Macrodontia (tooth)

Macrodontia 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 very 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.

Macrodontia (tooth)
Other names	Megadontia, megalodontia
Specialty	Dentistry

Definition

Males tend to have larger teeth than females,[1] and tooth size also varies according to race.[1] Abnormal tooth size is defined by some as when the dimensions are more than 2 standard deviations from the average.[1] Macrodontia is when the teeth are abnormally large, and microdontia is when they are abnormally small. It may cause different types of bites and crowding of the teeth. This is best investigated using radiographs.

Complications

The usual complications of macrodontia are associated with crowding, malocclusion and impaction unless treated.

Types

True generalized

In true generalized macrodontia, all teeth grow in larger than normal. This is seen in cases of growth hormone excess called pituitary gigantism. It is the rarest of the types. [2]. Other patients may have a disease called Rabson-Mendenhall syndrome which predisposes to generalised macrodontia. This causes insulin resistance and is an autosomal recessive disorder.[3]

Relative generalized

All teeth appear slightly larger than normal; usually, the jaws are smaller than average. It is sometimes called "pseudomacrodontia", as small jaws give the illusion that the teeth are abnormally large. Genetics play a major role in this type of macrodontia; offspring inherit small jaw size from one parent and relatively large teeth from the other parent.[2]

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.[2]

Causes

Macrodontia of a single tooth is attributed to a disturbance of morphodifferentiation. Generalized macrodontia is usually attributed to some hormonal imbalance (e.g., pituitary gigantism). It can also be associated with facial hemihyperplasia. Macrodontia stems from systematic disturbances. These include KBG syndrome, otodental syndrome, and insulin-resistant diabetes. [4] Ethnicity and gender also factors that influence macrodontia. Asians and males are more likely to be affected.[2]

Treatment

Before treatment the correct diagnosis must be made which is easily done by a radiograph. It can be seen the tooth/teeth concerned will be larger than normal which can be seen clinically in the mouth or whilst they are unerupted. 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.[2]

Teeth with macrodontia can go through treatment using a technique that does not harm the dental pulp. This is done using a tooth coloured filling material (composite resin)

References

1. Poulsen S; Koch G (2013). Pediatric dentistry: a clinical approach (2nd ed.). Chichester, UK: Wiley-Blackwell. p. 191. ISBN 9781118687192.
2. "All you need to know about macrodontia". dentagama.com. Retrieved 2017-03-30.
3. Mrinalini, Mahajan; Chetan, Chawla (2015-05-01). "True generalized macrodontia in a case of Rabson–Mendenhall syndrome". Journal of Oral and Maxillofacial Surgery, Medicine, and Pathology. 27 (3): 357–360. doi:10.1016/j.ajoms.2014.04.006. ISSN 2212-5558.
4. "Isolated bilateral macrodontia of mandibular second premolars: A case report (PDF Download Available)". ResearchGate. Retrieved 2017-03-30.

External links

Classification	D ICD-10: K00.2 ICD-9-CM: 520.2