1. Division of Periodontics; Department of Dentistry; Changhua Christian Hospital; Changhua Taiwan
2. Institute of Epidemiology and Preventive Medicine; College of Public Health, National Taiwan University; Taipei Taiwan
3. Periodontal Clinics, Department of Dentistry; Taipei Medical University Hospital; Taipei Taiwan
4. Division of Family Dentistry, Department of Dentistry; Taipei Medical University Hospital; Taipei Taiwan
5. Division of Oral and Maxillofacial Surgery, Department of Dentistry; Shuang Ho Hospital; Taipei Taiwan
6. Division of Periodontics; College of Oral Medicine, Taipei Medical University; Taipei Taiwan