1. Department of Orthodontics, Faculty of Dentistry, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
2. Department of Oral and Maxillofacial Radiology, Faculty of Dentistry, Kyushu University, Fukuoka, Japan
3. Dental School of Orthodontics, Jacksonville University, Jacksonville, FL, USA