1. Department of Masticatory Disorders; School of Dental Medicine; University of Zurich; Zurich Switzerland
2. Department of Oral Diagnostic Sciences; School of Dental Medicine; University at Buffalo; Buffalo NY USA
3. Departments of Orthodontics & Dentofacial Orthopedics and Oral & Craniofacial Sciences; School of Dentistry; University of Missouri-Kansas City; Kansas City MO USA
4. Department of Biostatistics & Epidemiology; East Tennessee State University; Johnson City TN USA