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PERCEPTIONS OF FACIAL ATTRACTIVENESS: OUTCOMES OF
ORTHOGNATHIC SURGERY
by
BRITTANY REID
CHUNG HOW KAU, COMMITTEE CHAIR
AMJAD JAVED
NATHANIEL LAWSON
NADA SOUCCAR
A THESIS
Submitted to the graduate faculty of The University of Alabama at Birmingham,
in partial fulfillment of the requirements for the degree of
Master of Science
BIRMINGHAM, ALABAMA
2015
PERCEPTIONS OF FACIAL ATTRACTIVENESS: OUTCOMES OF
ORTHOGNATHIC SURGERY
BRITTANY REID
DEPARTMENT OF ORTHODONTICS
ABSTRACT
Perceptions of physical attractiveness contribute to generalized assumptions that
can create significant bias in social decision-making. Because these biases exist, patients
often seek ways to improve facial harmony and overall appearance. Orthodontics and
orthognathic surgery are treatment modalities that may be considered as a means to
achieve facial balance. Orthodontists and oral surgeons must have an understanding of
facial beauty and how to properly carry out techniques in order to preserve or improve
facial balance. More importantly, the treatment goals of the patient and clinician(s) must
coincide. The objectives of this study were to evaluate perceptions of orthognathic
surgery outcomes, evaluate whether panels of observers with different levels of
orthodontic experience assess facial attractiveness similarly, and to determine what soft
tissue features influence assessment of facial attractiveness. In a three-part questionnaire,
laypersons, dental students, orthodontic residents, orthodontists, oral surgery residents,
and oral surgeons were asked to rate facial attractiveness of surgical and non-surgical
patients, select a preference for surgical “before-and-after” photographs, and rank facial
features that contribute to facial attractiveness. Although assessors perceived postsurgical patients as less attractive than non-surgical patients, a far greater percentage of
assessors preferred the post-surgical face to the pre-surgical face. The association
between attractiveness rating and treatment modality (surgical vs. non-surgical) did not
vary by the assessor’s background. There seems to be no consensus on a hierarchy of
ii
facial features that contribute to facial attractiveness; however, based on the overall
average rank, raters perceived the eyes and nose as contributing most to facial
attractiveness, and the nasolabial angle, labiomental sulcus, and chin-neck contour
contributing the least.
Keywords: orthognathic surgery, facial attractiveness
iii
ACKNOWLEDGMENTS
I would like to acknowledge Drs. Chung How Kau, Amjad Javed, and Nathaniel
Lawson for their willingness to serve as members of my committee. I appreciate the
thoughtful counsel provided by each of these members throughout this project.
I would like to express the deepest appreciation to my faculty mentor, Dr. Nada
Souccar. Without her guidance, patience, and encouragement, this thesis would not have
been possible. The unending support she has provided me during residency has been
invaluable.
Sincere gratitude is extended to those who agreed to participate in this study, to
Kelli Eberhardt for providing countless hours of data entry, and to Dr. Russell Griffin
who so graciously assisted me in the organization, analysis, and interpretation of the data.
I would also like to express gratitude to my family who has supported me
throughout my education, and to my loving husband Kaleb for his unwavering love and
encouragement.
Most importantly, I am thankful for our Almighty God as the source of all
knowledge and the provider of many blessings.
iv
TABLE OF CONTENTS
Page
ABSTRACT ........................................................................................................................ ii
ACKNOWLEDGMENTS ................................................................................................. iv
LIST OF TABLES ............................................................................................................. vi
LIST OF FIGURES .......................................................................................................... vii
CHAPTER
1 INTRODUCTION ............................................................................................................1
2 LITERATURE REVIEW .................................................................................................3
3 AIMS AND HYPOTHESES ..........................................................................................23
4 MATERIALS AND METHODS ....................................................................................24
5 RESULTS .......................................................................................................................32
6 DISCUSSION .................................................................................................................47
7 CONCLUSIONS.............................................................................................................56
LIST OF REFERENCES ...................................................................................................57
APPENDIX: IRB APPROVAL .........................................................................................60
v
LIST OF TABLES
Table
Page
1
Surgical patients for assessment ..................................................................................37
2
Non-surgical patients for assessment ...........................................................................38
3
Basic demographics of raters participating in study ....................................................39
4
Characteristics of dental raters participating in the study as given in N(%) ................40
5
Basic demographics of layperson raters participating in study ...................................41
6
Comparison of mean attractiveness ratings by type of rater and stratified by age and
gender of rating subject ................................................................................................42
7
Comparison of attractiveness preference before and after orthognathic surgery
stratified by age and gender of rating subject ..............................................................43
8
Comparison of mean rankings of facial features’ contribution to facial attractiveness
by type of rater .............................................................................................................44
9
Rankings of facial features’ contribution to facial attractiveness by type of rater ......44
10 Intraclass correlation coefficients and 95% confidence intervals for facial feature
rankings and attractiveness ratings ..............................................................................45
11 Kappa agreement statistic for choice of whether the pre-surgery or post-surgery
face was more attractive...............................................................................................46
vi
LIST OF FIGURES
Figure
Page
1
The Visual Analog Scale (VAS) ..................................................................................25
2
Composite of extraoral photographs ............................................................................27
3
Extraoral photographs for comparison.........................................................................28
4
List of facial features to be ranked by the assessors ....................................................29
5
Pre-treatment and post-treatment composites of surgical patients ..............................30
vii
1
CHAPTER 1
INTRODUCTION
Human attraction has inherently become a major focus of our culture. Although
there are many components that lead to one person’s attraction to another, modern society
places emphasis on physical attraction. Physical attraction is a multifaceted concept and
can be defined differently depending on cultural norms and individual subjective
preferences.1 Perceptions of physical attractiveness contribute to generalized assumptions
that can create significant bias in social decision-making. Because these biases exist,
patients often seek ways to improve facial harmony and overall appearance. Orthodontics
and orthognathic surgery are treatment modalities that may be considered as a means to
achieve facial balance in some of these patients.2, 3
Clinicians have a duty to present all pertinent information, including risks and
benefits of each treatment option, to a patient so that they may make an informed
decision about what treatment is best for them. When presented with the option of
orthognathic surgery, most patients will rely on both the orthodontist and oral surgeon to
collect enough information to adequately diagnose a case before treatment options are
presented.4, 5 This team of clinicians must have an understanding of facial beauty, know
how to evaluate facial form, and know how to properly carry out techniques in order to
preserve or improve facial balance.4, 5 It is critical for the clinician to assess whether or
not the patient’s goals are reasonable and obtainable. It is equally important for the
clinician to have a general level of agreement with the patient, the patient’s family and
2
peers, and the general public about what an esthetic outcome would be. Once the case has
been appropriately diagnosed, the orthodontist and oral surgeon must formulate a
treatment plan and should be confident that an invasive procedure is worth the risk if
orthognathic surgery is proposed as an option. This is particularly important in
“borderline” cases in which it is less obvious that orthognathic surgery is necessary to
correct an esthetic problem.6
It is assumed that if a proper diagnosis is made, and techniques are carried out
without fault, then the outcome of a surgical procedure will be a success. But, what if the
clinicians planning the case and the patient have a different perception of what is
attractive, and the goals of treatment are inadvertently different from the start? Or, what if
the clinicians’ and patient’s general perceptions of facial attractiveness are similar, but
translation and execution of these treatment objectives fall short? Is the orthodontic and
surgical team routinely producing a face that is more acceptable when perceived by the
lay public? Can a post-surgical patient expect to be perceived as equally attractive as their
non-surgical peers? The primary objective of this study is to evaluate perceptions of
orthognathic surgery outcomes. Is the “post-surgical face” perceived as attractive? How
does the “post-surgical face” compare in attractiveness to the average (non-surgical)
face? The secondary objectives of this study are (1) to evaluate whether panels of
observers with different levels of orthodontic experience assess facial attractiveness
similarly and (2) to determine what soft tissue features influence assessment of facial
attractiveness. The results of this study would provide clinicians with more information
that would assist patients in treatment decisions.
3
CHAPTER 2
LITERATURE REVIEW
Historical perspective
Prehistory-Ancient Egypt: Evolution of the Idealized Facial Form
Artistic renderings from the Stone Age contain little representation of human
form. This finding is likely due to the fact that prehistoric man was so consumed with
survival tactics that he had little time to express esthetic awareness. When the human
form was presented in Paleolithic art, it is described as “vague, grotesque, and
distorted.”1 This representation of the human form is likely not because humans during
this period were grossly unattractive. Instead, this finding reflects the culture during that
time period – conscious considerations of esthetics were simply not a priority.1 Concepts
of beauty and attractiveness first became a focus of cultural art during the time of the
ancient Egyptians (2600-2000 BC).7 The statues created of Egyptian royalty often were
idealized versions of the individual and showed only vague resemblance to the subject.
These renderings depicted well-balanced facial features, harmonious proportions, and
symmetry. Individuals of lower social stature were often depicted more realistically.1, 8
The Greeks and Romans: Expanding the Concept of Aesthetics
The ancient Greeks expanded on the concept of “aesthetics” to encompass human
emotion in addition to physical beauty.1, 9 Although they took a more philosophical
4
approach, Greek philosophers still urged that “beautiful creations” followed certain
geometrical laws.7 It was during this period that sculptures of the human form adhered to
certain geometric rules or canons that stressed “ideal bodily proportions and harmonious
anatomic relationships in human representation.”1 Ancient Greek mathematicians and
artists can also be credited with first describing the concept of the golden proportion.1, 6, 9
This geometrical concept suggests that if a line is divided into two parts, the longer part
divided by the smaller part is also equal to the whole length divided by the longer part.
This ratio is seen in certain design elements in ancient history as well as naturally
occurring phenomenon, including the human face. The concept suggests the emphasis on
the proportion of vertical or horizontal parts to the whole as being esthetically pleasing.1,
6, 9
Greek philosophers adhered to the importance of balance in beautiful things.
According to Plato, “The qualities of measure and proportion invariably constitute beauty
and excellence.”6 It was during the Golden Age of Greece that principles, or canons, for
ideal facial form were established.6, 8
The Romans also expressed vast interest in the human form through art and
sculpture. They appreciated the idealized human form, but adopted a more realistic
interpretation of their subjects in sculpture.1, 7, 8 The Romans are historically known for
depicting a harmonious facial form.1, 10 After the collapse of the Roman Empire, the
focus shifted from outward physical beauty to a more introspective spiritual beauty.1, 7
This suppression in the focus on physical beauty continued until the Renaissance.
The Renaissance: Reemergence of Realistic Esthetics
Artists of the Renaissance like Leonardo Da Vinci (1452-1519) and Michelangelo
(1475-1564) had a strong influence on the reemergence of esthetics in cultural art.
5
Michelangelo’s work captured a realistic representation of the human form.1 His
sculpture David epitomizes the esthetic ideal of the Italians during his time.1 Da Vinci
further defined ideal proportion by intense study of the human form and applied these
canons to his artwork. His studies consisted of measurements on live humans and
focused on sizes and proportions of the forehead, nose, mouth, and chin relative to the
whole head.9, 10 According to Da Vinci, the well-balanced face has a distance from the
chin to the nostrils, from nostrils to eyebrows, and from eyebrows to hairline that are
equal in length. Furthermore, the ears are equal in length to the nose and the upper lip is
equivalent in length to the one-third of the lower facial height.9, 10 His findings suggest
that there is natural variability in human form and a range of acceptability.9, 11 Therefore,
it is important that less stress be placed on strict adherence to absolute numeric values
that are considered “normal” and more of a focus on balanced proportions that may be
considered acceptable for that particular person.
The Present: Assessing Facial Balance
There is no question that humans have been interested in the concept of beauty
and attractiveness for centuries. Individuals have attempted to describe and create
objective guidelines for what is considered beautiful for generations.5 Beauty is defined
as a characteristic that provides a perceptual experience of pleasure or satisfaction. To
describe something as beautiful often involves an interpretation of some entity as being in
balance and harmony with nature, which may lead to feelings of attraction and emotional
well-being.12 Attractiveness is defined as the perception of the physical traits of an
individual human person as pleasing or beautiful.13 These terms, by definition, are
6
subjective. If our definitions of beauty and attractiveness are somewhat abstract, then
how do we as clinicians define what is a beautiful face? Arnett best describes this
quandary: “A person’s ability to recognize a beautiful face is innate, but translating this
into defined treatment goals is problematic.”5 Peck describes several concepts that
contribute to facial beauty1:

Facial equilibrium – the correspondence in size, form, and arrangement of facial
features on the opposite sides of the median sagittal plane. Symmetry and balance
are critical components of the “attractive” human face.
•
Facial harmony – the orderly and pleasing arrangement of the facial parts in
profile
•
Profile “flow” – regularity and evenness are preferred over irregularities or acute
curves
•
Facial proportion – comparative relation of facial elements in profile
Planning an improvement in facial form first requires objective standards or guidelines of
an ideal form that can be used for comparison. Clinicians must consider symmetry and
balance, facial harmony, and facial proportions while in the diagnosis of a case.
Although anecdotal in nature, the classical canons first described by the ancient
Greeks and utilized by artists of the Renaissance are still considered loose guidelines that
aid in assessment of the facial form today.8 The eleven neoclassical canons as described
by Bashour8 include the following:
1.
The head can be divided into two equal halves with a horizontal line passing
through the eyes.
2.
The face can be divided into equal thirds.
7
3.
The head can be divided into equal fourths.
4.
The length of the ear equals the length of the nose.
5.
The distance between the eyes equals the width of the nose.
6.
The distance between the eyes equals to the width of each eye.
7.
The width of the mouth equals one and one-half width of the nose.
8.
The width of the nose equals one-fourth the width of the face.
9.
The nose inclination equals the ear inclination.
10.
The lower face height can be divided into equal thirds.
11.
The lower face height can be divided into equal quarters.
Farkas challenged the validity of these canons by using soft tissue anthropometry to
measure and compare more than 100 dimensions and proportions in hundreds of people.
He used these measurements to define standards of soft tissue components of the head
and face.10, 14 Farkas found that the canons and the golden proportion described
previously were only present in a highly selective group of people, not in the majority of
the population.14 Because these observations are not evidence-based, they should only be
considered as a “rough working guide” to analyzing the human face.8
More recent methods to assess facial form have transitioned from anthropometric
systems utilized in the eighteenth and nineteenth centuries to cephalometric analysis.8, 15
In 1931, Broadbent introduced cephalometric radiography to measure hard and soft
tissues of the head and face.16 As interest in facial esthetics increased, multiple hard and
soft tissue cephalometric analyses and norms were developed to evaluate the position of
the nose, lips, and chin, among other facial features.16-19 Although cephalometric analysis
aids in the diagnosis of a case, it is not adequate to solely treat a case based on
8
cephalometric norms. In addition to cephalometric measurements, Arnett stresses the
importance of the clinical exam in order to “reverse negative traits and maintain positive
traits” when treating a patient with orthodontics or orthognathic surgery.5 Arnett utilizes a
clinical exam that assesses the dental occlusion and describes nineteen facial components
in three planes of space.4 He urges that without an organized and comprehensive
assessment, a clinician’s ability to adequately diagnose and treat a case is limited. 4, 5
Social aspect of attractiveness
It is evident that physical attractiveness is a characteristic that may contribute to
how one person may interact with other individuals. Multiple studies have demonstrated
that people formulate assumptions based on physical appearance, and then use these
assumptions to judge that person in regards to intelligence level, employability, and
relationships, among other traits.
Alley and Hildebrant suggest that the face is the most important contributor to
physical attractiveness, and subsequently has a major influence on social interactions and
an individual’s development.20 Several authors describe a “beauty-is-good” stereotype in
which individuals with attractive faces are perceived as being more competent and more
likeable than their less attractive peers, and this level of facial attractiveness promotes
positive expectations and impressions with a resultant gain in interpersonal advantages.20,
21
In a study by Clifford and Walster, fifth-grade teachers were provided with
questionnaires and facial photographs of twelve fifth-grade boys and girls who were
preselected based on level of attractiveness (attractive or unattractive) and asked to
9
speculate on the child’s Intelligence Quotient (IQ), the child’s social relationships with
their peers, and parental attitudes towards school. The teachers were also asked to predict
what level of education the child would achieve in the future. The authors found that
attractive children were perceived by their teachers as having higher intelligence levels
and better social skills than unattractive children. The teachers also reported that they
expected the attractive children to achieve a higher level of education and to have parents
that were more invested in their child’s academic performance than their less attractive
peers.22 In a similar double-blind study by Ross and Salvia, teachers were given
photographs of attractive and unattractive children with similar report cards that
described a poor academic performance. The authors found that attractive children were
rated more favorably that unattractive children in regards to future academic and social
development. The teachers also reported lower expectations for academic success for the
unattractive children.23
Algozzine further investigated the effect of attractiveness on student interactions.
In this study, teachers were instructed to give a report on the number of positive,
negative, and neutral interactions that each child in the classroom had with the teacher
and their classmates. The teachers were then asked to give each child an attractiveness
rating. The results indicated that attractive children had more positive interactions with
their teachers and peers than did unattractive children.24
Rosen and Underwood examined the relationship between facial attractiveness,
aggression, and popularity. Teachers were asked to provide attractiveness ratings of
students from facial photographs and report on level of physical aggression and social
acceptance. These authors found that for the students with low facial attractiveness
10
scores, physical aggression had a negative effect on popularity level. On the other hand,
highly aggressive students that were perceived as attractive had higher popularity
scores.25
Additional studies have shown that the influence of physical attractiveness carries
into the workplace and relationships later in life as well. In accordance with the “beautyis-good” stereotype, most studies suggest that physical attractiveness is advantageous in
social scenarios. Some studies, however, have shown that physical attractiveness may
actually act as a hindrance in certain situations. In a study by Johnson et al., participants
were asked to rate employment suitability of potential job applicants who had previously
been selected according to their physical attractiveness. Their results indicate that
physical attractiveness benefits both men and women applying for a variety of jobs, in
regards to their perceived level of employment suitability. However, high levels of
attractiveness may be detrimental for women applying for more masculine-type jobs for
which physical appearance was considered to be unimportant.26 In a study by Agthe et
al., participants were given photographs of four individuals that had been previously
selected according to attractiveness level (one attractive male, one unattractive male, one
attractive female, and one unattractive female) and job applications for each candidate.
Each application was fabricated so that each candidate was similar in regards to job
qualifications. The participants were then asked to select one applicant that would be
most suitable for a specified job. The results indicate that attractiveness is a hindrance
when the person being evaluated is of the same sex as the evaluator. It was suggested that
the negative response of a same-sex evaluator may be in an attempt to avoid a perceived
self-threat from the same-sex individual that was regarded as highly attractive.27
11
Taken together, these studies suggest that stereotyping in regards to facial
attractiveness begins during childhood and continues throughout adolescence and
adulthood, where attractiveness plays a pivotal role in the interactions and subsequent
relationships that a person will develop with other individuals. It is suggested that
attractive people may have higher levels of self-esteem and thus feel more comfortable in
social settings, thus resulting in more positive interactions and social gains than those
who do not exhibit the same level of self-confidence.21, 27 It is concluded that, in general,
attractive individuals are perceived as being more intelligent, more sociable and wellliked by their peers, and more apt to obtain a high level of success in future endeavors. It
is important to note, however, that although attractiveness does contribute greatly to the
perception of an individual’s abilities, it is not the only contributing factor. It is apparent
that facial attractiveness may have an impact on an individual’s quality of life. Because
of the social implications that degree of facial attractiveness can have, some patients will
consider invasive procedures, including orthognathic surgery, to improve their facial
appearance.
Orthognathic surgery
Patients often seek orthodontic or orthognathic treatment as a means to improve
facial harmony and overall appearance.2, 3, 28 Orthognathic surgery is used to correct
conditions of the jaw and face related to skeletal disharmonies, abnormal growth, sleep
apnea, and TMJ disorders that cannot be treated with orthodontics alone.29, 30 A surgical
approach may improve function, and aid in both the stability and esthetic value of
treatment.
12
Skeletal Patterns
The classification and analysis of facial skeletal patterns is complex and involves
comparisons in three planes of space.31, 32 The ideal facial skeleton can be described as
orthognathic in which components of the hard and soft tissue skeleton are harmonious
with each other. Patients that exhibit orthognathism are often classified as a skeletal Class
I. The maxilla and mandible are positioned in such a way that neither jaw projects
significantly more than the other, and the maxillomandibular complex is in a wellbalanced position relative to the anterior cranial base. Prognathism can be used to
describe a patient with one jaw more protrusive than the other (mandibular prognathism,
for example), or both jaws protrusive relative to the cranial base (bimaxillary
protrusion).31 In a similar manner, retrognathism can be used to describe a patient with
one jaw more retrusive than the other (mandibular retrognathism, for example), or both
jaws retrusive relative to the cranial base (bimaxillary retrusion).31 An ideal jaw
relationship also requires that neither jaw is deficient or excessive in vertical and
transverse dimensions.
Patients with a Class II skeletal pattern may exhibit maxillary excess, mandibular
retrognathia, or both. A skeletal Class II pattern may also result from vertical maxillary
excess and the resultant downward and backward (clockwise) rotation of the mandible.
Patients with a Class III skeletal pattern may exhibit maxillary deficiency, mandibular
prognathism, or both. A skeletal Class III pattern may also result from vertical maxillary
deficiency and the resultant upward and forward (counterclockwise) rotation of the
mandible. These skeletal discrepancies often result in less than ideal soft tissue drape
13
and/or dental malocclusions.5, 31Skeletal asymmetries may also exacerbate these
problems.
Skeletal Discrepancies: To Correct or Camouflage?
Orthognathic surgery is an approach to treat skeletal malocclusions that cannot
satisfactorily be treated with growth modification or “camouflage” treatment. Growth
modification is reserved for the adolescent patient who is actively growing, and utilizes
different fixed or removable appliances that can affect the final jaw position. Headgear,
for example, can be used to restrict growth of the maxilla and allow the growing
mandible to “catch up.” Functional appliances, as described by Proffit, can also be used
to “posture the mandible, [and the resultant] stretch of the muscles and soft tissues are
transmitted to the dental and skeletal structures, thus moving teeth and modifying
growth” in Class II patients.32 Although skeletal changes are seen, the majority of the
correction with growth modification is dentoalveolar in nature.31, 32 Johnston argues that
functional appliances do not change the inherent growth pattern, but rather “make clever
use of the normal pattern.”33 He further argues that “favorable mandibular growth
produces maxillary dentoalveolar compensations that prevent the excess mandibular
growth from having any marked effect on the malocclusion. Functional appliances may
avoid this mesial movement of the maxillary dentition by dissociating mandibular
displacement from the condylar growth that normally accompanies it.”33 By posturing the
mandibular anteriorly, and maintaining this advanced position long enough for
remodeling at the condyle and glenoid fossa, functional appliances such as the Twin
Block and Herbst are able to correct skeletal Class II discrepancies.32, 33
14
According to Proffit, differential jaw growth, even in the most favorable of
circumstances, may not be sufficient to correct the skeletal discrepancy, and additional
dental compensations are often necessary.32
Camouflage treatment utilizes dental extractions to put the remaining teeth in a
position that compensates for, and essentially masks, the skeletal malocclusion.32 In a
Class II patient with mandibular retrognathia, maxillary first premolars may be extracted
to retract the maxillary anterior teeth. Extractions would be avoided in the deficient
mandibular arch, and the lower incisors would be proclined to further reduce the
overjet.32 In a Class III patient, lower first premolars may be extracted to retract lower
incisors while the maxillary anteriors are proclined to create positive overjet. Depending
on the amount of crowding, inclination of the incisors, or other factors, it may be prudent
to extract premolars in both arches to create a more functional occlusion or produce more
favorable esthetics.32 Proffit asserts the camouflage treatment results in less favorable
outcome for patients that exhibit a dolichocephalic facial pattern, moderate to severe
anteroposterior jaw discrepancies, severe crowding, or skeletal discrepancies.32
When growth modification cannot be achieved or camouflage would result in a
poor outcome, a surgical approach may be considered a viable option for a patient. The
American Association of Oral and Maxillofacial Surgeons (AAOMS)34 asserts that
orthognathic surgery should be considered as medically appropriate in the following
circumstances:
A. Anteroposterior discrepancies (established norm = 2 mm)
a. Maxillary/Mandibular incisor relationship:
i. Horizontal overjet of +5 mm or more
15
ii. Horizontal overjet of zero to a negative value
b. Maxillary/Mandibular anteroposterior molar relationship discrepancy
of 4 mm or more (established norm = 0 to 1 mm)
c. These values represent two or more standard deviations from
published norms
B. Vertical discrepancies
a. Presence of a vertical facial skeletal deformity which is two or more
standard deviations from published norms for accepted skeletal
landmarks
b. Open Bite
i. No vertical overlap of anterior teeth
ii. Unilateral or bilateral posterior open bite greater than 2 mm
c. Deep overbite with impingement or irritation of buccal or lingual soft
tissues of the opposing arch
d. Supraeruption of a dentoalveolar segment due to lack of occlusion
C. Transverse discrepancies
a. Presence of a transverse skeletal discrepancy which is two or more
standard deviations from published norms
b. Total bilateral maxillary palatal cusp to mandibular fossa discrepancy
of 4 mm or greater, or a unilateral discrepancy of 3 mm or greater,
given normal axial inclination of the posterior teeth
D. Asymmetries
a. Anteroposterior, transverse, or lateral asymmetries greater than 3 mm
with concomitant occlusal asymmetry
16
Orthognathic Surgery: A Brief Overview
Rudimentary surgical techniques to correct mandibular prognathism originated in
the early 1900s.32 These techniques were refined during the first half of the century, and
the sagittal split ramus osteotomy was first introduced in 1957. This method, commonly
referred to now as the bilateral sagittal split osteotomy (BSSO), was introduced as a
means to treat mandibular retrognathism or prognathism by lengthening or reducing the
mandible, respectively.32, 35 BSSO is the most commonly performed orthognathic surgical
technique, and involves sagittal cuts through the mandibular ramus via an intraoral
approach to correct mandibular discrepancies.32, 35 Other techniques, such as the inverted
“L” osteotomy or intraoral vertical ramus osteotomy (IVRO) may be used to address
more extensive mandibular setbacks.35 Genioplasty to move the chin relative to the body
of the mandible is often utilized in single or two-jaw surgical procedures, or can be
performed alone as an adjunct to camouflage treatment.32
It was not until the 1960s that surgeons successfully developed a technique to
reposition the maxilla. The LeFort I osteotomy involves cuts that extend from the nasal
septum and along the apices of the maxillary teeth. The pterygoid plates are spared by
making a cut through the pterygomaxillary junction 32, 36 This technique allows for the
maxilla to be repositioned vertically, anterior-posteriorly, and transversely.36 Because this
technique allows for repositioning of the maxilla in all three planes of space, the Lefort I
procedure is routinely used to correct Class II and Class III malocclusions, mid-face
deficiencies, vertical maxillary excess, and dentoskeletal asymmetries.36 With the advent
of internal rigid fixation in the 1990s, techniques to reposition one or both jaws, as well
17
as the chin, had been refined such that even patients with severe dentofacial deformities
could be treated successfully with stable and predictable results.32
Orthognathic Surgery: Successful Outcomes
Treatment success is dependent on several factors. For orthognathic surgery to
“succeed,” a proper diagnosis must be made, a thorough treatment plan must be devised,
and techniques must be executed flawlessly to ensure a stable and predictable result.5, 32
When presented with the option of orthognathic surgery, most patients will rely on the
both the orthodontist and oral surgeon to collect enough information to adequately
diagnose a case before treatment options are presented.4, 5 This team of clinicians must
have an understanding of facial beauty, know how to evaluate facial form, and know how
to properly carry out techniques in order to preserve or improve facial balance.4, 5 A
critical step in this process is for the clinician to gain insight on why the patient is seeking
treatment. The clinician must understand the patient’s motive for seeking care, and must
decide if the patient’s goals are reasonable and obtainable. If this step is overlooked,
treatment may be considered a failure before treatment is initiated.5
It is equally important for the clinician to have a general level of agreement with
the patient, the patient’s family and peers, and the general public about what an esthetic
outcome would be. Once the case has been appropriately diagnosed, the orthodontist and
oral surgeon must formulate a treatment plan and should be confident that an invasive
procedure is worth the risk if orthognathic surgery is proposed as an option. This is
particularly important in “borderline” cases in which it is less obvious that orthognathic
surgery is necessary to correct an esthetic problem.6
18
In a study by Jacobson in 1984, fifty patients who had undergone orthognathic
surgery to correct different skeletal anomalies were surveyed about their reactions and
attitudes before, during, and after surgery. The results indicate that the single most
important reason for having orthognathic surgery was to improve facial appearance.
Eighty-eight percent of patients responded positively when asked if they would
recommend surgery to a friend. The patients who would not recommend surgery stated
that they responded negatively because they were either inadequately informed about the
procedure or has results that did not meet their expectations.37 A more recent study
suggests similar satisfaction ratings. When patients that were treated with a bimaxillary
osteotomy to correct a Class III skeletal pattern were surveyed about their perception in
improvement after surgery, 77.9% were satisfied with post-operative outcomes and 73%
reported that they would recommend treatment to other patients. Additionally, 67.5%
reported an increase in self-confidence as a result of improved facial appearance and
chewing function, and postoperative satisfaction correlated positively with opinions of
family and friends.38
In a study by Trovik et al., patients were followed 10-14 years after BSSO for
mandibular advancement. Participants rated their perceived treatment outcome on items
concerning oral function and appearance and were asked to rate their overall satisfaction
(very satisfied, relatively satisfied, and not satisfied) with orthognathic treatment. Most
responders were only reasonably satisfied with the treatment. Whether peers noticed a
change in appearance after treatment was a significant factor affecting both treatment
satisfaction and reporting a good quality of life. These findings are consistent with other
studies that suggest that self-perception is not the only thing that matters, and a patient’s
19
satisfaction with treatment can be positively influenced by how other individuals perceive
them after treatment. 38, 39 These findings suggest that perceptual assessment may be
equally important as clinical findings in determining successful outcomes of surgical
treatment.
Levels of agreement between raters
Some studies suggest that there is a significant amount of agreement when
judging facial beauty within and between populations.1 In general, people of different
races, professions, sexes, and age groups tend to agree on levels of facial attractiveness.20
Some studies show that laypersons, orthodontists, and oral surgeons generally agree on
preferences of facial attractiveness.2, 40
In a study by Juggins et al., 40 patients, 20 orthodontists, and 20 oral surgeons
were asked to rate the patients’ perceived need for orthognathic surgery based on facial
appearance, dental appearance, function, and overall need using clinical photographs and
models. Both orthodontists and oral surgeons rated a greater need for surgery based on
facial appearance than did the patients. Oral surgeons rated treatment need based on
facial appearance significantly higher than did orthodontists.41
In a study by Knight and Keith, dental clinicians and non-dental laypersons were
asked to rank students based on facial attractiveness level by arranging their photographs
in a pile accordingly. The primary objective of the study was to see if dental experts and
non-dental laypersons could agree upon an order of levels of facial attractiveness. The
results show that there was total agreement between the most attractive and most
unattractive faces. In other words, both clinicians and laypersons agreed on the “ideal”
20
faces. There were, however, differences in rankings between clinicians and laypersons in
the intermediate levels of attractiveness.42
In a study by Maple et al., photographs of three men and three women were
altered incrementally to change anteroposterior and vertical dimensions. Orthodontists,
oral surgeons, and laypersons were then asked to rate facial attractiveness on a visual
analog scale (VAS). The results of this study indicate that laypersons and clinicians
tended to agree on facial attractiveness.40 These authors concluded that it is critical for
clinicians to be able to predict patient satisfaction. In a similar study by Vargo et al.,
“experts” (orthodontists and oral surgeons) and “naïve” raters were asked to rate facial
attractiveness of facial photographs and give a recommendation on treatment need and
compare these assessments to patient motivations. These authors found that both groups
of clinicians the laypersons had a significant level of agreement when assessing facial
attractiveness. Furthermore, the laypersons’ profile attractiveness rating and the patient’s
expected change in self-consciousness were the strongest predictors for a patient’s
motivation to pursue orthognathic surgery. These results suggest that patients are strongly
influenced by the reactions of their peers, and their motivations for seeking orthognathic
surgery cannot always be objectively defined.2
Soh and Wong found significant levels of agreement between orthodontists and
oral surgeons when rating Chinese facial profile attractiveness. Normal and bimaxillary
protrusive Chinese males and females were judged as being highly attractive by
orthodontists and oral surgeons, and Chinese males and females with protrusive
mandibles judged as least attractive. Orthodontists and oral surgeons had differing
perceptions on the most attractive male profile. Orthodontists preferred flatter profile and
21
oral surgeons preferred more protrusive profile. Furthermore, the gender of the dental
professionals and number of years in clinical practice had an effect on profile rankings.43
In a series of studies et al., clinicians, laypersons, and pre-surgical patients were
asked to assess facial images in which certain facial elements (chin height, chin
prominence, lower facial profile convexity) had been altered incrementally. In regards to
chin height, surgical correction was desired with chin height greater than 50-58% and less
than 20%-23% of lower anterior facial height (LAFH). Patients and clinicians were found
to be more critical than laypeople, but there were no significant differences found
between clinicians and patients.44 In regards to chin prominence, surgery was desired
for chin protrusions greater than 6 mm and retrusions greater than 10 mm, and the greater
the retrusion or prominence of the chin, the lower the attractiveness rating and the greater
the desire for surgical correction. There were, however, no significant differences
between assessors when rating chin prominence.45 In regards to lower facial profile
convexity, a straight profile was perceived as most attractive and greater degrees
of convexity or concavity were deemed as progressively less attractive. In this study, the
results indicate that patients are the most critical, and clinicians are more critical than
laypeople.46
As modern society places strong emphasis on physical attractiveness, mass media
has been shown to play a role in the layperson’s perception of attractiveness. Some
authors suggest that because dental professionals have a more academic and less
emotional perception of facial beauty, their preferences of facial attractiveness may differ
from those of the general population.1, 28 If this is true, are orthodontists and oral surgeons
routinely producing a face that is esthetically pleasing to lay persons? Clinicians have a
22
duty to assess every treatment outcome and decide what factors lead to the success or
failure of that case. In the case of a poor outcome, what factors can be identified as
contributing to that failure? Was it poor diagnosis? Poor case set-up? Poor execution of
surgical technique? Was the patient given a less-than-ideal result? Was the case executed
well, but the patient had unrealistic expectations on the final outcome? It is assumed that
if a proper diagnosis is made, and techniques are carried out without fault, then the
outcome of a surgical procedure will be a success. But, what if the clinicians planning the
case and the patient have a different perception of what is attractive, and the goals of
treatment are inadvertently different from the start? These are all questions that must be
considered and addressed to ensure that a patient’s experience with orthognathic surgery
is nothing but positive. An improved understanding of treatment outcomes may lead to
better communication between clinicians and patients, and will undoubtedly benefit the
patient.
23
CHAPTER 3
AIMS AND HYPOTHESES
Aims
The aims of this study are: (1) to evaluate whether panels of observers with
different levels of orthodontic experience assess facial attractiveness similarly, and (2) to
determine what soft tissue features influence assessment of facial attractiveness.
Hypotheses
The null hypotheses of this study are: (1) There is no difference in perceptions of
facial attractiveness of the “average” face when compared to the “post-surgical” face
when observers rate 2-dimensional (2D) photographs on a visual analog scale, and (2)
There is no difference in perceptions of facial attractiveness among raters with different
levels of dental education
24
CHAPTER 4
MATERIALS AND METHODS
Case selection
Cases for presentation were selected from the University of Alabama at Birmingham
School of Dentistry Orthodontic Clinic patient database. All cases for presentation were
selected retrospectively by the PI and co-investigator. All ages and ethnic groups were
considered for inclusion in both groups. Patients with cleft lip/palate and severe
craniofacial abnormalities were excluded from both groups. The patients’ rationales for
pursuing treatment included improving facial esthetics and/or improving function. This
study was approved by the University of Alabama at Birmingham’s Institutional Review
Board.
Surgical faces
Using the management software (Dolphin Management and Imaging Systems,
Chatsworth, CA), a report was created of all patients who had undergone orthognathic
surgery by using surgical search terms (surgery, jaw surgery, orthognathic surgery, 2-jaw
surgery, LeFort osteotomy, LeFort I, segmental osteotomy, 3-piece maxilla, 2-piece
maxilla, maxillary advancement, BSSO, and mandibular advancement). Thirty
consecutive surgical cases (14 males, 16 females) were selected (Table 1). All skeletal
malocclusions (anterior open bite, Class II, Class III, etc.) were considered for inclusion.
25
All orthognathic surgery procedures (maxillary advancement, mandibular advancement,
two-jaw surgery, etc.) were also considered for inclusion. Extraoral pretreatment
photographs and photographs from the debond appointment were included for
assessment.
Non-surgical faces
Using the Dolphin Management software, a report was created of all patients who
had been treated with orthodontics and debonded from 2011-2013. Sixty consecutive
patients were selected for initial assessment. Extraoral photographs from the debond
appointment were included for assessment. The investigators rated attractiveness of each
patient using a visual analog scale (VAS). The VAS was graded from 0 (very
unattractive) to 10 (very attractive) (Fig. 1).
Very unattractive____|____|____|____|____|____|____|____|____|____Very attractive
0
1
2
3
4
5
6
7
8
9
10
Figure 1. The Visual Analog Scale (VAS)
Facial attractiveness ratings from the investigators were compared. If the investigators
disagreed on a rating by more than two points, the patient was excluded. Facial
attractiveness ratings were then averaged for each patient. Thirty “average” patients (9
males, 21 females) were selected for presentation (Table 2). An attempt was made to
match non-surgical patients in gender and age to the surgical patients previously selected.
Once patients were selected for each group, facial photographs were cropped and
arranged in a composite: profile, frontal, frontal smiling. All photographs were cropped
26
in the same manner. An attempt was made to crop out as many distracting features (hair,
clothing, etc.) as possible.
Participants
The participants (ages 19-65) for this study consisted of four groups with various
levels of dental education: laypersons, dental students, orthodontic residents, orthodontic
faculty members, oral surgery residents, and oral surgery faculty members. All dental
students, residents, faculty members were studying or teaching at the University of
Alabama at Birmingham School of Dentistry. The laypersons were patrons of the same
school. The following assumptions were made about each group: laypersons have no
orthodontic or orthognathic experience, dental students have very limited, if any,
orthodontic or orthognathic experience; residents have “some” orthodontic/orthognathic
experience; and orthodontists and oral surgeons have the most orthodontic/orthognathic
experience of all groups. (The terms participants, assessors, and raters will be used
interchangeably from this point forward.)
Ethical approval and informed consent for this study were obtained from the
Institutional Review Board of the University of Alabama at Birmingham and participants
of this study, respectively. Each participant was assigned a unique code at the time
consent was given in order to collect and to analyze the data anonymously.
Assessing Images
Photographs were arranged in two separate PowerPoint presentations. The first
presentation included both surgical and non-surgical patients. The second presentation
27
included surgical patients only. Assessors were asked to create a ranked list of facial
features that they perceive as contributing to facial attractiveness between presentations.
Section 1: Comparing Surgical and Non-surgical Faces
All 60 (surgical and non-surgical) patients were included for assessment. Patients
were grouped according to age and gender (under 40 females, over 40 females, under 40
males, over 40 males), but surgical and non-surgical patients were intermixed within
these groupings. The order of presentation of the patient composites within each grouping
was assigned using a random numbers table.
A patient’s composite (Fig. 2) was presented to the assessors, and the assessor
was asked to rate the patient’s facial attractiveness on the VAS (Fig. 1). Assessors were
given eight seconds to rate each patient. Patient composites were presented individually
for four or five patients, then frontal smiling photographs from all patients from that set
were presented together (Fig. 3). The assessors were then asked to select the most
attractive and most unattractive patient from that set. Assessors were given ten seconds to
make this selection. Assessors were asked to rate and compare all sixty patients in this
manner before proceeding with the next section.
Figure 2. Composite of extraoral photographs
28
Figure 3. Extraoral photographs for comparison
Section 2: Ranking Facial Features that Contribute to Facial Attractiveness
After assessing facial attractiveness of all 60 patients, participants were asked to
complete a questionnaire that contained a list of 12 facial features: vertical proportions,
horizontal proportions, lower face height, chin, nasolabial angle, nose, lips, labiomental
sulcus, chin-neck contour, skin complexion, eyes, and “other” (Fig. 4). They were asked
to rank these facial features from 1 (contributing the most to facial attractiveness) to 12
(contributing the least to facial attractiveness). If the participant did not know the
meaning of an item on the list, they were asked to cross it off the list before ranking and
not include that item in the ranked list. Participants were also asked to add “other” items
29
to the list prior to ranking each item. Multiple “other” items could be added to the list.
The final ranking could include more or less than 12 items.
Facial Feature
Rank
Vertical proportions
Horizontal proportions
Lower face height
Chin
Nasolabial angle
Nose
Lips
Labiomental sulcus
Chin-neck contour
Skin complexion
Eyes
"Other"
Figure 4. List of facial features to be ranked by the assessors
Section 3: Selecting a Preference of Pre-treatment and Post-treatment Surgical Faces
All thirty surgical patients were included for assessment. Patients were grouped
according to age and gender (under 40 females, over 40 females, under 40 males, over 40
males). The order of presentation of the patient composites within each grouping was
assigned using a random numbers table.
A patient’s pre-treatment composite and post-treatment composite (Fig. 5) were
presented to the assessors. Each pre-treatment composite was randomly assigned letter A
or B, then the post-treatment composite was assigned the other letter such that the pretreatment composite did not always precede the post-treatment composite. Assessors
30
were asked to select a preference for the composite that they found was more attractive. If
they did not have a preference, they were given the option to select “no preference.”
Figure 5. Pre-treatment and post-treatment composites of surgical patients
Statistical Analysis
Descriptive statistics using frequency and percent as well as mean and standard
deviation were computed for categorical and continuous variables, respectively, for each
of the six groups of assessors. The association between both facial feature rankings and
attractiveness ratings and rater group was estimated using an analysis of variance
(ANOVA) and repeated measures ANOVA, respectively. For each ANOVA model in
which the overall F-test was significant, pairwise comparisons using Tukey’s range test
was used to determine which groups differed while accounting for multiple comparisons.
31
For attractiveness ratings, models were stratified by the age and gender of the rated
subject (four strata total). To determine the reliability of rankings and ratings, an
intraclass correlation coefficient and 95% confidence limits were computed for each
ranking or rating overall and stratified by rater group.
A chi-square test was used to examine whether the pre- or post-surgery image was
more attractive was differential by rater group. A kappa statistic was calculated to
determine whether agreement varied overall and by rater group.
32
CHAPTER 5
RESULTS
Cases for Assessment
The demographics for the patients included for assessment are given in Tables 1
and 2. The patients are grouped by age and gender. The skeletal classification prior to
bonding was noted for each patient. A general surgical procedure and the surgery date
were noted for each surgical patient based on information input into the patient’s
treatment card. The bond date was denoted at the start of comprehensive treatment when
one arch of appliances was placed and the age at bonding was calculated for each patient.
The final records were obtained at the debond date when all fixed appliances were
removed.
Participants
The participants (181 total) included 101 (56.4%) males and 78 (43.6%) females.
Two participants (both dental students) did not provide their gender. This group included
42 laypersons (19 male, 23 female), 100 dental students (54 male, 46 female), 15
orthodontic residents (7 male, 8 female), 10 orthodontic faculty members (all male), 9
oral surgery residents (8 male, 1 female), and 5 oral surgery faculty members (all male).
The basic demographics of the raters that participated in the study are included in Table
3. Table 4 shows the demographics of each rater group with dental experience.
33
Orthodontists and oral surgeons reported an average of 23.7 years and 22.4 years,
respectively, of experience in their field. Two oral surgery residents and two oral
surgeons noted additional training in plastic and/or reconstructive surgery (Table 4).
Table 5 shows the demographics of the layperson participants. The majority of layperson
raters (52.4%) had at least some college education, and 21.4% had a doctoral or
professional degree (Table 5).
Comparing Surgical and Non-Surgical Faces
Table 6 shows the comparison of mean attractiveness ratings by type of rater
estimated from a repeated measures ANOVA. These data are stratified by age and gender
of the subject who was being rated. Mean attractiveness ratings were 0.55 points lower
for surgical patients compared to non-surgical patients. This finding was significant for
all groups of patients when categorized by age and gender (p < 0.0001 for all groups)
such that surgical patients, on average, were rated 0.50-0.65 points lower than the nonsurgical patients. The p-value for the three-way interaction between the type of rater, type
of patient (surgical vs non-surgical), and age-gender assignment of the patient was not
significant (Table 6).
Selecting a Preference of Pre-treatment and Post-treatment Surgical Faces
Table 7 shows the comparison of attractiveness preference before and after
surgery. These data are stratified by age and gender of the subject who was being rated.
The raters most often chose the post-surgical face as more attractive than the pre-surgical
face. This finding was statistically significant.
34
Ranking Facial Features
The comparison of mean rankings of facial features’ contribution to facial
attractiveness is shown in Table 8. These data are stratified by rater category.
Significantly different mean values (p < .05) between rater groups were found for the
following characteristics: vertical proportions, horizontal proportions, lower face height,
labiomental sulcus, skin complexion, and eyes. Pairwise comparisons using Tukey’s
range test was used to determine which groups differed while accounting for multiple
comparisons. For vertical proportions, significantly different mean values were found
between the orthodontic resident versus layperson groups. Although significantly
different mean values were found between rater groups for horizontal proportions and
lower face height, there were no significant pairwise comparisons when further analyzed
with the Tukey range test. Significantly different mean values were found between dental
students versus laypersons when ranking labiomental sulcus, but the standard deviation
for the layperson group was considerably high, thus indicating a lot of variation in
responses. Mean values that were significantly different for skin complexion were found
between dental students versus laypersons, orthodontic residents versus laypersons, and
orthodontists versus laypersons. There was also a difference in mean values for eyes
between dental students versus orthodontic residents and orthodontic residents versus
laypersons that was significant.
The rankings of facial features’ contribution to facial attractiveness is shown in
Table 9. These data are stratified by rater category. Means for each facial feature were
used to create a ranked list within each rater group. If two features averaged the same
rank, the median was used as a tiebreaker to assign the final rank. Based on the overall
35
average rank, raters perceived the eyes, nose, and vertical proportions as contributing
most to facial attractiveness and the nasolabial angle, labiomental sulcus, and chin-neck
contour contributing the least. Dental students, oral surgery residents, orthodontists, and
laypersons all ranked eyes as the top facial feature contributing to facial attractiveness.
Orthodontic residents and oral surgeons ranked vertical and horizontal proportions as the
most important features (Table 9). All groups ranked the nose at the top one-third of their
lists. Of the rank list generated for the laypersons, 33.3% of laypersons did not rank
vertical proportions, horizontal proportions, or lower facial height. Similarly, 83.3% of
laypersons did not rank nasolabial angle, and 95.2% did not rank the labiomental sulcus.
Reliability and Agreement Levels
Six orthodontic residents and seven laypersons were surveyed a second time at
least two weeks after the initial assessment to minimize recall bias. Table 10 shows the
intraclass correlation coefficients and 95% confidence intervals for facial feature rankings
and attractiveness ratings. Overall, there is moderate reliability of facial feature rankings
and facial attractiveness ratings. Orthodontic residents were more reliable with facial
feature rankings when compared with attractiveness ratings. Laypersons were more
reliable with attractiveness ratings when compared with facial feature rankings (Table
10).
Table 11 shows the Kappa agreement statistic for choice of whether the presurgery or post-surgery face was more attractive. Overall, the Kappa statistic was low
(0.48). Agreement was equally low for both the orthodontic resident group (0.53) and
layperson group (0.44) who took the assessment the second time. The agreement was
36
especially poor when “no preference” for the pre- or post-surgical image was selected at
the first assessment (Table 11).
37
Table 1. Surgical patients for assessment
Skeletal
Surgical
Bond
Age at
Surgical
Final
Pt.
Gender Classification
Other
Procedure
Date
Bonding
Date
Records
1
F
III
M axilla
10/01/10 15 y 10 m 06/01/11
03/01/12
2
F
II
M andible
10/01/09
12 y 9 m
03/01/12
08/01/12
3
F
II
AOB, CR M ax/M and, G 01/01/12
22 y 5 m
02/01/13
07/01/13
4
F
II
M ax/M and
01/01/03
16 y 1 m
12/01/04
06/01/05
5
F
II
M ax/M and, G 09/01/09
16 y 0 m
06/01/12
11/01/13
6
F
II
M andible
07/01/10
13 y 7 m
07/01/12
08/01/13
7
F
I
AOB
M axilla, G
10/01/06
19 y 6 m
03/01/07
06/01/07
8
F
II
M andible
10/01/10
14 y 2 m
12/01/11
08/01/12
9
F
II
M andible
11/01/08
16 y 0 m
08/01/11
02/01/12
10
F
II
M andible
06/01/09
16 y 2 m
09/01/11
03/01/12
11
F
III
A
M ax/M and
02/01/12
17 y 0 m
09/01/13
06/01/14
12
F
II
M andible
09/01/03
52 y 1 m
04/01/05
08/01/05
13
F
III
M axilla
09/01/11 56 y 10 m 02/01/13
09/01/13
14
F
II
A
M ax/M and
06/01/11
50 y 6 m
11/01/12
01/01/12
15
F
II
M andible, G
04/01/08
53 y 3 m
10/01/09
04/01/10
16
F
II
M ax/M and, G 08/01/12 65 y 11 m 09/01/13
04/01/14
17
M
III
AOB
M ax/M and
02/01/07
19 y 9 m
05/01/07
03/01/08
18
M
III
M ax/M and
03/01/05
18 y 2 m
06/01/06
04/01/07
19
M
II
AOB
M axilla
08/01/10
16 y 1 m
01/01/13
06/01/13
20
M
III
AOB, A M ax/M and, G 12/01/10 19 y 10 m 06/01/11
10/01/12
21
M
III
AOB
M ax/M and, G 08/01/07
17 y 9 m
05/01/09
02/01/10
22
M
III
AOB
M axilla
08/01/11
18 y 1 m
07/01/12
03/01/13
23
M
II
AOB
M axilla
07/01/08
18 y 3 m
07/01/09
08/01/09
24
M
II
M andible
01/01/05
14 y 7 m
07/01/07
03/01/08
25
M
II
A
M ax/M and
07/01/11
19 y 1 m
08/01/12
03/01/14
26
M
II
M ax/M and
11/01/12
13 y 5 m
12/01/13
04/01/14
27
M
III
M ax/M and, G 04/01/08
26 y 5 m
12/01/08
06/01/09
28
M
II
OSA
M ax/M and
03/01/13
39 y 4 m
11/01/13
04/01/14
29
M
III
M axilla
11/01/10
43 y 2 m
05/01/11
12/01/11
30
M
II
M ax/M and, G 03/01/10
37 y 6 m
03/01/11
01/01/12
* A = Asymmetry, AOB = Anterior Open Bite, CR = Condylar Replacement, G = Genioplasty, OSA = Obstructive
Sleep Apnea
38
Table 2. Non-surgical patients for assessment
Pt.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Skeletal
Gender Classification
F
II
F
I
F
III
F
II
F
II
F
II
F
I
F
I
F
I
F
II
F
I
F
I
F
II
F
II
F
II
F
II
F
II
F
I
F
I
F
II
F
II
M
II
M
II
M
I
M
II
M
III
M
II
M
II
M
I
M
I
Bond
Date
10/01/11
09/01/11
08/01/11
05/01/11
10/01/11
08/01/11
08/01/11
10/01/11
10/01/09
10/01/11
09/01/11
04/01/12
09/01/11
07/01/10
04/01/10
08/01/11
07/01/12
08/01/12
05/01/12
09/01/11
03/01/10
05/01/11
08/01/11
09/01/11
02/01/12
06/01/10
10/01/09
10/01/11
09/01/11
05/01/12
Age at
Bonding
12 y 9 m
12 y 0 m
11 y 9 m
13 y 2 m
27 y 9 m
16 y 10 m
12 y 3 m
16 y 1 m
14 y 5 m
14 y 5 m
13 y 1 m
13 y 6 m
13 y 7 m
12 y 10 m
11 y 10 m
13 y 3 m
40 y 11 m
60 y 2 m
55 y 10 m
40 y 0 m
40 y 8 m
15 y 5 m
14 y 7 m
13 y 9 m
14 y 7 m
13 y 1 m
17 y 5 m
13 y 4 m
12 y 6 m
41 y 11 m
Final
Records
09/01/13
10/01/13
03/01/13
10/01/13
06/01/12
11/01/13
01/01/14
04/01/13
08/01/12
11/01/13
05/01/13
01/01/14
02/01/13
04/01/13
02/01/13
12/01/13
01/01/14
02/01/14
11/01/12
07/01/13
08/01/13
08/01/13
04/01/13
02/01/13
09/01/13
08/01/12
12/01/12
03/01/13
02/01/14
06/01/13
39
Table 3. Basic demographics of raters participating in study
N (%)
Gender
M ale
Female
101 (56.4)
78 (43.6)
Race
Caucasian
African-American
Asian-Indian
Spanish/Hispanic
Asian
American Indian/Alaskan Native
Other
139 (76.8)
12 (6.6)
4 (2.2)
7 (3.9)
16 (8.8)
1 (0.6)
2 (1.1)
Age (years)
≤18
19-25
26-29
30-35
36-39
40-45
46-49
50-55
56-59
60-65
≥66
0 (0.0)
97 (53.6)
26 (14.4)
18 (9.9)
3 (1.7)
10 (5.5)
1 (0.6)
13 (7.2)
7 (3.9)
4 (2.2)
2 (1.1)
Job title
Dental student
Orthodontic resident
Oral surgery resident
Orthodontist
Oral surgeon
Layperson
100 (55.3)
15 (8.3)
9 (5.0)
10 (5.5)
5 (2.8)
42 (23.2)
40
Table 4. Characteristics of dental raters participating in the study as given in N(%)
Dental
Orthodontic Oral surgery Orthodontist Oral surgeon
student
resident
resident
(n=10)
(n=5)
(n=100)
(n=15)
(n=9)
Gender
M ale
53 (54.1)
7 (46.7)
8 (88.9)
10 (100.0)
4 (80.0)
Female
45 (45.9)
8 (53.3)
1 (11.1)
0 (0.0)
1 (20.0)
Race
Caucasian
African-American
Asian-Indian
Spanish/Hispanic
Asian
American Indian/Alaskan Native
Other
71 (71.0)
8 (8.0)
3 (3.0)
3 (3.0)
12 (12.0)
1 (1.0)
2 (2.0)
10 (66.7)
1 (6.7)
1 (6.7)
2 (13.3)
1 (6.7)
0 (0.0)
0 (0.0)
7 (77.8)
2 (22.2)
0 (0.0)
0 (0.0)
0 (0.0)
0 (0.0)
0 (0.0)
7 (70.0)
0 (0.0)
0 (0.0)
2 (20.0)
1 (10.0)
0 (0.0)
0 (0.0)
2 (40.0)
1 (20.0)
0 (0.0)
0 (0.0)
2 (40.0)
0 (0.0)
0 (0.0)
Age (years)
≤18
19-25
26-29
30-35
36-39
40-45
46-49
50-55
56-59
60-65
≥66
0 (0.0)
92 (92.0)
4 (4.0)
3 (3.0)
1 (1.0)
0 (0.0)
0 (0.0)
0 (0.0)
0 (0.0)
0 (0.0)
0 (0.0)
0 (0.0)
0 (0.0)
10 (66.7)
3 (20.0)
1 (6.7)
1 (6.7)
0 (0.0)
0 (0.0)
0 (0.0)
0 (0.0)
0 (0.0)
0 (0.0)
0 (0.0)
4 (44.0)
4 (44.0)
0 (0.0)
1 (11.1)
0 (0.0)
0 (0.0)
0 (0.0)
0 (0.0)
0 (0.0)
0 (0.0)
0 (0.0)
0 (0.0)
0 (0.0)
0 (0.0)
4 (40.0)
0 (0.0)
1 (10.0)
3 (30.0)
0 (0.0)
2 (20.0)
0 (0.0)
0 (0.0)
0 (0.0)
1 (20.0)
0 (0.0)
0 (0.0)
1 (20.0)
1 (20.0)
0 (0.0)
2 (40.0)
0 (0.0)
-
-
-
23.7±11.8
22.4±13.5
2 (22.2)
0 (0.0)
2 (40.0)
Education level (year in dental school or residency for respective group)
1 60 (60.0)
4 (28.6)
2 (22.2)
2
40 (4.0)
6 (42.9)
2 (22.2)
3
0
4 (28.6)
2 (22.2)
4
0
1 (11.1)
5
2 (22.2)
6
M ean years practicing
-
-
Has additional training in plastic or reconstructive surgery (%)
0 (0.0)
0 (0.0)
41
Table 5. Basic demographics of layperson raters participating in study
N (%)
Gender
M ale
19 (45.2)
Female
23 (54.8)
Race
Caucasian
42 (100.0)
Age (years)
≤18
19-25
26-29
30-35
36-39
40-45
46-49
50-55
56-59
60-65
≥66
0 (0.0)
5 (11.9)
8 (19.1)
7 (16.7)
1 (2.4)
4 (9.5)
0 (0.0)
11 (26.2)
4 (9.5)
2 (4.8)
0 (0.0)
Current education level
Less than high school
High school
College
M aster’s degree
Doctor or professional degree
Other
0 (0.0)
4 (9.5)
22 (52.4)
6 (14.3)
9 (21.4)
1 (2.4)
4.82± 1.79
5.04± 1.71
N on-s urgical
4.25± 2.03
N on-s urgical
4.71± 1.72
N on-s urgical
0.9180
5.67± 1.32
5.56± 1.12
5.14± 1.29
5.05± 1.11
4.98± 1.06
4.64± 0.93
5.60± 1.18
5.08± 1.41
5.38± 1.22
5.04± 1.21
res ident
O ral s urgery
* S = surgical, NS = non-s urgical, B = beta, R C = rater category
* Estim ated from a rep eated m easures A N O VA , s ignificant at p < .05
p = 0.0600
6.20± 1.26
5.40± 1.54
Patient age/gender interaction
5.49± 1.24
4.97± 1.58
Surgical
5.58± 1.29
4.79± 1.32
5.25± 1.26
4.43± 1.15
5.66± 1.29
4.81± 1.63
5.57± 1.28
4.81± 1.42
N on-s urgical
O VER 40 M A LE
4.28± 1.66
Surgical
U N D ER 40 M A LE
3.83± 1.86
Surgical
O VER 40 F EM A LE
4.40± 1.74
Surgical
U N D ER 40 F EM A LE
4.31± 1.74
N on-s urgical
res ident
Surgical
O VER A LL
M ean ranking
O rthodontic
D ental
student
6.10± 0.99
4.97± 0.85
5.56± 1.05
4.70± 1.21
5.34± 1.24
4.58± 1.30
5.46± 1.15
4.95± 1.60
5.50± 1.14
4.79± 1.34
6.40± 1.52
6.53± 1.19
5.85± 1.39
5.22± 1.64
4.84± 1.28
4.96± 1.40
5.61± 2.00
5.20± 1.83
5.58± 1.75
5.30± 1.67
O rthodontist O ral s urgeon
5.78± 1.68
5.00± 1.68
4.69± 1.75
4.18± 1.70
4.59± 1.79
3.93± 1.64
5.13± 1.64
4.48± 1.81
4.95± 1.72
4.32± 1.75
Lay p ers on
B eta
-0.5473
-0.4967
-0.5105
-0.6463
-0.5586
(S v N S)
Table 6. C omp arison of m ean attractiveness ratings by ty p e of rater and stratified by age and gender of rating subject
< 0.0001
< 0.0001
< 0.0001
< 0.0001
< 0.0001
p -value B
0.5938
0.1537
0.4421
0.7396
0.0600
p -value RC
42
43
Table 7. Comparison of attractiveness preference before and after orthognathic surgery stratified by age and gender
of rating subject
Dental
student
Choice (%)
OVERALL
Pre-surgery
Post-surgery
Neither
Orthodontic Oral surgery
Orthodontist
resident
resident
Oral
surgeon
Layperson
p-value
16.5
64.8
18.7
10.4
72.7
16.9
14.8
63.3
21.9
6.7
70
23.3
9.3
71.3
19.3
15.8
65.4
18.8
<0.0001
UNDER 40 FEM ALE
Pre-surgery
18.6
Post-surgery
63.7
Neither
17.7
10.9
74.6
14.6
21.2
58.6
20.2
4.6
72.7
22.7
7.3
70.9
21.8
15.4
69.1
15.6
0.0009
OVER 40 FEM ALE
Pre-surgery
16
Post-surgery
65.6
Neither
18.5
11.5
68.5
20
12.1
66.7
21.2
10.9
64.6
24.6
16.4
65.5
18.2
18
61.9
20.1
0.5018
UNDER 40 M ALE
Pre-surgery
14.6
Post-surgery
64
Neither
21.4
5.3
78.7
16
11.1
64.4
24.4
2
76
22
4
72
24
11
64.3
24.8
0.0793
6.7
70
23.3
0
93.3
6.7
17.5
0
15.9
0.4588
OVER 40 M ALE
Pre-surgery
14.3
13.3
7.4
Post-surgery
67.3
71.1
66.7
Neither
18.3
15.6
25.9
* Estimated from a chi-square test, significant at p < .05
44
Table 8. Comparison of mean rankings of facial features’ contribution to facial attractiveness by type of rater
Dental
student
Vertical proportions
Orthodontic Oral surgery
Orthodontist Oral surgeon Layperson
resident
resident
p-value
5.60±2.92
3.60±3.29
4.44±2.74
5.60±4.09
2.80±1.48
6.68±2.67
0.0086
Horizontal proportions 6.05±2.90
4.80±3.63
6.11±2.15
8.10±3.48
4.20±3.56
7.32±2.40
0.0160
Lower face height
8.04±3.02
6.27±2.79
6.78±3.15
5.70±3.80
6.40±2.19
7.86±2.07
0.0479
Chin
5.76±2.32
6.53±2.59
6.44±2.46
6.20±1.69
8.40±2.30
5.44±1.79
0.0671
Nasolabial angle
8.57±2.46
8.67±2.82
10.33±1.00
7.60±2.12
7.60±2.07
8.86±1.77
0.1921
Nose
4.10±2.22
4.93±2.28
3.22±1.64
4.50±1.90
4.20±2.2
3.98±1.71
0.4793
Lips
5.08±2.38
6.67±2.79
4.00±2.60
5.30±3.09
5.20±2.39
5.28±2.60
0.1969
Labiomental sulcus
9.82±1.98
9.40±2.10
9.67±1.80
7.90±2.73
9.60±1.14
5.00±5.67
0.0050
Chin-neck contour
6.67±2.90
7.27±2.91
6.44±2.96
8.30±2.95
9.00±2.35
6.21±2.12
0.1262
Skin complexion
5.79±3.42
7.73±3.28
6.22±2.49
7.20±3.43
4.20±2.77
3.60±2.57
0.0001
Eyes
3.01±2.74
6.07±3.61
3.00±2.65
* Estimated from an ANOVA, significant at p < .05
3.30±3.23
4.40±3.97
3.29±2.70
0.0099
Table 9. Rankings of facial features’ contribution to facial attractiveness by type of rater
Dental
student
Orthodontic Oral surgery
Orthodontist
resident
resident
Oral
surgeon
Layperson
Overall
Average Rank
Vertical proportions
#4
#1
#4
#4
#1
#8
3.67
Horizontal proportions
#7
#2
#5
#10
#2
#9
5.83
Lower face height
#9
#5
#9
#5
#7
#10
7.5
Chin
#5
#6
#7
#6
#9
#6
6.5
Nasolabial angle
#10
#10
#11
#8
#8
#11
9.67
Nose
#2
#3
#2
#2
#4
#3
2.83
Lips
#3
#7
#3
#3
#6
#5
4.5
Labiomental sulcus
#11
#11
#10
#9
#11
#4
9.33
Chin-neck contour
#8
#8
#8
#11
#10
#7
8.67
Skin complexion
#6
#9
#6
#7
#3
#2
5.5
Eyes
#1
#4
#1
#1
#5
#1
2.17
45
Table 10. Intraclass correlation coefficients and 95% confidence intervals for
facial feature rankings and attractiveness ratings
ICC
LCB
UCB
OVERALL
Facial feature rankings
0.67
0.56
0.76
Attractiveness ratings
Overall
<40 years of age female
>40 years of age female
<40 years of age male
>40 years of age male
0.68
0.7
0.58
0.68
0.7
0.64
0.64
0.45
0.61
0.53
0.72
0.75
0.68
0.74
0.81
ORTHODONTIC RESIDENTS
Facial feature rankings
0.71
0.57
0.81
Attractiveness ratings
Overall
<40 years of age female
>40 years of age female
<40 years of age male
>40 years of age male
0.59
0.6
0.48
0.58
0.71
0.52
0.49
0.26
0.45
0.45
0.65
0.69
0.65
0.69
0.86
LAYPERSONS
Facial feature rankings
0.6
0.41
0.74
Attractiveness ratings
Overall
<40 years of age female
>40 years of age female
<40 years of age male
>40 years of age male
0.75
0.79
0.66
0.74
0.69
0.71
0.73
0.51
0.65
0.44
0.79
0.84
0.77
0.81
0.84
46
Table 11. Kappa agreement statistic for choice of whether the pre-surgery or post-surgery face was more
attractive
A
OVERALL
First rating
A
B
C
Column total
Kappa (95% CI)
141 (36.3)
23 (5.9)
24 (6.2)
188 (48.3)
0.48 (0.41-0.55)
ORTHODONTIC RESIDENTS
First rating
A
68 (38.0)
B
12 (6.7)
C
12 (6.7)
Column total
92 (51.4)
Kappa (95% CI)
0.53 (0.42-0.63)
LAYPERSONS
First rating
A
B
C
Column total
Kappa (95% CI)
72 (34.8)
11 (5.2)
12 (5.7)
96 (45.7)
0.44 (0.34-0.53)
Second rating
B
C
Row total
20 (5.1)
114 (29.3)
18 (4.6)
152 (39.1)
16 (4.1)
22 (5.7)
11 (2.8)
49 (12.6)
177 (45.5)
159 (40.9)
53 (13.6)
8 (4.5)
53 (29.6)
10 (5.6)
71 (39.7)
3 (1.7)
6 (3.4)
7 (3.9)
16 (8.9)
79 (44.1)
71 (39.7)
29 (16.2)
12 (5.7)
61 (29.1)
8 (3.8)
81 (38.6)
13 (6.2)
16 (7.6)
4 (1.9)
33 (15.7)
98 (46.7)
88 (41.9)
24 (11.4)
47
CHAPTER 6
DISCUSSION
The aims of this study were to evaluate whether panels of observers with different
levels of orthodontic experience assess facial attractiveness similarly, and to determine
what soft tissue features influence assessment of facial attractiveness. More specifically,
the investigators aimed to determine if post-surgical outcomes are favorable.
Previous studies have contradictory results on levels of agreement between
assessors of different backgrounds. Several studies show differences in agreement on
facial attractiveness between clinicians and non-dental assessors.41, 42, 44, 46 In a two-part
study by Ng et al, orthodontists, art students, and laypersons rated pre- and post-surgical
frontal and lateral photographs of 10 patients (5 male, 5 female) who had undergone
BSSO for mandibular advancement. In the first part of the study, assessors were given
pre- and post-operative photographs that were randomly assigned A or B, and were asked
to score overall facial attractiveness on a VAS. In the second part of the study, the
investigators were given the same photographs, but the pre- and post-operative
photographs were matched and the operative status was disclosed to the assessors.47 This
study design is similar to our study, except that all of the patients had undergone
orthognathic surgery. Contrary to the findings in our study, Ng et al found that ratings of
facial attractiveness varies among groups of raters with different backgrounds, and
significant differences were found between orthodontists and art students.47
48
Several studies have demonstrated a general level of agreement among
laypersons, orthodontists, and oral and maxillofacial surgeons concerning facial
apperance.20, 40, 48 Similar to these studies, our findings suggest that the rater category
(layperson, orthodontist, oral surgeon, etc.) has no bearing on facial attractiveness ratings.
In our study, all groups of raters rated surgical patients, on average, 0.55 points lower
than non-surgical patients. These findings were true for all patient subjects in each
age/gender category such that, on average, patients who had undergone orthognathic
surgery were perceived as being less attractive than those who were treated with
orthodontics alone. Although the mean ratings for surgical patients were lower than those
for non-surgical patients, raters most often chose the post-surgery image when pre- and
post-surgery images of the patient were presented in a “before and after” format. In fact,
on average, if the assessors did not prefer the post-surgical face, they selected “no
preference” (neither option) over selecting the pre-surgical face. This is similar to the
findings in the second part of the study by Ng et al in that attractiveness scores were
significantly higher for post-operative photographs when they were paired with the preoperative photographs.47
When assessors are asked to compare faces, there are several confounding
variables (hairstyle, facial hair, skin color/complexion, etc.) that are not influenced by the
treatment modality that make it difficult to compare different patients. It is evident that
rating facial attractiveness is very subjective, especially when comparing individuals to
one another. In our study; however, when assessors were asked to rate the same face,
there was a very strong level of agreement such that the vast majority preferred the postsurgical face. Taken together, our findings suggest that a “before and after” format
49
(photos from the same patient) may be the more reliable way to assess perceived
outcomes of orthognathic surgery.
In order to ethically recommend an invasive procedure to a patient, it is critical to
know if the benefits outweigh the risks. In order to recommend orthognathic surgery to a
patient, we must be confident that this treatment modality is consistently providing a
favorable outcome. In a study by Phillips et al, orthodontists, oral surgeons, and first-year
dental students were asked to rate pre- and post-treatment photographs of 13 orthodontic
camouflage and 13 orthognathic surgery patients on a VAS.49 The results suggest that the
dental students were most critical, whereas orthodontists and oral surgeons tended to give
higher attractiveness scores overall. There was no significant change noted in the mean
facial attractiveness scores for the orthodontic camouflage group, whereas the
orthognathic surgery group mean scores showed significant improvement in facial
attractiveness. Furthermore, even through the orthognathic surgery group showed vast
improvement in facial attractiveness after treatment, this group was still considered
significantly less attractive than the orthodontic camouflage group.49 These findings are
similar to our study in that, although patients who had undergone orthognathic surgery
had a favorable outcome (post-surgical face preferred over pre-surgical face), mean
attractiveness scores were rated lower for the surgical patients than the non-surgical
patients.
It is well understood that facial attractiveness is a multifactorial concept.
Although some people may have individual facial features that are exceptionally
attractive, it is usually the combination of multiple parts working in tandem to create an
overall attractive appearance. In an effort to better understand how individuals perceive
50
facial attractiveness, assessors were asked to rank facial features in order of importance
relating to overall attractiveness. Previous studies have found that lower facial height,
tooth alignment, and overall facial harmony contribute to facial attractiveness, but there is
no consensus in the literature that suggests a hierarchy of facial features that define facial
attractiveness.3, 50 The facial features selected for the questionnaire for this study are
commonly assessed during a clinical examination, but are not meant to be a
comprehensive list of all features that contribute to facial attractiveness. An “other”
category was included to allow for assessors to contribute additional facial features that
they felt were important. Our results indicate differences between groups when ranking
facial features that contribute to facial attractiveness.
Although there was no consensus across all groups on a hierarchy of facial
features that contribute to facial attractiveness, there were several commonalities between
lists. A significant difference was found between orthodontic residents and laypersons
when ranking skin complexion and eyes, whereas laypersons perceived these features as
more important contributors to facial attractiveness than orthodontic residents.
Orthodontic residents and oral surgeons ranked vertical and horizontal proportions as the
top two items on their lists. Oral surgery residents and orthodontists ranked eyes, nose,
and lips as their top three items. Laypersons also ranked eyes and nose in their top three.
Taken together, these findings only weakly support a previous study that suggests that
clinicians may have a more “academic” and laypersons a more “emotional” approach to
assessing facial features.28 Overall, our findings do suggest that oral surgeons and oral
surgery residents tend to rank facial features most similarly to all other groups.
51
A limitation to the rank list provided to assessors was that the list included various
terms (nasolabial angle, for example) that are not common knowledge without some level
of dental education. Several of the laypersons did not rank items with which they were
unfamiliar. For example, 33.3% of laypersons did not rank vertical proportions,
horizontal proportions, or lower facial height. Similarly, 83.3% of laypersons did not rank
nasolabial angle, and 95.2% did not rank the labiomental sulcus. It is possible that the
ranks lists provided by the laypersons may not accurately reflect a true understanding of
each term. The rank list provided also had a section where the assessors could write in
“other” facial features that were not included on the list. Some of these items included
teeth, smile, hairstyle, symmetry, facial hair, and eyebrows, among others, but there were
too few repeat answers to report rank lists of these items.
An argument against using the VAS is that, because individuals are not equally
calibrated, it is a subjective method to collect data. Numerous studies suggest that the
VAS can provide a quick, simple, and reliable way to assess facial attractiveness.40, 49, 51
Phillips et al defend the VAS as a good instrument to rate continuous variables: “The
rating scores can detect differences in overall perceptions of facial attractiveness between
panels [of assessors] and … [can] indicate the direction of change as well as the extent of
change.”49 Intrarater reliability for our study using the VAS to rate facial attractiveness
was good (ICC = 0.67). These findings are consistent with those of Maple et al (ICC =
0.71).40
Some critics argue that facial attractiveness cannot be assessed with 2D
photographs alone. Most clinicians would agree that the best way to assess a patient is at
the clinical exam.4, 5 This method for rating facial attractiveness simply was not feasible
52
for this study. Although 2D photographs provide a static representation of a dynamic
form, they have been consistently used in orthodontic treatment planning for decades.
Three-dimensional (3D) technology is advancing such that more sophisticated methods of
treatment planning are being utilized, but the clinical exam accompanied with 2D
photographs continues to be the norm for treatment planning both surgical and nonsurgical cases. Phillips et al reported that, when assessing facial photographs, there is not
a single view consistently favored as the most attractive. They did suggest that showing
multiple views of a subject simultaneously is the most appropriate method of presenting
2D facial photographs for assessment.52 This supports the presentation of frontal and
profile views of each subject in this study.
Although the use of 2D photographs for this study is reasonable, the lack of
standardization of the facial photographs used in this study may have resulted in less
reliable ratings of these particular photographs. Because several different clinicians took
the photographs, there were invariably items that were not well controlled. It was evident
in some photographs that the lighting was less than ideal, and, even though an attempt
was made to crop out distracting features, this was not always possible. (Cropping out
facial hair or hairstyles that covered portions of the face was not possible without grossly
distorting the photograph.) There were also two surgical patients included in the study
that did not have pre-treatment photographs available. The first set of progress photos
(with fixed appliances on) was used for these patients instead.
Another potential limitation of the study was the inevitable selection bias that
accompanies a convenience sample. For example, all laypersons were Caucasian and the
majority of the other rater groups was also only marginally diversified for ethnicity. Also,
53
all of the orthodontist assessors were male, and only two of the oral surgeons were
female. A more diversified sample for assessors would be ideal, but the sample may not
necessarily misrepresent the population. In fact, the demographics of the dental
professional do parallel those reported by the American Dental Association (ADA) and
American Dental Education Association (ADEA).
In this study, the majority of all participants was male, but not by a large margin.
There was about a 60/40 split males:females for dental professionals. This suggests a
trend towards a slight increase in female dentists similar to that reported by the ADA in
2011.53 In this demographic update, there were 77.8% professionally active male dentists
and 22.2% professionally active female dentists in the United States in 2009. Among new
professionally active dentists in 2009, 62.1% were male and 37.9% were female.53 In this
study, the percentages of male and female participants in the dental student and
orthodontic resident groups were more evenly split between males and females, with
slight female predominance in the orthodontic resident group. This finding represents a
drastic increase in females entering the dental profession since the 1980s where female
dentists comprised only 3% of the dental profession. In this study, 88.9% of oral surgery
residents, 80% of oral surgeons, 100% of orthodontists were male. The demographics of
this study suggest that these specialties are still predominantly male.
The majority of dental professional participants (non-laypersons) were Caucasian
(70.8%). Asian or Asian-Indians (2.9%), Spanish/Hispanics (0.7%), African-Americans
(8.7%), American Indian/Alaskan Native or Other (2.2%) comprised the remainder of the
participant pool. These percentages loosely correspond with demographics reported by
54
the ADEA in 2010, where the racial demographics were 65% Caucasian, 5% Asian, 16%
Hispanic, 12% African-American, 1% American-Indian/Alaskan Native or Other.54
Our findings suggest that there is a level of agreement between groups of different
backgrounds and that orthognathic surgery in this sample did provide favorable
outcomes. Future studies may also consider asking the patients whose photographs were
used in this study to assess facial attractiveness of the same set of patients, including
themselves. Previous studies suggest that patients who pursue treatment are more critical
than laypersons and clinicians.46 It would also be valuable to attempt to assess the clinical
characteristics of the patients that had the most favorable outcomes in the hopes of being
able to translate these outcomes to future treatment planning attempts. In other words,
was there a trend of reliable facial attractiveness ratings associated with specific surgical
procedures? If so, what additional steps can we take that may aid in creating a more
objective method to plan and execute orthognathic surgery cases?
Our findings suggest that outcomes of orthognathic surgery were favorable in our
patient sample, but clinicians should still be selective in evaluating cases for treatment.
This is especially true for those patients in which surgical movements may be small.
Patients must understand what esthetic changes may or may not occur as a result of
surgery. Communication is critical between the patient and clinicians for the treatment
outcome to be successful. Even if the surgery is a technical success in that the jaws are
positioned in a favorable position to allow the teeth to fit together ideally and for the face
to be balanced, it may still be a failure if the treatment outcomes are different than the
pre-treatment expectations of the patient. Thorough communication will undoubtedly
55
assist patients in making appropriate treatment decisions, thus resulting in more favorable
outcomes.
56
CHAPTER 7
CONCLUSIONS

On average, assessors of different backgrounds (laypersons, dental students,
orthodontic residents, orthodontists, oral surgery residents, and oral surgeons)
tend to rate the facial attractiveness of post-surgical patients as slightly less
attractive than patients treated with orthodontics alone.

Although assessors perceived post-surgical patients as less attractive than nonsurgical patients, a far greater percentage of assessors preferred the post-surgical
face to the pre-surgical face.

The association between attractiveness rating and treatment modality (surgical vs.
non-surgical) does not vary by the assessor’s background.

There seems to be no consensus on a hierarchy of facial features that contribute to
facial attractiveness; however, based on the overall average rank, raters perceived
the eyes and nose as contributing most to facial attractiveness, and the nasolabial
angle, labiomental sulcus, and chin-neck contour contributing the least.

Oral surgeons and oral surgery residents tend to rank facial features most
similarly to all other groups.
57
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APPENDIX A
INSTITUTIONAL REVIEW BOARD APPROVAL
61