Yuichi Maeda1, Shingo Kuroda2, Khaliunaa Ganzorig1, Rima Wazen3, Antonio Nanci4, Eiji Tanaka5. 1. Graduate student, Department of Orthodontics and Dentofacial Orthopedics, Tokushima University Graduate School of Oral Sciences, Tokushima, Japan. 2. Associate professor, Department of Orthodontics and Dentofacial Orthopedics, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan. Electronic address: kuroda@tokushima-u.ac.jp. 3. Research associate, Laboratory for the Study of Calcified Tissues and Biomaterials, Faculty of Dentistry, Université de Montréal, Montréal, Québec, Canada. 4. Professor, Laboratory for the Study of Calcified Tissues and Biomaterials, Faculty of Dentistry, Université de Montréal, Montréal, Québec, Canada. 5. Professor and chair, Department of Orthodontics and Dentofacial Orthopedics, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan; distinguished adjunct professor, King Abdulaziz University, Jeddah, Saudi Arabia.
Abstract
INTRODUCTION: Our objective was to evaluate the effect of overloading on the palatal movement of the maxillary molar. METHODS: The maxillary first molars of male C57Bl/6 mice were moved palatally with loads of 10 or 30 g for 14 days, and the amount of tooth movement was longitudinally measured on microcomputed tomography images. Bone remodeling around the molar root with the 30-g load was evaluated at days 3, 5, 7, and 14 after the start of tooth movement using histomorphometry and immunodetection of bone-restricted interferon inducible transmembrane-like protein, a novel marker of active bone formation. RESULTS: In the 10-g load group, the amount of tooth movement increased dramatically between days 5 and 7 and increased gradually thereafter. Tooth movement at days 5 and 7 was significantly lower in the 30-g-load group than in the 10-g load group; however, the total tooth movement at 14 days was similar in the 2 groups. An orthodontic load of 30 g stimulated bone formation on the sinus wall, but bone resorption on the periodontal ligament side was delayed because of hyalinization, which means that strong force application did not accelerate tooth movement. Moreover, some root resorption was induced by the excessive force. CONCLUSIONS: Root penetration into the sinus and bone height reduction do not occur because new bone formation on the maxillary sinus is induced before bone resorption on the periodontal side, even though an excessive orthodontic force is applied. However, an excessive force can induce root resorption.
INTRODUCTION: Our objective was to evaluate the effect of overloading on the palatal movement of the maxillary molar. METHODS: The maxillary first molars of male C57Bl/6 mice were moved palatally with loads of 10 or 30 g for 14 days, and the amount of tooth movement was longitudinally measured on microcomputed tomography images. Bone remodeling around the molar root with the 30-g load was evaluated at days 3, 5, 7, and 14 after the start of tooth movement using histomorphometry and immunodetection of bone-restricted interferon inducible transmembrane-like protein, a novel marker of active bone formation. RESULTS: In the 10-g load group, the amount of tooth movement increased dramatically between days 5 and 7 and increased gradually thereafter. Tooth movement at days 5 and 7 was significantly lower in the 30-g-load group than in the 10-g load group; however, the total tooth movement at 14 days was similar in the 2 groups. An orthodontic load of 30 g stimulated bone formation on the sinus wall, but bone resorption on the periodontal ligament side was delayed because of hyalinization, which means that strong force application did not accelerate tooth movement. Moreover, some root resorption was induced by the excessive force. CONCLUSIONS: Root penetration into the sinus and bone height reduction do not occur because new bone formation on the maxillary sinus is induced before bone resorption on the periodontal side, even though an excessive orthodontic force is applied. However, an excessive force can induce root resorption.
Authors: Ehab A Abdulghani; Maged Sultan Alhammadi; Abeer A Al-Sosowa; Abeer A Almashraqi; Hasan M Sharhan; Hanan Al-Fakeh; BaoCheng Cao Journal: Clin Oral Investig Date: 2022-03-20 Impact factor: 3.606
Authors: Ehab A Abdulghani; Abeer A Al-Sosowa; Maged Sultan Alhammadi; Hanan Al-Fakeh; Waseem Saleh Al-Gumaei; Abeer A Almashraqi; Hasan M Sharhan; BaoCheng Cao Journal: Head Face Med Date: 2022-04-12 Impact factor: 2.151