Mapping gaps in CBCT-based evidence of external apical root resorption following orthognathic surgery: a scoping review.

External apical root resorption (EARR) is a recognized adverse outcome of orthodontic treatment that may also be influenced by orthognathic surgery. However, the body of evidence on this combined effect is nascent and has not been mapped. The aim of this scoping review was to systematically map and characterize the available literature on EARR measured using cone-beam computed tomography (CBCT) in surgical versus non-surgical jaws in orthognathic patients, and to identify key methodological and knowledge gaps to guide future research. The PRISMA-ScR guidelines were followed. Five electronic databases were searched, to December 2025. Two reviewers independently performed the study selection and data extraction, followed by a synthesis to map the evidence. The review identified four retrospective cohort studies involving 250 patients and over 2300 teeth. Three of the four included studies (75%) originated from a single research group. All studies assessed EARR using CBCT-derived measurements of root length and volume .Three of the studies reported greater EARR in surgical jaws, particularly involving the maxillary incisors, canines, and premolars . Volumetric analysis showed more pronounced changes than analysis of linear measurements . All studies were judged to have a moderate risk of bias, and substantial methodological heterogeneity was observed. In conclusion, this scoping review maps a limited evidence base that preliminarily reports an association between orthognathic surgery and increased EARR. The certainty of the evidence is low, and independent validation is absent. Well-designed prospective studies with standardized protocols are required to clarify clinical significance.