Affiliation: | 1. Department of Oral Medicine, University of Pennsylvania School of Dental Medicine, 240 South 40th Street, Philadelphia, PA 19104, USA;2. University of Pennsylvania School of Dental Medicine, 240 South 40th Street, Philadelphia, PA 19104, USA;3. Department of Oral and Maxillofacial Medicine and Diagnostic Sciences, CWRU School of Dental Medicine, Office # 245 C, 9601 Chester Avenue, Cleveland, OH 44106, USA |