency
of anomalies.
A few of the subjects had started fixed appliance therapy prior to the
study and some were midtreatment with functional appliances. This
could have influenced their perception that their teeth looked better than
50
the normative need registered on the pre-treatment study models, and
therefore influenced the results. However, statistical analysis of
interaction did not show that this had influenced the perception of
malocclusion of these subjects.
In Paper III: association between self-perceived and normative need,
groups B and C were more homogeneous because only students with
both parents from the same geographic origin were included. Compared
with the samples in the previous studies (papers I and II), the subjects
were recruited from more circumscribed geographic areas in both Eastern
Europe and Asia. Consequently, these groups comprised fewer subjects.
In Paper IV: follow-up of perceived need and malocclusion frequency,
attrition was considerable. Many 18-19 year-olds are in transition,
studying elsewhere or travelling a lot and some had left the district.
Greater attrition was therefore not unexpected. As the comparison
between the telephone interviews and the group which underwent
examination disclosed no difference in self-perceived treatment need, it
was assumed that the non-participants did not differ from those in the
study group.
In Paper V: a qualitative study of the influence of poor dental aesthetics
on young adults, the participants were strategically selected: the aim was
to compile a heterogeneous group, thereby maximizing the range of
experience among the participants. The number of participants in this
study was quite small, but considered adequate for the method applied.
During the years in which the studies were conducted, the criteria
applied in Sweden to describe “a person of immigrant background” were
officially changed. To allow comparison of the results of early and later
studies, the earlier definition was retained throughout the studies, i.e. a
person of immigrant background is defined as someone with at least one
parent born abroad.
The questionnaires used in papers I, III and IV were new constructions
of different domains. Some of the questions had been used in earlier
studies and some were new. Most of the questions had not been
validated, but had frequently been used in other questionnaires.
In Paper I, when differences between groups were disclosed, no further
analysis was conducted to pinpoint the differences. Continuing with
analysis increases the risk of a random false positive result.
51
In this initial study most of the subjects were in the late mixed dentition
period. Although the IOTN index was constructed primarily for
application to the permanent dentition and has various shortcomings, it
is the most frequently applied instrument for measuring treatment
need.100 The founders of the Index of Orthodontic Treatment Need have
claimed high validity for the index, but another study has reported the
opposite, for both the DHC and AC components.31 This indicates the
diversity of opinion on the validity of the index. Analysis of registrations
of the AC of the IOTN should be interpreted with some caution. There
are obvious shortcomings, such as the lack of illustrations of such
conditions as hypodontia, frontal spacing and Class II div 2
malocclusion. There is always some uncertainty in assessing photographs
of different types of malocclusion in order to identify one picture which
corresponds most closely with one’s own dental appearance. This index is
constructed for Caucasians, and it has been suggested that the 10
photographs should be complemented with photographs of subjects from
other ethnic backgrounds.101
In Paper II and the clinical examination in Paper IV, the subjects were
not stratified according to gender. There are several reasons. Firstly,
earlier studies have disclosed little or no gender-based differences with
respect to normative treatment need,47,48,102 although there are some
exceptions, reporting higher treatment need in boys.7 Secondly, because
of the composition of the sample, some gender-based groups would have
been too small for statistical analysis.
Most of the variability in the frequency of malocclusions reported in the
literature is probably attributable to differences in the subjective criteria
for the recorded items.47 Comparison of such results is therefore usually
unreliable. However, comparisons within one particular study, for
instance, between the frequencies for the different groups in papers II
and IV, are more reliable.
In Paper II, when primary molar extractions were evaluated, the age limit
was set to extraction before 7.5 years of age, as earlier studies have shown
that space loss is considerable if the primary molars are lost before 7-8
103 104
years of age.
An important note must be made, although differences might be
statistically significant at some level, this does not mean that they are of
52
clinical importance. The statistical significance may be a result from a
large population, as well as a non significant result might be a result of a
small population.
The grounded theory method, used in Paper V, provides deeper insight
into such phenomena as feelings, thought processes and emotions, which
are difficult to extract or learn about through more conventional research
methods. A possible weakness in this study was that the interviewer was
an orthodontist, because professional attitudes and preconceptions may
influence the interviews and the generation of the theory. However, the
data analysis was made by both professionals and non-professionals.
Despite the quite low number of participants, the saturation was
considered adequate.
A study of teenagers’ decisions about whether or not to undergo
orthodontic treatment reported that teenage boys had difficulty
expressing themselves in in-depth interviews.105 In the present study, with
somewhat older informants, no such problems arose: the subjects were
able to express their opinions on for example appearance and the culture
of beauty. This was an illuminating way of obtaining information from
the young adult informants and their response to the method seemed
very positive.
Frequency of malocclusion and normative orthodontic
treatment need
The frequency of malocclusion traits was consistent with other reports
for most of the variables,6,106,107 and for most of the malocclusion traits
there were no differences among the groups. At the initial examination,
12-13 years of age, the subjects of Swedish origin had a statistically
significant increased overjet compared to subjects of Asian origin. The
subjects of Swedish origin had also significantly more anterior crowding
and greater contact point displacements in the anterior segments than
the subjects of Eastern/Southeastern European and Asian origin. This
may be because subjects in group A (Sweden) had had fewer primary
molar extractions and therefore more crowding in the anterior segment.
In this study the mean value for anterior space condition was negative,
which was not unexpected, as crowding is more frequent than spacing.6
53
Other explanations may be the method of measurement, i.e. rectilinear,
implying that a zero value is not necessarily synonymous with no
crowding. Another factor may be the stage of occlusal development.
Thilander and Myrberg6 found that crowding was the most common
occlusal anomaly recorded.
At 18-19 years of age, the frequency of class II and class III
malocclusions had increased in adolescents of Asian origin. This is a
result after finished growth. It is recognized that class III occlusal
relationships are more common in those of South Asian origin than in
other ethnic groups. Compared to subjects of immigrant background,
the Swedish subjects had a higher frequency of previous orthodontic
treatment, probably because at 12-13 years of age the Swedish subjects
(group A) had a higher mean value for overjet and a lower mean value for
anterior available space. Over time, the adolescents in the different
groups had undergone orthodontic treatment and some malocclusions
had self-corrected. Therefore, at group level, the frequency of
malocclusion in the groups had leveled out. Another reason why fewer
subjects of immigrant than non-immigrant background received
orthodontic treatment may be attributed to lower dental awareness
among immigrant parents, less attention given to these subjects by the
dentist or communication/language problems.108 The fact that high
frequencies of some occlusal deviations persisted shows that not all of
these malocclusions were assessed as needing treatment.
Studies on Scandinavian children have shown a trend toward a reduction
in the difference between the transverse dimensions of the maxilla and
mandible. Thus the risk of developing a posterior crossbite is greater in
this group today than a few decades ago109 and also over a much longer
time perspective,110 which affects treatment need.
In Paper II, the normative need in grades 4 and 5 was 37 per cent. This
finding may be viewed in the context of treatment need assessed in other
studies (Table 1). Although some differences in malocclusion traits were
present in the different origin groups, this was not expressed in the
normative part of the index of orthodontic treatment need, IOTNDHC.
The marked decrease in caries frequency in Scandinavian children during
111,112
the past few decades has had a positive effect on dental arch length.
54
However, despite the general improvement in dental health, the
orthodontic treatment need, in terms of IOTN-DHC, has not improved.
Most of the subjects of these studies were born in Sweden or had come
to Sweden at an early age. They were also quite young at the time of the
initial examination. Immigrants arriving at later ages might have, and
probably have, more compromised dentitions. The results of the present
studies should not be extrapolated to those who arrive in late
adolescence.35
Self-perceived orthodontic treatment need and satisfaction
with dental appearance
This thesis demonstrates the change in self-perceived treatment need
during the adolescent period. In the initial study, the subjects were 12-13
years of age and the girls of Swedish origin had the highest frequency of
orthodontic treatment demand. In the follow-up study at the age of 1819 years, the self-perceived treatment need was 11.8 per cent, somewhat
higher than reported in other studies of Swedish 19-year-olds.36,40 At this
age, the frequency of self-perceived treatment need was lowest among the
subjects of Swedish origin and highest in subjects of Asian origin.
However, this result was not confirmed by the frequency of aesthetically
disturbing malocclusion, which was similar in the three groups. Thus in
the six year interval between the initial and follow-up studies, the selfperceived need in subjects of Swedish origin had decreased and in the
subjects of Asian origin remained unchanged.
The results at 12-13 years of age are also confirmed by the self-assessed
aesthetic component of the index of orthodontic treatment need, IOTNAC. The Swedish subjects (Group A) had a higher IOTN-AC than
groups B and C. This reflects a greater treatment need and desire for
treatment in group A and may also be a result of the higher prevalence of
malocclusion in the subjects of Swedish origin. The orthodontist’s
ratings for treatment need in Paper II exceeded self-assessments by the
subjects. This has also been reported in other studies. 71,84,113,114
Paper IV disclosed that perceptions of orthodontic treatment need are
influenced by factors other than measures of normative orthodontic
treatment need and perception of aesthetics. When a self-perceived need
55
exists, it is important that the patient has a realistic insight in treatment
benefits, risks and prognosis before decision is taken about treatment.
Even subjects who are aware of a malocclusion do not consider the need
for treatment to be as high as the orthodontist does.69,115 Factors that may
contribute to this phenomenon are age, social class, economic issues,
individual perceptions of psychosocial benefits, attitude to orthodontic
appliance therapy and dental fear.71 Surprisingly, in Paper I, the subjects
of Eastern/Southeastern European origin had the lowest self-perceived
need and were also most concerned about treatment-related pain. Care
must be taken not to generalize these findings.
The prevalence of dissatisfaction with their own dental appearance (18 19 per cent) was almost unchanged between 12-13 and 18-19 years of
age. While the subjects of Swedish origin were most dissatisfied, they
were not as interested in orthodontic treatment as the subjects of Asian
origin. The greatest dissatisfaction was with tooth colour116 but irregular
anterior teeth also caused dissatisfaction. These findings are in agreement
with those of other reports.117-119
With respect to the gravity of poor dental aesthetics, a mild reverse
overjet did not seem to bother the subjects. They considered that
disproportional gingival display in the upper anterior region was ugly
and their own main concerns were increased overjet or crowded upper
incisors, with associated incomplete lip closure. These findings support
those from other studies in different cultures. Abu Alhaija & AlKhateeb120 reported that a mild reverse overjet is aesthetically acceptable
to young people. Van der Geld et al.116 reported that critical factors for an
aesthetically acceptable smile were tooth colour and gingival display. In a
study of 18-year-old males, Traebert & Peres119 showed that incisor
crowding and anterior maxillary irregularity >2mm had an impact on
smiling, laughing and showing teeth without embarrassment.
Although based on a limited sample in Paper V, there was a tendency for
subjects of immigrant background to be more concerned about dental
aesthetics than those of Swedish background. The former were more
likely to want to avoid showing their teeth, or intended to seek
orthodontic treatment. One reason may be that these young adults are
more critically aware of dental appearance.
56
During adolescence, a person is very sensitive to the responses of
significant others, especially concerning appearance. A decision about
treatment involving appearance is better delayed until the individual has
passed through adolescence and is more confident of his/her identity.105,121
The findings in the present study support this approach to the timing of
orthodontic treatment in adolescents, who are sensitive to social pressure.
Association between self-perceived orthodontic treatment
need and malocclusion
The results in Paper III showed a strong association between subjects
who perceived that they needed an orthodontic appliance and IOTNDHC grades 4 and 5, and anterior crossbite. In contrast to the Swedish
group (A), in the Eastern/Southeastern European and Middle Eastern
groups (B and C), only a few morphological variables were closely
associated with perceived orthodontic treatment need. A possible
explanation is the small number of subjects in groups B and C.
In Paper III, 44 per cent of the subjects with IOTN-DHC grades 4 and
5 thought they needed an orthodontic appliance, compared with 7 per
cent of subjects with grades 1 and 2. Among subjects reporting selfperceived treatment need, 73 per cent were classified as IOTN-DHC 4
and 5. Consequently, 12-13-year-old subjects who think that they need
treatment also have an objective need according to the IOTN-DHC.
This association between malocclusion and self-perceived treatment need
is consistent with other studies.115,122,123
The occlusal variables with an obvious discrimination in the subjects
who thought that they needed orthodontic appliance therapy, were
overjet >6 mm, anterior crossbite and maxillary contact point
displacement >2 mm. These occlusal characteristics represented a
majority of the subjects with IOTN-DHC grades 4 and 5. This may be a
quite good validation for the normative part of this index and also a good
predictor of self-perceived orthodontic treatment need. These findings
are in concordance with the results of Hamdan55 who found in a study of
orthodontic treatment need according to IOTN-DHC that tooth
displacements of more than 4 mm and “increased overjet greater than 6
57
mm but less than or equal to 9 mm” were two of the three main occlusal
features determining allocation to “definite need”.
After studying the prediction of the IOTN on uptake of orthodontic
treatment, Mandall et al.14 claimed that assessment of future manpower
requirements will probably require IOTN-DHC data to fully assess
dental health risks. In contrast, Mohlin and Kurol33 found that IOTNDHC could not serve the basic purpose of creating relevant cut-off
points for treatment need. Several authors have expressed the opinion
that there is only a modest correlation between patients’ perception of
their need for orthodontic treatment and an objective, professional
evaluation of their malocclusion.71,85,124 Other factors may also contribute
to treatment demand, such as social class, financial limitations,
individual perceptions of psychosocial benefits and attitude to
appliances.71
In both the Swedish and the Eastern/Southeastern European group the
variable IOTN-DHC grades 4 and 5 was in close agreement with the
perceived need for an appliance, but no such association was found in the
Middle Eastern group. Thus in the latter group other factors determine
the perceived need for braces. An intriguing finding is that while subjects
of Swedish background and those of Middle Eastern origin have a similar
perceived need for treatment, no association with malocclusion was
observed in the Middle Eastern group.
Subjects of Eastern/Southeastern European origin were more
apprehensive than subjects of Swedish origin, about treatment-related
pain. This may be one explanation for the lower perceived treatment
need in the Eastern/Southeastern European group. Another reason may
be a higher frequency of aesthetically objectionable malocclusions in
subjects of Swedish origin, than among those of Eastern/Southeastern
European origin. Sayers and Newton125 found that compared with
Caucasians, non-Caucasians anticipated more treatment-related pain and
expressed more negative expectations of orthodontic treatment, implying
that the anticipation of pain differs between groups of different origin.
58
General appearance
External factors such as group pressure to be like everyone else and not
be different, are important to adolescents and young adults. The subjects
in these studies were more concerned about their overall physical
appearance than their general facial appearance. In both the initial and
the follow- up study, the girls of Swedish origin were the most
dissatisfied with their overall appearance. It is unclear why more subjects
of Swedish origin than other subjects have a comparatively poor
perception of their appearance.
In a qualitative study of Scandinavian high-school students, almost all
the girls claimed to be dissatisfied with their bodies and it was concluded
that girls’ “bad body talk” was both a form of social critique and a way of
defining and materializing feminine gender. 126
From these studies, both at the age of 12-13 and 18-19 years, the general
opinion in all adolescents was that good-looking people are more
successful and a pleasant appearance is important for self-esteem and
career prospects. However, general appearance did not seem to influence
self-perceived orthodontic treatment need in any of the groups.
Temporomandibular symptoms and signs
There are no previous studies of temporomandibular symptoms and
signs in immigrant adolescents in Sweden. Therefore, the findings in
Paper IV offer new insight into this aspect of Swedish adolescent health.
The highest frequency of headache was found in subjects of Asian
background, greater in girls than in boys. The reason for this is unclear.
Psychosomatic problems such as headache are increasing in Swedish
schoolchildren. The cause is multifactorial, but stress is one important
factor.127,128 Swedish studies of 17-year-olds 129 and of adults130 reported a
higher frequency of tenderness to palpation of the masticatory muscles in
subjects with recurrent headache. In the present study, the frequency of
headache in 18-19 year olds of Swedish origin, correspond well with the
results of other Swedish studies.131-133
An association between posterior crossbite, deep bite and an increased
risk of headache in children and adolescents has been reported.134
However, in Paper IV, no significant inter-group differences emerged
59
with respect to these occlusal characteristics. In a review article of
association between TMD and malocclusion, the majority of the papers
reviewed failed to identify any significant and clinically important
associations. TMD could not be correlated to any specific type of
malocclusion.135-137 The obvious individual variations in signs and
symptoms of TMD over time make it even more difficult to claim that
malocclusion is a risk factor for TMD.138 The influence of malocclusion
on chewing ability and speech also seems in general to be minor.136,137
In adolescents with TMD, stress, somatic complaints and emotional
problems play a more important role,139 and this is possibly more
pronounced in girls of Asian origin.
Psychosocial functioning
Orthodontists have traditionally considered oral health and function as
the principal goals of treatment.140 However, recently there has been
growing acceptance of aesthetics and its psychosocial impact as an
important treatment benefit.136,141 Some patients report markedly
improved body image and appearance-related self-confidence after
orthodontic treatment: good dental aesthetics and previous orthodontic
treatment might have a beneficial influence on oral health related
attitudes, behaviour and self-esteem of young adults.142,143 Earlier studies
have shown that in adolescents, dental appearance is important for
quality of life.144,145 In Paper IV the opinion was that satisfactory dental
appearance is important for self esteem.
To measure aspects of quality of life in relation to orthodontic treatment
need, different oral health related quality of life (OHRQL)
questionnaires are used. These focus mostly on function and illness. A
correlation has been found between the Children’s Perception
Questionnaire (CPQ 11-14) and IOTN-DHC for the factors emotional
and social wellbeing. The impact of malocclusion on adolescents’ quality
of life may be substantial.144 In contrast, it has also been shown that
malocclusion and orthodontic treatment do not affect general or oral
health related quality of life to a measurable degree.146 However, young
adults have special opinions and expectations of dental care and there are
60
often other factors of importance, such as treatment time and treatment
cost, that will not be revealed in different measurements. 147
With respect to psychological wellbeing in early adolescence (12-13
years), no differences were found according to geographic origin, but
boys had somewhat poorer psychosocial function than girls. At this age,
the prevalence of self-perceived treatment need in boys of Asian origin
was higher than that of all others except the girls of Swedish origin.
However, there was no association between self-perceived need and
psychosocial functioning.
At the age of 18-19 years, girls had poorer psychological wellbeing and
higher frequency of self-perceived treatment need and headache, than
boys. Girls of Asian origin had significantly poorer psychological
wellbeing than boys of Asian origin, and also had more frequent
headaches than the subjects of Eastern/Southeastern European origin.
Self-perceived treatment need in the subjects of Asian origin was higher
than in the subjects of Swedish origin, but not reflected in the clinical
results. Nor was any association between self-perceived treatment need
and psychological wellbeing disclosed at this age.
The findings are in accordance with other reports showing reduced
psychological wellbeing in young women (16-24 years of age) in Sweden
and higher risk in those of immigrant background.148 There is a tendency
for girls of Asian origin to be more exposed to negative factors associated
with wellbeing than other adolescents of immigrant background, but the
reason is unclear. It is assumed that all have had similar experiences as
immigrants or as the children of immigrants. There is no evidence in the
literature that experience of war or being a refugee during childhood
predisposes to psychological problems in the future.149 The experience is
that most can have good lives as adults if they can grow up in a safe
environment. A possible explanation for the higher self-perceived need in
subjects with Asian origin may be that they do not perceive themselves to
be as good-looking as subjects of Swedish origin. They do not want to be
different. Several measures are taken to improve appearance, and one
aspect is dental appearance (interview with a female immigrant from The
Middle East).
61
“Another fight is that you have a foreign name. With an immigrant
background you have to do everything a little bit better than your
Swedish friends do.”
This series of studies implies that adolescents of Eastern/Southeastern
European origin seem to be more satisfied with their lives and with
themselves than adolescents of Asian origin, even if the differences are
not statistically significant for all variables.
Stress may be implicated in the decreased psychological wellbeing and
higher frequency of headache.127,128 The people closest to us are an
important source of psychological stress.150 In Paper V, the subjects
perceived that they were conscious of most of the existing norms and felt
ashamed that they felt compelled to accept them, even against their
better judgment. It can be very stressful for individuals to follow social
conventions, especially if they are in conflict with their own aims and
values.150 In the present study, while some subjects felt stressful pressure
from those around them, some did not seem unduly concerned.
School performance is another stressful factor for young adults. School
statistics shows that girls achieve higher results than boys, irrespective of
social class, ethnicity or housing area.151 In this context, for those of
immigrant background, living conditions are also an important factor.
How young people react to school results, would contribute to
psychological ill-health in Sweden today.
The influence of individual personality traits on OHQoL cannot be
ignored and this may explain why some individuals are concerned about
very minor malocclusions whereas others quite happily accept major
deviations from the norm. Philips and Beal152 found that self-perceived
level of the attractiveness or “positive” feelings toward the dentofacial
region is more strongly related to self-concept than the severity of
malocclusion. Agou et al.153 also found that in children with low selfesteem the impact of malocclusion on quality of life is substantial. This
may explain why some of the subjects in Paper V were more concerned
about dental aesthetics than others. It is not always easy for a young
teenager to foresee consequences or consider alternatives and to make a
balanced decision about orthodontic treatment, particularly as dental fear
105
also seems to be a contributing factor. Therefore, it is important to
62
improve self-esteem in adolescents, to help them to resist the pressure of
social norms.105
Inconsistencies between normative orthodontic need as assessed by
IOTN, and oral health-related quality of life have been found and it has
been noted that these aspects can only be addressed fully by developing a
more comprehensive measure of orthodontic need.154 Psychosocial
problems have to be taken seriously and therefore call “for an attitude
directed to understand to what extent malocclusion interferes with
psychosocial wellbeing without calling attention to something the patient
has not felt to be a serious problem”.136
Shaw et al.89 found that those with a prior need for orthodontic
treatment that was met have a more favourable perception of, and higher
satisfaction with, their own teeth than those with an unmet need.
However, although initial analysis indicated that these were accompanied
by higher levels of self-esteem and reported quality of life, these gains
were lost when account was taken of pre-treatment self-esteem, 20 years
earlier. Thus, the results for 31-year-olds confirm those which emerged
when the cohort was in adolescence: visible malocclusion has no
discernible negative effect on social and psychological well-being, and
orthodontic treatment has no discernible positive effect. The conclusion
was that lack of orthodontic treatment when there was need did not lead
to psychological difficulties in later life and had little or no effect on
psychological well-being.155
63
Key findings
•
At 12-13 years of age, subjects of immigrant background have a
lower perceived orthodontic treatment need than subjects of
Swedish background. Girls of Swedish origin have the highest
self-perceived treatment need, seem to be least satisfied with their
dental appearance and are also most positive to orthodontic
treatment.
•
Girls of non-Swedish background are most concerned that fixed
appliance therapy will be painful.
•
In a few of the variables measured at 12-13 years of age, there was
a difference between the Swedish and the Eastern/Southeastern
European and Asian groups. The Swedish group exhibited the
greatest space deficiency and irregularity in both the maxillary
and mandibular anterior segments and greater overjet.
•
The orthodontic treatment need IOTN-DHC grades 4 and 5
ranged from 30 to 40 per cent, without any inter-group
differences.
•
There were strong associations between subjects perceiving a
need for orthodontic treatment and IOTN-DHC grades 4 and 5,
anterior crossbite, avoiding smiling because they were selfconscious about their teeth and the perception that their teeth
look somewhat worse or much worse than those of their peers.
•
At the age of 18-19 years, the frequency of malocclusion was
similar in all groups, regardless of geographic origin.
•
Subjects of Asian origin had a higher self-perceived orthodontic
treatment need than their Swedish counterparts and a higher
frequency of headache than those of Eastern/Southeastern
European origin.
64
•
At 18-19 years of age, subjects of Asian background had a lower
frequency of earlier orthodontic treatment than subjects of
Swedish background.
•
Girls had a higher self-perceived orthodontic treatment need and
a higher frequency of headache and TMD signs than boys.
•
Psychological wellbeing was reduced in nearly one quarter of the
sample, more frequently in girls than boys. The highest
frequency was found in girls of Asian origin.
•
No association was found between self-perceived orthodontic
treatment need and psychological wellbeing.
•
In the qualitative study the core category was that young adults
“are under the pressure of social norms”.
•
Having to make a final decision about orthodontic treatment at
an early age is problematic for some individuals. Undisclosed
dental fear is an important barrier to acceptance of orthodontic
treatment in early adolescence.
65
Conclusions
•
Despite demographic changes due to immigration, no major
change in the prevalence of malocclusion and normative
orthodontic treatment need has been disclosed. This does not
apply to adolescents and adults who immigrated at an older age.
•
In late adolescence, subjects of Asian background had a lower
frequency of earlier orthodontic treatment than subjects of
Swedish background.
•
Subjects suffering from dental fear in early adolescence should
have the option of deferring orthodontic treatment. Funding
systems with a cut-off age for treatment should be extended to an
age beyond that of the participants in this study.
•
There is a need for dentists to improve their understanding of
young adults who have adjusted to living with poor dental
aesthetics and to identify those who are not as well-adjusted and
would probably benefit from treatment.
•
It is important to improve self-esteem in adolescents and young
adults, to help them to resist the pressure of social norms.
•
The studies have disclosed data about the orthodontic status and
treatment needs of Swedish adolescents of immigrant
background and greater insight into their attitudes to
orthodontics. This is important information for future planning
of orthodontic resources.
66
Summary in Swedish
Svensk sammanfattning
Det har skett ett ökat inflöde av flyktingar och invandrare till Sverige
under de senaste tre decennierna. Det övergripande syftet med denna
avhandling var i första hand att öka kunskapen om bettavvikelser och
ortodontiskt behandlingsbehov, både självupplevt och normativt, hos
barn och ungdomar med varierande geografisk bakgrund. Syftet var
också att bedöma om eventuella skillnader i uppfattning om det egna
utseendet och psykosocialt välbefinnande var kopplat till geografiskt
ursprung.
Delarbete I och II handlar om självupplevt och normativt ortodontiskt
behandlingsbehov. Cirka 500 12-13-åriga ungdomar, indelade i olika
grupper: A-Sverige, B-Östra/Sydöstra Europa, C-Asien och D-övriga
länder, besvarade ett frågeformulär och genomgick en klinisk
undersökning av författaren. I delarbete III analyseras sambandet mellan
de två variablerna i delarbete I och II. Delarbete IV är en uppföljande
studie, vid 18-19 års ålder, av sambandet mellan geografiskt ursprung,
förekomst av bettavvikelser, självupplevt behandlingsbehov, symptom i
käksystemet och psykologiskt välbefinnande. I delarbete V gjordes en
kvalitativ studie av unga vuxna, för att identifiera hur de hanterade
förekomsten av kvarstående estetiska bettavvikelser.
De huvudsakliga resultaten är att vid 12-13 års ålder har ungdomar med
utländsk bakgrund ett lägre självupplevt ortodontiskt behandlingsbehov
än ungdomar med svensk bakgrund. Flickor med svensk bakgrund har
det högsta självupplevda behandlingsbehovet, medan flickor med
utländsk bakgrund är mest bekymrade för behandlingsrelaterad smärta.
För några få variabler, registrerade vid 12-13 års ålder, uppvisar den
svenska gruppen den största platsbristen och oregelbundenheten i både
över- och underkäkens frontparti och större horisontellt överbett jämfört
med grupperna Östra/Sydöstra Europa och Asien. Den kliniska
betydelsen av detta är obetydlig. Ortodontiskt behandlingsbehov enligt
”Index of Orthodontic Treatment Need” ”Dental Health Component”
(IOTN-DHC) grad 4 och 5, varierar mellan 30 och 40 procent, utan
några skillnader mellan grupperna. Det finns ett starkt samband mellan
67
individer med ett självupplevt ortodontiskt behandlingsbehov och
IOTN-DHC grad 4 och 5, frontal invertering och att man undviker att
le på grund av tändernas utseende.
Vid 18-19 års ålder, är förekomsten av bettavvikelser lika i alla grupper.
Ungdomar, 18-19 år med asiatiskt ursprung, har ett högre självupplevt
ortodontiskt behandlingsbehov jämfört med sina svenska jämnåriga, och
en högre frekvens av huvudvärk jämfört med ungdomar med
Öst/Sydösteuropeiskt ursprung. Ett lågt psykologiskt välbefinnande
noteras hos nästan en fjärdedel av ungdomarna, vanligare bland flickor
än pojkar. Något samband mellan självupplevt ortodontiskt
behandlingsbehov och psykologiskt välbefinnande finns ej.
“Att vara under trycket från sociala normer” är den teori som genererades
i delarbete V, och den kan användas för att öka vår förståelse för unga
vuxna som har anpassat sig att leva med en estetisk bettavvikelse och
också identifiera de som inte anpassat sig, och som troligen skulle tjäna
på att få behandling. Dold tandvårdsrädsla är ett betydande hinder för att
acceptera ortodontisk behandling i tidiga ungdomsår.
Sammanfattningsvis konstateras att trots demografiska förändringar
orsakade av invandring, kan inga stora förändringar i förekomst av
bettavvikelser eller normativt ortodontiskt behandlingsbehov noteras.
68
Acknowledgements
The completion of this thesis would not have been achieved without the
support of many people, to whom I wish to express my gratitude,
specially to all the subjects who participated in the studies.
I also wish to acknowledge the following people for their invaluable
contributions :
My research supervisor, Associate Professor Krister Bjerklin, for sharing
with me his great knowledge of the field of orthodontics, for his steadfast
belief in this project and for guiding me through the many small steps in
the research process.
My co-supervisor, Associate Professor Rune Lindsten, for excellent advice
in all methodological discussions, never-ending patience and personal
support.
My co-author, Professor Lillemor Hallberg, for introducing me to the
field of qualitative research and guiding me through the qualitative
study.
My co-author, Professor emeritus Arne Halling, who encouraged me to
begin this journey, for his expert knowledge, good spirits and support.
Professor Tomas Magnusson, for excellent advice and training in the
field of Stomatognathic Physiology.
Dr Thomas Björnestedt, Motala, for allowing me the use of his clinic for
most of the examinations and for many years of support and friendship.
Marie Kindgren, orthodontic assistant, Motala, for excellent assistance
and administrative help throughout the study.
69
Annette Thimén, orthodontic assistant, Jönköping, for help with the
clinical examinations and excellent support when I away from the
Institute.
Annica Stavander, dental assistant, Department of Orthodontics,
Jönköping, for excellent co-ordination of patient administration
throughout the studies.
My colleagues and the staff at the Department of Orthodontics, The
Institute for Postgraduate Dental Education, Jönköping, for never-failing
support and friendship throughout this project.
My colleagues and the staff at the Orthodontic Clinic, Motala, for all
help and support at the start of this project.
Joan Bevenius-Carrick PhD, for professional language revision, advice on
research writing and friendship.
Elisabeth Wilhelm, statistician, Linköping, Birgit Ljungquist PhD,
Jönköping, and Mats P Nilsson, epidemiologist, Jönköping, for
invaluable statistical help and advice.
Thanks to librarians Åsa Zetterling and Gudrun Ahrén, for assistance
with the references.
Kent, my life companion, for love and never- ending patience.
Hanna and Lovisa, my lovely daughters, for their frank criticism and for
keeping me in touch with reality.
The research was supported by grants from the Medical Research
Council of Southeast Sweden, Public Dental Health Service of
Östergötland County, Futurum – the Academy for Healthcare, County
Council, Jönköping and The Sigrid de Verdier Memorial Fund.
70
References
1.
Nilsson Å. Efterkrigstidens invandring och utvandring. Stockholm: Statistiska
centralbyrån; 2004.
2.
Statistical yearbook of Sweden. Årg. 95, 2009. Stockholm: Statistiska
centralbyrån; 2008.
3.
Scully C, Wilson NHF. Culturally sensitive oral healthcare. London:
Quintessence; 2006.
4.
Statistical yearbook of Sweden. Årg. 87, 2000. Stockholm: Statistiska
centralbyrån; 2001.
5.
Thilander B, Pena L, Infante C, Parada SS, de Mayorga C. Prevalence of
malocclusion and orthodontic treatment need in children and adolescents in
Bogota, Colombia. An epidemiological study related to different stages of dental
development. Eur J Orthod 2001;23:153-167.
6.
Thilander B, Myrberg N. The prevalence of malocclusion in Swedish
schoolchildren. Scand J Dent Res 1973;81:12-20.
7.
Ingervall B, Seeman L, Thilander B. Frequency of malocclusion and need of
orthodontic treatment in 10-year old children in Gothenburg. Sven Tandlak
Tidskr 1972;65:7-21.
8.
Medin L, Bjerklin K, Bondemark L. Ortodontistbrist reellt hot.
Tandläkartidningen 2008;100:87-91.
9.
Kvam E. Hvem trenger tannregulering? Nor Tannlaegeforen Tid 1990;100:364371.
10.
Helm S. Offentlig finansiering av kjeveortopedisk behandling. Modeller og deres
økonomiske og kliniske konsekvenser. Tandlaegebladet 1990;94:365-369.
11.
Mohlin B, Domgaard P, Egermark I, Kurol J, Pietilä T. Hälsorisker vid
obehandlade malocklusioner. Nor Tannlaegeforen Tid 2007;117:24-29.
12.
Kurol J. Bettavvikelser. In: Hugoson A, Koch G, Svensson G, editors.
Consensus: Tandhälsotillståndet hos olika befolkningsgrupper i Sverige. Solna:
LIC; 1991. p. 29-47.
13.
Järvinen S. Indexes for orthodontic treatment need. Am J Orthod Dentofacial
Orthop 2001;120:237-239.
71
14.
Mandall NA, Wright J, Conboy F, Kay E, Harvey L, O'Brien KD. Index of
orthodontic treatment need as a predictor of orthodontic treatment uptake. Am
J Orthod Dentofacial Orthop 2005;128:703-707.
15.
Theis JE, Huang GJ, King GJ, Omnell ML. Eligibility for publicly funded
orthodontic treatment determined by the handicapping labiolingual deviation
index. Am J Orthod Dentofacial Orthop 2005;128:708-715.
16.
Svedström-Oristo AL, Pietilä T, Pietilä I, Alanen P, Varrela J. Outlining the
morphological characteristics of acceptable occlusion. Community Dent Oral
Epidemiol 2000;28:35-41.
17.
Otuyemi OD, Jones SP. Methods of assessing and grading malocclusion: a
review. Aust Orthod J 1995;14:21-27.
18.
Beglin FM, Firestone AR, Vig KW, Beck FM, Kuthy RA, Wade D. A
comparison of the reliability and validity of 3 occlusal indexes of orthodontic
treatment need. Am J Orthod Dentofacial Orthop 2001;120:240-246.
19.
Mockbil N, Huggare J. Uniformity in selection for subsidized orthodontic care-focus on borderline treatment need. Swed Dent J 2009;33:19-25.
20.
Brattström V. [Public health treatment-need index in orthodontics--a critical
study]. Tandläkartidningen 1987;79:704-707.
21.
Grainger RM. Orthodontic treatment priority index. Vital Health Stat 2;
1967:1-49.
22.
Swedish national board of health. Kungliga medicinalstyrelsens cirkulär. MF No.
71. Stockholm; 1967.
23.
Linder-Aronson S. Orthodontics in the Swedish Public Dental Health Service.
Trans Eur Orthod Soc 1974:233-240.
24.
Lundström A. [Indication index for the evaluation of the demand for treatment
of malocclusions]. Tandläkartidningen 1978;70:508-516.
25.
Bergström K, Halling A, Medin L, Filipsson R, Hannerz H, Jensen R. An
analysis of factors influencing the decision of orthodontic treatment.
Kieferorthop Mitteilungen 1995;9:195-210.
26.
Svedström-Oristo AL, Pietilä T, Pietilä I, Helenius H, Peutzfeldt P, Varrela J.
Selection of criteria for assessment of occlusal acceptability. Acta Odontol Scand
2002;60:160-166.
72
27.
Brook PH, Shaw WC. The development of an index of orthodontic treatment
priority. Eur J Orthod 1989;11:309-320.
28.
Evans R, Shaw W. Preliminary evaluation of an illustrated scale for rating dental
attractiveness. Eur J Orthod 1987;9:314-318.
29.
Richmond S, Buchanan IB, Burden DJ, O'Brien KD, Andrews M, Roberts CT
et al. Calibration of dentists in the use of occlusal indices. Community Dent
Oral Epidemiol 1995;23:173-176.
30.
Younis JW, Vig KW, Rinchuse DJ, Weyant RJ. A validation study of three
indexes of orthodontic treatment need in the United States. Community Dent
Oral Epidemiol 1997;25:358-362.
31.
O'Brien KD, Shaw WC, Roberts CT. The use of occlusal indices in assessing the
provision of orthodontic treatment by the hospital orthodontic service of
England and Wales. Br J Orthod 1993;20:25-35.
32.
So LL, Tang EL. A comparative study using the Occlusal Index and the Index of
Orthodontic Treatment Need. Angle Orthod 1993;63:57-64.
33.
Mohlin B, Kurol J. A critical view of treatment priority indices in orthodontics.
Swed Dent J 2003;27:11-21.
34.
Holmes A. The subjective need and demand for orthodontic treatment. Br J
Orthod 1992;19:287-297.
35.
Linder-Aronson S, Bjerrehorn K, Forsberg CM. Objective and subjective need
for orthodontic treatment in Stockholm County. Swed Dent J 2002;26:31-40.
36.
Berset GP, Eilertsen IM, Lagerström L, Espeland L, Stenvik A. Outcome of a
scheme for specialist orthodontic care. Swed Dent J 2000;24:39-48.
37.
Lagerström L, Stenvik A, Espeland L, Hallgren A. Outcome of a scheme for
orthodontic care: a comparison of untreated and treated 19-year-olds. Swed
Dent J 2000;24:49-57.
38.
Bergström K, Halling A. Orthodontic care provided by general practitioners and
specialists in three Swedish counties with different orthodontic specialist
resources. Swed Dent J 1996;20:35-50.
39.
Lilja-Karlander E, Kurol J, Josefsson E. Attitudes and satisfaction with dental
appearance in young adults with and without malocclusion. Swed Dent J
2003;27:143-150.
73
40.
Lilja-Karlander E, Kurol J. Outcome of orthodontic care in 19-year-olds
attending the Public Dental Service in Sweden: residual need and demand for
treatment. Swed Dent J 2003;27:91-97.
41.
Kerosuo H, Laine T, Kerosuo E, Ngassapa D, Honkala E. Occlusion among a
group of Tanzanian urban schoolchildren. Community Dent Oral Epidemiol
1988;16:306-309.
42.
Kerosuo H, Laine T, Nyyssonen V, Honkala E. Occlusal characteristics in
groups of Tanzanian and Finnish urban schoolchildren. Angle Orthod
1991;61:49-56.
43.
Ahmed B, Gilthorpe MS, Bedi R. Agreement between normative and perceived
orthodontic need amongst deprived multiethnic school children in London. Clin
Orthod Res 2001;4:65-71.
44.
Perillo L, Masucci C, Ferro F, Apicella D, Baccetti T. Prevalence of orthodontic
treatment need in southern Italian schoolchildren. Eur J Orthod 2010;32:49-53.
45.
Abu Alhaija ES, Al-Khateeb SN, Al-Nimri KS. Prevalence of malocclusion in
13-15 year-old North Jordanian school children. Community Dent Health
2005;22:266-271.
46.
Manzanera D, Montiel-Company JM, Almerich-Silla JM, Gandia JL.
Orthodontic treatment need in Spanish schoolchildren: an epidemiological study
using the Index of Orthodontic Treatment Need. Eur J Orthod 2009;31:180183.
47.
Helm S. Malocclusion in Danish children with adolescent dentition: an
epidemiologic study. Am J Orthod 1968;54:352-366.
48.
Myrberg N, Thilander B. Orthodontic need of treatment of Swedish
schoolchildren from objective and subjective aspects. Scand J Dent Res
1973;81:81-84.
49.
Kerosuo H, Abdulkarim E, Kerosuo E. Subjective need and orthodontic
treatment experience in a Middle East country providing free orthodontic
services: a questionnaire survey. Angle Orthod 2002;72:565-570.
50.
Lew KK, Foong WC, Loh E. Malocclusion prevalence in an ethnic Chinese
population. Aust Dent J 1993;38:442-449.
51.
Burden DJ, Holmes A. The need for orthodontic treatment in the child
population of the United Kingdom. Eur J Orthod 1994;16:395-399.
74
52.
Wang G, Hägg U, Ling J. The orthodontic treatment need and demand of
Hong Kong Chinese children. Chin J Dent Res 1999;2:84-92.
53.
Hosseini KR, Dahlström M, Huggare J. Malocclusion and the need for
orthodontic treatment in 9-year-old immigrant children in Stockholm, Sweden.
Swed Dent J 1999;23:209-216.
54.
Abdullah MS, Rock WP. Assessment of orthodontic treatment need in 5,112
Malaysian children using the IOTN and DAI indices. Community Dent Health
2001;18:242-248.
55.
Hamdan AM. Orthodontic treatment need in Jordanian school children.
Community Dent Health 2001;18:177-180.
56.
Onyeaso CO. Prevalence of malocclusion among adolescents in Ibadan, Nigeria.
Am J Orthod Dentofacial Orthop 2004;126:604-607.
57.
Ngom PI, Diagne F, Dieye F, Diop-Ba K, Thiam F. Orthodontic treatment
need and demand in Senegalese school children aged 12-13 years. An appraisal
using IOTN and ICON. Angle Orthod 2007;77:323-330.
58.
Sidlauskas A, Lopatiene K. The prevalence of malocclusion among 7-15-year-old
Lithuanian schoolchildren. Medicina (Kaunas) 2009;45:147-152.
59.
Chu CH, Choy BH, Lo EC. Occlusion and orthodontic treatment demand
among Chinese young adults in Hong Kong. Oral Health Prev Dent 2009;7:8391.
60.
Safavi SM, Sefidroodi A, Nouri M, Eslamian L, Kheirieh S, Bagheban AA.
Orthodontic treatment need in 14-16 year-old Tehran high school students.
Aust Orthod J 2009;25:8-11.
61.
Mtaya M, Brudvik P, Åstrøm AN. Prevalence of malocclusion and its
relationship with socio-demographic factors, dental caries, and oral hygiene in
12- to 14-year-old Tanzanian schoolchildren. Eur J Orthod 2009;31:467-476.
62.
Myllärniemi S. Malocclusion in Finnish rural children: An epidemiological study
of different stages of dental development. Suom Hammaslaak Toim
1970;66:219-264.
63.
Foster TD, Day AJ. A survey of malocclusion and the need for orthodontic
treatment in a Shropshire school population. Br J Orthod 1974;1:73-78.
64.
Björk A, Krebs A, Solow B. A method for epidemiological registration of
malocclusion. Acta Odontol Scand 1964;22:27-41.
75
65.
Tickle M, Kay EJ, Bearn D. Socio-economic status and orthodontic treatment
need. Community Dent Oral Epidemiol 1999;27:413-418.
66.
Egermark I, Carlsson GE, Magnusson T. A prospective long-term study of signs
and symptoms of temporomandibular disorders in patients who received
orthodontic treatment in childhood. Angle Orthod 2005;75:645-650.
67.
Souames M, Bassigny F, Zenati N, Riordan PJ, Boy-Lefevre ML. Orthodontic
treatment need in French schoolchildren: an epidemiological study using the
Index of Orthodontic Treatment Need. Eur J Orthod 2006;28:605-609.
68.
Fox D, Kay EJ, O'Brien K. A new method of measuring how much anterior
tooth alignment means to adolescents. Eur J Orthod 2000;22:299-305.
69.
Mandall NA, McCord JF, Blinkhorn AS, Worthington HV, O'Brien KD.
Perceived aesthetic impact of malocclusion and oral self-perceptions in 14-15year-old Asian and Caucasian children in greater Manchester. Eur J Orthod
2000;22:175-183.
70.
Ngom PI, Brown R, Diagne F, Normand F, Richmond S. A cultural comparison
of treatment need. Eur J Orthod 2005;27:597-600.
71.
Birkeland K, Boe OE, Wisth PJ. Orthodontic concern among 11-year-old
children and their parents compared with orthodontic treatment need assessed
by index of orthodontic treatment need. Am J Orthod Dentofacial Orthop
1996;110:197-205.
72.
Danaei SM, Amirrad F, Salehi P. Orthodontic treatment needs of 12-15-yearold students in Shiraz, Islamic Republic of Iran. East Mediterr Health J
2007;13:326-334.
73.
Ciuffolo F, Manzoli L, D'Attilio M, Tecco S, Muratore F, Festa F et al.
Prevalence and distribution by gender of occlusal characteristics in a sample of
Italian secondary school students: a cross-sectional study. Eur J Orthod
2005;27:601-606.
74.
Migale D, Barbato E, Bossu M, Ferro R, Ottolenghi L. Oral health and
malocclusion in 10-to-11 years-old children in southern Italy. Eur J Paediatr
Dent 2009;10:13-18.
75.
O'Brien K, McComb JL, Fox N, Wright J. Factors influencing the uptake of
orthodontic treatment. Br J Orthod 1996;23:331-334.
76.
Christopherson EA, Briskie D, Inglehart MR. Objective, subjective, and selfassessment of preadolescent orthodontic treatment need--a function of age,
gender, and ethnic/racial background? J Public Health Dent 2009;69:9-17.
76
77.
Shaw WC, Rees G, Dawe M, Charles CR. The influence of dentofacial
appearance on the social attractiveness of young adults. Am J Orthod
1985;87:21-26.
78.
Zhang M, McGrath C, Hägg U. Orthodontic treatment need and oral healthrelated quality among children. Community Dent Health 2009;26:58-61.
79.
Hassan AH, Amin Hel S. Association of orthodontic treatment needs and oral
health-related quality of life in young adults. Am J Orthod Dentofacial Orthop
2010;137:42-47.
80.
Klages U, Bruckner A, Zentner A. Dental aesthetics, self-awareness, and oral
health-related quality of life in young adults. Eur J Orthod 2004;26:507-514.
81.
de Paula Júnior DF, Santos NC, da Silva ET, Nunes MF, Leles CR.
Psychosocial impact of dental esthetics on quality of life in adolescents. Angle
Orthod 2009;79:1188-1193.
82.
Bernabe E, Tsakos G, Messias de Oliveira C, Sheiham A. Impacts on daily
performances attributed to malocclusions using the condition-specific feature of
the Oral Impacts on Daily Performances Index. Angle Orthod 2008;78:241247.
83.
Kenealy PM, Kingdon A, Richmond S, Shaw WC. The Cardiff dental study: a
20-year critical evaluation of the psychological health gain from orthodontic
treatment. Br J Health Psychol 2007;12:17-49.
84.
Shaw WC, Lewis HG, Robertson NR. Perception of malocclusion. Br Dent J
1975;138:211-216.
85.
Shaw WC. Factors influencing the desire for orthodontic treatment. Eur J
Orthod 1981;3:151-162.
86.
Kenealy P, Frude N, Shaw W. An evaluation of the psychological and social
effects of malocclusion: some implications for dental policy making. Soc Sci
Med 1989;28:583-591.
87.
O'Brien K, Wright J, Conboy F, Sanjie Y, Mandall N, Chadwick S et al.
Effectiveness of early orthodontic treatment with the Twin-block appliance: a
multicenter, randomized, controlled trial. Part 1: Dental and skeletal effects. Am
J Orthod Dentofacial Orthop 2003;124:234-243.
88.
Liu Z, McGrath C, Hägg U. The impact of malocclusion/orthodontic treatment
need on the quality of life. A systematic review. Angle Orthod 2009;79:585-591.
77
89.
Shaw WC, Richmond S, Kenealy PM, Kingdon A, Worthington H. A 20-year
cohort study of health gain from orthodontic treatment: psychological outcome.
Am J Orthod Dentofacial Orthop 2007;132:146-157.
90.
Albino JE, Lawrence SD, Tedesco LA. Psychological and social effects of
orthodontic treatment. J Behav Med 1994;17:81-98.
91.
Secord PF, Jourard SM. The appraisal of body-cathexis: body-cathexis and the
self. J Consult Psychol 1953;17:343-347.
92.
Pertschuk MJ, Whitaker LA. Social and psychological effects of craniofacial
deformity and surgical reconstruction. Clin Plast Surg 1982;9:297-306.
93.
Kiyak HA, Zeitler DL. Self-assessment of profile and body image among
orthognathic surgery patients before and two years after surgery. J Oral
Maxillofac Surg 1988;46:365-371.
94.
McDowell I, Newell C. Measuring health: a guide to rating scales and
questionnaires. New York: Oxford Univ. Press; 1996.
95.
Glaser BG, Strauss AL. The discovery of grounded theory: strategies for
qualitative research. New York: Aldine de Gruyter; 1967.
96.
Kvale S. Issues of validity in qualitative research. Lund: Studentlitteratur; 1989.
97.
Armitage P, Berry G, Matthews JNS. Statistical methods in medical research.
Oxford: Blackwell Science; 2002.
98.
Landis JR, Koch GG. The measurement of observer agreement for categorical
data. Biometrics 1977;33:159-174.
99.
Väkiparta MK, Kerosuo HM, Nyström ME, Heikinheimo KA. Orthodontic
treatment need from eight to 12 years of age in an early treatment oriented
public health care system: a prospective study. Angle Orthod 2005;75:344-349.
100. Tausche E, Luck O, Harzer W. Prevalence of malocclusions in the early mixed
dentition and orthodontic treatment need. Eur J Orthod 2004;26:237-244.
101. Dawjee SM, Ackerman A, Shaw WC. An aesthetic component of the IOTN for
black subjects. SADJ 2002;57:258-263.
102. Mi CB, Fan XL, Tian Y, Peng L, Guo H. [The prevalence of orthodontic
treatment need in Urumqi Han's adolescent]. Shanghai Kou Qiang Yi Xue
2003;12:11-13.
78
103. Haavikko K, Rahkamo A. Changes in the dental arches induced by premature
extractions of deciduous molars. Proc Finn Dent Soc 1977;73:14-20
104. Bjerklin K, Lindsten R. The effect of caries in the primary dentition on dental
arch development. In: Hugoson A, Falk M, Johansson S, editors. Consensus
Conference on Caries in the Primary Dentition and its Clinical Management.
Stockholm: Gothia; 2002. p. 35-47.
105. Trulsson U, Strandmark M, Mohlin B, Berggren U. A qualitative study of
teenagers' decisions to undergo orthodontic treatment with fixed appliance. J
Orthod 2002;29:197-204.
106. Egermark-Eriksson I. Malocclusion and some functional recordings of the
masticatory system in Swedish schoolchildren. Swed Dent J 1982;6:9-20.
107. Grahnén H. Hypodontia in the permanent dentition. A clinical and genetical
investigation. Odontol Revy 1956;7:28-39.
108. Bissar AR, Oikonomou C, Koch MJ, Schulte AG. Dental health, received care,
and treatment needs in 11- to 13-year-old children with immigrant background
in Heidelberg, Germany. Int J Paediatr Dent 2007;17:364-370.
109. Lindsten R, Øgaard B, Larsson E. Transversal dental arch dimensions in 9-yearold children born in the 1960s and the 1980s. Am J Orthod Dentofacial Orthop
2001;120:576-584.
110. Lindsten R, Øgaard B, Larsson E, Bjerklin K. Transverse dental and dental arch
depth dimensions in the mixed dentition in a skeletal sample from the 14th to
the 19th century and Norwegian children and Norwegian Sami children of
today. Angle Orthod 2002;72:439-448.
111. Lindsten R, Øgaard B, Larsson E. Difference in dental lateral arch length
between 9-year-olds born in the 1960s and the 1980s. Am J Orthod Dentofacial
Orthop 2000;117:663-668.
112. Lindsten R, Øgaard B, Larsson E. Dental arch space and permanent tooth size in
the mixed dentition of a skeletal sample from the 14th to the 19th centuries and
3 contemporary samples. Am J Orthod Dentofacial Orthop 2002;122:48-58.
113. Prahl-Andersen B, Boersma H, van der Linden FP, Moore AW. Perceptions of
dentofacial morphology by laypersons, general dentists, and orthodontists. J Am
Dent Assoc 1979;98:209-212.
114. Mandall NA, Wright J, Conboy FM, O'Brien KD. The relationship between
normative orthodontic treatment need and measures of consumer perception.
Community Dent Health 2001;18:3-6.
79
115. Espeland LV, Stenvik A. Perception of personal dental appearance in young
adults: relationship between occlusion, awareness, and satisfaction. Am J Orthod
Dentofacial Orthop 1991;100:234-241.
116. Van der Geld P, Oosterveld P, Van Heck G, Kuijpers-Jagtman AM. Smile
attractiveness. Self-perception and influence on personality. Angle Orthod
2007;77:759-765.
117. Kerosuo H, Hausen H, Laine T, Shaw WC. The influence of incisal
malocclusion on the social attractiveness of young adults in Finland. Eur J
Orthod 1995;17:505-512.
118. Svedström-Oristo AL, Pietilä T, Pietilä I, Vahlberg T, Alanen P, Varrela J.
Acceptability of dental appearance in a group of Finnish 16- to 25-year-olds.
Angle Orthod 2009;79:479-483.
119. Traebert ES, Peres MA. Do malocclusions affect the individual's oral healthrelated quality of life? Oral Health Prev Dent 2007;5:3-12.
120. Abu Alhaija ES, Al-Khateeb SN. Attractiveness ratings of anterior open bites and
reverse overjets using the aesthetic component of the Index of Orthodontic
Treatment Need. Eur J Orthod 2005;27:134-139.
121. Espeland LV, Ivarsson K, Stenvik A, Alstad TA. Perception of malocclusion in
11-year-old children: a comparison between personal and parental awareness.
Eur J Orthod 1992;14:350-358.
122. Helm S, Petersen PE, Kreiborg S, Solow B. Effect of separate malocclusion traits
on concern for dental appearance. Community Dent Oral Epidemiol
1986;14:217-220.
123. Momeni Danaei S, Salehi P. Association between normative and self-perceived
orthodontic treatment need among 12- to 15-year-old students in Shiraz, Iran.
Eur J Orthod 2010.
124. Kok YV, Mageson P, Harradine NW, Sprod AJ. Comparing a quality of life
measure and the Aesthetic Component of the Index of Orthodontic Treatment
Need (IOTN) in assessing orthodontic treatment need and concern. J Orthod
2004;31:312-318.
125. Sayers MS, Newton JT. Patients' expectations of orthodontic treatment: part 2-findings from a questionnaire survey. J Orthod 2007;34:25-35.
126. Ambjörnsson F. I en klass för sig: genus, klass och sexualitet bland
gymnasietjejer. Stockholm: Ordfront; 2004.
80
127. Victorin Cederquist A. Psychiatric and psychosomatic symptoms are increasing
problems among Swedish schoolchildren. Acta Paediatr 2006;95:901-903.
128. Hjern A, Alfven G, Östberg V. School stressors, psychological complaints and
psychosomatic pain. Acta Paediatr 2008;97:112-117.
129. Wänman A. Craniomandibular disorders in adolescents. A longitudinal study in
an urban Swedish population. Swed Dent J Suppl 1987;44:1-61.
130. Magnusson T, Carlsson GE. Recurrent headaches in relation to
temporomandibular joint pain-dysfunction. Acta Odontol Scand 1978;36:333338.
131. List T, Wahlund K, Wenneberg B, Dworkin SF. TMD in children and
adolescents: prevalence of pain, gender differences, and perceived treatment
need. J Orofac Pain 1999;13:9-20.
132. Egermark-Eriksson I. Prevalence of headache in Swedish schoolchildren. A
questionnaire survey. Acta Paediatr Scand 1982;71:135-140.
133. Egermark-Eriksson I, Ingervall B, Carlsson GE. The dependence of mandibular
dysfunction in children on functional and morphologic malocclusion. Am J
Orthod 1983;83:187-194.
134. Lambourne C, Lampasso J, Buchanan WC, Jr., Dunford R, McCall W.
Malocclusion as a risk factor in the etiology of headaches in children and
adolescents. Am J Orthod Dentofacial Orthop 2007;132:754-761.
135. Mohlin B, Axelsson S, Paulin G, Pietilä T, Bondemark L, Brattström V et al.
TMD in relation to malocclusion and orthodontic treatment. Angle Orthod
2007;77:542-548.
136. Mohlin B, Kurol J. To what extent do deviations from an ideal occlusion
constitute a health risk? Swed Dent J 2003;27:1-10.
137. Holm A-K, Statens beredning för medicinsk utvärdering. Bettavvikelser och
tandreglering i ett hälsoperspektiv: en systematisk litteraturöversikt. SBU-rapport
nr 176, 2005.
138. Egermark I, Magnusson T, Carlsson GE. A 20-year follow-up of signs and
symptoms of temporomandibular disorders and malocclusions in subjects with
and without orthodontic treatment in childhood. Angle Orthod 2003;73:109115.
81
139. Wahlund K. Temporomandibular disorders in adolescents. Epidemiological and
methodological studies and a randomized controlled trial. Swed Dent J Suppl
2003;164:2-64.
140. O'Brien K, Kay L, Fox D, Mandall N. Assessing oral health outcomes for
orthodontics--measuring health status and quality of life. Community Dent
Health 1998;15:22-26.
141. Cunningham SJ, Hunt NP. Quality of life and its importance in orthodontics. J
Orthod 2001;28:152-158.
142. Klages U, Claus N, Wehrbein H, Zentner A. Development of a questionnaire
for assessment of the psychosocial impact of dental aesthetics in young adults.
Eur J Orthod 2006;28:103-111.
143. Bernabé E, Sheiham A, Tsakos G, Messias de Oliveira C. The impact of
orthodontic treatment on the quality of life in adolescents: a case-control study.
Eur J Orthod 2008;30:515-520.
144. O'Brien C, Benson PE, Marshman Z. Evaluation of a quality of life measure for
children with malocclusion. J Orthod 2007;34:185-193.
145. Traebert ES, Peres MA. Prevalence of malocclusions and their impact on the
quality of life of 18-year-old young male adults of Florianopolis, Brazil. Oral
Health Prev Dent 2005;3:217-224.
146. Taylor KR, Kiyak A, Huang GJ, Greenlee GM, Jolley CJ, King GJ. Effects of
malocclusion and its treatment on the quality of life of adolescents. Am J Orthod
Dentofacial Orthop 2009;136:382-392.
147. Johansson G, Fridlund B. Young adults' views on dental care--a qualitative
analysis. Scand J Caring Sci 1996;10:197-204.
148. Folkhälsa:Lägesrapporter 2006. Stockholm:Socialstyrelsen, 2007. Available from
http://www.socialstyrelsen.se/publikationer2007/2007-131-15. Access date
2009-11-01.
149. Malmström C, Allmänna barnhuset. Satsa på barnens vardagsmiljöer:
mottagande och introduktion av flyktingbarn och ungdomar. Stockholm:
Stiftelsen Allmänna barnhuset; 2006.
150. Lazarus RS. Stress and emotion : a new synthesis. New York: Springer; 1999.
151. Björnsson M. Kön och skolframgång : tolkningar och perspektiv : ett uppdrag
för Myndigheten för skolutveckling. Stockholm: Myndigheten för
skolutveckling, Sverige; 2005.
82
152. Phillips C, Beal KN. Self-concept and the perception of facial appearance in
children and adolescents seeking orthodontic treatment. Angle Orthod
2009;79:12-16.
153. Agou S, Locker D, Streiner DL, Tompson B. Impact of self-esteem on the oralhealth-related quality of life of children with malocclusion. Am J Orthod
Dentofacial Orthop 2008;134:484-489.
154. de Oliveira CM, Sheiham A. Orthodontic treatment and its impact on oral
health-related quality of life in Brazilian adolescents. J Orthod 2004;31:20-27.
83