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.

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.

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.

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.