Dentistry is a branch of medicine that is involved in the study, diagnosis, prevention, and treatment of diseases, disorders and conditions of the oral cavity, commonly in the dentition but also the oral mucosa, and of adjacent and related structures and tissues, particularly in the maxillofacial (jaw and facial) area. Although primarily associated with teeth among the general public, the field of dentistry or dental medicine is not limited to teeth but includes other aspects of the craniofacial complex including the temperomandibular and other supporting structures. The term dentistry comes from odontology (from Ancient Greek ὀδούς (odoús, "tooth")) – the study of the structure, development, and abnormalities of the teeth. Because of their substantial overlap in concept, dentistry is often also understood to subsume the now largely defunct medical specialty of stomatology (the study of the mouth and its disorders and diseases) for which reason the two terms are used interchangeably in certain regions.
Dentistry is important to one's overall health. Dental treatments are carried out by the dental team, which often consists of a dentist and dental auxiliaries (dental assistants, dental hygienists, dental technicians, as well as dental therapists). Most dentists either work in private practices (primary care), dental hospitals or (secondary care) institutions (prisons, armed forces bases, etc.).
The history of dentistry is almost as ancient as the history of humanity and civilization with the earliest evidence dating from 7000 BC. Remains from the early Harappan periods of the Indus Valley Civilization (c. 3300 BC) show evidence of teeth having been drilled dating back 9,000 years. It is thought that dental surgery was the first specialization from medicine.
Dentistry usually encompasses very important practices related to the oral cavity. Oral diseases are major public health problems due to their high incidence and prevalence across the globe with the disadvantaged affected more than other socio-economic groups.
The majority of dental treatments are carried out to prevent or treat the two most common oral diseases which are dental caries (tooth decay) and periodontal disease (gum disease or pyorrhea). Common treatments involve the restoration of teeth, extraction or surgical removal of teeth, scaling and root planing and endodontic root canal treatment.
All dentists in the United States undergo at least three years of undergraduate studies, but nearly all complete a bachelor's degree. This schooling is followed by four years of dental school to qualify as a "Doctor of Dental Surgery" (DDS) or "Doctor of Dental Medicine" (DMD). Dentists need to complete additional qualifications or continuing education to carry out more complex treatments such as sedation, oral and maxillofacial surgery, and dental implants.
By nature of their general training they can carry out the majority of dental treatments such as restorative (fillings, crowns, bridges), prosthetic (dentures), endodontic (root canal) therapy, periodontal (gum) therapy, and extraction of teeth, as well as performing examinations, radiographs (x-rays) and diagnosis. Dentists can also prescribe medications such as antibiotics, sedatives, and any other drugs used in patient management.
Dentists also encourage prevention of oral diseases through proper hygiene and regular, twice yearly, checkups for professional cleaning and evaluation. Conditions in the oral cavity may be indicative of systemic diseases such as osteoporosis, diabetes, or cancer. Many studies have also shown that gum disease is associated with an increased risk of diabetes, heart disease, and preterm birth. The concept that oral health can affect systemic health and disease is referred to as "oral-systemic health".
Some dentists undertake further training after their initial degree in order to specialize. Exactly which subjects are recognized by dental registration bodies varies according to location. Examples include: