Analysis of gaze points for mouth images using an eye tracking system

Examining gaze behavior in undergraduate students and educators during the evaluation of tooth preparation: an eye-tracking study

BACKGROUND

Gaze behavior can serve as an objective tool in undergraduate pre-clinical dental education, helping to identify key areas of interest and common pitfalls in the routine evaluation of tooth preparations. Therefore, this study aimed to investigate the gaze behavior of undergraduate dental students and dental educators while evaluating a single crown tooth preparation.

METHODS

Thirty-five participants volunteered to participate in the study and were divided into a novice group (dental students, n = 18) and an expert group (dental educators, n = 17). Each participant wore a binocular eye-tracking device, and the total duration of fixation was evaluated as a metric to study the gaze behavior. Sixty photographs of twenty different tooth preparations in three different views (buccal, lingual, and occlusal) were prepared and displayed during the experimental session. The participants were asked to rate the tooth preparations on a 100 mm visual analog rating scale and were also asked to determine whether each tooth preparation was ready to make an impression. Each view was divided into different areas of interest. Statistical analysis was performed with a three-way analysis of the variance model with repeated measures.

RESULTS

Based on the participants' mean rates, the "best" and the "worst" tooth preparations were selected for analysis. The results showed a significantly longer time to decision in the novices compared to the experts (P = 0.003) and a significantly longer time to decision for both the groups in the best tooth preparation compared to the worst tooth preparation (P = 0.002). Statistical analysis also showed a significantly longer total duration of fixations in the margin compared to all other conditions for both the buccal (P < 0.012) and lingual (P < 0.001) views.

CONCLUSIONS

The current study showed distinct differences in gaze behavior between the novices and the experts during the evaluation of single crown tooth preparation. Understanding differences in gaze behavior between undergraduate dental students and dental educators could help improve tooth preparation skills and provide constructive customized feedback.

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 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.

Influencing Factors on Aesthetics: Highly Controlled Study Based on Eye Movement and the Forensic Aspects in Computer-Based Assessment of Visual Appeal in Upper Front Teeth

First impressions are formed by the external appearance and, in this respect, essentially by an examination of the face. In the literature, the teeth, especially the maxillary front, are among an eye-catching and sensitive area that plays a significant role in the overall evaluation of appearance. In this study, the first eye fixation of 60 subjects with different levels of dental training (layperson, trained layperson, dental student, and dentist) is recorded using an eye-tracking system, and their subsequent evaluation of the images is recorded. Ten unedited original photographs of different maxillary anterior teeth and ten subsequently edited photographs will be used to evaluate forensic aspects such as the effect of symmetry and color on the overall evaluation. The results will be used to determine which areas of the maxillary anterior are demonstrably viewed and whether knowledge of dental esthetics influences evaluation and viewing.

Laypeople's and dental students' perceptions of a diastema between central and lateral incisors: Evaluation using scanpaths and colour-coded maps

OBJECTIVE

This study aimed to use eye tracking to analyse people's visual perceptions of smiles with a diastema between the maxillary central and lateral incisors, based on different categories of observers.

SETTING AND SAMPLE POPULATIONS

An image of a diastema between the maxillary central and lateral incisors was shown to dental students and laypeople.

MATERIALS AND METHODS

Our null hypothesis was that there would be no difference in the visual perception of the different graduations of diastemas between the two groups. The diastemas were edited in Photoshop® to gradually increase the distance between the maxillary central and lateral incisors from no diastema to 1.5 mm and 3.5 mm diastemas. These diastemas were evaluated by using a TheEyeTribe© tracker in conjunction with OGAMA^© 5.0 software. A total of 37 dental students and 33 laypeople looked at eight randomly arranged images of smiles. The data were analyzed using color coded maps, scanpaths, and the Kruskal-Wallis test with a level of significance of 5%.

RESULTS

Laypeople tended to observe the eyes, focusing more on the right than the left, and spent less time focusing on the diastema region than did the dental students. There were differences for the same magnitude of diastema within participant groups. As the width of the diastema increased, both students and laypeople focused more on the diastema region.

CONCLUSIONS

The two groups of evaluators presented different perceptions of smiles in cases of diastema between the maxillary central and lateral incisors when evaluated using eye-tracking.