Histomorphometric analysis of overloading on the palatal tooth movement into the maxillary sinus

Objectives: To evaluate the effect of overloading on the palatal movement of the maxillary molar.
Materials and methods: The maxillary first molar of male C57Bl/6 mice was moved palatally with 10-g or 30-g load for 14 days, and amount of tooth movement was longitudinally measured on micro-computed tomography images (each group, N=5). Bone remodeling around the molar root under the 30-g load was evaluated at days 3, 5, 7, and 14 after the starting of tooth movement using histomorphometry and immunodetection of bone-restricted Ifitm (interferon inducible transmembrane)-like protein, a novel marker of active bone formation (each group, N=5).
Result: In the 10-g load group, the amount of tooth movement increased dramatically between day 5 to day 7, and gradually increased thereafter. In 30-g load group, tooth movement at day 5 and day 7 was significantly lower than those in the 10-g load group; however, total tooth movement for 14 days was similar in both groups. Orthodontic load of 30-g stimulated bone formation on the sinus wall, but bone resorption on the periodontal ligament side was delayed because of the hyalinization, which means strong force application was not accelerate tooth movement. Moreover, some root resorption was induced under the excessive force application.
Conclusion: Root penetration into sinus and bone height reduction does not occur because new bone formation on the maxillary sinus is induced prior to bone resorption on the periodontal side, even though excessive orthodontic force is applied. However, excessive force is subject to induce root resorption.

内容要旨・審査要旨・論文本文の公開:
内容要旨 : LID201507301004.pdf
審査要旨 : LID201507301005.pdf
論文本文 : k2861_fulltext.pdf
著者の申請により要約(2015-09-18公開)に替えて論文全文を公開(2019-06-06)
本論文は, 著者Yuichi Maedaの学位論文として提出され, 学位審査・授与の対象となっている。

© 2015. This manuscript version is made available under the CC-BY-NC-ND 4.0
license http://creativecommons.org/licenses/by-nc-nd/4.0/