The Administration of 4-Hexylresorcinol Accelerates Orthodontic Tooth Movement and Increases the Expression Level of Bone Turnover Markers in Ovariectomized Rats.

Kwang-Hyo Choi,Dae-Won Kim,Suk Keun Lee,Seong-Gon Kim,Tae-Woo Kim

doi:10.3390/ijms21041526

Abstract

Surgical methods for accelerating orthodontic tooth movement are limited by possible damage to the tooth root and patient discomfort. 4-Hexylresorcinol (4HR) has been shown to increase bone remodeling and may potentially facilitate tooth movement. This study investigated the (1) effect of 4HR administration on osteoblast-like cells and (2) effect of 4HR administration on tooth movement in ovariectomized rats. Saos-2 cells were treated with either 4HR or solvent (control). Protein expression levels were investigated 2, 8, and 24 h after treatment. Thirty ovariectomized Sprague-Dawley rats were divided into two experimental groups (A and B) and one control group. After installation of an orthodontic tooth movement device, groups A and B received subcutaneous weekly injections of 4HR (1.28 and 128 mg/kg). Micro-computerized tomography and histological analyses were performed after 2 weeks of tooth movement. The application of 4HR elevated expression of osteogenic markers in Saos-2 cells. Movement of the first molars was significantly greater in rats administered 4HR. Furthermore, the expression of bone morphogenic protein-2, receptor activator of nuclear factor kappa-B ligand, osteocalcin, and tartrate-resistant acid phosphatase were increased after 4HR administration. 4HR application demonstrated increased expression of osteogenic markers in Saos-2 cells and accelerated orthodontic tooth movement in rats.

Highlights

Orthodontic treatment involves tooth movement, which requires the remodeling of the surrounding tissues
In order for tooth movement to occur without damaging the surrounding tissues, the alveolar bone is resorbed on the side towards which the tooth is being moved, and new bone formation occurs on the opposite side [2,3]
We have recently reported that 4HR increases the expression of transforming growth factor-β1 (TGF-β1) [19]

Summary

Introduction

Orthodontic treatment involves tooth movement, which requires the remodeling of the surrounding tissues. Studies have evaluated the effectiveness of increasing the amount of orthodontic force used [3,4], as well as the use of vibration [5]. Surgical interventions such as corticotomy, micro-perforation, and piezocision have been assessed for their ability to induce accelerated bone remodeling [6,7]. Such procedures may damage the tooth root and cause discomfort and pain. The stimulation of bone resorption may result in delayed bone formation on the tension side, leading to periodontal problems

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