Department of Orthodontics, School of Dentistry, Iwate Medical University
Abstract
歯科矯正治療についての知識や情報が一般的に知られ,歯の健康に対する意識や審美的意識の向上により,なかでも成人女性の矯正治療を希望する割合は年々増加する傾向にある。しかし,女性は40歳をさかいに骨密度が減少すると言われている。骨粗鬆症と歯槽骨の関係に関してはいくつかの報告があるが,歯の移動に関する報告はほとんどない。本研究では,12週齢の正常ラットと骨粗鬆症ラットの臼歯部に,矯正治療用ゴムリングを挿入し歯の移動を行った。歯槽骨の組織学的観察は一次抗体にTGF-β1抗体を用いた免疫組織染色法にて行った.その結果,骨粗鬆症であっても矯正力でTGF-β1は誘導され,歯槽骨骨梁の骨芽細胞ならびに破骨細胞に作用し,骨形成と骨吸収の両作用を活性化することにより歯槽骨の改造を引き起こすが,骨粗鬆症群では骨吸収の亢進と骨形成開始の遅延が生じている可能性が示唆された。With recently prevailed knowledge and information on orthodontic treatment as well as improved awareness about dental health and aesthetic concerns, the proportion of adult female orthodontic patients has tended to increase yearly. The decreases of bone density in females forty and older are known. Although several reports have investigated the possible relationship between osteoporosis and the alveolar bone, we could not find a report concerning the tooth movement in relation to this disease. In this study, we confirmed that tooth movement was experimentally induced by inserting a gum ring for orthodontic treatment onto the molar site of normal and osteoporotic rats 12 weeks postpartum. The histological study of the alveolar bone was performed with immunohistological staining using TGF- β 1 antibody as a primary antibody. As a result, we found that TGF-β 1 is induced by orthodontic force and acts on osteoblasts and osteoclasts in the alveolar bone and ultimately induces a reconstruction of alveolar bone through activation of both bone formation and resorption. This also occurred even in the case of osteoporosis, however, an enhanced bone resorption and delayed initiation of bone formation was suggested in the osteoporotic group
