[1] Capital Med Univ, Sch Stomatol, Outpatient Dept Oral & Maxillofacial Surg, Tian Tan Xi Li 4, Beijing 100050, Peoples R China
[2] Chinese Acad Med Sci, Dept Stomatol, 41 Damucang Hutong, Beijing 100032, Peoples R China
[3] Peking Union Med Coll Hosp, 41 Damucang Hutong, Beijing 100032, Peoples R China
[4] Beijing Citident Stomatol Hosp, Beijing 100032, Peoples R China