Low-Energy Laser Irradiation Accelerates the Velocity of Tooth Movement via Stimulation of the Alveolar Bone Remodeling

  • Takamasa Yoshida, Department of Orthodontics, Nihon University School of Dentistry at Matsudo, Japan, Japan
  • Masaru Yamaguchi, Department of Orthodontics, Nihon University School of Dentistry at Matsudo, Japan, Japan
  • Tadahiko Utsunomiya, Department of Oral Pathology, Nihon University School of Dentistry at Matsudo, Japan, Japan
  • Yoshinori Arai, Nihon University School of Dentistry, Tokyo, Japan, Japan
  • Hirotsugu Yamamoto, Department of Oral Pathology, Nihon University School of Dentistry at Matsudo, Japan, Japan
  • Kazutaka Kasai, Department of Orthodontics, Nihon University School of Dentistry at Matsudo, Japan, Japan
  • Hirotsugu Yamamoto, Department of Oral Pathology, Nihon University School of Dentistry at Matsudo, Japan, Japan
  • Kazutaka Kasai, Department of Orthodontics, Nihon University School of Dentistry at Matsudo, Japan, Japan

Introduction: Previously, the authors have reported the acceleration of tooth movement and osteoclastogenesis on the pressure side in an experimental tooth movement model by low-energy laser irradiation (LELI), which stimulated the RANK / RANKL system and c-fms / M-CSF system. However, the effect of LELI on osteogenesis on the tension side is not known clearly. Moreover, the temporal changes in alveolar bone during tooth movement have not been investigated, as yet. Therefore, the present study was designed to examine the effects of LELI on alveolar bone remodeling during experimental tooth movement, and to observe the temporal bone mineral density (BMD) using micro-computed tomography (µCT).
Materials and Methods: To induce experimental tooth movement in rats, 10 g force was applied to the upper right first molar with NT-coil. Next, a gallium-aluminum-arsenide (Ga-Al-As) diode laser was used to irradiate the area around the moved tooth, and BMD and the amount of tooth movement were measured by µCT scanning for 21 days. Histopathological examination was also performed.
Results: The amount of tooth movement in the LELI group was significantly greater than that in the non-irradiation group by the end of the experimental period. Further, compared with non-irradiation group, the fall of BMD was less in the LELI group.
Conclusion: These findings suggest that LELI accelerates the velocity of tooth movement via stimulation of the alveolar bone remodeling.