How Does the Anterior Maxillary Arch Change After Unilateral Lip Repair? A Systematic Review and Meta-Analysis

Area of Science:

• Craniofacial Surgery
• Pediatric Plastic Surgery
• Orthodontics

Background:

• Unilateral cleft lip and palate (UCLP) presents complex morphological challenges in the anterior maxillary arch.
• Quantifying changes in anterior cleft width (CW) and anterior curvature angle (ACA) post-primary lip repair is crucial for understanding long-term outcomes.

Purpose of the Study:

• To systematically review and meta-analyze the morphological changes in the anterior maxillary arch following primary lip repair in UCLP patients.
• To quantify changes in anterior cleft width (CW) and anterior curvature angle (ACA).
• To assess the influence of baseline cleft width and follow-up duration on these changes.

Main Methods:

• A comprehensive systematic search of major databases (PubMed, Google Scholar, DOAJ, Cochrane Library) was performed.
• Ten studies with 265 participants reporting quantitative pre- and post-operative data were included.
• Random-effects model meta-analysis and meta-regression were used to calculate pooled effect sizes and assess predictors.

Main Results:

• Primary lip repair resulted in a significant reduction in anterior cleft width (mean difference: -6.217 mm) and anterior curvature angle (mean difference: -14.66°).
• Initial cleft width was a significant predictor of postoperative CW changes (β = -0.842, P = .002).
• Substantial heterogeneity was observed for both CW (I² = 81.8%) and ACA (I² = 88.1%), with very low certainty of evidence.

Conclusions:

• Primary lip repair demonstrably improves anterior arch dimensions in children with UCLP.
• A predictive model incorporating initial cleft width and follow-up duration may assist in early treatment planning.
• Given the high heterogeneity and low certainty of evidence, findings should be interpreted cautiously and considered exploratory.