[1] Taipei Med Univ, Coll Oral Med, Sch Dent, 250 Wu Hsing St, Taipei 110, Taiwan
[2] Tokyo Med & Dent Univ, Grad Sch Med & Dent Sci, Gerodontol & Oral Rehabil, Tokyo 1138510, Japan
[3] Shuang Ho Hosp, Dept Dent, New Taipei 23561, Taiwan
[4] Taipei Med Univ Hosp, Dept Dent, 250 Wu Hsing St, Taipei 110, Taiwan
[5] Chang Gung Mem Hosp, Dept Dent, Taipei 106, Taiwan
[6] Chang Gung Univ, Grad Inst Dent & Craniofacial Sci, Taoyuan 333, Taiwan
[7] China Med Univ, Coll Med, Sch Dent, Taichung 404, Taiwan
[8] Taipei Med Univ Hosp, Dent Dept, Taipei 110, Taiwan