Dentists in St John are doctors who practice dentistry. They are involved in the study, diagnosis, prevention, and treatment of diseases, disorders and conditions of the oral cavity, maxillofacial area and the adjacent and associated structures and their impact on the human body. Dentistry is widely considered necessary for complete overall health. The dentist's supporting team aids in providing oral health services, which includes dental assistants, dental hygienists, dental technicians and dental therapists. The American Dental Association recognizes nine dental specialties: Public Health Dentistry, Endodontics, Oral and Maxillofacial Pathology, Oral and Maxillofacial Radiology, Oral and Maxillofacial Surgery, Orthodontics, Pediatric Dentistry, Periodontics, Prosthodontics, and General Dentistry.