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THE ATTITUDES, AWARENESS AND PERCEPTIONS OF ORTHODONTISTS
WITH REGARDS TO ORTHODONTIC LITERATURE ON
INTERCEPTIVE TREATMENT OF CLASS II
MALOCCLUSIONS IN THE MIXED
DENTITION
Devin A. Conaway, D.M.D.
A Thesis Presented to the Graduate Faculty of
Saint Louis University in Partial Fulfillment
of the Requirements for the Degree of
Master of Science in Dentistry
2015
COMMITTEE IN CHARGE OF CANDIDACY:
Professor Eustaquio A. Araujo,
Chairperson and Advisor
Associate Professor Ki Beom Kim
Assistant Professor Hiroshi Ueno
i
DEDICATION
This work is dedicated to my dog, Sammie.
We were
obligated to sacrifice much of our personal time together
in order for me to complete this thesis.
She has always
been there for me at times when I need her, and she helps
me forget about many of my stresses along the way.
I
couldn’t ask for a better friend.
I would also like to thank my parents, who instilled
in me a strong work ethic from a young age.
They have
always believed in me and have never let me slack.
All of
my successes in life are either directly or indirectly a
result of my upbringing.
I cannot thank my parents enough
for all they have done for me.
ii
ACKNOWLEDGMENTS
This thesis was completed with help from the following
individuals:
Dr. Eustaquio Araujo.
Thank you for your constant
inspiration and motivation.
You are one the greatest
orthodontists I’ll ever meet, and you have taught me so
much during my time at Saint Louis University.
My
education would not have been the same without you.
Your
wisdom and knowledge will be with me throughout all of my
future orthodontic endeavors.
Dr. Rolf Behrents.
Thank you for giving me the
opportunity to obtain such a great orthodontic education.
You have a brilliant mind, and I aspire to think
critically, as I so often see you do.
You are an
indispensable bank of orthodontic knowledge, and I’m glad I
had the opportunity to learn from you.
Dr. Ki Beom Kim.
I have learned a tremendous amount
from you during the course of my training, both in the
classroom and on the clinic floor.
I admire your
progressive thinking, and you never failed to ask me
challenging questions.
Thank you for all of your guidance
and help.
Dr. Hiroshi Ueno.
Unfortunately my time with you
during my residency was limited, yet still invaluable.
iii
I
admire your chairside demeanor with patients, and I could
not have completed this thesis without you, thank you.
iv
TABLE OF CONTENTS
LIST OF TABLES........................................... vi
LIST OF FIGURES......................................... vii
CHAPTER 1: INTRODUCTION................................... 1
CHAPTER 2: REVIEW OF THE LITERATURE....................... 4
Randomized Clinical Trials .............................. 4
Skeletal Effects ....................................... 10
Treatment Time ......................................... 15
Treatment Results ...................................... 18
Psychological Effects .................................. 22
Trauma ................................................. 25
Practice Management .................................... 28
Goals of This Study .................................... 31
References ............................................. 33
CHAPTER 3: JOURNAL ARTICLE...............................
Abstract ...............................................
Introduction ...........................................
Methods and Materials ..................................
Survey Design ........................................
Survey Validity ......................................
Survey Distribution ..................................
Data Collection and Analysis .........................
Results ................................................
Response Rate ........................................
Demographics .........................................
Literature ...........................................
Treatment Priorities .................................
Discussion .............................................
Summary and Conclusions ................................
References .............................................
38
38
39
42
42
42
43
43
44
44
44
46
50
52
60
63
APPENDIX A............................................... 65
APPENDIX B............................................... 68
VITA AUCTORIS............................................ 73
v
LIST OF TABLES
Table 2.1:
Characteristics of Randomized Clinical
Trials (RCTs) for Interceptive Class II
Orthodontic Treatment...................... 7
Table 2.2:
Effects of Interceptive Treatment of Class
II Malocclusions as Supported by Orthodontic
Literature................................ 29
Table 3.1:
Orthodontic Literature Questions.......... 48
Table 3.2:
Responses to Orthodontic Literature
Questions................................. 48
Table 3.3:
Significance of Demographics on Response to
Orthodontic Literature Questions.......... 49
Table 3.4:
Treatment Priorities...................... 51
Table 3.5:
Responses to Orthodontic Treatment
Priorities................................ 51
Table 3.6:
Significance of Demographics on Orthodontic
Treatment Priorities...................... 52
Table 3.7:
Comparison of Survey Demographics with
Madhavji 2009............................. 53
Table 3.8:
Rankings of Treatment Benefits............ 57
vi
LIST OF FIGURES
Figure 2.1:
Hierarchy of Scientific Evidence........... 4
Figure 3.1:
Gender of Participant Pool................ 45
Figure 3.2:
Age Distribution of Participant Pool...... 45
Figure 3.3:
Education of Participant Pool............. 45
Figure 3.4:
Educational Involvement of Participant
Pool...................................... 46
Figure B1:
Question 5 Distribution of Responses...... 68
Figure B2:
Question 6 Distribution of Responses...... 68
Figure B3:
Question 7 Distribution of Responses...... 68
Figure B4:
Question 8 Distribution of Responses...... 69
Figure B5:
Question 9 Distribution of Responses...... 69
Figure B6:
Question 10 Distribution of Responses..... 69
Figure B7:
Question 11 Distribution of Responses..... 70
Figure B8:
Question 12 Distribution of Responses..... 70
Figure B9:
Question 13 Distribution of Responses..... 70
Figure B10:
Question 14 Distribution of Responses for
Treatment Priority Reduced Risk of Trauma
to the Incisors........................... 71
Figure B11:
Question 14 Distribution of Responses for
Treatment Priority Increased Patient SelfEsteem.................................... 71
Figure B12:
Question 14 Distribution of Responses for
Treatment Priority Enhanced Orthopedic
Changes................................... 71
Figure B13:
Question 14 Distribution of Responses for
Treatment Priority Shorter Phase II
Treatment Time............................ 72
vii
Figure B14:
Question 14 Distribution of Responses for
Treatment Priority Better Result with TwoPhase Treatment than a Single Phase of
Treatment................................. 72
Figure B15:
Question 14 Distribution of Responses for
Treatment Priority Practice Management
Decision.................................. 72
viii
CHAPTER 1: INTRODUCTION
The purpose of orthodontic diagnosis and treatment
planning is not only deciding if treatment is necessary,
but also deciding when to initiate treatment.
When dealing
with Angle Class II malocclusions, it is often not the
former, but rather the latter that causes controversy among
orthodontists, specifically initiating treatment in the
mixed dentition.
This topic is prominent in orthodontic
literature, with many investigators mentioning the
controversy of interceptive treatment of Class II
malocclusions in the mixed dentition.1-5
Interceptive orthodontic treatment has been defined as
procedures that eliminate or reduce the severity of a
developing malocclusion.6
It is traditionally conducted
during the mixed dentition, with the understanding that
oftentimes a second phase of treatment (phase II) is
necessary in the late mixed or early permanent dentition to
achieve all orthodontic treatment goals.
For this reason
interceptive treatment is often synonymous with the terms
“early orthodontic treatment” or “phase I treatment.”
A common goal of interceptive treatment of Class II
malocclusions is growth modification of the jaws to address
any underlying skeletal discrepancies.1
1
Presumably this
will lead to a shorter, less complex second phase of
treatment, and possibly better results, compared to a
single phase of treatment later in adolescence.
Several randomized clinical trials (RCTs) concluded
that interceptive Class II treatment resulted in skeletal
improvements compared to untreated controls.2-5,7-9
However,
after a second phase of treatment no differences were found
when compared to a matched sample having undergone a single
phase of treatment in the late mixed or early permanent
dentition.2-5,7,8
Additionally, phase II treatment was not
shorter than a single phase of treatment, and yielded
similar results.
Overall, total treatment time was longer
for 2-phase treatment as compared to 1-phase treatment.
Although these findings discredit many proposed
benefits of interceptive treatment of Class II
malocclusions, some investigators suggest there are other
reasons to perform interceptive treatment.2,7,8
Possible
benefits of interceptive treatment include increased selfconcept and reduced risk of trauma.10-12
Unfortunately, due to the vast amount of orthodontic
literature available on interceptive treatment of Class II
malocclusions in the mixed dentition, and varying levels of
evidence, it may be hard for orthodontists to identify
these findings.
In fact, 59% of orthodontists believe that
2
orthodontic literature is ambiguous or conflicting.13
This
finding is disheartening, since it is imperative that
orthodontists be able to evaluate literature without being
confused.
Orthodontists must be aware of the true benefits
of interceptive treatment in order to provide proper
informed consent to every patient, and to ensure that
treatment decisions are made on the basis of sound,
scientific evidence.
The purpose of this study is to determine the
attitudes, awareness and perceptions of orthodontists with
regards to orthodontic literature on interceptive treatment
of Class II malocclusions in the mixed dentition.
Furthermore, this study is intended to determine
orthodontists’ priorities for interceptive Class II
orthodontic treatment in the mixed dentition.
The results
of this study could aid in the development of treatment
guidelines.
Additionally, findings could help guide
further research on interceptive orthodontic treatment of
Class II malocclusions in the mixed dentition to diminish
any remaining controversy on the topic.
3
CHAPTER 2: REVIEW OF THE LITERATURE
Randomized Clinical Trials
Randomized clinical trials (RCTs) are often heralded
as the gold standard of scientific research.14
In the
hierarchy of research designs, RCTs are only succeeded by
systematic reviews/meta-analyses, which are often directly
based on RCTs (Figure 2.1).
The advantage of RCTs over
other research designs is that they eliminate confounding
variables by distributing subjects randomly into groups.
The theory being that if subjects are distributed randomly,
then all variables, both known and unknown, are distributed
evenly amongst the groups.
Therefore, it can be assumed
that any differences between groups are due solely to the
variable being investigated.
Figure 2.1: Hierarchy of Scientific Evidence14
4
Unfortunately, RCTs are not always plausible,
especially in healthcare.
This can be due to ethical
reasons or practical issues.14
Depending on the research,
assigning patients to a control group that consists of no
treatment, or inferior treatment, can be deemed unlawful
and unethical.
Consequently, healthcare researchers must
resort to other research designs when investigating certain
topics.
While other research designs (i.e. case reports,
case-control studies, cohort studies, expert opinions,
etc.) have limitations, they should not be discredited;
however, they should be evaluated critically for biases and
confounding variables.
Fortunately for orthodontists, several RCTs have been
conducted regarding interceptive, or early, treatment of
Class II malocclusions in the mixed dentition.
Three
studies were funded by the National Institute of Dental
Research (NIDR) in the early 1990s.15
These studies were
conducted at the University of North Carolina, the
University of Florida, and the University of Pennsylvania.
Additionally, another trial was undertaken at the
University of Manchester, in the United Kingdom (UK).
Collectively, these studies evaluated the
effectiveness of various treatment modalities for
interceptive Class II treatment compared to untreated
5
controls.1,3-5,8
Subjects were then treated later in
adolescence, during the late mixed or early permanent
dentition, with fixed appliances.
Conclusions about
interceptive treatment, and subsequently about one-phase
versus two-phase treatments, were similar across all of the
studies.
The RCT conducted at the University of North Carolina
(UNC) in Chapel Hill, NC lasted from 1988-2000.1,8
Inclusion criteria for the study included children in the
mixed dentition, at least 1 year away from their peak
height velocity, with overjet greater than 7 mm, and no
previous orthodontic treatment (see Table 2.1).
The
children were then randomly assigned to one of three
possible groups.
Two of the groups underwent early
treatment, and one group was a control.
Of the two
treatment groups, one group was treated with a headgear and
the other was treated with a modified bionator.
The
control group was observed during active treatment of the
two treatment groups.
During the second part of the study,
all patients from phase I, both treatment groups and the
control group, were randomly assigned for comprehensive
fixed appliance treatment during the early permanent
dentition.
6
Table 2.1: Characteristics of Randomized Clinical Trials (RCTs) for
Interceptive Class II Orthodontic Treatment
Name
Location
Inclusion
Interventions
Criteria
North Carolina
Univ. of North
 Mixed
 Headgear
(UNC)
Carolina
dentition
 Modified
Chapel Hill, NC
 1 yr before
bionator
peak height
 Control
velocity
 Overjet > 7 mm
 No prior
orthodontic
treatment
Florida (UF)
Univ. of Florida  Mixed
 Headgear and
Gainesville, FL
dentition
biteplane
 All permanent
 Bionator
1st molars
 Control
 Bilateral
Class II molar
 Positive
overjet &
overbite
 Good general
health
Manchester (UM)
Univ. of
 Mixed
 Twin-block
Manchester
dentition
 Control
Manchester, UK
 Class II
Division 1
 Overjet ≥ 7 mm
 No
craniofacial
syndromes
Pennsylvania
Univ. of
 Age 7-13 years  Headgear
(UPENN)
Pennsylvania
 Class II
 Frankel (FRPhiladelphia, PA
Division 1
2)
 ANB ≥ 4.5°
 No prior
orthodontic
treatment
The RCT conducted at the University of Florida (UF) in
Gainesville, FL was carried out from 1990 to 2000.4
Inclusion criteria for the study included: mixed dentition
(less than 3 permanent cuspids or bicuspids), all permanent
first molars, bilateral Class II molar relationship,
7
positive overjet and overbite, and good general health.
Like the UNC study, subjects were randomly assigned to
three groups, two treatment and one control.
Similarly the
two treatment groups were a bionator group and a headgear
group, the difference being that the headgear group was
also treated with a bite plane.
The control group was
observed during the same time period.
Patients were then
monitored during a 12-month observation or retention period
before being treated with full fixed orthodontic
appliances.
The RCT conducted at the University of Manchester
(UM), was conducted over a 10-year period.5
Inclusion
criteria for the study included children with Class II
Division 1 malocclusions in the mixed dentition (at least
erupted permanent incisors and first molars), an overjet of
7 mm or greater and no craniofacial syndromes.
Unlike the
studies done at UNC and UF, this study randomized patients
into two groups instead of three, a treatment and a
control.
One group underwent interceptive treatment with a
Twin-block appliance and the other was delayed
comprehensive treatment for a minimum of 15 months.
All
patients were then treated with comprehensive orthodontic
treatment in adolescence.
8
The RCT conducted at the University of Pennsylvania
(UPENN) was undertaken in Philadelphia, PA.2
This study was
somewhat dissimilar to the other three RCTs conducted at
UNC, UF and UM.
Unlike the three other RCTs, this study
had no control group, and subjects were not treated with a
second phase of comprehensive fixed appliances.
Inclusion
criteria for the study included: children age 7-13 years
with Class II Division 1 malocclusions (bilaterally), an
ANB angle equal to or greater than 4.5 degrees and no prior
orthodontic treatment.
Patients were randomly assigned to
one of two treatment groups at different ages based on the
eruption of permanent cuspids, bicuspids and second molars.
Subjects were treated with either a headgear or a Frӓnkel
functional regulator type II (FR-2) appliance.
A Cochrane systematic review was developed based upon
the findings of three of the four aforementioned RCTs (UNC,
UF and UM).12
As noted previously, systematic reviews are
considered to be the highest form of scientific evidence,
trumping even RCTs.
Cochrane reviews are part of the
Cochrane Library, and base their findings on the results of
studies that meet certain quality criteria, since the most
reliable studies will provide the best evidence for making
decisions.16
9
This Cochrane review included RCTs involving children
age 16 years or younger, with Class II division 1
malocclusions, who received early orthodontic treatment.12
Studies including patients with craniofacial deformities or
syndromes were excluded.
Seventeen trials were identified;
however, 14 were late treatment studies, and thus excluded.
Articles reporting on the 3 early treatment RCTs (UNC, UF and
UM) were included.
Skeletal Effects
A common objective of interceptive Class II treatment
is modification of growth to address skeletal
discrepancies.
Various treatment modalities (e.g.
headgear, functional appliances, etc.) are used to achieve
this goal, sometimes by different methods.
This was
verified by the RCTs conducted at UNC, UF, UPenn and
UM.1,4,5,8,9,17-20
All of these studies showed evidence of
favorable skeletal changes as a result of interceptive
treatment in the mixed dentition.
Results from the UNC RCT showed that early treatment
with either a headgear or a modified bionator led to a
favorable improvement in ANB for 75% of the treated
patients.1
Maxillary advancement was restricted in the
headgear group, resulting in a reduction of SNA.17
10
SNB and
mandibular length increased in the functional group,
suggesting the mandible was primarily affected.
Comparatively, 30% of the untreated control group
experienced a favorable change in ANB during the same
time,21
while about 15% showed an unfavorable change.1
Similarly, the RCT from UF showed a decrease in ANB
for both treatment groups, bionator and headgear/biteplane,
compared to the untreated control group.4
Results showed
that treatment predominantly affected the mandible in both
groups.18-20
However, 14% of patients treated with a
headgear and biteplane, and 6% of those treated with a
bionator, showed an increase in ANB.4
Likewise, 27% of the
control group showed an increase in ANB.
A similar result was reported by the RCT conducted at
the University of Manchester; a significant reduction in
ANB was noted for the Twin-block treatment group compared
to the control group.5
both jaws.
The Twin-block showed effects in
Maxillary advancement was inhibited, and
mandibular advancement was enhanced.
However, skeletal
effects only contributed to 27% of overjet change and 41%
of molar change.9
The majority of class II correction was
found to be due to dentoalveolar compensation.
Much like the other three RCTs, the RCT held at UPENN
showed an overall decrease in ANB after treatment with a
11
headgear or a Frӓnkel appliance (FR-2).2
The headgear group
experienced a decrease in SNA while the FR-2 group
experienced an increase in SNB.
Unfortunately results
could not be compared to a control group for this study.
Part 2 of the RCTs went on to investigate whether or
not skeletal effects achieved during interceptive phase I
treatment were transient or not.
All subjects underwent
comprehensive phase II treatment with fixed orthodontic
appliances.
Post-treatment results were evaluated and it
was concluded that interceptive treatment did not result in
significant skeletal differences after phase II treatment.35,8,19
That is to say, there were no significant differences
between subjects who were treated with 2 phases versus
those who were treated with 1 phase.
The UNC trial concluded that at the end of fixed
appliance treatment (phase II), no significant differences
existed between any of the groups for all skeletal
measures; any skeletal changes achieved during early
treatment were lost.3,8
Likewise, at UF, it was concluded
that ANB was similar for all groups after treatment with
fixed appliances.4,19
Additionally, the percentages of
subjects in each group that showed unfavorable, favorable
or highly favorable change were the same.
12
Results of the
UM RCT supported those of UNC and UF, no difference in
skeletal pattern after phase II treatment.5
Additional studies have investigated the skeletal
effects of interceptive orthodontic treatment on Class II
malocclusions in the mixed dentition.
Retrospective
studies were conducted by Livieratos and Johnston,
Wieslander, and McNamara et al.22-24
These studies compared
various interceptive treatments in the mixed dentition to
matched control samples.
The study done by Livieratos and Johnston compared
one-phase and two-phase non-extraction treatment of matched
Class II samples.22
One-phase treatment involved the use of
an edgewise fixed appliance during adolescence, whereas
two-phase treatment consisted of a bionator in preadolescence followed by the edgewise fixed appliance in
adolescence.
The samples consisted of 25 two-phase and 28
one-phase non-extraction treatment patients.
At the end of
treatment, the samples were nearly identical with regard to
skeletal changes.
The only difference between the groups
was a slight discrepancy in post-treatment age, and thus a
slight difference in size.
The study conducted by Wieslander investigated the
long-term effect of treatment with a headgear-Herbst
appliance in the early mixed dentition.23
13
The study
compared 24 patients treated with a headgear-Herbst
appliance to a matched control sample of 12 untreated Class
II children.
Initially the only difference between the
groups was that the control group possessed a less severe
Class II malocclusion than the treatment group.
The
treatment group began treatment with a headgear-Herbst
appliance, at an average age of 8 years 8 months, for 5
months followed by a retention period of 3-5 years with an
activator appliance.
Long-term records were taken at a
mean age of 17 years 4 months to be compared to the control
group.
Long-term skeletal effects on the mandible relapsed
to a nonsignificant measure.
Comparatively, maxillary
skeletal effects did not relapse, but rather improved longterm.
However, the author states that results should be
interpreted cautiously due to the small sample size and
individual variability.
A retrospective study by McNamara et al. looked at
skeletal and dental changes following functional regulator
therapy on Class II patients.24
The treatment group
consisted of 51 Class II patients in the mixed dentition,
with an average age of 8 years 8 months.
The matched
control group consisted of 41 untreated Class II cases.
The only skeletal difference between the matched samples
was lower anterior facial height.
14
The treatment group was
treated with the FR-2 appliance for 2 years.
Results
showed there was a 0.5° decrease in the treatment group
compared to a 0.6° increase in SNA for the control group.
Additionally, the mandibular length increased 6.4 mm in the
treatment group compared to 4.0 mm in the control group.
However, the study did not go on to investigate whether or
not these results lasted after orthodontic treatment in
adolescence.
Treatment Time
Another assumption associated with interceptive
treatment of Class II malocclusions is that it will lead to
shorter phase 2 treatment time, or greater efficiency.1
This theory is based on the idea that interim results
achieved by early orthodontic treatment, most importantly
skeletal changes, will persist into adolescence.
This will
lead to a less severe malocclusion upon complete eruption
of the permanent dentition, and a less severe malocclusion
requires less time to treat.
However, findings of the UNC
RCT contradict this hypothesis.
Collectively the RCTs,
along with other studies, concluded that interceptive
treatment is associated with a longer overall treatment
time, rendering it less efficient than 1-phase
treatment.2,5,7,8,22,25
15
The UNC RCT determined that treatment time for
comprehensive fixed appliance was approximately the same
for the early treatment groups as for the control group.7,8
Interceptive treatment with either a headgear or a modified
bionator did not lead to shorter phase II treatment
compared to untreated controls who received 1-phase
treatment.
In addition, treatment time was broken down
into three categories: short (< 18 months), expected (18-33
months) and long (>33 months).
Results showed that
percentages of patients from the headgear, modified
bionator and control groups were evenly distributed among
these categories, again suggesting that phase II treatment
time is not shorter following interceptive treatment in the
mixed dentition.8
The UM study found that at the end of treatment
patients who received interceptive treatment in the mixed
dentition, and thus two phases of treatment, had an overall
longer treatment time than patients who received 1-phase
treatment later in adolescence.5
Interceptive treatment
resulted in increased number of appointments, treatment
duration, and cost of treatment.
However, length of phase
II treatment time was not evaluated in this study.
The UPenn RCT did not directly investigate length of
treatment time, because the study did not include treatment
16
with fixed appliances.
However, it did suggest that
treatment in adolescence, compared to treatment in the
mixed dentition, could be more efficient.2
Treatment time
would be shorter due to the fact that an intermediate
retention phase would not be necessary for 1-phase
treatment.
The retrospective study by Livieratos and Johnston did
not mention any difference in fixed appliance treatment
time between 1-phase and 2-phase treatment, only that 2phase treatment averaged 18 months of extra treatment
time.22
However, the study did investigate rates of change
for the treatment methods.
Skeletal rate of change,
specifically mandibular advancement relative to cranial
base, was different between the two treatment methods, but
not significant.
A retrospective study by von Bremen and Pancherz
investigated the efficiency of early and late Class II
Division 1 treatment.25
The study included records of the
following Class II Division 1 malocclusions: 54 in the
early mixed dentition, 104 in the late mixed dentition and
46 in the permanent dentition.
Results of the study showed
that treatment duration decreased with increasing dental
maturation.
The mean treatment times for early mixed, late
mixed and permanent dentition were as follows: 57 months,
17
33 months and 21 months.
It was concluded that overall
treatment time is increased with early treatment of Class
II Division 1 malocclusions, and that treatment in the
permanent dentition is more efficient.
Treatment Results
Besides the assumption that interceptive treatment of
Class II malocclusions leads to more efficient treatment,
it is also assumed by some to be more effective, or produce
better results.1
The thought is that if major discrepancies
are addressed in phase I, a milder malocclusion will exist
for treatment in phase II.
A less severe malocclusion is
easier to treat, requires less complex treatment, and will
translate to better results.
One way of measuring treatment outcome is the Peer
Assessment Rating (PAR) score or the change in PAR score.
The PAR score was developed as a standardized way to
evaluate treatment outcome.26
The score serves as an
estimate of how much the occlusion deviates from normal.
A
score of zero would represent a perfect or ideal occlusion.
Higher scores are indicative of greater deviation from
normal alignment and occlusion.
The change in PAR score,
from initial to final, gauges the degree of improvement and
success of treatment.
18
Unlike treatment outcome, there is no standardized
method for evaluating treatment complexity.
However, it
can be assumed that treatment involving extractions and/or
orthognathic surgery increases treatment complexity, since
extractions and/or surgery often require more treatment
planning and more detailed biomechanics.
That being said,
the RCTs on interceptive treatment of Class II
malocclusions, as well as other studies, provide evidence
refuting the claim that interceptive treatment leads to
more effective and/or less complex overall treatment.
In
fact, results from the UM RCT showed inferior final results
for the early treatment group, and Von Bremen and Pancherz
found greater reductions in PAR score for later treatment
compared to treatment in the mixed dentition.5,25
Additionally, Vasilakou found that interceptive treatment
of Class II malocclusions produced a smaller change in
Discrepancy Index score than interceptive treatment of
Class I or Class III malocclusions.27
The UNC RCT compared initial (pre-phase I) and final
(post-phase II) PAR scores of a headgear, modified bionator
and control group.
PAR scores were not significantly
different among the three groups for either of time
points.3,7,8
Additionally, PAR scores were divided into
three categories: excellent, satisfactory and less than
19
satisfactory.
There was no difference of distribution into
these categories between the three groups.8
There also was
no difference in extraction and/or orthognathic surgery
rates among the three groups.
The study at UF recorded pre-treatment, pre-phase II
and final PAR scores.
There was no difference in pre-
treatment or final PAR scores among the three groups
(headgear/biteplane, bionator, control), nor was there a
difference in total percentage change of PAR score.28
There
was a difference between the two early treatment groups and
the control group for pre-phase II PAR scores; the early
treatment groups had lower pre-phase II PAR scores than the
control group.
These findings suggest that interceptive
treatment does produce interim improvements in PAR score,
but not overall improvements, similar to previously
discussed findings on skeletal effects.
The UM RCT compared pre-treatment and final PAR scores
between a Twin-block and a control group.
Although there
was no difference in pre-treatment PAR scores between the
two groups, at the end of treatment the Twin-block group
had significantly higher PAR scores than the control group,
indicating inferior final results for the Twin-block group.5
The difference in extraction rates for the Twin-block and
control group was not statistically significant.
20
Von Bremen and Pancherz recorded both pre-treatment
and post-treatment PAR scores for patients treated in the
early mixed, late mixed and permanent dentition.
Pre-
treatment PAR scores increased with progressing dental
maturation, whereas post-treatment PAR scores decreased
with progressing dental maturation.25,29
Thus, reduction in
PAR score increased with progressing dental maturation.
However, difference in reduction of PAR score was only
significant between the early mixed dentition group and the
permanent dentition group.
Worth mentioning is a study on interceptive
orthodontic treatment by Vasilakou.27
This study did not
compare interceptive (or two-phase) treatment to one-phase
treatment, but rather investigated the effectiveness of
interceptive treatment in reducing case complexity.
The
study consisted of 300 patients who received two-phase
treatment.
examined.
Pre-phase I and pre-phase II records were
Discrepancy Index (DI) scores were recorded for
each time point and the change in DI score was calculated
to determine the reduction in case complexity, or
improvement.
Class II malocclusions only experienced a
34.5% improvement compared to a 49.3% and a 58.5%
improvement experienced by Class I and Class III
malocclusions respectively.
Therefore, interceptive
21
treatment of Class II malocclusions is less likely to
reduce case complexity compared to interceptive treatment
of Class I or III malocclusions.
Psychological Effects
Even if interceptive treatment of Class II
malocclusions in the mixed dentition does not prove to be
more effective or more efficient, many argue in its favor
for possible psychological effects.
Patients, and their
parents, expect orthodontic treatment to improve the
patient’s quality of life.30
This is ever so important
since children with normal dental appearance are perceived
by their peers to be more attractive and intelligent, and
to make better friends.31
Additionally, children are judged
by their teachers on physical attractiveness, which
influences the teacher’s expectations and evaluation of the
child.32
Considering that large overjet is the most
significant predictor of the decision to seek orthodontic
treatment, and since it is associated with unfavorable
self-perception and bullying, it is logical to assume that
interceptive treatment of Class II malocclusions could have
a positive psychological impact.31,33-35
Unfortunately,
evidence on this topic is limited, with the strongest
22
evidence available opposing this claim.12
However, there is
not a strong conclusion.
The RCT at UNC compared 104 children from the trial to
105 patients in the UNC graduate orthodontic clinic to
evaluate the effect of interceptive treatment on selfconcept.36
The study used the Piers-Harris children’s self-
concept scale to measure self-concept.
The study found
that there was no difference in mean changes of selfconcept between the interceptive treatment groups and the
control group.
Change in severity of malocclusion did not
correlate with change in self-concept.
The study concluded
that Class II malocclusions and orthodontic treatment only
account for a small variation in self-concept, and early
treatment may only provide a benefit to children who are
experiencing teasing or bullying.
The UM RCT utilized various measures to evaluate the
psychological impact of interceptive treatment: the PiersHarris Children’s Self-Concept Scale, the Childhood
Experience Questionnaire, and a modified questionnaire on
perceptions of orthodontic treatment impact.10
Results of
the study showed that early treatment with the Twin-block
had a positive impact on self-concept, and led to fewer
negative social experiences compared to the untreated
control group.
However, both groups, treatment and
23
control, recorded higher values of self-concept at baseline
compared to values of the general population.
Children
from the Twin-block treatment group also reported benefits
such as “feeling better about themselves” and “improvement
in appearance”, suggesting that treatment positively
affected self-esteem.
Unfortunately, after the end of
phase II treatment all positive psychological effects
achieved by interceptive treatment had diminished, and no
differences were found between the Twin-block and control
group.5
The Cochrane systematic review, which formed its
conclusions based on the RCTs conducted at UNC, UF and UM,
concluded that early treatment offers no advantages with
regard to self-esteem compared to one-phase treatment.12
However, the following statement from the systematic review
should be noted:
Unfortunately, it appears that the effect of early orthodontic
treatment diminishes with time. Nevertheless, we do not know the
effect of the increase in self-esteem that occurred after early
intervention; this may have clinical importance, particularly if
a child is subjected to excessive teasing or bullying.12
Interpretation of this statement suggests that
although evidence from the RCTs opposes the notion that
interceptive treatment results in positive psychological
effects, a strong conclusion cannot be formed, and further
research is necessary.
24
Trauma
Another supposed benefit of interceptive treatment of
Class II malocclusions is reduced risk of incisor trauma.
This benefit is argued specifically in the case of
prominent maxillary incisors associated with Class II
Division 1 malocclusions.
The theory is that if overjet is
reduced, there is a smaller risk of these teeth being
injured.
Furthermore, if overjet is reduced at an earlier
age, there is less chance for injury.
This theory is
supported by literature on interceptive treatment of Class
II malocclusions, including a Cochrane systematic review,12
a pertinent finding considering that 21% of traumatic
dental injuries are attributable to increased overjet, or
over 2 million cases worldwide.37
The UNC RCT recorded information on incisor trauma at
every stage of the trial using the Third National Health
and Nutrition Examination Survey (NHANES III).38
Using this
information the study compared trauma incidence between the
control group and the two interceptive treatment groups.
During phase 1 treatment the control group and headgear
group had statistically higher incidences of new maxillary
incisor trauma (MIT) compared to the functional appliance
group.
Coincidently, the functional appliance group had
the largest reduction in overjet, while the control group
25
had the smallest change in overjet.
This finding suggests
that there may be a correlation between increased overjet
and increased risk of MIT, thus promoting interceptive
treatment capable of reducing overjet.
The RCT at UF also recorded information on incisor
trauma at every stage of the study, but instead utilized
the Ellis index.39
The study evaluated the effect of early
treatment, with either a headgear/biteplane or bionator, on
incidence of incisor trauma.
At initial examination, 25%
of the patient population had previous MIT.
During the
study, 28% of the patients experienced new MIT, which was
statistically not significant.
Additionally, there was no
difference in new MIT between the three groups during
treatment.
Unlike the RCTs at UNC and UF, the RCT at Manchester
did not record incidence of dental trauma at every stage.5
Instead the occurrence of new dental trauma at any point in
the study was recorded as a simple “yes” or “no”. That
being said, eleven patients experienced new dental trauma
during the study, 4 from the early treatment group and 7
from the control group.
The difference between the groups
was not statistically significant.
A cross-sectional study was conducted by BorzabadiFarahani et al. investigating the association between
26
facial profile and maxillary incisor trauma.40
Five hundred
and two subjects, ages 11-14, were examined and included in
the study. Subjects were categorized by overjet for
statistical analysis.
Conclusions of the study showed that
the following children are more likely to experience
maxillary incisor trauma: boys more than girls, Class II
skeletal patterns more than Class I skeletal patterns, and
overjets > 3.5 mm more than overjets ≤ 3.5 mm.
Nguyen et al. conducted a systematic review on the
relationship between overjet size and traumatic dental
injuries.11
In total, eleven studies were evaluated after
the literature search and selection procedure.
From the
study it was concluded that children with overjets > 3 mm
were about twice as likely to experience trauma to the
anterior teeth as compared to children with overjets < 3
mm.
Additionally, as overjet increases, so does the risk
of dental injury.
A cross-sectional study conducted by Årtun et al.
examined 795 adolescent girls and 788 adolescent boys using
a stratified cluster sampling method.41
After evaluation,
the study found that MIT is 3.7 times higher for overjets >
9.5 mm, and 2.8 times higher for overjets 6.5-9.0 mm,
compared to normal overjet.
Additionally, the study
27
concluded that the risk of MIT increases 13% for every
additional millimeter of overjet.
The Cochrane systematic review, which included the 3
previously mentioned RCTs, concluded that incisor trauma is
reduced by early treatment.12
Groups treated with
functional appliances experienced a 33% reduction in the
risk of trauma, and 41% for groups treated with headgear.
After further calculations, it was determined that
interceptive treatment with functional appliances prevents
dental trauma in 1 of 10 patients, and headgear 1 of 6
patients.
In fact, the review culminated with a bold
conclusion, stating that the only advantage of 2-phase
treatment over 1-phase treatment is a reduction of dental
trauma incidence.
Practice Management
Given the reviewed literature, and the quality of the
literature, it should be evident that, barring the
infrequent exception, interceptive treatment of Class II
malocclusions in the mixed dentition should be limited to
circumstances of high risk of dental trauma and arguably
psychological distress, such as bullying (see Table 2.2).
In fact, Gianelly estimates that around 90% of Class II
malocclusions can be treated in the late mixed dentition.42
28
Or put another way, about 10% of Class II malocclusions
could benefit from interceptive treatment.
However,
estimates suggest that roughly 33% of children are treated
in two phases.43
Furthermore, some are concerned that many
orthodontic practices provide two-phase treatment to 100%
of their pre-adolescent patients.44,45
Granted these
estimates were made before the availability of much of the
reviewed literature, it is not irrational to believe that
significantly higher than 10% of Class II malocclusions are
being treated with some form of interceptive treatment in
the mixed dentition.
Table 2.2: Effects of Interceptive Treatment of Class II Malocclusions
as Supported by Orthodontic Literature
Skeletal
Phase
Tx
Psych.
Trauma
Pract.
Effects
II Tx
Results
Effects
Manag.
Time
UNC RCT1,8,21
NSF
NSF
NSF
NSF
+
N/A
UF RCT4,20,28
NSF
N/A
NSF
N/A
NSF
N/A
UM RCT5,9,10
NSF
N/A
-
NSF
NSF
N/A
Cochrane
Review12
NSF
NSF
NSF
NSF
+
N/A
Livieratos
& Johnston22
NSF
N/A
N/A
N/A
N/A
+
Wieslander23
+
N/A
N/A
N/A
N/A
N/A
Von Bremen
& Pancherz25
N/A
N/A
-
N/A
N/A
N/A
Johnston46,47
N/A
N/A
N/A
N/A
N/A
+
NSF
N/A
+ =
- =
= No Significant Findings
= Not Evaluated
Positive Effect
Negative Effect
29
Johnston believes that Class II interceptive treatment
is performed in such a high volume predominantly as a
practice management decision.22,46,47
He states:
Given a real or claimed absence of data (“We just don’t know…”),
it is possible to camouflage practice management decisions as
biological imperatives. The intrusion of data, therefore,
constitutes for many a threat to the quiet enjoyment of a
successful practice.48
He argues that significant evidence must be produced
to treat in any other way than the gold standard
(conservation of E-space and maxillary distalization).49
He
believes that because there is no penalty to the
orthodontist for being wrong or right, and because all
treatment “works” and pays the bills, most orthodontists do
not view clinical data as a practical necessity.46,48
However, maybe orthodontists don’t disregard the
literature, as Johnston might suggest.
It’s possible that
orthodontists interpret the literature incorrectly, or
maybe they can’t discern between high quality evidence and
that which is not.
It could be that many are simply are
unaware of the literature that exists.
This is what is
suggested by the study done by Madhavji.13
She found that
59% of orthodontists believe that orthodontic literature is
ambiguous and conflicting, and that 55% are unaware of the
Cochrane Database.
30
Goals of This Study
Whether the choice to perform interceptive treatment
for Class II malocclusions in the mixed dentition is a
biological imperative, a practice management decision, a
misperception of the literature, or simply ignorance,
orthodontists must strive to practice evidence-based
orthodontics.
As a learned profession, the foundation of
orthodontics must be formed by strong scientific evidence,
and this must be the driving force behind all decisions
that are made.
Johnston said it best when he said:
…the specialty has a fiduciary responsibility to be appropriately
concerned with the significance of its treatment choices.
Concerned enough to demand proof. Concerned enough to be able to
distinguish between good data and bad. Concerned enough to apply
these good data (and a bit of critical thought) to the various
therapeutic decisions that affect the patient.48
The goal of this study is to assess orthodontists’
attitudes, awareness and perceptions of orthodontic
literature on interceptive treatment of Class II
malocclusions in the mixed dentition, and evaluate how it
compares to actual scientific evidence.
The study will
also investigate orthodontists’ priorities for interceptive
orthodontic treatment in the mixed dentition, and determine
if these priorities are supported by evidence in the
literature.
The results of this study will help develop
treatment guidelines to aid orthodontists with treatment
decisions.
Additionally, findings will promote future
31
research on interceptive orthodontic treatment of Class II
malocclusions in the mixed dentition to help diminish any
remaining controversy on the topic.
32
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2. Ghafari J, Shofer FS, Jacobsson-Hunt U, Markowitz DL,
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3. Proffit WR, Tulloch JFC. Preadolescent Class II
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4. Dolce C, McGorray SP, Brazeau L, King GJ, Wheeler TT.
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5. O'Brien K, Wright J, Conboy F, Appelbe P, Davies L,
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6. Freeman JD. Preventive and interceptive orthodontics: a
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7. Proffit WR. The timing of early treatment: an overview.
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9. O’Brien K, Wright J, Conboy F, Sanjie Y, Mandall N,
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10. O'Brien K, Wright J, Conboy F, Chadwick S, Connolly I,
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11. Nguyen QV, Bezemer PD, Habets L, Prahl-Andersen B. A
systematic review of the relationship between overjet size
and traumatic dental injuries. Eur J Orthod.
1999;21(5):503-15.
12. Thiruvenkatachari B, Harrison J, Worthington H, O'Brien
K. Early orthodontic treatment for Class II malocclusion
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13. Madhavji A, Araujo EA, Kim KB, Buschang PH. Attitudes,
awareness, and barriers toward evidence-based practice in
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14. Proffit WR, Fields HW, Sarver DM. Contemporary
Orthodontics. 5th ed. St. Louis: Mosby; 2013.
15. Darendeliler MA. Validity of Randomized Clinical Trials
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Orthod. 2006;12:67-79.
16. Cochrane Library: John Wiley & Sons, Inc.; 2015.
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17. Tulloch JF, Phillips C, Koch G, Proffit WR. The effect
of early intervention on skeletal pattern in Class II
malocclusion: a randomized clinical trial. Am J Orthod
Dentofac Orthop. 1997;111(4):391-400.
18. Keeling SD, Wheeler TT, King GJ, Garvan CW, Cohen DA,
Cabassa S, et al. Anteroposterior skeletal and dental
changes after early Class II treatment with bionators and
headgear. Am J Orthod Dentofac Orthop. 1998;113(1):40-50.
19. Dolce C, Schader RE, McGorray SP, Wheeler TT.
Centrographic analysis of 1-phase versus 2-phase treatment
for Class II malocclusion. Am J Orthod Dentofac Orthop.
2005;128:195-200.
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20. Wheeler TT, McGorray SP, Dolce C, Taylor MG, King GJ.
Effectiveness of early treatment of Class II malocclusion.
Am J Orthod Dentofac Orthop. 2002;121:9-17.
21. Tulloch JF, Proffit WR, Phillips C. Influences on the
outcome of early treatment for Class II malocclusion. Am J
Orthod Dentofac Orthop. 1997;111(5):533-42.
22. Livieratos FA, Johnston LE, Jr. A comparison of onestage and two-stage nonextraction alternatives in matched
Class II samples. Am J Orthod Dentofac Orthop.
1995;108(2):118-31.
23. Wieslander L. Long-term effect of treatment with the
headgear-Herbst appliance in the early mixed dentition.
Stability or relapse? Am J Orthod Dentofac Orthop.
1993;104(4):319-29.
24. McNamara JA, Jr., Bookstein FL, Shaughnessy TG.
Skeletal and dental changes following functional regulator
therapy on class II patients. Am J Orthod Dentofac Orthop.
1985;88(2):91-110.
25. von Bremen J, Pancherz H. Efficiency of early and late
Class II Division 1 treatment. Am J Orthod Dentofac Orthop.
2002;121:31-7.
26. Richmond S, Shaw WC, O'Brien KD, Buchanan IB, Jones R,
Stephens CD, et al. The development of the PAR Index (Peer
Assessment Rating): reliability and validity. Eur J Orthod.
1992;14(2):125.
27. Vasilakou ND. Quantitative assessment of the
effectiveness of phase 1 orthodontic treatment utilizing
the ABO discrepancy index. [Unpublished Master's Thesis]
St. Louis: Saint Louis University; 2014.
28. King GJ, McGorray SP, Wheeler TT, Dolce C, Taylor M.
Comparison of peer assessment ratings (PAR) from 1-phase
and 2-phase treatment protocols for class II malocclusions.
Am J Orthod Dentofac Orthop. 2003;123:489-96.
29. Pancherz H. Treatment timing and outcome. Am J Orthod
Dentofac Orthop. 2002;121(6):559.
30. Tung AW, Kiyak HA. Psychological influences on the
timing of orthodontic treatment. Am J Orthod Dentofac
Orthop. 1998;113(1):29.
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31. Shaw WC. The influence of children's dentofacial
appearance on their social attractiveness as judged by
peers and lay adults. Am J Orthod Dentofac
Orthop.79(4):399-415.
32. Kiyak HA, Bell R. Psychosocial considerations in
surgery and orthodontics. In: Profiit WR, White R (eds).
Surgical-orthodontic treatment. St. Louis: Mosby, 1990:7191.
33. Kilpeläinen PV, Phillips C, Tulloch JF. Anterior tooth
position and motivation for early treatment. Angle Orthod.
1993;63(3):171-4.
34. Shaw WC, Meek SC, Jones DS. Nicknames, teasing,
harassment and the salience of dental features among school
children. Br J Orthod. 1980;7(2):75-80.
35. Helm S, Kreiborg S, Solow B. Psychosocial implications
of malocclusion: A 15-year follow-up study in 30-year-old
Danes. Am J Orthod Dentofac Orthop. 1985;87(2):110-8.
36. Dann C, Phillips C, Broder HL, Tulloch JFC. Selfconcept, Class II malocclusion, and early treatment. Angle
Orthod. 1995;65(6):411-6.
37. Petti S. Over two hundred million injuries to anterior
teeth attributable to large overjet: a meta-analysis. Dent
Traumatol. 2015;31(1):1-8 p.
38. Koroluk LD, Tulloch JFC, Phillips C. Incisor trauma and
early treatment for Class II Division 1 malocclusion. Am J
Orthod Dentofac Orthop. 2003;123:117-25.
39. Chen DR, McGorray SP, Dolce C, Wheeler TT. Effect of
early Class II treatment on the incidence of incisor
trauma. Am J Orthod Dentofac Orthop. 2011;140(4):e155-60.
40. Borzabadi-Farahani A, Borzabadi-Farahani A, Eslamipour
F. An investigation into the association between facial
profile and maxillary incisor trauma, a clinical nonradiographic study. Dent Traumatol 2010;26(5):403-8.
41. Årtun J, Behbehani F, Al-Jame B, Kerosuo H. Incisor
trauma in an adolescent Arab population: Prevalence,
severity, and occlusal risk factors. Am J Orthod Dentofac
Orthop. 2005;128:347-52.
36
42. Gianelly A. Phase I treatment. Am J Orthod Dentofac
Orthop. 1997;111(2):239-40.
43. Gottlieb EL, Nelson AH, Vogels DS, 3rd. 1990 JCO study
of orthodontic diagnosis and treatment procedures. 2.
Breakdowns of selected variables. J Clin Orthod.
1991;25(4):223-30.
44. Rozene RF. One phase versus two phase orthodontic
treatment. Am J Orthod Dentofac Orthop. 1996;109(2):17A-A.
45. Ferguson JL, Jr. Comment on two-phase treatment. Am J
Orthod Dentofac Orthop. 1996;110(1):14A-5A.
46. Johnston LE. Functional appliances: a mortgage on
mandibular position. Aust Orthod J. 1996;14(3):154-7.
47. Johnston LE. If wishes were horses: functional
appliances and growth modification. Prog Orthod.
2005;6(1):36-47.
48. Johnston LE. The value of information and the cost of
uncertainty: Who pays the bill? Angle Orthod.
1998;68(2):99-102.
49. Johnston LE. Answers in search of questioners. J Am
Acad Gnathol Orthop. 2006;23(4):14-5.
37
CHAPTER 3: JOURNAL ARTICLE
Abstract
Purpose: This study investigated the attitudes, awareness
and perceptions of orthodontists with regards to
orthodontic literature on interceptive treatment of Class
II malocclusions in the mixed dentition.
Methods: A survey
consisting of 14 questions pertaining to participant
demographics, orthodontic literature on interceptive
treatment of Class II malocclusions in the mixed dentition,
and Class II interceptive treatment priorities was randomly
distributed to 2,300 orthodontists via the AAO Partners in
Research program.
Results: A total of 168 orthodontists
responded to the survey, resulting in a 7.3% response rate.
Orthodontists’ perceptions of the literature generally
agreed with findings of the strongest available evidence.
The majority or participants agreed that orthodontic
literature cites increased patient self-esteem and reduced
risk of trauma as benefits of Class II interceptive
treatment, 60.1% and 58.3% respectively.
Increased patient
self-esteem and reduced risk of trauma were the most
important treatment priorities for orthodontists, with
66.1% and 62.5% of participants ranking them as a first or
second treatment priority respectively.
38
Conclusion:
Although orthodontists are confident in their knowledge of
orthodontic literature on interceptive treatment of Class
II malocclusions in the mixed dentition, and their
perceptions of the literature on this topic are reasonably
accurate, it does not appear that their treatment
priorities are based upon their views of the literature.
Introduction
The purpose of orthodontic diagnosis and treatment
planning is not only deciding if treatment is necessary,
but also deciding when to initiate treatment.
When dealing
with Angle Class II malocclusions, it is often not the
former, but rather the latter that causes controversy among
orthodontists, specifically initiating treatment in the
mixed dentition.
This topic is prominent in orthodontic
literature, with many investigators mentioning the
controversy of interceptive treatment of Class II
malocclusions in the mixed dentition.1-5
Interceptive orthodontic treatment has been defined as
procedures that eliminate or reduce the severity of a
developing malocclusion.6
It is traditionally conducted
during the mixed dentition, with the understanding that
oftentimes a second phase of treatment (phase II) is
necessary in the late mixed or early permanent dentition to
39
achieve all orthodontic treatment goals.
For this reason
interceptive treatment is often synonymous with the terms
“early orthodontic treatment” or “phase I treatment.”
A common goal of interceptive treatment of Class II
malocclusions is growth modification of the jaws to address
any underlying skeletal discrepancies.1
Presumably this
will lead to a shorter, less complex second phase of
treatment, and possibly better results, compared to a
single phase of treatment later in adolescence.
Several randomized clinical trials (RCTs) concluded
that interceptive Class II treatment resulted in skeletal
improvements compared to untreated controls.2-5,7-9
However,
after a second phase of treatment no differences were found
when compared to a matched sample having undergone a single
phase of treatment in the late mixed or early permanent
dentition.2-5,7,8
Additionally, phase II treatment was not
shorter than a single phase treatment, and yielded similar
results.
Overall, total treatment time was longer for 2-
phase treatment as compared to 1-phase treatment.
Although these findings discredit many proposed
benefits of interceptive treatment of Class II
malocclusions, some investigators suggest there are other
reasons to perform interceptive treatment.2,7,8
40
Possible
benefits of interceptive treatment include increased selfconcept and reduced risk of trauma.10-12
Unfortunately, due to the vast amount of orthodontic
literature available on interceptive treatment of Class II
malocclusions in the mixed dentition, and varying levels of
evidence, it may be hard for orthodontists to identify
these findings.
In fact, 59% of orthodontists believe that
orthodontic literature is ambiguous or conflicting.13
This
finding is disheartening, since it is imperative that
orthodontists be able to evaluate literature without being
confused.
Orthodontists must be aware of the true benefits
of interceptive treatment in order to provide proper
informed consent to every patient, and to ensure that
treatment decisions are made on the basis of sound,
scientific evidence.
The purpose of this study is to determine the
attitudes, awareness and perceptions of orthodontists with
regards to orthodontic literature on interceptive treatment
of Class II malocclusions in the mixed dentition.
Furthermore, this study is intended to determine
orthodontists’ priorities for interceptive Class II
orthodontic treatment in the mixed dentition.
The results
of this study could aid in the development of treatment
guidelines.
Additionally, findings could help guide
41
further research on interceptive orthodontic treatment of
Class II malocclusions in the mixed dentition to diminish
any remaining controversy on the topic.
Methods and Materials
Survey Design
A survey was designed to investigate orthodontists’
attitudes, awareness and perceptions of orthodontic
literature regarding interceptive treatment of Class II
malocclusions in the mixed dentition.
A recruitment
statement was attached to the survey for each participant
to review prior to responding to the survey.
The survey
consisted of 14 total questions, divided into three
categories: demographics, literature and treatment
priorities.
All questions were multiple choice, with no
open-ended questions.
The survey can be viewed in its
entirety in Appendix A.
IRB approval was obtained prior to
distribution of the survey.
Survey Validity
A pilot study was distributed to 13 orthodontic
residents at the Saint Louis University Center for Advanced
Dental Education (CADE) in St. Louis, MO.
Each resident
was asked to provide feedback after completing the survey
to ensure that the questions were not ambiguous.
42
Feedback
from the pilot study was used to modify and improve the
clarity of questions of the survey.
Survey Distribution
The final version of the survey was submitted to the
American Association of Orthodontists (AAO) Partners in
Research program.
The program is established for
electronic distribution of surveys on behalf of faculty
and/or students of ADA-accredited orthodontic programs.
An
email containing a link to the survey was randomly
distributed to 2,300 active AAO members to ensure
anonymity.
The link directed participants to the survey,
which was completed using the online survey software
SurveyMonkey® (surveymonkey.com, Portland, OR).
All
responses were recorded anonymously by SurveyMonkey®.
second reminder email was sent two weeks later.
A
In total,
the survey was active for 1 month.
Data Collection and Analysis
Data collected from the survey was analyzed using IBM
SPSS® 23 software (SPSS Inc., Chicago, IL).
Non-parametric
statistics were used to evaluate the ordinal data.
The
Mann-Whitney U test was used to test for differences
between the dichotomous groupings (gender, master’s degree,
teaching/research).
The Kruskal-Wallis H test was used to
43
test for differences between age groupings.
A p-value of
≤ 0.05 was considered significant.
Results
Response Rate
The survey was distributed to 2,300 orthodontists who
are active members of the AAO.
Of the 2,300 orthodontists
who were emailed, 168 provided responses to the survey,
amounting to a 7.3% response rate.
Demographics
The demographics section of the survey consisted of 4
questions which were used to group the respondent pool.
Participants of the survey were grouped by gender, age,
whether or not they are involved in teaching or research at
a university, and whether or not they possess a master’s
degree.
Age groupings consisted of: 21-30 years, 31-40
years, 41-50 years, 51-60 years and > 60 years.
The participant pool was 75.6% male and 24.4% female
(Figure 3.1), and was predominantly between 31 and 60 years
of age (83.9%) (Figure 3.2).
Most participants had
master’s degrees (76.2%) (Figure 3.3) and were not involved
in teaching or research at a university (68.5%) (Figure
3.4).
44
Gender
75.6%
41
Male
Female
24.4%
127
Figure 3.1: Gender of Participant Pool
Age
35%
30%
25%
20%
15%
10%
5%
0%
21-30
Years
31-40
Years
41-50
Years
51-60
Years
> 60 Years
Figure 3.2: Age Distribution of Participant Pool
Master's Degree
40
23.8%
Yes
No
76.2%
128
Figure 3.3: Education of Participant Pool
45
Teaching and/or Research
53
31.5%
Yes
No
68.5%
115
Figure 3.4: Educational Involvement of Participant Pool
Literature
The literature section of the survey consisted of 9
questions regarding orthodontic literature regarding
interceptive treatment of Class II malocclusions in the
mixed dentition (Table 3.1).
Each question was multiple
choice, with 5 possible responses.
Possible responses
included: strongly agree, agree, neutral, disagree, and
strongly disagree.
Participants mostly disagreed (41.1%) that there is
not enough literature on interceptive orthodontic treatment
of Class II malocclusions in the mixed dentition (Table
3.2); however, most agreed (48.8%) that literature on this
subject is ambiguous and/or conflicting.
More than half
agreed (58.3%) that literary evidence claims reduced risk
of incisor trauma to the incisors as a benefit of
interceptive treatment, and a majority of participants
agreed (60.1%) that increased patient self-esteem is a
46
benefit of interceptive treatment supported by scientific
literature.
In contrast, 47.0% disagreed with the
statement that orthodontic literature cites increased
orthopedic changes as a benefit of interceptive treatment,
and 44.1% disagreed that it supports shorter phase II
treatment as a treatment benefit.
Additionally, a majority
(69.7%) disagreed that according to the literature,
interceptive treatment followed by a second phase of
treatment yields better results than single phase of
treatment in the permanent dentition.
More than half
agreed (51.7%) that orthodontic literature claims
interceptive treatment of Class II malocclusions to be a
practice management decision rather than a treatment
advantage.
Finally, a majority agreed (67.2%) that they
are confident in their knowledge of literature on
interceptive treatment of Class II malocclusions in the
mixed dentition.
Distributions of responses to individual
questions on orthodontic literature are listed in Appendix
B (Figures B1-B9).
47
Question
Number
Q5
Q6
Q7
Q8
Q9
Q10
Q11
Q12
Q13
Table 3.1: Orthodontic Literature Questions
Question
There is not enough literature on interceptive orthodontic
treatment of Class II malocclusions in the mixed dentition.
Literature on interceptive orthodontic treatment of Class II
malocclusions in the mixed dentition is ambiguous and/or
conflicting.
According to the literature, interceptive orthodontic
treatment of Class II malocclusions in the mixed dentition
reduces the risk of trauma to the incisors.
According to the literature, interceptive orthodontic
treatment of Class II malocclusions in the mixed dentition
increases patient self-esteem.
According to the literature, interceptive orthodontic
treatment of Class II malocclusions in the mixed dentition
increases orthopedic changes.
According to the literature, interceptive orthodontic
treatment of Class II malocclusions in the mixed dentition
results in a shorter phase II treatment in the permanent
dentition.
According to the literature, interceptive orthodontic
treatment of Class II malocclusions in the mixed dentition
followed by a second phase of treatment yields better results
than a single phase of treatment in the permanent dentition.
According to the literature, interceptive orthodontic
treatment of Class II malocclusions in the mixed dentition is
a practice management decision rather than a treatment
advantage.
I feel confident in my knowledge of the literature on
interceptive orthodontic treatment of Class II malocclusions
in the mixed dentition.
Table 3.2: Responses to
Question
Number
Strongly
Agree
Agree
Q5
4.8%
20.8%
(n=8)
(n=35)
Q6
4.8%
44.0%
(n=8)
(n=74)
Q7
14.3%
44.0%
(n=24)
(n=74)
Q8
9.5%
50.6%
(n=16)
(n=85)
Q9
1.8%
17.9%
(n=3)
(n=30)
Q10
2.4%
21.4%
(n=4)
(n=36)
Q11
1.8%
3.6%
(n=3)
(n=6)
Q12
7.1%
44.6%
(n=12)
(n=75)
Q13
10.7%
56.5%
(n=18)
(n=95)
Orthodontic Literature Questions
Response
Neutral
Disagree
24.4%
(n=41)
11.9%
(n=20)
18.5%
(n=31)
23.2%
(n=39)
24.4%
(n=41)
23.2%
(n=39)
15.5%
(n=26)
22.0%
(n=37)
16.7%
(n=28)
37.5%
(n=63)
29.2%
(n=49)
14.3%
(n=24)
7.1%
(n=12)
40.5%
(n=68)
38.7%
(n=65)
42.9%
(n=72)
15.5%
(n=26)
6.5%
(n=11)
48
Strongly
Disagree
3.6%
(n=6)
1.2%
(n=2)
0.0%
(n=0)
0.6%
(n=1)
6.5%
(n=11)
5.4%
(n=9)
26.8%
(n=45)
2.4%
(n=4)
0.6%
(n=1)
No
Response
8.9%
(n=15)
8.9%
(n=15)
8.9%
(n=15)
8.9%
(n=15)
8.9%
(n=15)
8.9%
(n=15)
9.5%
(n=16)
8.3%
(n=14)
8.9%
(n=15)
Male participants were more likely than female
participants to disagree with the claim that according to
orthodontic literature, interceptive treatment of Class II
malocclusions in the mixed dentition followed by a second
phase of treatment yields better results that a single
phase of treatment in the permanent dentition (Table 3.3).
In addition, males were more likely to feel confident in
their knowledge of the literature on interceptive
orthodontic treatment.
Orthodontists not involved in
teaching or research at a university were more likely to
disagree with the claim that literature cites increased
orthopedic changes as a benefit of interceptive treatment.
Also, orthodontists between the ages of 21 and 40 years
were more likely to disagree with this claim than
orthodontists between the ages of 51 and 60 years.
Table 3.3: Significance of Demographics on Response to Orthodontic
Literature Questions
Question
Gender
Age
Master’s
Teaching/Research
Degree
Q5
NS
NS
NS
NS
Q6
NS
NS
NS
NS
Q7
NS
NS
NS
NS
Q8
NS
NS
NS
NS
Q9
NS
0.028*
NS
0.023*
Q10
NS
NS
NS
NS
Q11
0.009*
NS
NS
NS
Q12
NS
NS
NS
NS
Q13
0.007*
NS
NS
NS
* = Significant (< 0.05)
NS = Not Significant
49
Treatment Priorities
The treatment priorities section of the survey
consisted of 1 question regarding personal priorities when
deciding whether or not to perform interceptive orthodontic
treatment on Class II malocclusions in the mixed dentition
(Table 3.4).
The question asked participants to rank the
listed priorities.
Priorities could be ranked from 1 to 6,
with 1 being the most important, and 6 being the least
important.
Reduced risk of trauma to the incisors and increased
patient self-esteem were the two highest ranked priorities
for the majority of orthodontists.
Reduced risk of trauma
was the highest priority for 32.1% of respondents, and the
second highest priority for 30.4% (Table 3.5).
Similarly,
increased self-esteem was the highest priority for 35.1% of
respondents, and the second highest priority for 31.0%.
Enhanced orthopedic effects was the third highest treatment
priority for 25% of orthodontists.
Shorter phase II
treatment time, better results and practice management
decision were most likely to be ranked as the fourth
(28.6%), fifth (28.6%) and sixth (42.3%) treatment
priorities, respectively.
Distribution of responses for
individual treatment priorities are listed in Appendix B
(Figures B10-B15).
50
Question 14
Table 3.4: Treatment Priorities
Priority
Q14.1
Reduced risk of trauma to the incisors
Q14.2
Increased patient self-esteem
Q14.3
Enhanced orthopedic changes
Q14.4
Shorter phase II treatment time
Q14.5
Better result with two-phases than a single phase of
treatment
Practice management decision
Q14.6
Question
14
Q14.1
Q14.2
Q14.3
Q14.4
Q14.5
Q14.6
Table 3.5: Responses to Orthodontic Treatment Priorities
Priority
1st
2nd
3rd
4th
5th
6th
32.1%
(n=54)
35.1%
(n=59)
8.9%
(n=15)
1.8%
(n=3)
5.4%
(n=9)
5.4%
(n=9)
30.4%
(n=51)
31.0%
(n=52)
8.3%
(n=14)
7.1%
(n=12)
5.4%
(n=9)
6.0%
(n=10)
11.3%
(n=19)
10.1%
(n=17)
25.0%
(n=42)
16.7%
(n=28)
7.7%
(n=13)
13.7%
(n=23)
6.5%
(n=11)
8.9%
(n=15)
16.7%
(n=28)
28.6%
(n=48)
13.1%
(n=22)
8.9%
(n=15)
4.8%
(n=8)
1.8%
(n=3)
14.3%
(n=24)
23.8%
(n=40)
28.6%
(n=48)
9.5%
(n=16)
0.6%
(n=1)
1.2%
(n=2)
9.5%
(n=16)
3.0%
(n=5)
23.2%
(n=39)
42.3%
(n=71)
No
Response
14.3%
(n=24)
11.9%
(n=20)
17.3%
(29)
19.0%
(n=32)
16.7%
(n=28)
14.3%
(n=24)
Women were more likely to rank trauma as a higher
treatment priority than men (Table 3.6).
Younger
orthodontists, between the ages of 21 and 30 years, were
more likely to rank practice management decision as a
higher treatment priority than other ages.
51
Table 3.6: Significance of Demographics on Orthodontic Treatment
Priorities
Gender
Age
Master’s
Teaching/Research
Degree
Q14.1
0.010*
NS
NS
NS
Q14.2
NS
NS
NS
NS
Q14.3
NS
NS
NS
NS
Q14.4
NS
NS
NS
NS
Q14.5
NS
NS
NS
NS
Q14.6
NS
0.012*
NS
NS
* = Significant (< 0.05)
NS = Not Significant
Discussion
The response rate of 7.3% for this survey was
considerably lower than the range of 10-58% reported by
other orthodontic surveys.13-16
However, efforts were made
to achieve the highest response rate possible.
Brevity was
of the utmost importance when designing the survey in an
attempt to gain maximum participation.
The final survey
was considerably shorter than Madhavji’s, 14 questions
versus 35 questions, yet fell significantly short of the
32% response rate achieved with that study.13
Since
interceptive orthodontic treatment is a controversial
subject, the online survey software SurveyMonkey® was used
for the purpose of anonymity.
This was to ensure
participants that their responses would not be judged by
peers.
The AAO Partners in Research program was utilized
to distribute the survey to a large number of orthodontists
(2,300); however, there is no way of knowing how many of
these orthodontists received the survey.
52
The email
addresses used by the Partners in Research program to
distribute the survey may not have been active and/or they
may have been office email addresses rather than personal
email addresses.
If this were the case, the survey may
have been received by an office staff member rather than
the orthodontist, and thus never completed.
This could
explain for the unexpectedly low response rate.
Madhavji’s
response rate of 32% was based on the number of
orthodontists who opened the survey (4,771), not the number
of orthodontists to whom the survey was distributed
(8,455).13
However, if the response rate was based on
distribution, like this survey, it would have dropped to
17.9%.
Nonetheless, the demographics of this participant
pool were comparable to that of Madhavji’s, except that
this sample had a higher percent of participants with
master’s degrees (Table 3.7).
Table 3.7: Comparison of Survey Demographics with Madhavji 200913
Demographic
Conaway
Madhavji
2015
2009
Age (Modal)
31-40 Years
41-50 Years
Gender
76%/24%
79%/21%
(Male/Female)
Master’s Degree
76%
59%
Teaching/Research
31%
28%
As for orthodontists’ perceptions of the literature,
most believed that there is enough literature on
interceptive treatment of Class II malocclusions in the
53
mixed dentition.
This is assuring for the specialty of
orthodontics, as an abundance of scientific resources is
necessary to make evidence-based decisions.
However,
almost half (48.8%) of the participants agreed that
literature on interceptive treatment is ambiguous and/or
conflicting.
This finding is disconcerting, but not
unexpected as authors and researchers frequently voice
their concerns of controversy associated with interceptive
treatment of Class II malocclusions.1-5
In comparison, this
number is lower than the 59% reported by Madhavji in
regards to ambiguity of orthodontic literature in general.13
A majority (58.3%) of respondents agreed that
orthodontic literature cites reduced risk of incisor trauma
as a benefit of interceptive Class II treatment.
This
result coincides with scientific evidence, as a reduced
risk of trauma is the only benefit of interceptive Class II
treatment strongly supported by a Cochrane systematic
review.12
However, this means that 41.7% of respondents
didn’t agree with this statement.
This may be alarming
since reduced risk of trauma is so strongly supported by
orthodontic literature.
It’s hard to comprehend why such a
high number or orthodontists are not aware of such strong
scientific evidence.
54
A slightly larger percentage of the survey sample,
60.1%, responded that they believe orthodontic literature
claims increased self-esteem as a benefit of interceptive
treatment.
Unlike reduced risk of trauma, increased self-
esteem is not strongly supported by literature; however, a
Cochrane review does suggest that interim effects of
interceptive treatment on self-esteem are unknown and could
have clinical importance in instances of bullying.12
These
results are comparable to a survey conducted by Mendes et
al. in 2005.17
This study also found that a larger
percentage of orthodontists mentioned improvement in selfesteem (78.5%) as a benefit of interceptive Class II
treatment than reduced risk of incisor trauma (63.6%).
Although a large number of respondents (47%) indicated
that they believe interceptive Class II treatment is not
credited by orthodontic literature to produce increased
orthopedic changes, there were significant differences
between groups in regards to this topic.
Orthodontists 51-
60 years of age were more likely than those 21-40 years of
age to perceive the literature to support increased
orthopedic changes as a result of interceptive Class II
treatment.
Also, orthodontists involved in teaching or
research at university were more likely to have this same
perception.
This finding could possibly be explained by
55
the fact that older orthodontists may not be as current on
orthodontic literature as younger orthodontists.
However,
this same assumption would not hold true for orthodontists
who are involved at a university, for it is generally
assumed that those associated with an academic environment
are more aware of scientific literature.
It could be that
orthodontists’ views of the literature are influenced or
biased by their own experiences.
A survey by Yang et al.
found that orthodontists’ experiences influenced their
early treatment decisions.16
Perhaps different experiences
lead to different interpretations of the literature as
well.
As for orthodontists’ treatment priorities for Class
II interceptive treatment, participants clearly favored
reduced risk of trauma to the incisors and increased
patient self-esteem.
Increased patient self-esteem and
reduced risk of trauma were ranked as a first or second
treatment priority by 66.1% and 62.5% of orthodontists
respectively.
The rankings for the other treatment
priorities were not as strong.
These findings could
indicate that orthodontic literature has an influence on
orthodontists’ treatment priorities, since reduced risk of
trauma and increased self-esteem have the most scientific
support.
However, orthodontists’ rankings of treatment
56
priorities did not necessarily follow the same pattern as
their perceptions of literary support for the same topics
(Table 3.8).
Treatment
Benefit
Table 3.8: Rankings of Treatment Benefits
Presentation
Perceived
Ranked
Sequence in
Literary
Treatment
Survey
Support
Priority
Reduced Risk
of Trauma to
the Incisors
Increased
Patient
Self-Esteem
Enhanced
Orthopedic
Changes
Shorter
Phase II
Treatment
TimeSg
Better
Result w/
Two-Phase Tx
than SinglePhase Tx
Practice
Management
Decision
1
2
2
Perceived
Benefits
Mendes et
al.17
2
2
1
1
1
3
5
3
4
4
4
4
3
5
6
5
5
6
3
6
6
Interestingly, orthodontists’ treatment priority
rankings were similar to the sequence they were presented
in the survey.
In addition, participants’ treatment
priority rankings were comparable to rankings for perceived
benefits of interceptive treatment by Brazilian orthodontic
professors from a survey conducted by Mendes et al.17
Surveyed orthodontists perceived practice management
to be highly supported (ranked 3rd) by orthodontic
literature, but ranked it as their lowest treatment
57
priority (6th).
It brings to question why there is such a
distinct difference in ranking.
Possibly orthodontists
believe that others choose to perform interceptive
treatment as a practice management decision, yet believe
their personal decision to perform interceptive treatment
is primarily for purposes of increased patient self-esteem
and reduced risk of trauma
Additionally, orthodontists between the ages of 21-30
years were more likely to highly prioritize practice
management as an interceptive treatment priority.
Several
possibilities exist for this finding. First, and possibly
foremost, the sample size for this age group was small.
Second, because of rising student loan debt, it’s plausible
that young orthodontists perform interceptive treatment
more frequently as a practice management decision.
Finally, it’s possible that younger orthodontists are more
aware of orthodontic literature on interceptive Class II
treatment, and realize that many times interceptive
treatment is a practice management decisions rather than a
biologic imperative, as the literature suggests.
While this study resulted in significant findings,
there were still limitations.
Other studies have shown
that surveys are not always the most accurate method of
investigating perceptions of healthcare professionals when
58
dealing with complex issues.18,19
However, attempts were
made to minimize possibilities of inaccuracy.
A pilot
study was conducted to eliminate possibilities of
misinterpretation, and SurveyMonkey® was used for anonymity
to encourage honesty in responses.
This however does not
mean that there were not inconsistencies with respondents’
true perceptions and their recorded ones.
Participants
could have responded as they deemed to be “correct” rather
than with their truth beliefs.
This hypothesis could be
supported by the finding that participants’ recorded
treatment priorities closely paralleled the sequence they
were listed in the survey.
As was already mentioned, there was a low response
rate for this survey, however, an ample number or
orthodontists did respond.
While the demographics of this
sample were similar to Madhavji’s,13 there is always the
possibility that it was not representative of the
population of orthodontists as a whole.
It’s possible that
orthodontists who frequently utilize interceptive treatment
or who frequently survey orthodontic literature were more
likely to participate in the survey.
Therefore, some
skepticism should be used when generalizing findings of
this study to orthodontists as a whole.
59
Summary and Conclusions
Overall, orthodontists believed that there is enough
literature on interceptive treatment of Class II
malocclusions in the mixed dentition.
Although they
believed that literature on this topic is ambiguous and/or
conflicting, they felt confident in their knowledge of the
literature.
In general, orthodontists’ perceptions of
orthodontic literature on interceptive treatment of Class
II malocclusions in the mixed dentition were consistent
with the strongest scientific evidence.
However,
orthodontists’ Class II interceptive treatment priorities
didn’t necessarily parallel their perceptions of the
literature. Other significant findings of the study
included:

Orthodontists were most likely to perceive orthodontic
literature to support reduced risk of trauma and
increased patient self-esteem as benefits of
interceptive Class II treatment.

Orthodontists were most likely to rank reduced risk of
trauma and increased patient self-esteem as their
highest treatment priorities for interceptive Class II
treatment.
60

Orthodontists involved with teaching or research at a
university were more likely to perceive orthodontic
literature to support enhanced orthopedic changes as a
benefit of interceptive Class II treatment.

Orthodontists between the ages of 51-60 years were
more likely than orthodontists between the ages of 2140 years to perceive orthodontic literature to support
enhanced orthopedic changes as a benefit of
interceptive Class II treatment.

Orthodontists aged 21-30 years were more likely to
rank practice management decision as a higher
interceptive Class II treatment priority.
While overall orthodontists’ perceptions of
orthodontic literature on interceptive treatment of Class
II malocclusions are consistent with findings of the
strongest available literature, there are still many
orthodontists with misperceptions.
Additionally, it does
not appear that orthodontists base their interceptive Class
II treatment priorities on their perceptions of the
literature.
This being considered, it may be safe to say
that more research on interceptive Class II treatment will
not have a significant effect on orthodontists’ decisions.
It may be more pertinent to develop clinical guidelines,
61
based on existing evidence, for interceptive Class II
treatment instead.
However, even this may not make a
difference on orthodontists’ interceptive Class II
treatment planning.
In the end, orthodontists may not
always treat on the basis on scientific evidence, but
rather on their own intuition.
62
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extraction and non-extraction therapy. [Unpublished
Master's Thesis] St. Louis: Saint Louis University; 2009.
15. O'Connor BMP. Contemporary trends in orthodontic
practice : a national survey. [Unpublished Master's Thesis]
St. Louis: Saint Louis University; 1990.
16. Yang EY, Kiyak HA. Orthodontic treatment timing: A
survey of orthodontists. Am J Orthod Dentofac Orthop.
1998;113(1):96-103.
17. José Augusto Mendes M, Deise Lima C, Anderson de
Albuquerque C, Daniel K. Rationale for referring class II
patients for early orthodontic treatment J Appl Oral Sci.
2005(3):312.
18. O'Donnell CA. Attitudes and knowledge of primary care
professionals towards evidence-based practice: a postal
survey. J Eval Clin Pract. 2004;10(2):197-205.
19. Young J, Young JM, Ward JE. Evidence-based medicine in
general practice: beliefs and barriers among Australian
GPs. J Eval Clin Pract. 2001;7(2):201-10.
64
APPENDIX A
Survey
Demographics
1. Gender
o Male
o Female
2. Age
o
o
o
o
o
21-30 years
31-40 years
41-50 years
51-60 years
> 60 years
3. Do you have a master’s degree?
o Yes
o No
4. Are you currently involved in teaching or research at a
university?
o Yes
o No
Literature
The following questions are asked with regards to
literature on interceptive treatment of Class II
malocclusions in the mixed dentition.
5. There is not enough literature on interceptive
orthodontic treatment of Class II malocclusions in the
mixed dentition.
o Strongly Agree
o Agree
o Neutral
o Disagree
o Strongly Disagree
6. Literature on interceptive orthodontic treatment of
Class II malocclusions in the mixed dentition is
ambiguous and/or conflicting.
o Strongly Agree
65
o
o
o
o
Agree
Neutral
Disagree
Strongly Disagree
7. According to the literature, interceptive orthodontic
treatment of Class II malocclusions in the mixed
dentition reduces the risk of trauma to the incisors
o Strongly Agree
o Agree
o Neutral
o Disagree
o Strongly Disagree
8. According to the literature, interceptive treatment of
Class II malocclusions in the mixed dentition
increases patient self-esteem.
o Strongly Agree
o Agree
o Neutral
o Disagree
o Strongly Disagree
9. According to the literature, interceptive orthodontic
treatment of Class II malocclusions in the mixed
dentition increases orthopedic changes.
o Strongly Agree
o Agree
o Neutral
o Disagree
o Strongly Disagree
10. According to the literature, interceptive orthodontic
treatment of Class II malocclusions in the mixed
dentition results in a shorter phase II treatment in
the permanent dentition.
o Strongly Agree
o Agree
o Neutral
o Disagree
o Strongly Disagree
11. According to the literature, interceptive treatment of
Class II malocclusions in the mixed dentition followed
by a second phase of treatment yields better results
than a single phase of treatment in the permanent
dentition.
66
o
o
o
o
o
Strongly Agree
Agree
Neutral
Disagree
Strongly Disagree
12. According to the literature, interceptive treatment of
Class II malocclusions in the mixed dentition is a
practice management decision rather than a treatment
advantage
o Strongly Agree
o Agree
o Neutral
o Disagree
o Strongly Disagree
13. I feel confident in my knowledge of the literature on
interceptive orthodontic treatment of Class II
malocclusions in the mixed dentition.
o Strongly Agree
o Agree
o Neutral
o Disagree
o Strongly Disagree
Treatment Priorities
14. Please rank your priorities in deciding whether or not
to perform interceptive orthodontic treatment of Class
II malocclusions in the mixed dentition. Priorities
can be ranked from 1 to 6, with 1 being the most
important and 6 being the least important.
o Reduced risk of trauma to the incisors
o Increased patient self-esteem
o Enhanced orthopedic changes
o Shorter phase II treatment time
o Better result with two-phase treatment than a
single phase of treatment
o Practice management decision
67
APPENDIX B
Individual Question Distributions
Not Enough Literature
40%
30%
20%
10%
0%
Strongly
Agree
Agree
Neutral Disagree Strongly
No
Disagree Response
Figure B1: Question 5 Distribution of Responses
Ambiguous/Conflicting
50%
40%
30%
20%
10%
0%
Strongly
Agree
Agree
Neutral Disagree Strongly
No
Disagree Response
Figure B2: Question 6 Distribution of Responses
Trauma
50%
40%
30%
20%
10%
0%
Strongly
Agree
Agree
Neutral Disagree Strongly
No
Disagree Response
Figure B3: Question 7 Distribution of Responses
68
Self-Esteem
60%
50%
40%
30%
20%
10%
0%
Stongly
Agree
Agree
Neutral Disagree Strongly
No
Disagree Response
Figure B4: Question 8 Distribution of Responses
Orthopedic Changes
50%
40%
30%
20%
10%
0%
Strongly
Agree
Agree
Neutral Disagree Strongly
No
Disagree Response
Figure B5: Question 9 Distribution of Responses
Shorter Phase II
50%
40%
30%
20%
10%
0%
Strongly
Agree
Agree
Neutral Disagree Strongly
No
Disagree Response
Figure B6: Question 10 Distribution of Responses
69
Better Results
50%
40%
30%
20%
10%
0%
Strongly
Agree
Agree
Neutral Disagree Strongly Neutral
Disagree
Figure B7: Question 11 Distribution of Responses
Practice Management
50%
40%
30%
20%
10%
0%
Strongly
Agree
Agree
Neutral Disagree Strongly
No
Disagree Response
Figure B8: Question 12 Distribution of Responses
Knowledge
60%
50%
40%
30%
20%
10%
0%
Strongly
Agree
Agree
Neutral Disagree Strongly
No
Disagree Response
Figure B9: Question 13 Distribution of Responses
70
Trauma
35%
30%
25%
20%
15%
10%
5%
0%
Figure B10: Question 14 Distribution of Responses for Treatment
Priority Reduced Risk of Trauma to the Incisors
Self-Esteem
40%
30%
20%
10%
0%
Figure B11: Question 14 Distribution of Responses for Treatment
Priority Increased Patient Self-Esteem
Orthopedic Changes
30%
25%
20%
15%
10%
5%
0%
Figure B12: Question 14 Distribution of Responses for Treatment
Priority Enhanced Orthopedic Changes
71
Shorter Treatment Time
35%
30%
25%
20%
15%
10%
5%
0%
Figure B13: Question 14 Distribution of Responses for Treatment
Priority Shorter Phase II Treatment Time
Better Results
35%
30%
25%
20%
15%
10%
5%
0%
Figure B14: Question 14 Distribution of Responses for Treatment
Priority Better Result with Two-Phase Treatment than a Single Phase of
Treatment
Practice Management
Decision
50%
40%
30%
20%
10%
0%
Figure B15: Question 14 Distribution of Responses for Treatment
Priority Practice Management Decision
72
VITA AUCTORIS
Devin Allen Conaway was born on July 21st, 1987 in
Philipsburg, Pennsylvania to Roger and Kelly Conaway.
He grew up in Philipsburg, Pennsylvania and graduated
from Philipsburg-Osceola Area High School in 2005.
After
high school, he attended Juniata College in Huntingdon,
Pennsylvania, where he majored in biology and graduated in
2009 with a Bachelor of Science degree.
In 2009, he began
dental school at Case Western Reserve University and
graduated with a Doctor of Dental Medicine degree in 2013.
Afterwards, he moved to Saint Louis, Missouri to begin his
orthodontic residency program at Saint Louis University.
He plans to receive his Master of Science in Dentistry
degree in December 2015.
Upon graduating from Saint Louis University, Devin
plans on moving to Pennsylvania with his dog Sammie, where
he will practice orthodontics.
73