1. Division of Diagnostic and Surgical Sciences, UCLA School of Dentistry, Los Angeles, CA 90095, USA
2. Department of Oral Medicine and Pathology, School of Dentistry, National and Kapodistrian University of Athens, Athens 11527, Greece
3. Department of Diagnostic and Biomedical Sciences, School of Dentistry, University of Texas Health Science Center at Houston, Houston, TX 77054, USA