1. Department of Public Health; Faculty of Dentistry; The University of Hong Kong; Prince Philip Dental Hospital 3/F; Sai Ying Pun Hong Kong China
2. Department of Oral Rehabilitation; Faculty of Dentistry; The University of Hong Kong; Prince Philip Dental Hospital 4/F; Sai Ying Pun Hong Kong China
3. Department of Rehabilitation Medicine; Tung Wah Hospital; Sheung Wan Hong Kong China