Systematic review and meta-analysis of mandibular canal variations on cone beam computed tomography.

OBJECTIVE

The purpose of this systematic review was to evaluate the mandibular canal (MC) variations and their anatomical incidences using cone-beam computed tomography (CBCT).

DESIGNS

Related articles on the anatomical variations of the MC using CBCT were searched through PubMed, Cochrane, and China National Knowledge Infrastructure (CNKI) to identify all relevant articles eligible for inclusion. Data extracted included incidences of the anatomical variations of the MC including the accessory mental foramen (AMF), retromolar foramen (RMF), mandibular lingual foramina (MLF), and the bifid mandibular canal (BMC).

RESULTS

In total, 16 descriptive cross-sectional studies (one low quality and fifteen high quality) were included in the meta-analysis analyzing 8862 MC. The meta-analysis performed with a random-effects model showed that the incidence of AMF was 9.54% (95% CI 6.39-12.69%), the incidence of RMF was 23.64% (95% CI 14.44-32.84%). MLF was found in almost all adults studied, and the incidence of BMC was about 38.0%.

CONCLUSIONS

The foramina and canals branched from the MC presented significant anatomical variations among individuals. CBCT-based study on the anatomical variations of the MC could provide guidance for clinical practice.