This systematic review aimed to assess whether the initial apical position of impacted maxillary canines, evaluated using cone-beam computed tomography [CBCT], influences three-dimensional root displacement during orthodontic traction. An extensive literature search was conducted in PubMed/MEDLINE, Web of Science, Embase, Scopus, and the Cochrane Library up to November 2025. Prospective and retrospective clinical studies including pre-treatment CBCT assessment and reporting either direct apical displacement or CBCT-derived three-dimensional position parameters were considered eligible. Study selection, data extraction, and quality appraisal were carried out independently by two reviewers. Seven studies met the inclusion criteria. Substantial heterogeneity was observed in imaging protocols, reference systems, traction mechanics, and outcome measures, precluding quantitative synthesis. Only two studies directly quantified three-dimensional apical displacement using CBCT–CBCT or CBCT–STL superimposition methods, predominantly suggesting bodily movement patterns; although, this is based on limited direct evidence, with velocities ranging from 0.29 to 0.84 mm/month. The remaining studies provided indirect evidence based on angular changes, positional parameters, or traction duration. Taken together, the available evidence suggests that unfavorable initial apical positions, including palatal or bicortical impactions and increased root angulation, may be associated with greater biomechanical complexity and longer traction duration. Although CBCT-based three-dimensional evaluation provides clinically relevant diagnostic information, standardized measurement protocols are required to improve comparability and reproducibility across studies.

Background: Impaction of mandibular canines is an uncommon clinical condition, and transmigration represents a severe positional variant within this spectrum. In contrast to maxillary canine impaction, the management of impacted mandibular canines remains less standardized and largely experience-based. This systematic review aimed to critically evaluate the clinical outcomes of surgical exposure followed by orthodontic traction in impacted mandibular canines. Methods: A systematic search was conducted across five electronic databases (PubMed, Web of Science, Scopus, Embase, and Cochrane Library) up to February 2026. A total of 1512 records were identified; after duplicate removal, 1307 studies underwent title and abstract screening. Fifteen full-text articles were assessed for eligibility, and four retrospective analytical studies met the predefined inclusion criteria. The primary outcome was successful orthodontic alignment. Secondary outcomes included treatment duration and reported complications. Risk of bias was assessed using ROBINS-I, and certainty of evidence was evaluated according to the GRADE approach. Results: Success rates ranged from 57% to 100% across studies. Overall, 31/42 canines (73.8%) were reported as successfully aligned; however, heterogeneity in case selection, outcome definitions, and reporting precluded quantitative synthesis. In most studies, success was defined primarily as positional alignment within the dental arch, with limited or absent assessment of periodontal status, pulp vitality, functional integration, or long-term stability. All included studies were judged to have a serious overall risk of bias. According to GRADE, the certainty of evidence for all evaluated outcomes was very low. Conclusions: Surgical exposure followed by orthodontic traction may represent a feasible option in carefully selected cases of impacted mandibular canines, particularly in younger patients and in the absence of severe displacement. However, given the serious risk of bias, small cumulative sample size, and very low certainty of evidence, these estimates must be interpreted with extreme caution. Unlike maxillary canine impaction, the current evidence base does not support protocol-driven management for mandibular cases, and clinical decision-making remains primarily individualized.