Unilateral posterior crossbite and chin deviation: is there a correlation?

Area of Science:

• Dentistry
• Orthodontics
• Facial Aesthetics

Background:

• Chin deviation is a clinical observation, particularly relevant in cases of unilateral posterior crossbite (UPXB).
• Understanding the perception of chin deviation by both dental professionals and laypersons is crucial for accurate diagnosis.

Purpose of the Study:

• To investigate the correlation between UPXB and clinically apparent chin deviation.
• To compare the judgment of chin deviation between dental professionals and lay observers.
• To evaluate the concordance between visual and computer-assisted assessments of chin deviation.
• To determine the threshold for noticeable chin deviation.

Main Methods:

• A retrospective study involving 72 patients with UPXB and 72 controls matched for age and sex.
• Visual assessment of full-face images by orthodontists, dental students, and laypersons, with a computer-assisted assessment for comparison.
• Inclusion of computer-generated faces with varying degrees of chin deviation (0-8 mm).

Main Results:

• Moderate agreement was found among visual observers (kappa = 0.48).
• High correlation (ICC = 0.87) was observed between computer-assisted and visual assessments.
• Laypersons showed a tendency to perceive deviation opposite to the crossbite direction.
• A chin deviation of at least 4 mm was generally perceived by most observers.

Conclusions:

• A significant correlation exists between unilateral posterior crossbite and visually discernible chin deviation.
• Visual assessment of chin deviation by dental professionals and laypersons showed no major differences in perception.
• Computer-assisted assessment provides a reliable and standardized method for evaluating chin deviation, correlating well with visual scoring.