Retrospective Evaluation of Maxillary Sinus Volume Changes Following Bone-Anchored Midface Distraction Osteogenesis in Cleft Patients: A Case–Series Study

<b>Background/Objectives</b>: This study retrospectively evaluated maxillary sinus volume changes and linear changes in the craniofacial region after Le Fort I distraction osteogenesis using a rigid external distraction system. <b>Methods</b>: Ten patients who underwent LeFort 1 distraction osteogenesis between 2012 and 2025 were included in the study. Computed tomography scans and lateral cephalograms were obtained before and 12.3 ± 6.98 months after the surgery. The associated volumes of the maxillary left and right sinuses were subsequently measured using the semiautomatic segmentation method in the ITK-SNAP software. Linear measurements of the sinuses and cephalometric analysis were performed before and after the distraction. <b>Results</b>: The Wits appraisal (distance between perpendicular lines drawn from point A (on the maxilla) and point B (on the mandible) to the occlusal plane) presented an increase of 9.33 mm ± 7.93 mm, corresponding to an increase in the ANB angle by 9.88° ± 5.35°. There were statistically significant increases in the total sinus volume, by 3965 mm³ ± 5456 mm³ (n = 10, <i>p</i> = 0.047), and in the single maxillary sinus volume, by 1983 ± 2889 mm³ (n = 20, <i>p</i> = 0.003). A significant increase in height was also observed, with a mean value of 4.46 ± 2.94 mm (n = 20). <b>Conclusions</b>: Extraoral bone-anchored midface distraction osteogenesis led to increases in single sinus volume, total sinus volume and sinus height in the cleft cohort, resulting in improved maxillary retrusion and profile. However, the study group was small and non-uniform with different follow-up periods, indicating a need for further studies with larger, more homogenous cohorts.