Oral and maxillofacial pathology
Oral pathology is the study of the causes, processes, and effects of oral disease, together with the resultant alterations of oral structure and functions. The oral pathologist provides diagnoses on which treatment by other specialists will depend.
Endodontics
Endodontics deals with the treatment of diseases of the inside of the tooth, including the pulp chamber, the pulp canal, and contiguous structures. Root canal therapy and bleaching of nonvital teeth are standard treatments rendered by endodontists.
Public health dentistry
Dental public health is recognized as a specialty in Canada and the United States. The American Dental Association recognizes dental public health as a specialty if the holder of the master's degree proceeds to a further year of study in training and passes the examination of the American Board of Dental Public Health. Training in dental public health is also available in the United Kingdom. The specialty is not emphasized to the same degree in the rest of the world.
Oral and maxillofacial radiology
Oral and maxillofacial radiology deals with the use of X-rays for diagnosis and treatment of diseases or disorders of the mouth and jaw. It embraces not only the standard X-ray but also the panographic X-ray, as well as the use of radiation and radioactive materials in treatment of disease of the mouth and jaws.
Cosmetic dentistry
The face is the most recognizable feature of a person. The mouth, which includes the lips, cheeks, jaws, teeth, and gums, makes up the lower third of the face. Cosmetic (or aesthetic) dentistry may offer profound benefits to the quality of life for those people who need it.
Cosmetic dentistry may be classified as skeletal or dental. Skeletal changes may be achieved through oral surgery, which can change the position of the jaws. Dental changes may be achieved by either adding to, taking away from, or moving the teeth. The most common materials to add to teeth to change their appearance are bonding, a tooth-coloured plastic, or porcelain, a type of ceramic. Taking away tooth structure is accomplished with a drill. If only a slight amount of the tooth is removed, it is called sculpting or reshaping, and nothing is subsequently added. If a more substantial amount of tooth is removed, then porcelain may be added in a new position. Moving teeth is accomplished with braces, which can be either fixed or removable.
Reconstructive dentistry
Reconstructive dentistry involves any major rebuilding of the mouth, typically with porcelain and metal. Reconstructive dentistry may be needed by individuals who have many severe cavities, have generalized severe gum disease, or have been in an accident. Reconstructive dentistry frequently involves a combination of all the dental specialties; patients may need multiple crowns (caps), gum therapy, root canal therapy, braces, or oral surgery, including dental implants.
Reconstructions are planned to first stop the continuation of active disease and then repair the damage. Emotional components of treatment, such as fear, are frequently involved, and a dentist must be caring and have an understanding of psychology. Major potential sources of postoperative pain are often eliminated early in treatment by performing root canal therapy when indicated. The fabrication of final porcelain bridges usually begins 6 to 12 weeks following the completion of any necessary surgery. It is critical for patients to understand that reconstructed teeth require frequent cleanings and maintenance.
Implant dentistry
A dental implant is an artificial tooth root. It serves to attach artificial teeth to the underlying jawbone. Dental implants may be visualized as screws, and the jawbone may be considered a piece of wood. Under this analogy, a screw would be turned half its length into a piece of wood, and an artificial tooth would be glued to the part of the screw projecting above the wood. The tooth would be firmly attached to the screw, which in turn would be firmly anchored in the wood. A single dental implant may be used for one missing tooth. Four to eight dental implants may be placed in a jaw that is missing all the teeth.
Dental implants need to be placed in an adequate amount of bone that is free of infection. Sometimes surgical procedures are first necessary either to clean out existing infection or to create more bone for implantation procedures, such as bone ridge augmentation or nasal sinus elevation. The surgery to place the dental implants themselves is similar to that of tooth removal.
Dental implant reconstructions can take 6 to 12 months to complete, mostly because of the healing time necessary between surgeries. Because bone is living tissue, it needs time to respond favourably to the biocompatible titanium implants. The biophysics of the early cellular response of the hard (bone) and soft (skin and ligament) tissues to dental implantation is an area of intense research and debate. The benefits of this research carry over to orthopedics—for example, with the replacement of spinal rods and the healing of difficult broken bones, both of which require screws for immediate immobilization.
Implant dentistry has evolved into a very predictable treatment option for many people.
Oral microbiology
Oral microbiology, which is concerned with the effects of the more than 600 different species of oral bacteria on the teeth, gums, mouth, and other parts of the body that connect to the mouth through the digestive system and the circulation, is an important part of dental practice. Disease of the teeth and gums is generally bacterial in origin and can have a profound effect on general health. For example, the presence of certain species of bacteria in the gums can negatively influence the health of the heart and other important organs.
A significant amount of research in dentistry focuses on oral microbiology. Vaccines to prevent cavities are being studied, and antibiotics are used to treat periodontal (gum) disease. Vaccines and antibiotics work by suppressing or killing specific species of bacteria that have been identified as causative agents of disease.
Geriatric dentistry
Geriatric dentistry is concerned with the oral health of elderly persons, who usually have significant medical problems and are taking multiple medications. In addition, they may have psychological and socioeconomic problems that require sophisticated dental management. A basic premise of geriatric dentistry is that elderly people often experience symptoms of dental decay and gingival (gum) disorders that differ from symptoms experienced by younger people. Dental treatment for the elderly is therefore geared to any physical and mental limitations they may have.
Poor oral health in the elderly can lead to loss of appetite, malnutrition, metabolic disorders, and even, in cases of facial disfigurement, the onset of depression. Periodontal disease has been linked to heart disease, stroke, diabetes, osteoporosis, and other illnesses. With the number of elderly persons of advanced age (85 years or older) with mental disorders such as Alzheimer disease reaching epidemic proportions, dental management of affected individuals has become a major challenge in clinical dental practice. The elderly often take many medications, which have adverse side effects such as dry mouth, a major cause of dental decay. The effects of aging result in changes in lip posture, chewing efficiency, and ability to swallow and taste and in an increase in diseases of the hard and soft tissues of the mouth.
Although the majority of the elderly retain their natural teeth, dental decay, periodontal disease, and loss of teeth in individuals over the age of 65 have reached significant proportions. This backlog of oral disorders demands education, research, and advanced clinical training in geriatric dentistry.
Other disciplines
There are several other disciplines in dentistry that, although not true specialties or subspecialties, are nevertheless the principal field of expertise of various dentists, who devote all or a major portion of their practice to these fields. Among them are oral medicine and forensic dentistry.
Oral medicine, or stomatology, treats the variety of diseases that affect both the skin and the oral mucous membranes. Some of these diseases, such as pemphigus vulgaris, can develop their first manifestations in the mouth and can be life-threatening. Oral cancer also has a high mortality rate, partly because it grows in such close proximity to so many vital structures and readily involves them. With all such diseases of the oral cavity, removal of a portion of the lesion for examination under the microscope (biopsy) by an oral pathologist is an essential procedure, and many other laboratory procedures are often also required for the diagnosis of oral mucosal diseases.
Forensic dentistry is the study and practice of aspects of dentistry that are relevant to legal problems. It is a specialty practiced by few and is not usually part of dental education. Forensic dentistry is, however, of considerable legal importance for several reasons, one of the most important of which is the fact that the teeth are the structures of the body most resistant to fire or putrefaction. Moreover, the arrangement of the teeth or any restoration in them is virtually or completely unique to any given individual and, if dental records can be found, may enable identification with certainty similar to that provided by fingerprinting. For example, the identification of human remains after aircraft accidents can often be made only by this means. Minor irregularities of the teeth can also be reproduced in bite marks, which enables a suspect to be identified if he or she has bitten another person.
Dental education
Predental programs
In a majority of countries in the world, undergraduate training in dentistry is available. Many require predental training prior to acceptance into a school of dentistry. The predental training is in addition to primary and secondary education, which usually takes from 10 to 12 years. The required number of years in predental education varies from one to seven (a number of European countries require from five to seven years of medical education before entering dentistry). Predental course training usually includes such studies as biology, chemistry, physics, and mathematics. Certain faculties of dentistry in Canada and the United States require a bachelor's degree in arts or science as a prerequisite for admission into a dental faculty.
Dental school and training
After predental courses, training consists of four years in a faculty of dentistry to qualify as a doctor of dental surgery (D.D.S.) or doctor of dental medicine (D.M.D.), both degrees being equivalent. The program of studies during the four-year course includes the following biological sciences: human anatomy, biochemistry, bacteriology, histology, pathology, pharmacology, microbiology, and physiology, upon which the succeeding studies of the theory and techniques of dental practice are based. Studies required with respect to dental practice include restorative dentistry, prosthetics, orthodontics, surgery, preventive dentistry, medicine, dental public health, pedodontics, periodontics, radiology, clinical practice, and anesthesia.
Ancillary dental fields
Dental hygienists
The dental hygienist is a figure in the campaign to reduce periodontal disease and to improve physical well-being by promoting better care of the mouth.
The prevention of oral disease through education and treatment is the chief function of hygienists. The specific duties and services that they are allowed to perform depend on the bylaws of the licensing bodies, the requirements of the dental offices in which they are employed, or the aims and objectives of the public health programs in which they are engaged. Hygienists generally work under the effective supervision of a qualified dentist. In some cases, hygienists are permitted to work without supervision.
Hygienists employed in dental offices remove deposits and stains from the patient's teeth, apply fluorides, and observe and record conditions of decay and disease for the dentist's information. Further duties may include the taking of X-ray photographs of parts of the mouth, which the hygienist develops and mounts. Another function of the hygienist is to promote dental health by advising on diet and nutrition and encouraging oral hygiene.
Hygienists employed by educational authorities assist school dentists by performing such duties as examining children's teeth. They may also visit classrooms to explain the importance of oral hygiene and to give instruction in the proper care of the teeth and gums. In hospitals they perform mainly the same duties as for private practitioners.
Dental nurses and dental auxiliaries
In New Zealand, auxiliaries known as dental nurses (or dental therapists) have been carrying out a dental care program for children for a number of years. Traditionally, a dental nurse receives minimal supervision but is equipped to provide a dental care program for children and adolescents up to 18 years of age. In the past, a degree in dental therapy required two years of specialized training. Today a university-level Bachelor of Oral Health degree has replaced programs in dental therapy in New Zealand. To obtain a bachelor's in oral health, students are trained in both dental therapy and dental hygiene for a period of three years.
Dental assistants
The majority of dentists in private practice employ one or more dental assistants to provide such services as the reception of patients, the keeping of records and accounts, assistance for the dentist while he or she is treating patients, general upkeep of the office, developing of dental X-rays, and sterilization of instruments.
Dental technology
Organizations
In the United States, every state has its own dental society, which is subdivided into local societies. Membership in the local society automatically confers membership in the state society and the American Dental Association. In addition, the National Dental Association exists to represent ethnic minorities in dentistry in the United States. The National Dental Association was formed in 1932 by African American dentists, who were experiencing racial discrimination and were prevented from becoming members of organized dental societies. Today the American Dental Association will allow no form of racial bias to prevent membership. Dentists with similar interests have formed their own organizations, such as the American Association of Women Dentists, the National Association of Seventh Day Adventist Dentists, the American Academy of the History of Dentistry, and many others. In addition, every specialty has its own organization.
Associations of dentists, dental journals, and dental schools exist in almost every country of the world. The Fédération Dentaire Internationale (International Dental Federation) was founded in 1900 and has met annually except in times of war. It has sponsored international dental congresses that are planned to meet every five years. Other international organizations include the Association Internationale pour la Recherche Dentaire (International Association for Dental Research) and the Association pour les Recherches sur les Paradentopathies (Association for Research into Periodontal Diseases), which was organized in 1932. The International Dental Journal, published by the Fédération Dentaire Internationale, was founded in 1950.
Within the general framework of the World Health Organization, the dental health program has progressed steadily from the beginning. A proposal for a joint review of stomatology and dental hygiene in collaboration with the Fédération Dentaire Internationale was made at the first World Health Assembly in 1948.
Certain organizations, including the World Health Organization and the Fédération Dentaire Internationale, and countries such as New Zealand and the United States offer assistance to many developing countries in the provision of health educational and dental care services. For example, New Zealand has long given developing countries the benefit of its experience in the use of dental auxiliaries, or what are commonly known as school dental nurses. Direct assistance is provided in the development of other public health dental services to countries such as Sri Lanka, Malaysia, Singapore, Brunei, Thailand, Indonesia, and Papua New Guinea. Dentists from these countries have had the opportunity to study the New Zealand system, and a number of school dental nurses have received their training there, enabling them to assist in the establishment of training facilities in their home countries.