Microdontia is a condition in which one or more

teeth A tooth ( : teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, te ...

appear smaller than normal. In the generalized form, all teeth are involved. In the localized form, only a few teeth are involved. The most common teeth affected are the upper lateral incisors and third molars. Teeth affected by microdontia may also have abnormal shape, and the abnormal size may affect the whole tooth, or only a part of the tooth.

Definition

Males tend to have larger teeth than females, and tooth size also varies by race. Abnormal tooth size is defined by some as when the dimensions are more than 2 standard deviations from the average. Microdontia is when the teeth are abnormally small, and macrodontia is when the teeth are abnormally large.

Classification

There are 3 types of microdontia:

True generalized

All the teeth are smaller than the normal size. True generalized microdontia is very rare, and occurs in pituitary dwarfism. Due to decreased levels of

growth hormone Growth hormone (GH) or somatotropin, also known as human growth hormone (hGH or HGH) in its human form, is a peptide hormone that stimulates growth, cell reproduction, and cell regeneration in humans and other animals. It is thus important in ...

the teeth fail to develop to a normal size.

Relative generalized

All the teeth are normal size but appear smaller relative to enlarged jaws. Relative generalized microdontia may be the result of inheritance of a large jaw from one parent, and normal sized teeth from the other.

Localized (focal)

Localized microdontia is also termed focal, or pseudo-microdontia. A single tooth is smaller than normal. Localized microdontia is far more common than generalized microdontia, and is often associated with hypodontia (reduced number of teeth). The most commonly involved tooth in localized microdontia is the maxillary lateral incisor, which may also be shaped like an inverted cone (a "peg lateral"). Peg laterals typically occur on both sides, and have short roots. Inheritance may be involved, and the frequency of microdontia in the upper laterals is just under 1%. The second most commonly involved tooth is the maxillary third molars, and after this supernumerary teeth.

Causes

There are many potential factors involved. *

Congenital hypopituitarism Hypopituitarism is the decreased (''hypo'') secretion of one or more of the eight hormones normally produced by the pituitary gland at the base of the brain. If there is decreased secretion of one specific pituitary hormone, the condition is k ...

* Ectodermal dysplasia *

Down syndrome Down syndrome or Down's syndrome, also known as trisomy 21, is a genetic disorder caused by the presence of all or part of a third copy of chromosome 21. It is usually associated with child development, physical growth delays, mild to moderate ...

* Ionizing radiation to the jaws during tooth development ( odontogenesis) *

Chemotherapy Chemotherapy (often abbreviated to chemo and sometimes CTX or CTx) is a type of cancer treatment that uses one or more anti-cancer drugs (chemotherapeutic agents or alkylating agents) as part of a standardized chemotherapy regimen. Chemothe ...

during tooth development * Marshall syndrome *

Rieger syndrome Rieger and de Reiger are surnames. Notable people with the surname include: *August Rieger *Bernhard Rieger, German Prelate of the Roman Catholic Church *Durhane Wong-Rieger, Canadian physician * Erich Rieger, German astrophysicist *František Ladi ...

* Focal dermal hypoplasia * Silver-Russell syndrome *

Williams syndrome Williams syndrome (WS) is a genetic disorder that affects many parts of the body. Facial features frequently include a broad forehead, underdeveloped chin, short nose, and full cheeks. Mild to moderate intellectual disability is observed in people ...

* Gorlin-Chaudhry-Moss syndrome * Coffin–Siris syndrome *

Salamon syndrome Salamon may refer to: Given name * Salamon Berger (1858–1934), Croatian industrialist * Salamon Ferenc (1825–1892), Hungarian historian * Salamon Ferenc (water polo), Hungarian former water polo player * Salamon Mørkved (1891–1978), Norw ...

* Cleft lip and palate Others include trichorhinopharyngeal, odontotrichomelic, neuroectodermal and dermo-odontodysplasia syndromes.

Treatment

Unerupted microdonts may require surgical removal to prevent the formation of

cyst A cyst is a closed sac, having a distinct envelope and division compared with the nearby tissue. Hence, it is a cluster of cells that have grouped together to form a sac (like the manner in which water molecules group together to form a bubble ...

s. Erupted microdonts, peg laterals especially, may cause cosmetic concern. Such teeth may be restored to resemble normal sized teeth, typically with composite build ups or

crown A crown is a traditional form of head adornment, or hat, worn by monarchs as a symbol of their power and dignity. A crown is often, by extension, a symbol of the monarch's government or items endorsed by it. The word itself is used, partic ...

Orthodontics Orthodontics is a dentistry specialty that addresses the diagnosis, prevention, management, and correction of mal-positioned teeth and jaws, and misaligned bite patterns. It may also address the modification of facial growth, known as dentofacial ...

may be required in severe cases to close gaps between the teeth.

Epidemiology

Females are affected more than males, and the condition occurs in permanent (adult) teeth more than deciduous (baby teeth or milk teeth).

References

External links

Developmental tooth disorders {{oral pathology