Mandibular canal's anatomy in children with micrognathia: a computed tomography study

Abstract

Objective To assess the anatomy feature of mandibular canal in children with micrognathia by CT scanning.Methods Three thickness indexes of mandibular canal were measured in 36 cases of children with micrognathia on mandible's coronary CT,including the distance between the mandibular canal and the external surfaces of the mandible (buccal,lingual,and inferior) on each molar regions; the data were analyzed by SPSS13.0 software.Results The mean and standard deviation of three thickness indexes (buccal,lingual,and inferior) were as follows:in the second premolar area:(4.71±1.25),(2.77±1.02),(2.92±0.83) mm; in the first molar area:(2.64±0.99),(4.33±1.12),(2.38±0.72) mm; in the second molar area:(2.44±0.76),(4.20±0.89),(3.38±1.31) mm.There were no significant differences about all the indexes between left and right side.From the second premolar area to second molar area,mandibular canal locating at lingual side accounted for 94.4％ (68 sides),and locating at buccal side acounted for 5.6％ (4 sides).Mental foramen locating between the first and second premolar area acounted for 76.3％ (55 sides),and 23.7％ (17 sides) of mental foramen located in the second premolar area.The mandibular canal with a branch accounted for 3.5％ (3 sides).Conclusions Mandibular canal arises from mandibular foramen,courses the mandible on the inferior and lingual side,and ends in mental foremen.Some anatomical variations of mandibular canal should be noticed by the surgeons,such as a branch line of mandibular canal,coursing on the buccal side,with position of mental foremen moving backward. Key words: Computerized tomography (CT) ; Micrognathia; Mandibular canal