[1] Univ Catolica Portuguesa, Fac Med Dent, Viseu, Portugal
[2] Univ Catolica Portuguesa, Ctr Interdisciplinary Res Hlth, Inst Hlth Sci, Viseu, Portugal
[3] Univ Michigan, Ctr Comprehens Canc, Dept Periodont & Oral Med, Ann Arbor, MI 48109 USA
[4] Univ Michigan, Ctr Comprehens Canc, Lab Epithelial Biol, Ann Arbor, MI 48109 USA