Affiliation: | 1. Clinical Periodontics, School of Dentistry, College of Oral Medicine, Taipei Medical University, , Taipei, Taiwan;2. Clinical Periodontics of Dental Department, Taipei Medical University Hospital, , Taipei, Taiwan;3. Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, , Taipei, Taiwan;4. Division of Periodontics, Department of Dentistry, Changhua Christian Hospital, , Changhua, Taiwan |