Abstract
The aim of this study was to evaluate the thicknesses of cancellous and cortical bones, and to identify and
measure variation in the presence and extent of the anterior loop of the mandibular canal and canal itself in
the anterior and posterior regions. A total of 79 patients (52 males and 27 females; age range: 19-77 years; mean
age: 49 years) were scanned by computed tomography and the data were analyzed. The means and SD of
the cancellous (CAB) and cortical (COB) thicknesses ranged from 5.5 ± 1.2 mm to 11.1 ± 2.2 mm and from 4.5
± 1.0 mm to 5.3 ± 0.9 mm for males, respectively. For females, the cancellous and cortical thicknesses ranged
from 4.8 ± 1.3 mm to 10.3 ± 1.5 mm and from 3.8 ± 1.0 mm to 5.3 ± 1.2 mm, respectively. The morphology of
the mandible was classified into three types: type B (62%-72%), was the most common in the anterior region
for males, followed by type C (56%-58%) in the posterior region. For females, type C (25%-31%) in the posterior
region and type B (18%-30%) in the anterior region were the most common types. For implant placement on
the mandible, careful evaluation and full knowledge of the thicknesses of the cancellous and cortical thickness
are necessary; these results can help surgeons in terms of appropriate implant operation.
