Abstract

Macrodontia (or megadontia or megalodontia) is a type of localized gigantism in which teeth are larger than normal for the particular type(s) of teeth involved. The three types of macrodontia are true generalized macrodontia, relative generalized macrodontia, and macrodontia of a single tooth. True generalized macrodontia is rare. Macrodontia of a single tooth is more common. Some kind of macrodontia in the permanent dentition occurs in 1.1% of the total population. It should not be confused with taurodontism (bull teeth), fusion (double tooth) or the jaws being relatively small, giving the appearance of macrodontia.

Definition

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

Types | True generalized macrodontia

All teeth, although the same size, grow in larger than normal. This is seen in cases of growth hormone excess called pituitary gigantism. It is the rarest of the types.

Types | Relative generalized macrodontia

All teeth appear slightly larger than normal, usually occurring in cases with small jaws. It is called pseudomacrodontia because the small jaws give the illusion that they are abnormally large. Genetics plays a major role in this type of macrodontia, as the offspring inherits small jaw size from one of the parents and large teeth from the other parent.

Types | Macrodontia of a single tooth

A single tooth is larger than the rest. This is unusual and could be the result of fusion and germination that cause enlarged crowns.

Causes

Macrodontia of a single tooth is attributed to a disturbance of morphodifferentiation. Generalized macrodontia is usually attributed to some hormonal imbalance (e.g., pituirary gigantism). It can also be associated with facial hemihyperplasia. Macrodontia stems from systematic disturbances. These include KBG syndrome, otodental syndrome, and insulin-resistant diabetes. Ethnicity and gender also factors that influence macrodontia. Asians and males are more likely to be effected.

Treatment

Teeth affected by macrodontia are either contoured, aligned or extracted. Contouring involves shaving the tooth down to change shape and size. However, the result is minimal change as this could be dangerous for the dentin and dental pulp. Aligning involves the use of braces to straighten, align, and make space for larger teeth to grow. When extracted, they are replaced with an implant or bridge. This is done in cases in which the patient suffers from pain that cannot be treated by other methods.