1. Chronic Pain Unit, Clinica Alemana, Clinica Davila, Chile, Faculty of Medicine, Universidad del Desarrollo, Santiago, Chile
2. Pain Unit, Mutual de Seguridad Hospital, Chile, School of Dentistry, Faculty of Medicine, Pontificia Universidad, Católica de Chile, Santiago, Chile
3. Maxillofacial Surgery and Traumatology, Universidad Mayor, Santiago, Chile
4. Maxillofacial Surgery and Traumatology, Mutual de Seguridad Hospital, Santiago, Chile