Comparison of Lefort-1 advancement by internal and external distraction osteogenesis in non-syndromic cleft lip and palate: A systematic review and meta-analysis

Purpose: In 25 % of Cleft lip and palate (CLP) patients, midface hypoplasia (MH) is non-responsive to orthodontics. Post-surgical scarring in cleft patients causes large relapse with conventional osteotomies. Distraction osteogenesis (DO) has become the choice of treatment for midface hypoplasia in CLP patient. The systematic review aims to generate evidence to guide the selection of distraction devices for non-syndromic CLP associated maxillary hypoplasia. Materials and methods: A PRISMA-guided systematic review was planned. Studies with LeFort 1 distraction osteogenesis in non-syndromic CLP patients were included. Four literature databases (PubMed, Embase, Cochrane and Ovid) were searched. Identified studies were shortlisted based on PICOS criteria for data extraction. SNA, SNB and ANB angle measurements were extracted pre-distraction and within 1 year and after 1-year post-distraction. Forest plots were generated to understand the maxillary advancement and relapse associated with external and internal distractor. Risk of bias was evaluated for non-randomized studies and a traffic light plot as well as summary plot was generated for inference. Results: A total of 2395 articles were identified after a database search. 131 articles were included for full-text review and 31 articles were selected for data synthesis. A total of 361 patients underwent distraction osteogenesis, out of which 265 patients underwent external DO, and 96 underwent internal DO. Pooled data analysis revealed a larger increase in SNA angle for external distractors than internal distractors. Conclusion: External DO provide a greater degree of midface advancement than internal DO. The degree of relapse is more with external distraction.