Abstract:

Objective   To investigate the height, width and cortical  thickness of mandibular body of Han adults with average facial-skeletal pattern by cone beam CT (CBCT), and to determine the morphologic characteristics. Methods   A total of 108 adult patients from the Department of Orthodontics, School of Stomatology in Shandong University were enrolled in the research. All patients were examined with CBCT scan to measure the height, width and thickness of cortex of the cross-sections of mandibular body. Results   The height increased gradually from the posterior segments to the symphysis, with a maximum of 35.20mm. The upper one third width increased from the symphysis to the posterior segments; the lower one third width decreased from the premolar segments to lateral incisors, and increased in the symphysis. In the buccal side, the cortical  thickness of upper one third increased from the symphysis to the posterior segments, but the range of change was wide; the lower one third decreased from molar segments to lateral incisors and then increased in the symphysis. The cortex was the thickest in mandibular margin; the thickness increased from the symphysis to canine teeth segments and became thinner from canine teeth segments to posterior segments. In the lingual side, the thickness of cortical bone of lower one third increased from the molars segments to the symphysis; the upper one third increased gradually from the molar regions to the premolar segments and then decreased in the symphysis. Conclusion    Some morphological regularities are showed in the mandibular body in Han adults with average skeletal pattern, which can provide clinical reference for orthodontic treatment and surgical operations. 

Key words: Mandibular body; Cortical bone; Cone beam CT; Average skeletal pattern; Adults