OBJECTIVETo locate the mandibular canal accurately in the mandibular body of the young women and provide anatomic data for the mandibular angle plasty.

METHODS60 women whose age ranged from 20 to 39 years old were randomly selected, the average was 25.32 years old. CT scanning and 3-D reconstruction were applied to their mandibles. After the points were determined, the distances of the points to inferior mandibular borders were measured. The data was analyzed by SPSS 11.5.

RESULTSThe distance between the mandibular canal and the inferior mandibular border was least in the area which responsed to the second premolar. It decreases from the posterior margin of the third molar to the anterior margin of the first molar. It increases from the posterior margin to the mental hole.

CONCLUSIONSThe mandibular canal between the posterior and anterior margins of the second pre-molar is prone to be injuried and should be paid more attention to during mandibular angle plasty.