Dr. Toru Deguchi is an Associate Professor and Graduate Program Director in the Division of Orthodontics at the Ohio State University College of Dentistry. He completed his dental training at the Aichi-Gakuin University and received PhD at the Okayama University. He also had his orthodontic training at the Indiana University.He has been focusing his clinical interests in the field of temporary anchorage device (TADs), lingual orthodontics, and interdisciplinary cases. He has been also engaged in the research field such as histomorphometric studies related to tooth movement and pain related studies. Dr. Deguchi is a Diplomate of American Board of Orthodontics and a member of the Midwest Angle Society. Dr. Deguchi has lectured as invited speaker at the European Orthodontic Society, American Association of Orthodontics and in other international meetings all around the world.

Title of Talk

Biomechanical Characteristics in the Use of TADs


One of the most concerns in using temporary anchorage devices (TADs) is the high failure rate. In the past, we have been using cone beam CT (CBCT) to evaluate root proximity of TADs that is suggested to be one of the most important failure factors. However, it would be beneficial for patients if there were ways to predict the stability of TADs without radiation. Thus, we have investigated the usefulness of Periotest and resonance frequency analysis (RFA) to predict the stability of TADs and analyzed the correlation with CBCT and mechanical data in artificial bone, animal bone, and in actual patients. Mechanical characteristics in different types of TADs were also investigated. Unfortunately, most of the commercially available TADs are large and placed perpendicular to the tooth. The size such as the diameter and the length, and placement angulation would have a significant impact in the root proximity and in the failure rate. In addition, since we suggest that drilling procedure enables us to avoid root contact and increased insertion torque, we also have compared the outcome between self-drilling and self-tapping methods.