[1] Sichuan Univ, West China Hosp Stomatol, Natl Clin Res Ctr Oral Dis, State Key Lab Oral Dis, Chengdu, Peoples R China
[2] Sun Yat Sen Univ, Hosp Stomatol, Guanghua Sch Stomatol, Guangzhou, Peoples R China
[3] Univ Michigan, Univ Michigan Rogel Canc Ctr, Sch Dent, Dept Periodont & Oral Med, Ann Arbor, MI USA