Transverse maxillary deficiency is a common component of craniofacial deformities in patients with cleft lip and palate (CLP). In skeletally mature patients, conventional orthopedic expansion is frequently insufficient because of increased circummaxillary skeletal resistance, scar tissue, and altered maxillary anatomy. Surgically assisted rapid palatal expansion (SARPE) enables controlled skeletal widening of the maxilla; however, treatment protocols, surgical techniques, and outcome assessment remain highly heterogeneous.

To critically evaluate the available evidence on SARPE and related surgically assisted transverse maxillary expansion procedures in patients with cleft lip and/or palate, summarize current clinical considerations, and identify important evidence gaps regarding surgical planning, expansion protocols, stability, and complications.

A PRISMA 2020–compliant systematic review was conducted, with protocol registration in PROSPERO. Studies involving patients with cleft lip and/or palate, without restriction based on chronological age, who underwent SARPE or distraction-assisted transverse maxillary expansion procedures were included. Skeletal maturity was recorded when reported but was not used as an eligibility criterion. Prospective and retrospective clinical studies and case series published between 2015 and 2026 were identified through systematic database searches. Data extraction focused on surgical technique, osteotomy design, expander type, quantitative expansion outcomes, postoperative stability, and complications. Meta-analysis was not feasible because of substantial clinical and methodological heterogeneity across studies, including differences in patient populations, surgical protocols, outcome measures, and follow-up duration. Methodological quality was assessed using the MINORS instrument for non-comparative observational studies and the JBI Critical Appraisal Checklist for the retrospective case series.

Four retrospective studies were included. Three studies provided direct treatment-outcome data for 33 patients with cleft lip and/or palate undergoing SARPE or distraction-assisted transverse maxillary expansion. One large retrospective orthognathic cohort of 1095 patients provided indirect contextual evidence: 98 patients had maxillary transverse deficiency treated with SARPE and 19 had cleft lip and/or palate, but the overlap between these groups and CLP-specific SARPE outcomes were not reported. Among the studies providing direct CLP-specific outcomes, conventional SARPE and distraction-based expansion procedures produced reported transverse widening ranging from 7.3 ± 2.1 mm to 12.7 mm, with postoperative stability described as favorable in the original studies, although relapse assessment was inconsistent and based on heterogeneous outcome measures during follow-up periods extending up to 8 years. Sequential distraction osteogenesis protocols additionally enabled simultaneous sagittal advancement of 20–22 mm in severe deformities. Reported adverse events included appliance debonding, distractor or screw instability, tooth root injury, and transient occlusal disturbances. However, complication definitions and reporting were inconsistent, and none of the included studies used a standardized grading system. The small retrospective samples and incomplete adverse-event reporting were insufficient to evaluate uncommon or severe complications reliably. The certainty of the available evidence was limited by retrospective designs, small CLP-specific samples, absence of comparative groups, heterogeneous outcome reporting, and incomplete reporting of follow-up and complications.

The available evidence suggests that surgically assisted transverse maxillary expansion is feasible and may provide clinically meaningful correction in selected patients with cleft lip and/or palate. Current data are insufficient to establish the comparative effectiveness, long-term stability, or safety of specific techniques. Treatment decisions should therefore remain individualized, and prospective comparative studies with standardized morphometric, complication, and patient-reported outcomes are required.