Investigation of bone resorption mechanism caused by cortical bone microdamage associated with orthodontic miniscrew insertion

2022 Fiscal Year Final Research Report

• Project/Area Number: 18K17248
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 57070:Developmental dentistry-related
• Research Institution: Tokyo Medical and Dental University
• Principal Investigator: UEZONO Masayoshi 東京医科歯科大学, 大学院医歯学総合研究科, 助教 (80737346)
• Project Period (FY): 2018-04-01 – 2023-03-31
• Keywords: 歯科矯正用アンカースクリュー / マイクロダメージ / 模擬皮質骨 / resorption cavity / ストレスホワイトニング / 骨圧縮

Outline of Final Research Achievements

Orthodontic miniscrews can provide reliable anchorage for tooth traction, on the other hands, they also have such a problem as relatively higher rate of loosening in clinical usage. Many studies were conducted to investigate the factor of the miniscrew loosening. Especially, in resent year, microdamage to the cortical bone associated with the miniscrew insertion has been reported as a cause of loosening. However, it is still unclear whether microdamage causes acute cortical bone resorption around the miniscrew. In this research, the relationship between microdamage caused during the miniscrew insertion and cortical bone resorption around the miniscrew was investigated by using human bone analogue, extracted bone, and animal experiments.

Free Research Field

矯正歯科

Academic Significance and Societal Importance of the Research Achievements

研究開始当初は、動物実験モデルを作製し、皮質骨マイクロダメージによって急速な骨吸収が生じる機序の解明を行うことが目的だった。しかし、COVID19の流行によって動物実験を計画的に進めることが困難な状況に陥り、生体を用いない実験系を模索した。その結果、グラスファイバー強化エポキシ樹脂シートを用いた、新たな評価体系を確立することができた。これによって、不必要な動物実験を回避でき、実験期間の短縮や動物実験倫理の観点で有意義であった。また新たな実験系から得られた成果は、歯科矯正用アンカースクリューの改良の基礎となり、今後さらなる発展が望まれた。