Cleft Type Influences Volumetric Asymmetry of the Maxillary Sinus and Nasal Cavity: A CT Volumetric Study

OBJECTIVE: To investigate whether cleft type influences volumetric asymmetry of the maxillary sinus and nasal cavity using three-dimensional computed tomography (CT). MATERIALS AND METHODS: This retrospective study included 46 patients (24 unilateral cleft lip and palate [UCLP], 22 unilateral cleft lip and alveolus [UCLA]). Maxillary sinus and nasal cavity volumes were measured separately on the affected and non-affected sides using CT. An asymmetry index (AI, %) was calculated as (affected - non-affected)/(affected + non-affected) × 100. Within-group and between-group comparisons were performed, and multiple linear regression analysis was used to determine whether cleft type independently predicted volumetric asymmetry after adjustment for age and sex. RESULTS: Significant side-to-side differences in both maxillary sinus and nasal cavity volumes were observed in the UCLP group (both p < 0.001), whereas no significant asymmetry was detected in the UCLA group. The asymmetry index differed significantly between groups for both structures (p < 0.001). Cleft type independently predicted maxillary sinus asymmetry (β = 8.11, p = 0.002) and nasal cavity asymmetry (β = -6.42, p = 0.026). No significant correlation between sinus and nasal cavity asymmetry was found in UCLP, whereas a significant positive correlation was observed in UCLA (p = 0.006). CONCLUSION: Cleft type significantly influences volumetric asymmetry and the relationship between adjacent paranasal compartments. UCLP is associated with more pronounced asymmetry, whereas UCLA demonstrates more coordinated morphologic development. Cleft type-specific three-dimensional assessment should be considered in cleft care.