Correlation Between Facial Asymmetry and Maxillary Sinus Size or Volume Using Dental Cone-Beam Computed Tomography Images

Objectives This study investigated correlations between facial asymmetry and left-right differences in maxillary sinus size and volume, as well as their relationships with skeletal morphology. Methods The participants were 154 Japanese adults (56 men, 98 women) aged 18 to 38 years (mean age, 24.1 ± 5.3 years). Cone-beam computed tomography (CBCT) images were analyzed using InVivo™ 6 software (Anatomage, Inc., San Jose, CA, USA). Facial asymmetry was assessed at six landmarks: orbitale, condylion, and gonion (all bilateral); anterior nasal spine; deepest point in bony concavity (B point); and menton (at midline). Maxillary sinus height, width, length, and volume were measured. Participants were classified into skeletal classes (I, II, III) and vertical growth patterns (horizontal, average, vertical). Spearman's rank correlation coefficient was used to assess the relationships of these six facial asymmetry landmarks with differences in maxillary sinus linear measurements and volume. Results The facial asymmetry index was positively correlated with maxillary sinus length in the condylion region and height in the gonion region. As left-sided facial deviation increased, the right maxillary sinus became larger; conversely, as right-sided facial deviation increased, the left maxillary sinus became larger. Thus, the maxillary sinus on the nondeviated side tends to be larger. Vertical facial growth patterns showed greater maxillary sinus height and volume in the vertical growth group than in the average growth group. Conclusions Asymmetry in specific facial regions may be associated with region-specific variations in maxillary sinus morphology, and vertical skeletal patterns may influence maxillary sinus development. These findings offer insights into the relationship between facial asymmetry and maxillary sinus structure.