IntroductionOrofacial clefts are 1 of the most common congenital anomalies worldwide. Cleft lip repair has esthetic and functional benefits, but long-term, devastating sequelae such as midface hypoplasia (MFH) are poorly understood. Historically, experts believe cleft palate repair is the primary cause of MFH.1,2 This study examines whether surgical cleft lip repair contributes to MFH. MethodsA systematic literature review of 3780 articles was done in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Inclusion criteria included English-language articles examining operated or unoperated cleft lip patients. Twenty-seven met inclusion criteria, and 13 reported cephalometric measurements amenable to meta-analysis (sella-nasion-A point, SNA and A point, nasion, B point, ANB). Controls were participants with normal craniofacial morphology. ResultsThe 13 studies with patient-level cephalometric data had 224 males (68.7%) and 102 females (32.3%). Mean age for cases versus controls was 14 and 23.3 years, respectively (weighted average). Patients with cleft lip and palate who had cleft lip repair had significantly lower SNA than controls (mean 75.6o + 3.9 vs. 82.0 o +-3.2, P < .001). SNA in patients with cleft lip only (CL) who underwent lip repair was not significantly different than controls (P =.27). ConclusionPatients with cleft lip and palate who undergo surgical repair of the cleft lip only experience sagittal midface growth restriction. Patients with isolated cleft lip deformities who had cleft lip repair did not have sagittal midface growth restriction. Scarring and growth restriction after lip repair is an unlikely source of midface hypoplasia. These data suggest that cleft palate, even without palatoplasty, is a possible source of restricted midface growth. Further prospective studies are necessary to understand the role of cleft physiology and surgery on MFH.