CBCT analysis of pharyngeal airway dimensions in cleft lip and palate: A systematic review and meta-analysis

To systematically evaluate and synthesize the available evidence on pharyngeal airway dimensions in individuals with cleft lip and palate using cone-beam computed tomography (CBCT), and to quantitatively compare airway volumes between cleft and noncleft populations where feasible. An electronic literature search was conducted across multiple databases to identify CBCT-based case-control studies assessing pharyngeal airway dimensions in individuals with cleft lip and palate. Eligible studies were screened according to predefined inclusion criteria. Data extraction and qualitative synthesis were performed for all included studies. Methodological quality was assessed using the Newcastle-Ottawa Scale (NOS). Meta-analysis was conducted when three or more studies reported comparable outcome variables; pooled estimates were calculated using a random-effects model. Twenty-six case-control studies were included, all demonstrating low risk of bias (NOS score ≥7). Due to heterogeneity in outcome definitions and limited availability of comparable data, meta-analysis was feasible for only a few outcomes. Pooled analysis showed a significant reduction in total pharyngeal airway volume in individuals with unilateral cleft lip and palate compared with controls, while no significant difference was observed in nasopharyngeal airway volume. Qualitative synthesis indicated that oropharyngeal airway volume was the most consistently reduced region, particularly in patients with bilateral cleft lip and palate. Pharyngeal airway morphology in individuals with cleft lip and palate is region-specific and phenotype-dependent, with consistent reductions observed in total and oropharyngeal airway volumes, while nasopharyngeal airway dimensions remain variable. The limited feasibility of meta-analysis highlights the need for standardized CBCT airway assessment protocols, age-stratified analyses, and phenotype-specific reporting in future studies.