1. Division of Plastic and Reconstructive Surgery, Department of Surgery, School of Medicine, Stanford University, Palo Alto, CA, USA
2. State Key Laboratory of Oral Diseases and National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
3. Dr. Gerald Niznick College of Dentistry, University of Manitoba, Winnipeg, MB, Canada
4. Department of Stomatology, The Affiliated Hospital of Qingdao University, Qingdao, China