1. Department of Geriatrics, Shenzhen Longhua District Central Hospital, The Affiliated Central Hospital of Shenzhen Longhua District, Guangdong Medical University, Shenzhen, China
2. Department of Stomatology, Renmin Hospital, Hubei University of Medicine, Shiyan, China
3. Department of Stomatology, Taihe Hospital, Hubei University of Medicine, Shiyan, China.