Asymmetry of Maxillary Bone Structure in Unilateral Cleft Lip and Palate: A Cone Beam Computed Tomography Study

Objective To compare maxillary bone structure between right- and left-sided unilateral cleft lip and palate (UCLP), quantify cleft vs. non-cleft asymmetry, and determine whether the non-cleft side differs from healthy controls. Design Retrospective cross-sectional cohort study. Setting University hospital, Department of Oral and Dentomaxillofacial Radiology. Patients, Participants Fifty UCLP (25 right, 25 left; mean age 14.8 ± 5.1 years) and 50 controls (16.5 ± 4.6 years). Power calculation indicated n = 28/group sufficient. Interventions Cortical thickness measured on CBCT at 4-12 mm depth across 6 interradicular regions. Trabecular architecture assessed by fractal dimension (FD) (BoneJ/Fiji). Main Outcome Measures Cortical thickness and FD differences between right-/left-UCLP, cleft vs. non-cleft sides, non-cleft vs. controls. Results No differences between right- and left-UCLP cleft sides ( P > 0.05). Cleft side thickness was 0.05-0.07 mm less than non-cleft side in anterior regions ( P < 0.001, d = 0.30-0.38). Non-cleft side was thinner than controls by 0.12-0.18 mm ( P < 0.001), representing 86-92% of control thickness. FD showed similar patterns. Asymmetry increased from posterior to anterior. Conclusions UCLP is associated with bilateral maxillary bone deficits; the non-cleft side also shows significant deviations from controls. Side-specific assessment is essential. These differences may warrant caution in treatment planning, but prospective outcome studies are needed.