1. Departments of Periodontics and
2. Pathology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA;
3. Department of Preventive Dentistry, Periodontology, and Cariology, University of Zürich Dental School, Zürich, Switzerland;
4. Department of Oral Surgery and Stomatology, University of Bern, School of Dental Medicine, Bern, Switzerland; and
5. Department of Orthodontics, Universidad Autonoma de Coahuila Facultad de Odontologia, Torreon, Mexico;