Shouichi MIYAWAKI, DDS, PhD
Dean, Faculty of Dentistry, Kagoshima University
Professor and Chair, Department of Orthodontics, Kagoshima University Graduate School of Medical and Dental Sciences
EDUCATION:
Osaka University Graduate School of Dentistry Ph.D. Orthodontics 1994
Osaka University Faculty of Dentistry D.D.S. 1989
PROFESSIONAL EXPERIENCE:
Dean, Faculty of Dentistry, Kagoshima University 2016- present
Vice-Dean, Graduate School of Medical and Dental Sciences, Kagoshima University, 2011-2016
Assistance Director, Kagoshima University Medical and Dental Hospital, 2009-2011
Professor and chair, Department of Orthodontics, Kagoshima University Graduate School of Medical and Dental Sciences, 2005-present
Associate Professor, Okayama University, 2005
Research fellow, Montreal University, Canada, 2001-2002
Lecturer, Okayama University, 1999-2005
Assistant Professor, Nara Medical University, 1997-1999
Postdoctoral Fellow, Osaka University, 1994-1997
LICENSE:
Instructor’s License approved by Japanese Society for Temporomandibular Joint, 2008
TMJ License approved by Japanese Society for Temporomandibular Joint, 2008
Supervisor Instructor’s License approved by the Japanese Orthodontic Society, 2005
Clinical Instructor (Minister of Health, Labour and Welfare), 2003
Instructor’s License approved by the Japanese Orthodontic Society, 2001
Orthodontic license approved by the Japanese Orthodontic Society, 1994
Japanese Dental License (Minister of Health, Labour and Welfare), 1989
PROFESIONAL ORGANIZATIONS:
Japanese Orthodontic Society (Editor in Chief, 2014-present; Editorial member 2008-present; Secretary on Editorial Board 2000-2001)
Kyushu Orthodontic Society (Vice-president 2017-present; Academic director 2005-present)
Japanese Society of Stomatognathic Function (Editorial member 2006-2014; Director 2006-present)
Factors related to the failure of miniscrew implants and the development of an auxiliary appliance to increase the retention force as its solution
At present, miniscrews as a skeletal anchorage device have been widely used as absolute anchorage during orthodontic treatment. To date, it has been reported that approximately 15% of miniscrews failed when they were implanted in the alveolar bone of the buccal molar region. However, there have been no solutions for the failure. The implantation of a conventional miniscrew is prohibited in children with mixed dentition due to the existence of tooth germ and soft alveolar bone.
As for the factors related to the failure of miniscrew implants, many studies have revealed several factors related to the failure such as diameter of the miniscrew, length, shape, pitch, insertion torque, angle of implantation to bone surface, implantation method, years of experience, thickness of the cortical bone, age, region to implant, and dentofacial morphology. According to several meta-analyses, it has been reported that both initial fixation (including thickness of cortical bone, diameter and pitch of miniscrew, age, mandibular morphology, insertion torque) and proximity of dental root (including implantation region, and length and shape of miniscrew) are very important factors related to the failed miniscrew implants.
Therefore, to solve the aforementioned related factors such as initial fixation and proximity of dental root, newly designed skeletal anchorages have recently been reported. We also invented a new auxiliary appliance with automatic implantation to reinforce the retention force of the miniscrew. I will explain the merits and problems in my presentation.