1. School of Dentistry; Chung Shan Medical University; Taichung Taiwan
2. Department of Dentistry; Chung Shan Medical University Hospital; Taichung Taiwan
3. School of Public Health; Chung Shan Medical University; Taichung Taiwan
4. Institute of Oral Sciences; Chung Shan Medical University; Taichung Taiwan
5. School of Dentistry; College of Oral Medicine; Taipei Medical University; Taipei Taiwan
6. Division of Oral and Maxillofacial Surgery; Department of Dentistry; Wan Fang Hospital; Taipei Medical University; Taipei Taiwan
7. Department of General Surgery; Changhua Christian Hospital; Changhua Taiwan