Visual perception of faces with unilateral and bilateral cleft lip and palate: An Eye-Tracking Study

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.

Perception of color mismatch or conspicuous marginal adaptation in extraoral prostheses with eye-tracking

STATEMENT OF PROBLEM

Color matching and marginal integrity are major challenges when providing extraoral maxillofacial prostheses. Which of the color and marginal harmony features are more important for the extraoral prostheses to be inconspicuous is unclear. Studies on the perception of these prostheses with objective evaluation criteria are lacking.

PURPOSE

The purpose of this observational study was to investigate the significance of color mismatch and conspicuous marginal adaptation in the perception of extraoral maxillofacial prostheses using eye-tracking technology. The secondary aim was to evaluate the perception of extraoral maxillofacial prostheses with regard to the observers' sex.

MATERIAL AND METHODS

Twenty-seven face images, in 3 groups, representing well-fitting orbital prostheses with a color mismatch (IC), prostheses with a good color match but distinct marginal adaptation (IM), and symmetrical face images, were viewed for 5 seconds by 52 laypeople. Time to first fixation (TFF), fixation duration (FD), and fixation count (FC) at defined areas of interest were recorded and analyzed by an eye-tracking device. Because of the nested structure of data, a sex- and age-adjusted random intercept linear mixed effects model was used to assess the difference between IC, IM, and SI. Bonferroni corrected P values were used for pairwise comparisons. The difference between observers' sex was evaluated with random intercept mixed model by adjusting for age for each image. For repeated measurement analysis, the lm4, lmerTest, and emmeans libraries in R version 4.3.1 (R Foundation for Statistical Computing) were used (α=.05 for all tests).

RESULTS

Significant differences were found between the symmetrical image group and other study groups at the facial prosthesis region in all parameters (each P<.001). Observers first focused on the facial prostheses in IC (0.72 seconds) and in IM (0.789 seconds). Longer fixation durations, 1.909, 1.989 seconds for IC and IM (PIC<.001, PIM<.001), respectively, and a higher fixation count for IC (5.28) (P<.001) and for IM (5.45) (P<.001) were recorded on facial prostheses compared with other areas of interest. Women were more focused on the prosthesis than men in the IC and IM groups considering FD (PIC=.003, PIM<.001) and FC values (PIC=.016, PIM<.001, PSI<.001). Fixation duration for women and men was 2.097 seconds and 1.739 seconds in the IC group, 2.219 seconds and 1.78 seconds in the IM group, and 1.364 seconds and 1.222 seconds in the SI group, respectively.

CONCLUSIONS

Since the color mismatch and distinct marginal adaptation of maxillofacial prostheses were recognized using eye-tracking technology, both features appeared to be equally significant to be considered in fabrication procedures.

Perception of aesthetic features after surgical treatment of craniofacial malformations by observers of the same age: An eye-tracking study

The aim of this study is to evaluate where exactly children and adolescents of the same group look when they interact with each other, and attempt to record and analyse the data recorded by eye-tracking technology.

MATERIALS AND METHODS

60 subjects participated in the study, evenly divided into three age categories of 20 each in pre-school/primary school age (5-9 years), early adolescence (10-14 years) and late adolescence/transition to adulthood (15-19 years). Age groups were matched and categorized to be used both for creating the picture series and testing. Photographs of patients with both unilateral and bilateral cleft lip and palate were used to create the series of images which consisted of a total of 15 photos, 5 of which were photos of patients with surgically treated cleft deformity and 10 control photos with healthy faces, that were presented in random order. Using the eye-tracking module, the data on "area of first view" (area of initial attention), "area with longest view" (area of sustained attention), "time until view in this area" (time of initial attention) and "frequency of view in each area" (time of sustained attention) were calculated.

RESULTS

Across all groups, there was no significant difference for the individual regions for the parameters of initial attention (area of first view), while the time until first fixation of one of the AOIs (time until view in this area) was significant for all facial regions. A predictable path of the facial scan is abandoned when secondary facial deformities are present and attention is focused more on the region of an existing deformity, which are the nose and mouth regions.

CONCLUSIONS

There are significant differences in both male and female participants' viewing of faces with and without secondary cleft deformity. While in the age group of the younger test persons it was still the mouth region that received special attention from the male viewers, this shifted in the male test persons of the middle age group to the nose region, which was fixed significantly more often and faster. In the female participants, the mouth and nose regions were each looked at for twice as long compared to the healthy faces, making both the mouth and the nose region are in the focus of observation.

The Use of Eye-tracking Technology in Cleft Lip: A Literature Review

Eye-tracking has become an increasingly popular research tool within the field of cleft lip and/or palate (CL+/-P). Despite this, there are no standardized protocols for conducting research. Our objective was to conduct a literature review of the methodology and outcomes of previous publications using eye-tracking in CL+/-P.

Methods

The PubMed, Google Scholar, and Cochrane databases were searched to identify all articles published up to August 2022. All articles were screened by two independent reviewers. Inclusion criteria included using eye-tracking, image stimuli of CL+/-P, and outcome reporting using areas of interest (AOIs). Exclusion criteria included non-English studies, conference articles, and image stimuli of conditions other than CL+/-P.

Results

Forty articles were identified, and 16 met the inclusion/exclusion criteria. Thirteen studies only displayed images of individuals following cleft lip surgery with three only displaying unrepaired cleft lips. Significant variation was found in study design, particularly in the AOIs used to report gaze outcomes. Ten studies asked participants to provide an outcome score alongside eye-tracking; however, only four compared outcome data to eye-tracking data. This review is primarily limited by the minimal number of publications in this area.

Conclusions

Eye-tracking can be a powerful tool in evaluating appearance outcomes following CL+/-P surgery. It is currently limited by the lack of standardized research methodology and varied study design. Before future work, a replicable protocol should be developed to maximize the potential of this technology.

Parents of Children with Cleft Lip Exhibit Heightened Visual Attention to the Perioral Area

Following high-quality surgical repair, children born with a cleft lip anomaly may still display lasting visual differences. We exposed control adults and parents of affected children to images of children with cleft deformity and compared their visual tracking patterns. The protocol investigated whether parental exposure to secondary cleft deformity heightens or diminishes visual attraction to this type of structural facial variation.

Method

Twenty participants (10 control adults, 10 parents of affected children) assessed 40 colored images of children's faces while their eye movements were tracked. Twenty-four control images and 16 repaired cleft lip images were displayed to observers. Nine bilateral facial aesthetic zones were considered as regions of interest. Percentage of time visually fixating within each region, and statistical differences in fixation duration percentage between the two participant groups and across the bilateral regions of interest were analyzed.

Results

While both groups of observers directed more visual attention to the nasal and oral regions of the cleft images than control images, parents of children with cleft lip spent significantly more time fixating on these areas (25% and 24% of the time, respectively) than did unaffected adults (14.6% and 19.3%; P < 0.001).

Conclusions

These results demonstrate that parents of cleft lip children exhibit heightened attention to this type of facial difference relative to the naive observer. These findings highlight that observer profile can meaningfully influence the perception of a facial deformity. Awareness of this information may enhance communication between surgeon and parents of an affected child by providing added insight into parental perspective.

Perception of orbital epitheses evaluated with eye tracker

PURPOSE

Orbital epitheses replace a missing eyeball and surrounding soft tissue. Perception of epithesis in public gaze and the attention areas on the face are of interest. This study aimed to examine the differences in perception of orbital epitheses by prosthodontists, dentistry students, and laypeople with an objective evaluation tool that utilized eye-tracking technology.

MATERIALS AND METHODS

Twenty-four frontal facial images of 12 patients who had orbital epitheses were viewed by 81 observers (prosthodontists, dentistry students, laypeople) in random order for 5 seconds each. Gaze data were analyzed. Kruskal-Wallis H test with Bonferroni correction was used to compare parameters in groups and areas of interest.

RESULTS

First fixation duration at the mouth for symmetrical images were 0.30, 0.28, and 0.25 seconds for prosthodontists, students, and laypeople, respectively. Fixation duration at the mouth for the laypeople (0.27 second) was shorter than students (0.29 second) and prosthodontists (0.31 second) at symmetrical images. Time to the first fixation to epithesis, nose, and eye was significantly lower than the forehead and mouth for all groups. Fixation count at epithesis was 6.36 for prosthodontists, 5.64 for students, and 5.34 for laypeople.

CONCLUSION

Eyes were of most significant interest for all observer groups in symmetrical images. Individuals dealing with dentistry, especially prosthodontists, paid more attention to the mouth region along with the eyes in symmetrical images, considering fixation duration and fixation count. Attention directed to epithesis by all groups was verified with objective and measurable criteria. Prosthodontists' attention to epithesis and mouth was evident considering the four parameters measured.

Visual perception of repaired cleft lip scarring face associated with different malocclusions via eye-tracking

Background. This study aimed to evaluate the visual facial perception in response to scars associated with repaired cleft lip (CL) on a male adolescent patient, as assessed via eye-tracking. Methods. Index of orthodontic treatment need (IOTN) malocclusions, grades 1, 5, and 8 were added to the frontal view facial image of an adolescent male model showing asymmetries of the nose and upper lip after CL surgery using the software Photoshop CS5® software. The eye movements of 91 laypeople observers were tracked by an Eye Tribe infrared sensor connected to OGAMA© software. A Kruskal–Wallis test was used to identify differences in total fixation time and time until the first fixation for the areas of interest. A visual analog scale (VAS) of attractiveness was also used in the study. Statistical analysis was performed adopting a significance level of P<0.05. Results. The area of interest (AOI) were found to be the mouth and teeth, which were more focused on gazed at than any other area, regardless of the grade of IOTN. For observers of different ages, there were significant differences in the time until the first fixation on the scar of the repaired CL region for IOTN grade 1 (P=0.007). Images showing IOTN grade 1 repaired CL regions received the highest VAS scores. The older the age, the greater the tendency to give a higher VAS score for the same malocclusion. Conclusion. The presence of a CL scar on the upper lip did not attract the eye of laypeople observers of different ages, regardless of the degree of malocclusion in the non-smile image. The age of the observers did influence the perception of attractiveness, with older observers giving higher scores than younger ones. As the severity of the malocclusion increased, they were found to be less attractive.

Look me in the eyes! A pre-registered eye-tracking study investigating visual attention and affective reactions to faces with a visible difference

This research aims to determine how disfigurement alters visual attention paid to faces and to examine whether such a potential modified pattern of visual attention to faces with visible difference was associated, in turn, with perceiver's stigmatizing affective reactions. A pilot study (N = 38) and a pre-registered experimental eye-tracking study (N = 89) were conducted. First, the visual explorations of faces with and without disfigurement were compared. The association of these visual explorations with affective reactions were investigated next. Findings suggest that disfigurement impacts visual attention toward faces; attention is not merely attracted to the disfigured area but it is also diverted particularly from the eye area. Disfigurement also eases disgust-related, surprise-related, anxiety-related, and, to a lesser extent, hostility-related affective states. Exploratory interaction effects between attention to the eyes and to the disfigured part of the face revealed a hybrid effect on disgust-related affect and an increase in surprise-related affect when participants fixated more upon the disfigured area and fixated less upon the eyes. Thus, perceiver's attention is captured by disfigurement and also diverted from face internal features which seems to play a role in the affective reactions elicited.

Visual facial perception of postsurgical cleft lip scarring assessed by laypeople via eye-tracking

OBJECTIVES:

This study aimed to evaluate the visual facial perception in response to scars associated with repaired cleft lip (CL) on a male adolescent model, as assessed by eye-tracking technology.

MATERIAL AND METHODS:

Unilateral and bilateral facial images of repaired CL on the upper lip and nasal asymmetry were added to an image of a male adolescent model, using Photoshop CS5 software. 40 laypeople eye movements were tracked by an infrared sensor of the Eye Tribe hardware in conjunction with OGAMA software. An analysis of variance was used to identify differences in total fixation time for the added areas of interest. A visual analog scale of attractiveness with a questionnaire were also incorporated into the study. Statistical analysis was performed using a significance level of P < 0.05.

RESULTS:

Significant differences were noted between the image with no scar and the image featuring a unilateral scar for total fixation time associated with the right eye (p = 0.002) and right nose area (p = 0.003), in addition to the numbers of fixations for the right eye (p = 0.005) and right nose area (p = 0.007). Comparing the image with no scar with the image featuring a bilateral scar showed a significant difference only for the number of fixations on the right eye (p = 0.005). The heatmaps and fixation point maps for both the unilateral and bilateral scar images indicated increased fixation for the scar areas. For the image with no scar, increased fixation was captured for the right eye area. Pearson's correlation coefficient test showed a moderate positive (p = 0.692) relationship when comparing to unilateral and bilateral cleft scars.

CONCLUSIONS:

The participating laypeople perceived the cleft-repaired faces and did not perceive any difference in attractiveness between the images featuring the unilateral and bilateral postsurgical clefts and lip scarring.

Social Perception of Facial Feminization Surgery Outcomes: Does Gender Identity Alter Gaze?

BACKGROUND

The evaluation of gender-affirming facial feminization surgery (FFS) outcomes can be highly subjective, which has resulted in a limited understanding of the social perception of favorable gender and aesthetic facial appearance following FFS. Eye-tracking technology has introduced an objective measure of viewer subconscious gaze.

OBJECTIVES

The aim of this study was to use eye-tracking technology to measure attention and perception of surgery-naive cisgender female and feminized transgender faces, based on viewer gender identity.

METHODS

Thirty-two participants (18 cisgender and 14 transgender) were enrolled and shown 5 photographs each of surgery-naive cisgender female and feminized transgender faces. Gaze was captured with a Tobii Pro X2-60 eye-tracking device (Tobii, Stockholm, Sweden) and participants rated the gender and aesthetic appearance of each face on Likert-type scales.

RESULTS

Total image gaze fixation time did not differ by participant gender identity (6.00 vs 6.04 seconds, P = 0.889); however, transgender participants spent more time evaluating the forehead/brow, buccal/mandibular regions, and chin (P < 0.001). Multivariate regression analysis showed significant associations between viewer gender identity, age, race, and education, and the time spent evaluating gender salient facial features. Feminized faces were rated as more masculine with poorer aesthetic appearance than surgery-naive cisgender female faces; however, there was no significant difference in the distribution of gender appearance ratings assigned to each photograph by cisgender and transgender participants.

CONCLUSIONS

These results demonstrate that gender identity influences subconscious attention and gaze on female faces. Nevertheless, differences in gaze distribution did not correspond to subjective rated gender appearance for either surgery-naive cisgender female or feminized transgender faces, further illustrating the complexity of evaluating social perception of favorable FFS outcomes.

Assessing Gender-Affirming Chest Surgery Outcomes: Does Gender Identity Alter Gaze?

BACKGROUND

Outcomes of gender-affirming chest surgery can be variable. Placement of nipple-areolar complexes and orientation of scars can drastically affect the aesthetic outcomes of these procedures, as may observer gender identity. Here, we compared attention and perception of outcomes following gender-affirming chest surgery between laypersons, based on gender identity.

METHODS

Transgender and cisgender participants were enrolled and shown images of surgery naïve chests and postoperative masculinized and feminized chests, blinded to the gender identity of the photographed subject. Gaze data were captured using the Tobii X2 60 eye-tracking device. Participants scored the perceived gender and aesthetic appearance of each image.

RESULTS

Eighteen cisgender and 14 transgender participants were enrolled. When viewing male chests, transgender participants spent significantly longer fixated on the nipples (naïve: 802 vs. 395 ms; p = 0.02, masculinized: 940 vs. 692 ms, p = 0.002). For masculinized chests, cisgender participants spent significantly longer fixated on the inframammary scar (483 vs. 391 ms; p = 0.04). On images of feminized chests, transgender participants spent longer viewing the nipples when compared to cisgender participants (1017 vs. 847 ms; p = 0.04). Cisgender viewers spent longer fixating on the postoperative scar on feminized chests (113 vs. 59 ms; p = 0.02) and also viewed feminized chests as significantly more masculine and masculinized chests as more feminine, when compared to transgender participants (p < 0.05).

CONCLUSIONS

This is the first study to use eye-tracking to assess how laypersons assess chests for gender determination. The findings suggest that observer gender identity has an effect on areas of focus and gender perception of chests that underwent gender-affirmation surgery.

LEVEL OF EVIDENCE III

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 Table of Contents or online Instructions to Authors www.springer.com/00266 .

Effect of Cleft Width on the Outcome of Presurgical Nasoalveolar Molding in Patients With Unilateral Cleft Lip and Palate

ABSTRACT

The purpose of this study was to investigate the short-term effects of presurgical nasoalveolar molding (PNAM) according to cleft width (CW) in patients with unilateral cleft lip and palate (UCLP). In this retrospective study, 32 newborns with nonsyndromic UCLP treated with PNAM were allocated to 2 groups based on CW (group A, CW ≤5 mm; and group B, CW >5 mm). The following measurements were carried out using standardized photographs taken before and after PNAM therapy (before primary lip surgery): nostril axis inclination of healthy (NAI-NC) and cleft sides (NAI-C), columellar angle (CA), nasal base inclination (NBI), nasal floor width ratio (NFWR), alar base height ratio (ABHR), and columellar length ratio. Before PNAM therapy, there were significant differences between the 2 groups with respect to NAI-C, NBI, NFWR, and ABHR, indicating greater deformation of the nose in group B. After PNAM therapy, CA, NAI-C, NAI-NC, NFWR, and columellar length ratio were significantly improved in both the groups, whereas NBI and ABHR significantly worsened in group B. The improvement in CA, NAI-C, and NFWR was significantly greater in group B. Although a larger CW had some negative effects on the outcome of PNAM, it was found to be advantageous for nasal symmetry, if initiated as early as possible. Nevertheless, it is important to consider those aspects of the nasolabial area that are involved in the perception of symmetry when evaluating the effect of CW on PNAM outcomes in UCLP.

Awareness of Orofacial Clefts in the Sultanate of Oman

INTRODUCTION

Cleft lip and/or palate (CL/P) is the most common craniofacial anomaly. In Oman, the incidence of CL/P is estimated to be 1.5 per 1000 live births per year. Knowledge, awareness, and attitude toward CL/P help to optimize the management of the condition and reduce social and emotional stress among this group of children and their family. In this survey, we assessed the public awareness, knowledge, and attitude toward this deformity in the Sultanate of Oman.

METHOD

A cross-sectional study was conducted using validated questionnaire that was distributed using Google forms.

RESULT

A total of 739 participants completed the survey. The majority is aware of cleft lip (86.7%) and palate (63.2%). In general, attitude toward patients with CL/P was positive. Females had higher knowledge compared to males, 54.4% and 32.9%, respectively. Online resources were the main source of information.

CONCLUSION

There are variations in knowledge, awareness, and attitude toward CL/P among participants. Omani population needs to be educated more about CL/P, its complications if not treated, and the available treatment.

An eye-tracking and visual analogue scale attractiveness evaluation of black space between the maxillary central incisors

Objective:

To study the influence of black space between the maxillary central incisors on the aesthetic visual perception of the face, via eye-tracking and visual analogue scale (VAS).

Methods:

Black space between the central incisors was created, for both sexes, as follows: control, 1-mm black space, 2-mm black space and 3-mm black space. Ninety raters participated in this study, divided into three groups: 30 laypeople, 30 nonorthodontists, and 30 orthodontists. After the visual calibration of each observer, eight photographs were presented in the Ogama^® software concomitant with the use of the hardware The Eye Tribe^®. Ogama generated information depending on the eye-tracking of each rater, regarding the time until the first fixation, time of fixation, heatmap, scanpath, and total time of fixation, to evaluate the areas deemed to be of interest according to the raters. Later on, the VAS was used, where each rater evaluated the images in an album on a scale of zero to 10 points.

Results:

The eyes and mouth were the areas more often noticed by the raters according to the heatmaps, while no significant difference was observed in time until the first fixation between the three groups of raters (p> 0.05). However, regarding the time of fixation on the mouth, a significant difference was observed (p< 0.05) when comparing the three groups.

Conclusion:

Black space has a negative effect on the aesthetic perception of the face. The amount of attention on the mouth is correspondent to the size of the black space.

Eye-Tracking Technology in Plastic and Reconstructive Surgery: A Systematic Review

BACKGROUND

The use of eye-tracking technology in plastic surgery has gained popularity over the past decade due to its ability to assess observers' visual preferences in an objective manner.

OBJECTIVES

The goal of this study was to provide a comprehensive review of eye-tracking studies in plastic and reconstructive surgery, which can aid in the design and conduct of high-quality eye-tracking studies.

METHODS

Through application of Preferred Reporting Items for Systematic review and Meta-Analysis (PRISMA) guidelines, a comprehensive search of articles published on eye-tracking across several databases was conducted from January 1946 to January 2019. Inclusion criteria included studies evaluating the use of eye-tracking technology in the field of plastic and reconstructive surgery. The resulting publications were screened by 2 independent reviewers.

RESULTS

A total of 595 articles were identified, 23 of which met our inclusion criteria. The most common application of eye-tracking was to assess individuals with cleft lip/palate (9 studies). All 19 studies that evaluated fixation patterns among conditions vs controls reported significant differences between the 2 groups. Five out of 7 studies assessing visual data between preoperative and postoperative patients identified significant differences between the preoperative and postoperative groups, whereas 2 studies did not. Nine studies examined the relation between severity indices, attractiveness scores, or personality ratings and gaze patterns. Correlation was found in 7 out of the 9 studies.

CONCLUSIONS

This systematic review demonstrates the utility of eye-tracking technology as a quantifiable objective assessment and emerging research tool for evaluating outcomes in several domains of plastic and reconstructive surgery.

Dermal Fat Grafting to Reconstruct the Parotidectomy Defect Normalizes Facial Attention

OBJECTIVES/HYPOTHESIS

Use validated eye-tracking technology to objectively measure 1) the attentional distraction of facial contour defects after superficial and total parotidectomy and 2) changes in attentional distraction with abdominal dermal fat graft reconstruction.

METHODS

Standardized frontal and oblique facial images of 16 patients who had undergone superficial or total parotidectomy with or without fat graft reconstruction; four normal controls were obtained. One hundred casual observers were recruited to view these images, and gaze data were collected using a Tobii Pro eye-tracking system. Gaze durations for predefined facial areas of interest were analyzed using mixed-effects linear regression to test study hypotheses.

RESULTS

For frontal images, total parotidectomy increased gaze to the operated parotid area compared to the contralateral nonoperated parotid area (92 milliseconds, 95% confidence interval [CI]: 48-138 milliseconds, P < .001). Fat grafting normalized the attentional distraction, with no difference in gaze time on the operated parotid region compared to normal control faces (P = .414). For oblique images, total parotidectomy increased gaze to the operated parotid area compared to the contralateral nonoperated parotid area (658 milliseconds, 95% CI: 463-854 milliseconds, P < .001). Fat grafting normalized this attentional distraction, with no difference in gaze time on the operated parotid region compared to normal control faces (P = .504). In both views, superficial parotidectomy demonstrated no significant attentional distractions, with or without fat grafting.

CONCLUSIONS

This eye-tracking study objectively demonstrates that total parotidectomy results in a facial contour deformity that is distracting to observers, whereas superficial parotidectomy does not. For total parotidectomy, this attentional distraction can be normalized with dermal fat graft reconstruction.

LEVEL OF EVIDENCE

3b Laryngoscope, 131:E124-E131, 2021.

The Use of Eye Tracking to Discern the Threshold at Which Metopic Orbitofrontal Deformity Attracts Attention

INTRODUCTION AND OBJECTIVES

Surgical treatment for trigonocephaly aims to eliminate a stigmatizing deformity, yet the severity that captures unwanted attention is unknown. Surgeons intervene at different points of severity, eliciting controversy. This study used eye tracking to investigate when deformity is perceived.

MATERIAL AND METHODS

Three-dimensional photogrammetric images of a normal child and a child with trigonocephaly were mathematically deformed, in 10% increments, to create a spectrum of 11 images. These images were shown to participants using an eye tracker. Participants' gaze patterns were analyzed, and participants were asked if each image looked "normal" or "abnormal."

RESULTS

Sixty-six graduate students were recruited. Average dwell time toward pathologic areas of interest (AOIs) increased proportionally, from 0.77 ± 0.33 seconds at 0% deformity to 1.08 ± 0.75 seconds at 100% deformity (P < .0001). A majority of participants did not agree an image looked "abnormal" until 90% deformity from any angle.

CONCLUSION

Eye tracking can be used as a proxy for attention threshold toward orbitofrontal deformity. The amount of attention toward orbitofrontal AOIs increased proportionally with severity. Participants did not generally agree there was "abnormality" until deformity was severe. This study supports the assertion that surgical intervention may be best reserved for more severe deformity.

Unilateral Cleft Lip Nasal Deformity: Three-Dimensional Analysis of the Primary Deformity and Longitudinal Changes following Primary Correction of the Nasal Foundation

BACKGROUND

Objective assessment of the unilateral cleft lip nasal deformity and the longitudinal changes with treatment is critical for optimizing cleft care.

METHODS

Consecutive patients undergoing cleft lip repair and foundation-based rhinoplasty were included (n = 102). Three-dimensional images preoperatively, postoperatively, and at 5 years of age were assessed and compared to age-matched controls. Images were normalized to standard horizontal, craniocaudal, and anteroposterior axes.

RESULTS

Cleft subalare was similar in position relative to controls but was 1.6 mm retrodisplaced. Subnasale was deviated 4.6 mm lateral to midline and had the greatest displacement of any landmark. Noncleft subalare was displaced 2.3 mm laterally. Regression analysis with deviation of subnasale from the midline as a dependent variable revealed progressive lateral displacement of noncleft subalare, narrowing of noncleft nostril, and intercanthal widening. Surgery corrected nasal base displacements along all axes, resulting in landmark positions similar to controls. Symmetry of nasal base correction persisted at 5-year follow-up, with no recurrent cleft alar base retrusion, regardless of initial cleft type.

CONCLUSIONS

Unilateral cleft lip nasal deformity may be "driven" by displacement of the anterior nasal spine and caudal septum. The cleft alar base is normal in position but retruded, whereas the noncleft alar base is displaced laterally. Changes with surgery involve anterior movement of the cleft alar base but also include medial movement of the noncleft alar base and columella. Symmetry of correction, including alar base retrusion, was stable over time and did not rely on alveolar bone grafting.

Measuring Outcomes of Mohs Defect Reconstruction Using Eye-Tracking Technology

Importance

Objectively measuring how Mohs defect reconstruction changes casual observer attention has important implications for patients and facial plastic surgeons.

Objective

To use eye-tracking technology to objectively measure the ability of Mohs facial defect reconstruction to normalize facial attention.

Design, Setting, and Participants

This observational outcomes study was conducted at an academic tertiary referral center from January to June 2016. An eye-tracking system was used to record how 82 casual observers directed attention to photographs of 32 patients with Mohs facial defects of varying sizes and locations before and after reconstruction as well as 16 control faces with no facial defects. Statistical analysis was performed from November 2018 to January 2019.

Main Outcomes and Measures

First, the attentional distraction caused by facial defects was quantified in milliseconds of gaze time using eye tracking. Second, the eye-tracking data were analyzed using mixed-effects linear regression to assess the association of facial defect reconstruction with normalized facial attention.

Results

The 82 casual observers (63 women and 19 men; mean [SD] age, 34 [12] years) viewed control faces in a similar and consistent fashion, with most attention (65%; 95% CI, 62%-69%) directed at the central triangle, which includes the eyes, nose, and mouth. The eyes were the most visually important feature, capturing a mean of 60% (95% CI, 57%-64%) of fixation time within the central triangle and 39% (95% CI, 36%-43%) of total observer attention. The presence of Mohs defects was associated with statistically significant alterations in this pattern of normal facial attention. The larger the defect and the more centrally a defect was located, the more attentional distraction was observed, as measured by increased attention on the defect and decreased attention on the eyes, ranging from 729 (95% CI, 526-931) milliseconds for small peripheral defects to 3693 (95% CI, 3490-3896) milliseconds for large central defects. Reconstructive surgery was associated with improved gaze deviations for all faces and with normalized attention directed to the eyes for all faces except for those with large central defects.

Conclusions and Relevance

Mohs defects are associated with altered facial perception, diverting attention from valuable features such as the eyes. Reconstructive surgery was associated with normalized attentional distraction for many patients with cutaneous Mohs defects. These data are important to patients who want to know how reconstructive surgery could change the way people look at their face. The data also point to the possibility of outcomes prediction based on facial defect size and location before reconstruction. Eye tracking is a valuable research tool for outcomes assessment that lays the foundation for understanding how reconstructive surgery may change perception and normalize facial deformity.

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.

Measuring visual attention to faces with cleft deformity

BACKGROUND

Limited data are available regarding observers' visual attention to faces with congenital difference. We implemented eye tracking technology to examine this issue, as it pertains particularly to faces with cleft deformity.

METHOD

Four hundred three observers assessed 273 clinical images, while their eye movements were unobtrusively tracked using an infrared sensor. Forty-one facial images of the repaired cleft lip, 137 images of other facial conditions, and 95 images of matched controls were assessed. Twenty facial regions of interest ("lookzones") were considered for all images observed. A separate cohort of 720 raters evaluated the images for attractiveness. Observer and image demographic information was collected. Visual fixation counts and durations were computed across all 20 lookzones for all images. The effect of a variety of variables on lookzone fixation was analyzed using factorial ANOVA testing.

RESULTS

Cleft-repaired faces were rated as less attractive and drew observers' attention preferentially to the affected upper lip lookzone (p<.001). Images rated as less attractive garnered greater visual attention in the cleft-affected lookzones (p<.001). The eye tracking methodology demonstrated exquisite sensitivity to laterality of cleft deformity (p<.001). Individuals reporting a personal or a family history of facial deformity fixated more on the perioral region of cleft-repaired faces than did naïve observers (p<.001).

CONCLUSION

These findings highlight the utility of eye tracking measures for understanding critical variables that influence the visual processing of faces with cleft deformity. The data may provide analytical tools for assessing surgical outcome and direct priority setting during surgeons' conversations with patients.

Objectively Measuring Observer Attention in Severe Thyroid-Associated Orbitopathy: A 3D Study

OBJECTIVE

Measure the attentional distraction of facial deformity related to severe thyroid-associated orbitopathy using three-dimensional (3D) images and eye-tracking technology.

METHODS

Observers recruited at an academic tertiary referral center viewed 3D facial images of patients with severe thyroid-associated orbitopathy (TAO) and controls without TAO. An infrared eye-tracking monitor recorded their eye movements and fixations in real time. Multivariate Hotelling's analysis, followed by planned posthypothesis testing, was used to compare fixation durations for predefined regions of interest, including the eyes, nose, mouth, central triangle, and remaining face without the central triangle between severe TAO patients and controls.

RESULTS

One hundred sixteen observers (mean age 26.4 years, 51% female) successfully completed the eye-tracking experiment. The majority of their attention was directed toward the central triangle (eyes, nose, mouth). On multivariate analysis, there were significant differences in the distribution of attention between control and severe TAO faces (T²  = 49.37; F(5,922) = 9.8314, P < 0.0001). On planned posthypothesis testing, observers attended significantly more to the eyes (0.77 seconds, P < 0.0001, 95% confidence interval [CI], 0.51, 1.03 seconds) and less to the nose (-0.42 seconds, P < 0.0001, 95% CI, -0.23, -0.62 seconds) in severe TAO patients. There was no significant difference in time spent on the mouth, the total time spent on the central triangle, or time spent in the remaining face between the two groups.

CONCLUSION

Severe TAO distracted observer attention toward the eyes compared to control patients. These data lend insight into how TAO may alter observers' perceptions of these patients. Future studies should investigate how these changes in observer gaze patterns may reflect the social perception of TAO patients.

LEVEL OF EVIDENCE

NA Laryngoscope, 129:1250-1254, 2019.