P54. Increasing Number of Cleft-related Surgeries Results in Worsened Maxillary Hypoplasia: A Cephalometric Study

PURPOSE: Surgical scarring has been hypothesized to contribute to maxillary hypoplasia in patients with cleft lip and palate (CLP), often requiring orthognathic surgery (OGS). The aim of this study was to identify factors associated with maxillary hypoplasia in skeletally mature patients with CLP using cephalometric measurements. METHODS: A retrospective review of patients with CLP at skeletal maturity with cone beam CT data was conducted. Cephalometric landmarks were identified using Mimics software. Medical data collected included the number and type of surgeries performed during childhood, cleft morphology, demographics, and need for OGS. RESULTS: There were 105 patients included in the study. About 47.2% of patients had bilateral cleft lip and palate and 49.5% of patients later underwent OGS. Over 50% of patients had four or more surgeries related to CLP by skeletal maturity. SNA angle, ANB angle, maxillary width, facial convexity angle, and Co-ANS (right/left) were all inversely related to total number of surgeries (p<0.05). SNA angle demonstrated the greatest effect size with a mean decrease of 4.43 degrees with greater than five cleft-related surgeries (p<0.001, Cohen’s d= 0.805). Bilateral cleft morphology was associated with a mean decrease of 2.87 mm in maxillary width (p=0.001, Cohen’s d=0.641). CONCLUSION: Increasing number of cleft-related surgeries before skeletal maturity is associated with progressively increasing maxillary growth restriction in both a sagittal and transverse plane based on cephalometric measurements.