1. Department of Oral and Maxillofacial Radiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan.
2. Department of Oral Diagnosis and Dentomaxillofacial Radiology, Okayama University Hospital, Okayama, Japan.
3. Department of Dental Informatics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan.
4. Oral Examination and Diagnosis Center, Okayama University Hospital, Okayama, Japan.