The Study on Course of the Inferior Alveolar Canal in the Mandibular Ramus Using Conebeam CT

Kim, Hyong Woo; Kwon, Kyung Hwan; Min, Seung Ki; Oh, Seung Hwan; Chee, Young Deok; Koh, Se Wook; Lee, Jae Hwan; Ohn, Byung Hun

Abstract

OBJECTIVES
This study was performed to evaluate course of the inferior alveolar canal in the mandibular ramus and to find safety zone when ramal bone is harvested.
PATIENTS AND METHODS
From January, 2009 to February, 2009, the 20 patients who visited in the Department of Oral and Maxillofacial Surgery, Sanbon Dental Hospital, Wonkwang University and the Conebeam CT was taken of various chief complaints, were selected. The patients who had left and right mandibular first molar and incisor missing, jaw fracture and bone pathology were excluded. The R point was defined as the point which occlusal plane was crossed to the mandibular anterior ramus(external oblique ridge). In the cross-sectional coronal and axial views, the inferior alveolar canal position to the R point, buccal bone width(BW), alveolar crest distance(ACD), distance from alveolar crest to occlusal plane (COD) and inferior alveolar canal to sagittal plane(CS) were measured and horizontal distance(HD), vertical distance(VD) and nearest distance(ND) were measured.
RESULTS
The inferior alveolar canal is located 6.19 +/- 1.21 mm from the R point. Horizontal distance from the R point were 13.07 +/- 2.45 mm, vertical distance from the R point were 14.24 +/- 2.41 mm and nearest distance from the R point were 10.12 +/- 1.76 mm. The course of the inferior alveolar canal was positioned within 0.61 +/- 0.68 mm. The distance from external buccal bone to the inferior alveolar canal was increased from the R point anteriorly.
CONCLUSIONS
It is considered that the mandibular ramus from the R point to 10 mm anteriorly can be harvested safely at ramal bone grafting.