Objective To investigate the impact of continuous positive airway pressure （CPAP） therapy on midfacial

growth in children with syndromic craniosynostosis （SCS） using three-dimensional cephalometric analysis， and to provide evidence for optimizing airway management and treatment strategies. Methods A retrospective cohort of 28 children with SCS was reviewed. Fifteen patients who received CPAP therapy were included in the mask group，13 patients without CPAP treatment were included in the no mask group， and 15 healthy children were served as healthy controls. Computed tomography （CT） scans obtained before CPAP initiation and prior to midfacial advancement surgery were reconstructed into three dimensional models. Quantitative cephalometric measurements were performed to assess dynamic changes in midfacial morphology， and intergroup as well as intragroup comparisons were conducted. Results Compared with healthy controls， children with SCS consistently demonstrated maxillary retrusion. After CPAP therapy， the mask group showed significantly reduced PNS_Vertical， ANS_Horizon， and SNA values compared with the no mask group （P<0.05）. Within-group analysis revealed a significant reduction in PNS_Horizon （P<0.05）. Furthermore， the ANB angle was significantly greater in the mask  group than in the no mask group （P<0.05）， indicating an exacerbated tendency toward a concave facial profile. Conclusion CPAP therapy may further aggravate midfacial retrusion in children with syndromic craniosynostosis， characterized by clockwise maxillary rotation. Clinicians should carefully balance the benefits of airway improvement against potential adverse craniofacial effects. Future multi-center， large-sample， prospective studies are warranted to validate these findings and to explore optimized mask designs or adjunctive orthodontic interventions that may mitigate unfavorable craniofacial outcomes while preserving airway function.

Craniosynostosis, Continuous positive airway pressure （CPAP）, Midfacial development, Three