What is the Success Rate of Alveolar Cleft Bone Grafting in Van der Woude and Popliteal Pterygium Syndrome?

Background: Patients with cleft lip with or without cleft palate (CL±P) and IRF6 -related disorders including Van der Woude syndrome (VWS) and popliteal pterygium syndrome (PPS) have been associated with worse outcomes following primary labiopalatoplasty. Outcomes following secondary alveolar bone grafting remain unknown. The purpose of this study was to determine whether alveolar bone graft success differs between VWS/PPS and nonsyndromic CL±P patients. Materials and Methods: This was a retrospective cohort study of subjects with CL±P who underwent secondary alveolar cleft bone grafting between 1999 and 2025 at Boston Children’s Hospital. The predictor variable was a history of VWS/PPS, and the primary outcome was radiographic alveolar bone graft success. Categorical variables were analyzed using Fisher exact tests, and continuous variables were assessed using Welchs 2-sample t tests. Significance was defined as P <0.05. Results: A total of 720 subjects were included: 15 (2.1%) with VWS/PPS and 705 (97.9%) with nonsyndromic CL±P. Mean age at grafting was 10.6±2.8 years in the VWS/PPS group and 10.2±1.2 years in the nonsyndromic group. The VWS/PPS group had a greater frequency of bilateral clefts (53.3% versus 32.5%, P =0.03) and preoperative visible fistulae (60.9% versus 31.3%, P =0.005). Despite these differences, bone graft success rates did not differ between groups (VWS/PPS: 95.7%; nonsyndromic: 95.4%, P >0.999). Conclusions: Subjects with VWS/PPS had more severe cleft phenotypes; however, alveolar bone graft outcomes were comparable to nonsyndromic subjects. These findings suggest that VWS/PPS may not be a significant risk factor for graft failure.