Dentistry is the art and science of prevention, diagnosis, treatment of conditions, diseases and disorders of the oral cavity, the maxillofacial region, and its associated structures as it relates to human beings. A dentist is a doctor qualified to treat diseases, malformations of, and injuries to teeth, the oral cavity, maxillofacial region and its associated structures. In most countries, several years of training in a university (usually 4-8) and some practical experience working with actual patients' dentition are required to become a qualified dentist. The patron saint of dentists is Saint Apollonia, martyred in Alexandria by having all her teeth violently extracted.

Specialties
Visits to the dentist are often feared or dreaded. There are nine dental specialties recognized by the American Dental Association and require 2-6 years of further formal university training after dental school. The specialties are Dental Public Health (study of dental epidemiology and social health policies), Endodontics (root canal therapy), Oral and Maxillofacial Pathology (study, diagnosis, and often the treatment of oral and maxillofacial related diseases), Oral and Maxillofacial Radiology (study and radiologic interpretation of oral and maxillofacial diseases), Oral and Maxillofacial Surgery (extractions and facial surgery), Orthodontics and Dentofacial Orthopedics (straightening of teeth), Pedodontics (pediatric dentistry; i.e. dentistry for children), Periodontics (treatment of gum disease), Prosthodontics (replacement of missing facial anatomy by prostheses such as dentures, bridges and implants).

Specialists in these fields are designated registrable (U.S. 'Board Eligible') and warrant exclusive titles such as orthodontist, oral surgeon, pedodontist, periodontist, or prosthodontist upon satisfying certain local (U.S. 'Board Certified') registry requirements.

Two other post-graduate formal advanced education programs: General Practice Residency (advanced clinical and didactic training with intense hospital experience) and Advanced Education in General Dentistry (advanced training in clinical dentistry) recognized by the ADA do not lead to specialization.

Other dental education exists where no post-graduate formal university training is required: cosmetic dentistry, dental implant, temporo-mandibular joint therapy. These usually require the attendance of one or more continuing education courses that typically last for one to several days. There are restrictions on allowing these dentists to call themselves specialists in these fields. The specialist titles are registrable titles and controlled by the local dental licensing bodies.

Forensic odontology consists of the gathering and use of dental evidence in law. This may be performed by any dentist with experience or training in this field. The function of the forensic dentist is primarily documentation and verification of identity.

Geriatric dentistry or gerodontics is the delivery of dental care to older adults involving the diagnosis, prevention and treatment of problems associated with normal aging and age-related diseases as part of an interdisciplinary team with other health care professionals.

Veterinary dentistry, a specialty of veterinary medicine, is the field of dentistry applied to the care of animals.

History
In 2001 archaeologists studying the remains of two men from Mehrgarh , Pakistan and made the discovery that the people of Indus Valley Civilization, even from the early Harappan periods (c. 3300 BC), had knowledge of medicine and dentistry. The physical anthropologist that carried out the examinations, Professor Andrea Cucina from the University of Missouri-Columbia, made the discovery when he was cleaning the teeth from one of the men (see History of medicine). Later research in the same area found evidence of teeth having been drilled, dating back nine thousand years.

Some information contained in the Edwin Smith Papyrus dates as early as 3000 BC and includes the treatment of several dental ailments. Hammurabi's Code contains some references to dental procedures and fees. The Ebers papyrus also discusses similar treatments. Examining the remains of some ancient Egyptians and Greco-Romans reveal early attempts at dental prosthetics and surgery.

Historically, dental extractions have been used to treat a variety of illnesses. During the Middle Ages and through the 19th century, dentistry was not a profession into itself, and often dental procedures were performed by barbers or general physicians. Barbers usually limited their practice to extracting teeth, which not only resulted in the alleviation of pain, but often cured a variety of ailments linked with chronic tooth infection. Instruments used for dental extractions date back several centuries. In the 14th century, Guy de Chauliac invented the dental pelican (resembling a pelican's beak) which was used through the late 18th century. The pelican was replaced by the dental key which, in turn, was replaced by modern forceps in the 20th century.