1989 Nihon University School of Dentistry at Matsudo, DDS
1994 Nihon University Graduate School of Dentistry at Matsudo, PhD (Orthodontics)
1995 The Japan Foundation for Aging and Health, Research resident
2001 Nihon University School of Dentistry at Matsudo, Department of Orthodontics,
Senior lecturer
2005 The University of Sydney, Research Fellow
2007- present
Nihon University School of Dentistry at Matsudo, Associate professor

Title of Talk

Analysis of microbial profile to failure of orthodontic anchor screw


The purposes of this study were to examine the potential factors affecting the failure rates of orthodontic anchor screws used for orthodontic anchorage, and to evaluate the relationship between orthodontic anchor screw failure and periodontopathogeneic bacteria.

One hundred eighty-eight (188) anchor screws were placed in 104 patients (83 females and 21 males) to provide indirect orthodontic anchorage. 162 screws placed in the maxilla and 26 were insert in the mandible. The success rate was calculated to different site of insertion in the buccal alveolar bone, palatal bone, and mandibular.
Furthermore, in the inflamed peri-implant tissue, Porphyromonas gingivalis (Pg) , Actinobacillus actinomycetemcomitans (Aa) , Treponema denticola (Td) , Tannerella forsythia (Tf) , Prevotella intermedia (Pi) were evaluated by real-time PCR analysis.

The results in this study demonstrated that the mean overall success rate of the orthodontic anchor screw was 84.6%, and both in the buccal inter-radicular bone and the palatal were 87.6%. However, the success rate in the mandibular was low. The anchor screws with inflammation of peri-implant tissue after insertion showed a significantly lower success rate than those without inflammation. The results of real-time PCR showed that Td and Tf were detected in the inflamed peri-implant tissue.

Inflammation of the peri-implant tissue and the increased abundances of Td and Tf may be associated with the failure of anchor screw.