The Effects of Tooth Extraction on Cortical Thickness and Bone Mineral Density of the Mandible: Evaluation with Computerized Tomography


Abstract: The cortical thickness of the mandible (CTM) and its bone mineral density may be affected by tooth extraction. There is little knowledge of how the number of teeth in the mandible affect the cortical thickness and bone mineral density of the mandible in 2 different parts. The purpose of this study was to demonstrate whether there is any relationship between the number of teeth extracted and the cortical thickness and bone mineral density of the mandible. A total of 64 cases were evaluated in this study. The patients were divided into four groups. Group 1 consisted of 24 patients who had not been subject to tooth extraction from the mandible. Group 2 consisted of 19 patients who had 11-15 teeth. Group 3 consisted of 12 patients who had 1-10 teeth and Group 4 consisted of 9 patients who had no teeth. The CTM and bone mineral density at the mandibular cortex (BMDC), spongiosa (BMDS) and lumbar spine (BMD VER) were calculated by quantitative computed tomography (QCT). The CTM and the bone mineral density of the cortex (BMDC) of the mandible showed significant decreases in Groups 1 to 4. The most significant decrease was observed in the CTM. No relations between the BMDS and the number of teeth extracted were found. The males exhibited greater values than age-matched females. The BMD VER also affected the bone mineral status of the mandible. The findings suggest that the CTM is the most important index affected by tooth extraction. BMDC decreased with the decreasing value of the bone mineral content of the lumbar spine and the increasing level of tooth extraction from the mandible. The males exhibited greater CTM and BMDC than age-matched females.

Keywords: Bone mineral density, mandible, lumbar spine, quantitative CT

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