The stability of the surgery-first approach (SFA) remains debated, as studies comparing SFA and conventional orthognathic surgery (COS) lack measurements at equivalent time points, and the period during which relapse is most likely to occur has not been established. This meta-analysis isolated the interval following occlusal-interference correction to compare skeletal changes during the later post-surgical period.

Studies comparing skeletal stability between SFA and COS in Class III patients were identified through searches of six databases (MEDLINE, EBSCO, Cochrane Library, LILACS, SCOPUS, and Google Scholar) up to April 2025, supplemented by manual reference searches. Two independent reviewers screened, extracted, and selected studies with comparable cephalometric measures and time points. Pooled analyses used a random-effects model, with study quality assessed by ROBINS-I and evidence certainty by GRADE.

Nineteen studies were included. SFA showed greater upward and forward mandibular movement during the 3–6-month postoperatively. After this period, no significant differences in horizontal or vertical skeletal stability were observed between SFA and COS from 6 months to 2 years postoperatively with very low to moderate evidence.

Relapse occurred primarily during the 3–6-month post-surgical interval, with SFA showing greater relapse than COS during this period. Beyond this window, skeletal stability was comparable between approaches in Class III patients. Clinicians should prioritize the 3–6-month post-surgical period when planning SFA treatment to account for its higher relapse risk.

CRD420251019537.