Human teeth function to mechanically break down items of food by cutting and crushing them in preparation for swallowing and digesting. As such, they are considered part of the human digestive system. Humans have four types of teeth: incisors, canines, premolars, and molars, which each have a specific function. The incisors cut the food, the canines tear the food and the molars and premolars crush the food. The roots of teeth are embedded in the maxilla or the mandible and are covered by gums. Teeth are made of multiple tissues of varying density and hardness.
Orthodontics is a dentistry specialty that addresses the diagnosis, prevention, management, and correction of mal-positioned teeth and jaws, as well as misaligned bite patterns. It may also address the modification of facial growth, known as dentofacial orthopedics.
The third molar, commonly called wisdom tooth, is the most posterior of the three molars in each quadrant of the human dentition. The age at which wisdom teeth come through (erupt) is variable, but this generally occurs between late teens and early twenties. Most adults have four wisdom teeth, one in each of the four quadrants, but it is possible to have none, fewer, or more, in which case the extras are called supernumerary teeth. Wisdom teeth may become stuck (impacted) and not erupt fully, if there is not enough space for them to come through normally. Impacted wisdom teeth are still sometimes removed for orthodontic treatment, believing that they move the other teeth and cause crowding, though this is no longer held as true.
Hyperdontia is the condition of having supernumerary teeth, or teeth that appear in addition to the regular number of teeth. They can appear in any area of the dental arch and can affect any dental organ. The opposite of hyperdontia is hypodontia, where there is a congenital lack of teeth, which is a condition seen more commonly than hyperdontia. The scientific definition of hyperdontia is "any tooth or odontogenic structure that is formed from tooth germ in excess of usual number for any given region of the dental arch." The additional teeth, which may be few or many, can occur on any place in the dental arch. Their arrangement may be symmetrical or non-symmetrical.
Alveolar osteitis, also known as dry socket, is inflammation of the alveolar bone. Classically, this occurs as a postoperative complication of tooth extraction.
Hypodontia is defined as the developmental absence of one or more teeth excluding the third molars. It is one of the most common dental anomalies, and can have a negative impact on function, and also appearance. It rarely occurs in primary teeth and the most commonly affected are the adult second premolars and the upper lateral incisors. It usually occurs as part of a syndrome that involves other abnormalities and requires multidisciplinary treatment.
Tooth development or odontogenesis is the complex process by which teeth form from embryonic cells, grow, and erupt into the mouth. For human teeth to have a healthy oral environment, all parts of the tooth must develop during appropriate stages of fetal development. Primary (baby) teeth start to form between the sixth and eighth week of prenatal development, and permanent teeth begin to form in the twentieth week. If teeth do not start to develop at or near these times, they will not develop at all, resulting in hypodontia or anodontia.
In orthodontics, a malocclusion is a misalignment or incorrect relation between the teeth of the upper and lower dental arches when they approach each other as the jaws close. The English-language term dates from 1864; Edward Angle (1855–1930), the "father of modern orthodontics", popularised it. The word derives from mal- 'incorrect' and occlusion 'the manner in which opposing teeth meet'.
A dental extraction is the removal of teeth from the dental alveolus (socket) in the alveolar bone. Extractions are performed for a wide variety of reasons, but most commonly to remove teeth which have become unrestorable through tooth decay, periodontal disease, or dental trauma, especially when they are associated with toothache. Sometimes impacted wisdom teeth cause recurrent infections of the gum (pericoronitis), and may be removed when other conservative treatments have failed. In orthodontics, if the teeth are crowded, healthy teeth may be extracted to create space so the rest of the teeth can be straightened.
Pericoronitis is inflammation of the soft tissues surrounding the crown of a partially erupted tooth, including the gingiva (gums) and the dental follicle. The soft tissue covering a partially erupted tooth is known as an operculum, an area which can be difficult to access with normal oral hygiene methods. The hyponym operculitis technically refers to inflammation of the operculum alone.
An odontoma, also known as an odontome, is a benign tumour linked to tooth development. Specifically, it is a dental hamartoma, meaning that it is composed of normal dental tissue that has grown in an irregular way. It includes both odontogenic hard and soft tissues. As with normal tooth development, odontomas stop growing once mature which makes them benign.
Tooth eruption is a process in tooth development in which the teeth enter the mouth and become visible. It is currently believed that the periodontal ligament plays an important role in tooth eruption. The first human teeth to appear, the deciduous (primary) teeth, erupt into the mouth from around 6 months until 2 years of age, in a process known as "teething". These teeth are the only ones in the mouth until a person is about 6 years old creating the primary dentition stage. At that time, the first permanent tooth erupts and begins a time in which there is a combination of primary and permanent teeth, known as the mixed dentition stage, which lasts until the last primary tooth is lost. Then, the remaining permanent teeth erupt into the mouth during the permanent dentition stage.
A dental laser is a type of laser designed specifically for use in oral surgery or dentistry.
In dentistry, crossbite is a form of malocclusion where a tooth has a more buccal or lingual position than its corresponding antagonist tooth in the upper or lower dental arch. In other words, crossbite is a lateral misalignment of the dental arches.
A gum lift is a cosmetic dental procedure that raises and sculpts the gum line. This procedure involves reshaping the tissue and/or underlying bones to create the appearance of longer or symmetrical teeth, thereby making the smile more aesthetically pleasing. This procedure is typically done to reduce excessively gummy smiles or to balance out an asymmetrical gum line. The procedure, also known as crown-lengthening, has historically been used to treat gum disease. It is only within the past three to five years that dentists have commonly used this procedure for aesthetic purposes. The practice of cosmetic gum lifts was first developed in the late 1980s, but there were few oral surgeons and dental practitioners available to perform the procedures. Gum lifts can also include bone shaping to reduce the prominence of the upper jaw and even out the tooth and gum ratio. This method provides permanent results, while simple gum contouring may result in relapse or regrowth of the gingiva.
Serial extraction is the planned extraction of certain deciduous teeth and specific permanent teeth in an orderly sequence and predetermined pattern to guide the erupting permanent teeth into a more favorable position.
Impacted wisdom teeth is a condition where the third molars are prevented from erupting into the mouth. This can be caused by a physical barrier, such as other teeth, or when the tooth is angled away from a vertical position. Completely unerupted wisdom teeth usually result in no symptoms, although they can sometimes develop cysts or neoplasms. Partially erupted wisdom teeth or wisdom teeth that are not erupted but are exposed to oral bacteria through deep periodontal pocket, can develop cavities or pericoronitis. Removal of impacted wisdom teeth is advised for the future prevention of or in the current presence of certain pathologies, such as caries, periodontal disease or cysts. Prophylactic (preventative) extraction of wisdom teeth is preferred to be done at a younger age to take advantage of incomplete root development, which is associated with an easier surgical procedure and less probability of complications.
Laser gingivectomy is a dental procedure that recontours or scalpels the gingival tissue to improve long term dental health or aesthetics. Compared to conventional scalpel surgery, soft-tissue dental lasers, such as laser diode, Nd:YAG laser, Er:YAG laser, Er,Cr:YSGG laser, and CO2 lasers, can perform this procedure, offering a precise, stable, bloodless, often less painful, and accelerated healing experience. However, the laser diode gained more popularity due to its versatility, less interaction with hard tissue, ease of use, and the less expensive set up.
Tooth transplantation is mainly divided into two types:
Orthodontic indices are one of the tools that are available for orthodontists to grade and assess malocclusion. Orthodontic indices can be useful for an epidemiologist to analyse prevalence and severity of malocclusion in any population.
