Course of the mandibular canal in hemifacial microsomia: a retrospective computed tomography study

ABSTRACT Objective The aim of this study was to evaluate the anatomic course of the mandibular canal in patients with hemifacial microsomia (HM). Study Design In this retrospective study, 77 patients were included and stratified according to the Pruzansky-Kaban classification. The mandibular canal and the mandible were reconstructed on the basis of computed tomography data. The entrance, route, and exit of the mandibular canal (representing the entrance, route, and exit of the inferior alveolar nerve [IAN], respectively), and the antilingula were analyzed in different types of mandibular deformities in patients with HM. Results No significant difference in the course of the mandibular canal was detected between the affected and unaffected sides in patients with type I and type IIa HM. Abnormalities were observed in some patients with type IIb and type III HM. Significant differences were found between patients with type IIb and type III HM in the entrance ( P  = .015) and route ( P  = .001) of the canals. The antilingula was identified only in patients with type IIb and type III HM and was more common in patients with type III HM than in those with type IIb HM. Conclusions Variation of the anatomic course of mandibular canal exists in patients with Pruzansky-Kaban type IIb and type III HM. Evaluation of the course of the canal in patients with HM is recommended before surgical intervention to avoid IAN damage.