1. Department of Pediatric Dentistry, School of Dentistry, Loma Linda University, Loma Linda, CA 92350, USA
2. School of Dentistry, College of Oral Medicine, Taipei Medical University, 250 Wu-Hsing Street, Taipei, Taiwan
3. Biomechanics Research Laboratory, Center for Dental Research, Orthodontics and Dentofacial Orthopedics, Loma Linda University, Loma Linda, CA 92350, USA
4. Dental Education Services, School of Dentistry, Loma Linda University, Loma Linda, CA 92350, USA
5. Division of Oral Rehabilitation and Center of Pediatric Dentistry, Department of Dentistry, Taipei Medical University Hospital, 252 Wu-Hsing Street, Taipei, Taiwan
6. Department of Endodontics, School of Dentistry, Loma Linda University, Loma Linda, CA 92350, USA