Role of facial attractiveness in patients with slight-to-borderline treatment need according to the Aesthetic Component of the Index of Orthodontic Treatment Need as judged by eye tracking

The Use of Eye-Tracking Technology in Dento-Maxillofacial Esthetics: A Systematic Review

The use of eye-tracking technology in dental esthetics has gained popularity over the past decade because of its ability to assess observers' visual preferences in an objective manner. The goal of this study was to provide a comprehensive review of eye-tracking studies in dentistry, which could provide a reference for the rational and effective application of eye-tracking technology by dentists in the future. A comprehensive search of articles on eye tracking, published from January 1946 to June 2023, was conducted across several databases using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The major criterion for inclusion was that the study evaluated the use of eye-tracking technology in the field of dentistry. Two independent reviewers screened the eligible studies. A total of 67 articles were identified, 41 of which met our inclusion criteria. The most common application of eye tracking was the assessment of perceptions of changes in specific dental conditions among different classes of observers. Overall differences between groups (different classes of observers, different types of conditions) among different areas or regions of interest were analyzed. This systematic review demonstrated the utility of eye-tracking technology as a quantifiable objective assessment and emerging research tool for evaluating outcomes in several domains of dentistry.

The relationship between different levels of facial attractiveness and malocclusion perception: an eye tracking and survey study

INTRODUCTION

The aim of this study was to investigate the relationship between levels of facial attractiveness and the perception of different types of malocclusion.

METHODS

A preliminary questionnaire was used to assign photographs of three female patients to low, moderate, and high facial attractiveness designations. Seven modified photographs for each smile photograph of each of these three patients were created. The evaluated photographs were as follows: P0: at rest position, P1: ideal smile, P2: - 2-mm (low) smile line, P3: + 4-mm gummy smile, P4: + 6-mm gummy smile, P5: maxillary anterior crowding, P6: median diastema, P7: polydiastema. An eye tracking device and a questionnaire were used to collect data from orthodontists, dentists, orthodontic patients, and laypeople.

RESULTS

Total fixation duration varied depending on the type of malocclusion, the level of facial attraction, and the participants' occupations. In general, orthodontists and dentists had higher total fixation duration scores than orthodontic patients and laypersons. The maxillary anterior crowding photograph had the lowest visual analysis scale score at each attractiveness level (low, medium, and high). Visual analysis scale scores became similar at each attractiveness level only in the P4 photographs, and thus the difference in facial attractiveness disappeared.

CONCLUSION

While a worsening of the ideal smile had a smaller impact on aesthetic perceptions in an individual with low facial attractiveness, it had a significant negative impact on a person with high facial attractiveness. Anterior crowding and diastema had a more negative impact on facial attractiveness than low or high smile lines.

Assessment of Orthodontic Treatment Need and Oral Health-Related Quality of Life in Asthmatic Children Aged 11 to 14 Years Old: A Cross-Sectional Study

This study investigated the need for orthodontic treatment in asthmatic children aged 11 to 14 years and how the treatment affected their oral health-related quality of life (OHRQoL).

MATERIALS AND METHODS

This cross-sectional study was conducted at the dental clinic of the University of Salamanca in 2020-2022. The study selected a consecutive sample of 140 children with asthma (52.1% girls; 47.9% boys). This study used the Orthodontic Treatment Needs Index (OTN) to analyze the need for orthodontic treatment and the Children's Perception Questionnaire (CPQ11-14) to assess OHRQoL.

RESULTS

Sex and age did not significantly influence the need for orthodontic treatment, although age may be considered influential for OHRQoL concerning oral symptoms (p < 0.01), functional limitations (p < 0.05), and total score on the CPQ_11-14 questionnaire (p < 0.05): the younger the age, the greater the effect of the need for orthodontic treatment on OHRQoL. The social well-being of the patients was much more significantly impacted by the need for orthodontic treatment (15.7 ± 1.91) than by oral symptoms (7.64 ± 1.39), which were the least impacted. In all parts of the CPQ_11-14 questionnaire and in the patients' total scores, we observed significant agreement (p < 0.01) that treatment influenced OHRQoL.

CONCLUSION

An inverse relationship exists between the severity of the treatment needed and OHRQoL.

The visual perception of aligned and crowded maxillary lateral incisors when smiling via eye tracking

Background

This study aimed to investigate whether the alignment of the teeth while smiling alters the visual perception by laypeople using eye tracking.

Methods

Facial images (two males and two females) were digitally edited to show a smile pattern with aligned teeth and one with crowded teeth. Sixty laypeople were selected to observe the images. The number of fixations, fixation duration, and time until the first fixation were recorded using an eye-tracking system. The results were qualitatively calculated with dot maps. Numerical data were analyzed using an independent Student's t test.

Results

There were no significant differences in fixation duration and the number of fixations in the crowded smile, mainly that of the male. The fixation times for the teeth were significantly different when the participants viewed the male subjects with a crowded smile (P<0.05). Dot maps showed greater attention to the smile with crowded teeth in both genders.

Conclusion

The crowded maxillary incisor smile attracted more visual attention to males from laypeople.

Perceived Age and Personality Profiling after Orthognathic Surgery

BACKGROUND

Recent studies suggest that orthognathic surgery can improve facial age and personality profiling. The authors expand on these findings by assessing the role of patient facial profile and sociodemographics on perceived changes following surgery.

METHODS

Preoperative and postoperative images of 65 patients operated on by a single surgeon were randomly assorted and rated by 30 respondents. Patient facial profiles were categorized as convex, concave, or straight. Paired and unpaired t tests were used to assess differences preoperatively and postoperatively. Multivariate regression and post hoc receiver operating characteristic curve analyses were used to quantify the influence of various patient factors.

RESULTS

Significant decreases in perceived age were seen following orthognathic surgery overall (-1.31 years; p < 0.01) and in the straight (-1.10 years; p = 0.02) and convex (-1.80 years; p ≤ 0.01) subgroups. After controlling for patient sociodemographics, there were no significant differences in age change based on facial profile. Older age at the time of surgery was independently associated with greater perceived age changes ( p = 0.04); older patients (>26.5 years, determined by receiver operating characteristic curve) experienced greater net decreases in perceived age in comparison to younger patients (-2.0 years versus -1.2 years; p < 0.01). Improvements were seen in overall attractiveness ( p < 0.01) and in each tested personality characteristic following surgery ( p < 0.01). These differences were not significantly associated with different patient sociodemographics or facial profile.

CONCLUSIONS

The authors' data add to the growing base of evidence that orthognathic surgery improves patient-perceived age and personality. Significant decreases in perceived age are more likely to be gained by patients undergoing surgery at an older age.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, II.

Perception of the Nose and Lower Face Before and After Orthognathic Surgery in Subjects with Dento-maxillofacial Deformities: An Eye-Tracking Study

BACKGROUND

Dento-maxillofacial deformities are often associated with nasal deviation, and patients often complain of nasal deviation after orthognathic surgery. This study aimed to quantitatively evaluate the facial visual attention given to dento-maxillofacial deformities accompanying nasal deviation from the perspective of patients and determine whether orthognathic surgery could alter this outcome.

METHODS

The scanning paths of 137 patients were recorded using an eye-tracking device; recordings were made while the patients viewed images of dento-maxillofacial deformities associated with various degrees of nasal deviation before or after orthognathic surgery. Visual attention focused on the lower face and nose was analyzed.

RESULTS

When viewing postoperative faces, the participants focused more visual attention on noses and less on the lower face than they did on preoperative faces. Interestingly, for preoperative faces, nasal deviation could significantly increase participants' visual attention to the lower face, and visual attention to noses was significantly increased when noses were deviated 12°, while for postoperative faces, a nasal deviation of 4° or more was associated with a significant increase in participants' visual attention to the nose.

CONCLUSIONS

Patients tended to focus their visual attention on the lower region of preoperative faces and ignored nose irregularities. Orthognathic surgery can alter visual attention, shifting it from the lower face to the nose, and a deviation of 4° or more could be a potential concern for patients. Clinicians must inform patients preoperatively about preexisting nasal deviations, which can guide surgical planning and help manage patient expectations.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

The perception of smile attractiveness to altered vertical position of maxillary anteriors by various groups

There is a gap in research about the differences in smile attractiveness. The problem the study addresses is how the vertical canine and incisor position affect smile attractiveness. The aim of this study was to assess the perception of the smile attractiveness between Saudi laypersons, orthodontists, non-orthodontist, and various dental students levels, and to determine how the canine and incisor vertical positions affect the attractiveness of smile. The study is a cross-sectional survey and was conducted at King Abdulaziz University, Jeddah, Saudi Arabia. Six groups of subjects participated in the study: Orthodontic residents (n = 31), prosthodontic, restorative, periodontics specialties residents specialties residents (n = 30), interns (n = 31), fifth year students (n = 41), 6th year students (n = 39), and laypeople (n = 39). Participants were asked to rate the attractiveness of a smile of a female subject photographed using a Minolta DiMage 7i digital camera. The image had been manipulated to produce 2 sets of images; 1 to modify the incisors and 1 to change the canines. The subjects were asked to choose the most and least attractive picture. For the best incisor positions, only the laypeople and prosthodontics liked the original picture, the rest liked +0.5 mm which accentuate the smile curve and make it follow the lower lip line. For the worst incisor position, all groups did not prefer the minus 1.5 reversed smile. For the best canine vertical position, all groups preferred the original position where canine was at the level of the incisal plane. For the worst canine position, they all disliked the minus 1.5 reversed smile. Results confirmed past findings that orthodontists are in general more critical about smile attractiveness than laypersons, but just like other dental specialists. The findings can be used in the esthetic dentistry field, but further research on the study population based on other dental design parameters remain necessary.

Characteristics of patients seeking orthodontic retreatment

BACKGROUND

The aim of this cross-sectional study was to investigate patients' experiences with previous orthodontic treatment for those seeking retreatment, and their expectations and motivation for doing so.

METHODS

A total of 72 patients were invited to answer an anonymous questionnaire. Of these, 36 (13 men and 23 women, mean age 26.3 ± 5.8 years) were seeking retreatment (study group), and 36 (13 men and 23 women, mean age 25.5 ± 6.8 years) were seeking treatment for the first time (control group). Casts from both groups were assessed with the index of complexity, outcome, and need (ICON) score, to objectively determine the treatment need and complexity. Student`s t test for independent samples, and paired Student`s t test, were performed for comparisons between the retreatment and control groups, and between retreatment and previous treatment, respectively.

RESULTS

There was no statistically significant difference between retreatment patients` motivation for the previous treatment and motivation for the retreatment. However, the mean visual analog scale (VAS) scores for motivation differed significantly between the retreatment and control groups (73.8 ± 23.9 and 87.5 ± 14.5, respectively). The mean ICON score of the retreatment group was lower than that for the control group (25 ± 14 and 31 ± 16, respectively).

CONCLUSIONS

Patients seeking retreatment were less motivated for treatment, and tooth irregularity was the chief reason for seeking treatment in both groups. Although an objective treatment need was not observed in the 2 groups, all of them had some occlusal traits that clinically justified the orthodontic treatment.

Facial visual attention to menton deviation: An objective evaluation by laypeople

PURPOSE

This study aimed to quantitatively evaluate whether the severity of menton deviation (MD) influenced facial perceptions of laypeople. We also aimed to determine the effectiveness of surgery in normalizing the distribution of the facial visual attention of laypeople.

METHODS

The scanning paths of 177 laypeople were recorded using an eye tracking device while observing images of individuals without MD and pre- and post-treatment subjects with different degrees of MD. The fixation durations on the areas of interest (AOIs) in each group were compared and analysed.

RESULTS

When observing the images of non-MD subjects, the eyes were the focus of the most significant fixation (higher than the fixations on the nose and lower face). When the MD increased to 3°, attention on the lower face increased (p = 0.001) with decreased attention to the eyes (p = 0.0126). At an MD of 9°, attention to the lower face sharply increased, even more so than that to the eyes, with decreased attention to the nose (p = 0.0104). Compared with the findings for the post-treatment images, the laypeople who observed the pretreatment images focused longer on the lower face and less on the eyes and nose (p = 0.001, p = 0.0322 and p = 0.0023, respectively). The distribution of the fixation duration when observing the post-treatment images was similar to that when observing the images of the non-MD subjects.

CONCLUSIONS

Laypeople can perceive an MD of 3°, which causes changes in the distribution of visual attention, with attention focusing on the MD. When the deviation reaches 9°, it is very noticeable. Surgery can normalize the distribution of the facial visual attention of laypeople, as shown by the responses to the post-treatment images.

Relationship of anteroposterior position of maxillary central incisors with the forehead in an adult Iranian subpopulation: A cross-sectional study

OBJECTIVE

This study aimed to assess the relationship of the anteroposterior position of maxillary central incisors with the forehead in an Iranian subpopulation residing in Kermanshah city.

MATERIALS AND METHODS

In this cross-sectional study, 12 orthodontists were requested to analyse full-smile profile photographs with complete maxillary incisor and forehead show in 70 patients with optimal facial harmony (35 males and 35 females) as the control group and 140 patients without optimal facial harmony (70 males and 70 females) as the test group. The inclusion criteria were (I) males and females between 18-60 years seeking orthodontic treatment and (II) willingness for participation in the study. The exclusion criteria were (I) presence of severe craniofacial anomalies, and (II) history of orthodontic treatment. The photographs were traced and analysed using Digimizer Image Analysis software 5.3.5. Data were analysed using STATA version 14.2 via independent t-test and linear regression.

RESULTS

A significant difference existed in the anteroposterior position of maxillary incisors in males between the test and control groups (P=0.002). However, this difference was not significant in females of the two groups (P=0.77). A significant difference was noted in the anteroposterior position of maxillary incisors between males and females in the test group (P=0.001) but not in the control group (P=0.80). The frontal angle had a significant correlation with gender and anteroposterior position of maxillary incisors in both groups (P<0.001).

CONCLUSIONS

According to the results, the anteroposterior position of maxillary incisors was significantly different in the test and control groups. The maxillary incisors in males were more retruded than in females. Also, the frontal angle had a significant correlation with the anteroposterior position of maxillary incisors, and by 1° increase in the frontal angle, the incisors were protruded by averagely 0.307mm.

Influence of facial components in class III malocclusion esthetic perception of orthodontists, patients, and laypersons

PURPOSE

The aim of the present study was to investigate the influence of different facial components (face length, lip volume, nose size, and cheekbone contour) on the perception of facial attractiveness of patients with Angle class III malocclusion in different categories of responders (orthodontists, laypersons, patients) with two-dimensional (2D) and three-dimensional (3D) simulations.

METHODS

An ideal standard 3D face was manipulated to create a class III facial malocclusion. Four facial components were modified (face length, lip volume, nose size and cheekbone contour) and the resulting simulations were used to obtain 2D figures and 3D videos, which were evaluated in a survey by orthodontists, patients, and laypersons.

RESULTS

No significant differences were detected between the 2D figures and 3D video simulations. Good correspondence was shown between the three categories of responders for the most and the least attractive faces. Smaller lips and bigger nose, regardless to the vertical dimension (short or long face), were found to be the least attractive features with agreement of all respondents.

CONCLUSION

Regarding class III facial attractiveness perception, the sum of all facial features and not the alteration of a single component alone seems to play a key role in the perception of facial attractiveness. The 2D or 3D perspective did not play a significant role in perception and the analyzed categories of responders did not show significant differences when perceiving facial attractiveness of the utilized simulations.

Influence of dental education on eye gaze distribution when observing facial profiles with varying degrees of lip protrusion

OBJECTIVES

The purpose of the present study was to investigate the influence of dental education on eye gaze distribution when perceiving facial profile images with varying degrees of lip protrusion.

METHODS

Fifty-one subjects with dental education (dental-education group) and 47 without dental education (no-dental-education group) were included in this study. The eye gaze distribution of the subjects was recorded for 10 seconds using a non-contact eye tracker when determining whether or not the subjects judged each various facial profile image inappropriate. The facial profile images had varying degrees of upper-lip and lower-lip protrusion. The frequency of eye fixation (lasting >0.06 seconds) was counted. The duration was measured as the total time of eye fixation. The facial images were divided into 4 regions of interest (ROIs): the forehead (ROI-I); the orbit and nose root (ROI-II); the nose tip and upper lip (ROI-III); and the lower lip and chin (ROI-IV). The frequency and duration of eye fixation on each ROI was compared.

RESULTS

The frequency of eye fixation on ROI-II was greater in comparison to ROI-I and ROI-IV. The frequency of eye fixation on ROI-III was also greater in comparison to ROI-I and ROI-IV. The duration of eye fixation on ROI-III in the dental-education group was longer in comparison to the no-dental-education group.

CONCLUSIONS

Dental education influenced the eye fixation on the nose tip and upper lip when perceiving facial profile images.

Esthetic perception of clear aligner therapy attachments using eye-tracking technology

INTRODUCTION

The purpose of this research was to assess and compare esthetic perceptions of clear aligner therapy with attachments and esthetic brackets by measuring differences in eye fixations using eye-tracking technology.

METHODS

The sample involved 250 adult subjects. The subjects gave verbal consent, then viewed photographs showing 4 variations of orthodontic appliances: clear aligner control with minimal attachments, clear aligner with anterior and posterior attachments, esthetic brackets, and clear aligner with posterior attachments. Images were displayed for 6 seconds each on a computer monitor. Location and time to first fixation, total fixation duration, and total visit count and duration for each type of appliance were measured. Subjects were then asked to complete an online survey.

RESULTS

Participants spent the least amount of time looking at the photograph of the control, followed by those of the ceramic brackets, posterior attachments, and anterior and/or posterior attachments. The anterior and/or posterior image had the least number of visits but garnered the longest visit duration (1.32 visits averaging 0.74 seconds per visit). This was followed by the images of the posterior attachments (1.40 visits, 0.70 seconds per visit), ceramic brackets (1.43 visits, 0.65 seconds per visit), and minimal attachments control (1.45 visits, 0.61 seconds per visit). The hierarchy of most preferred appliances across all 250 respondents was as follows: minimal attachments control, ceramic brackets, posterior attachments, and anterior and/or posterior attachments. Overall, 88.4% of subjects would compromise appliance esthetics during treatment for a better outcome (n = 221).

CONCLUSIONS

Eye-tracking data show that time to the first fixation was negatively correlated with its survey ranking and that an increase in attachments led to an increase in total fixation duration. There is a general desire for clear aligners without attachments and ceramic brackets over clear aligners with multiple attachments. Survey data suggest that although respondents viewed appliance esthetics as highly important, nearly all would compromise appliance esthetics during treatment if it resulted in a better outcome.

Contribution of the mandible position to the facial profile perception of a female facial profile: An eye-tracking study

INTRODUCTION

Studies concerning the visual attention of laypersons viewing the soft tissue facial profile of men and women with malocclusion are lacking. This study aimed to determine the visual attention to the facial profile of patients with different levels of mandibular protrusion and facial background attractiveness using an eye-tracking device.

METHODS

The scanning paths of 54 Chinese laypersons (50% female, 50% male, aged 18-23 years) were recorded by an eye-tracking device when they observed composite female facial profile images (n = 24), which were combinations of different degrees of mandibular protrusion (normal, slight, moderate, and severe) and different levels of facial background attractiveness (attractive, average, and unattractive). Dependent variables (fixation duration and first fixation time) were analyzed using repeated-measures factorial analysis of variance.

RESULTS

For normal mandibular profiles, the fixation duration of the eyes was significantly higher than that of other facial features (P <0.001). The lower face and nose received the least attention. As the degree of protrusion increased from slight to moderate, more attention was drawn to the lower face accompanied by less attention to eyes in the unattractive group (P <0.05). When protrusion degree increased from moderate to severe, attention shifted from nose to lower face significantly in the attractive group (P <0.05). Attention shift from eyes to lower face was also found in the average group when protrusion degree rose to moderate protrusion from normal profile (P <0.05). A significant interaction between facial attractiveness and mandibular protrusion was found in the lower face duration (P = 0.020). The threshold point (the point of mandibular protrusion degree that evoked attention to the lower face) of the attractive facial background was higher than that of the unattractive background. Once evoked, the effect of mandibular protrusion of the attractive group tended to be stronger than that of the unattractive group, though without statistical difference.

CONCLUSIONS

Eyes are the most salient area. The increasing degree of mandibular protrusion tends to draw attention to the lower face from other facial features. Background attractiveness can modify this behavior.

Retreatment of a patient: Orthognathic surgery-first approach with customized lingual appliances combined with miniplate anchorage

Orthognathic surgery is necessary when a patient's major complaints include skeletal discrepancies that cannot be corrected with orthodontic treatment alone. Currently, orthognathic surgery can be performed through conventional and surgery-first approaches. Some advantages are attributed to the surgery-first approach, such as shortened treatment time and immediate esthetic improvement. The aim of this case report is to present the retreatment of a patient presenting with a skeletal Class III malocclusion, with maxillary retrusion and mandibular protrusion, who was successfully treated with the surgery-first approach and customized lingual appliances, combined with miniplate anchorage in the postoperative orthodontic treatment. The total orthodontic treatment time was 8 months.

The effect of dental and background facial attractiveness on facial attractiveness and perceived integrity and social and intellectual qualities

INTRODUCTION

The purposes of this study were to assess the role of dental attractiveness in background facial attractiveness and to evaluate how facial and dental attractiveness influenced raters' opinions of the integrity, social attractiveness, and intellectual attractiveness of the models.

METHODS

Photographs of male and female individuals rated by peers as unattractive, average, and attractive were combined with oral images of 4 different levels of dental attractiveness (Index of Orthodontic Treatment Need [IOTN] 1, 5, 7, and 10). Sixty-seven participants meeting the inclusion criteria were recruited as raters. Raters viewed closed-lip smile and open-lip, posed smile of 24 models and rated them for facial attractiveness and integrity and multiple social/intellectual attractiveness dimensions using a Visual Analog Scale.

RESULTS

Intrarater reliability was fair to excellent. Analysis of variance showed significant 3-way interactions (P < 0.0001=aim 1; P < 0.005=aim 2) for model sex, facial attractiveness, and dental attractiveness. The contribution of dental attractiveness to facial attractiveness was not fixed or linear, but dependent on dental attractiveness level, background facial attractiveness, and model sex. For both sexes, dental impact on facial attractiveness was neutral or negative when teeth were less than ideal, beginning at IOTN 5 for all background facial attractiveness levels. The impact of dental attractiveness on integrity and social and intellectual attractiveness was also dependent on dental attractiveness level, background facial attractiveness, and model sex. Dental attractiveness can make dramatic differences in Average and Attractive male individuals.

CONCLUSIONS

The impact of dental attractiveness on facial attractiveness and integrity and social and intellectual attractiveness was dependent on dental attractiveness level, background facial attractiveness, and model sex. The effect of dental esthetics on facial attractiveness was neutral or negative for both male and female individuals when there was a need for treatment (IOTN 5 or higher) for all levels of facial attractiveness. For both male and female models, lower dental esthetics had a greater effect on more attractive faces. Judgments about integrity and social and intellectual attractiveness were strongly affected by dental esthetics, and these effects were more dramatic and consistent for male faces.

Perception of esthetic orthodontic appliances: An eye tracking and cross-sectional study

OBJECTIVE

To evaluate the perception of esthetic orthodontic appliances by means of eye-tracking measurements and survey investigation.

MATERIALS AND METHODS

En face and close-up images with different orthodontic appliances (aligner appliance [a], aligner appliance and attachments [b], lingual appliance [c], ceramic brackets [d], no appliance [e; control]) were shown to 140 participants. Eye movement and gaze direction was recorded by eye-tracking system. For different anatomical areas and areas of the appliances, time to first fixation and total fixation time were recorded. The questions included in a visual analog scale regarding individual sentiency were answered by the participants.

RESULTS

For all groups, the anatomical landmarks were inspected in the following order: (1) eyes, (2) mouth, (3) nose, (4) hair, and (5) ears. Only in group d, first fixation was on the mouth region (1.10 ± 1.05 seconds). All appliances except the lingual appliance (1.87 ± 1.31 seconds) resulted in a longer fixation on the mouth area (a, 2.97 ± 1.32 seconds; b, 3.35 ± 1.38 seconds; d, 3.29 ± 1.36 seconds). For close-up pictures, the fastest (0.58 seconds) and longest (3.14 seconds) fixation was found for group d, followed by group b (1.02 seconds/2.3 seconds), group a (2.57 seconds/0.83 seconds), and group c (3.28 seconds/0.05 seconds). Visual analog scale scoring of questions on visibility were consistent with eye-tracking measurements. With increasing visibility, the feeling of esthetic impairment was considered higher.

CONCLUSIONS

Lingual orthodontic appliances do not change how the face is perceived. Other esthetic orthodontic appliances may change the pattern of facial inspection and are different in subjective perception.

Objective assessment of the contribution of dental esthetics and facial attractiveness in men via eye tracking

INTRODUCTION

Recently, greater emphasis has been placed on smile esthetics in dentistry. Eye tracking has been used to objectively evaluate attention to the dentition (mouth) in female models with different levels of dental esthetics quantified by the aesthetic component of the Index of Orthodontic Treatment Need (IOTN). This has not been accomplished in men. Our objective was to determine the visual attention to the mouth in men with different levels of dental esthetics (IOTN levels) and background facial attractiveness, for both male and female raters, using eye tracking.

METHODS

Facial images of men rated as unattractive, average, and attractive were digitally manipulated and paired with validated oral images, IOTN levels 1 (no treatment need), 7 (borderline treatment need), and 10 (definite treatment need). Sixty-four raters meeting the inclusion criteria were included in the data analysis. Each rater was calibrated in the eye tracker and randomly viewed the composite images for 3 seconds, twice for reliability.

RESULTS

Reliability was good or excellent (intraclass correlation coefficients, 0.6-0.9). Significant interactions were observed with factorial repeated-measures analysis of variance and the Tukey-Kramer method for density and duration of fixations in the interactions of model facial attractiveness by area of the face (P <0.0001, P <0.0001, respectively), dental esthetics (IOTN) by area of the face (P <0.0001, P <0.0001, respectively), and rater sex by area of the face (P = 0.0166, P = 0.0290, respectively). For area by facial attractiveness, the hierarchy of visual attention in unattractive and attractive models was eye, mouth, and nose, but for men of average attractiveness, it was mouth, eye, and nose. For dental esthetics by area, at IOTN 7, the mouth had significantly more visual attention than it did at IOTN 1 and significantly more than the nose. At IOTN 10, the mouth received significantly more attention than at IOTN 7 and surpassed the nose and eye. These findings were irrespective of facial attractiveness levels. For rater sex by area in visual density, women showed significantly more attention to the eyes than did men, and only men showed significantly more attention to the mouth over the nose.

CONCLUSIONS

Visual attention to the mouth was the greatest in men of average facial attractiveness, irrespective of dental esthetics. In borderline dental esthetics (IOTN 7), the eye and mouth were statistically indistinguishable, but in the most unesthetic dental attractiveness level (IOTN 10), the mouth exceeded the eye. The most unesthetic malocclusion significantly attracted visual attention in men. Male and female raters showed differences in their visual attention to male faces. Laypersons gave significant visual attention to poor dental esthetics in men, irrespective of background attractiveness; this was counter to what was seen in women.