Macrodontia Explained

A healthy, attractive smile is often characterized by even rows of nicely sized teeth. But sometimes, as teeth are developing and filling in the mouth and gum line, abnormalities occur and one or several teeth grow at a different rate than others. The condition, known as macrodontia, is when a tooth (or teeth) grows bigger than normal, and this difference in size is noticeable in comparison to surrounding teeth. While macrodontia isn't very common, most of us have probably seen someone whose smile is dominated by a large front tooth or incisor.

In dentistry and medicine, macrodontia is referred to as a dental anomaly or dental manifestation. It isn't considered a deformity but instead, a peculiarity in morphology -- or how the teeth grow and form [sources: Chussid; NIH; Yang]. Some alternate names for macrodontia are megadontia, megalodontia and gigantism [source: Chussid].

As an adult, you won't start to develop or "get" macrodontia. It forms while teeth are growing. Having a large tooth or teeth into adulthood is simply the result of allowing them to grow into place alongside the more normal-sized teeth. Compared to a more serious problem such as a cleft palate, which most often requires surgical intervention, macrodontia has fewer complications and less-invasive treatment options.

Not all cases of macrodontia require treatment, though many are repaired in order to avoid problems with the bite, dental cavities from irregular surfaces and the overall appearance of a person's smile. Adults with macrodontia generally have had it throughout childhood and adolescence and may have no difficulties as a result of the irregular tooth size.

Whether or not macrodontia is treated and how it's treated can depend on where and how it develops. We'll look at the different types of this dental anomaly next.

Macrodontia in Detail

Teeth don't vary in size a great deal from person to person or mouth to mouth. And what constitutes a "large" tooth in one individual is relative only to how the size of the teeth compare to the teeth in the same mouth. For example, an oversized tooth will be obvious next to teeth of "normal" size. Macrodontia is characterized more by how many teeth and where they appear than by norms of measurement. Cases documenting large teeth represent a range of sizes from small child to adult. The main types of macrodontia include the following:

Localized or regional macrodontia -- One tooth or single teeth in one location or on one side of the mouth is larger than others, but otherwise normal in every other way.
True generalized or diffuse macrodontia -- A very rare form where all teeth in the mouth are larger than what would be considered normal for a person's mouth.
Relative generalized macrodontia -- Teeth may be normal size or slightly larger than normal but appear very large due to the small size of a person's jaw. This is not true macrodontia, but is relative to jaw size and gives the appearance of macrodontia [sources: Cameron and Widmer; Langland, et al.; NIH].

Some tooth or facial irregularities give the appearance of or are similar to macrodontia, such as micrognathia, which is the presence of normal-sized teeth in a small jaw. With micrognathia, however, the jaws are often too small to accommodate the teeth, which is rarely the main issue with macrodontia. Another condition that can mimic or give the appearance of macrodontia is fusion, or gemination. While macrodontia is the development of an oversized tooth, fusion is when two teeth grow together into one large tooth formation. It is a growth irregularity of more than one tooth [source: Cameron and Widmer].

Are there any similarities in people who experience the irregularity of large teeth? We'll look outside the mouth for some clues to who may develop macrodontia, next.

Will teeth become obsolete?

Studies have shown that teeth are trending downward in size. Thousands of years ago men and women needed large and strong incisors and molars just to break down the raw and chewy food they ingested, but advances in hunting, gathering and preparing foods may be leading to a tooth evolution. Softer foods mean less work for the teeth, and according to theories, the teeth themselves may have evolved. Teeth are said to be getting smaller than ever [source: Wilford].

Who is likely to have macrodontia?

Having a single large tooth -- or localized macrodontia -- is rare and those who have it may have no common characteristics with others who have it. There are simply unique cases where teeth have developed irregularly at some point during growth and hormonal development [sources: Cameron and Widmer; NIH]. Often, however, macrodontia is a characteristic of those who have certain physical conditions or abnormalities and hereditary or familial patterns. Some conditions connected with macrodontia include the following:

KBG syndrome -- This condition is rare and has macrodontia as one of its main characteristics, along with developmental delays or mental retardation, broad facial features and skeletal abnormalities. KBG and related macrodontia also can be linked genetically within families.
Hemifacial hyperplasia -- Another rare disorder causing enlargement of tissues and bones on one side of the face and head and sometimes presenting with macrodontia on the affected side.
Pituitary gigantism -- Also rare, gigantism leads to excessive growth of bones and involves hormonal imbalances that may be at root in isolated cases of macrodontia, as well [sources: Langland, et al.; Yang].

Some studies also identify ethnic or regional groups with a higher incidence of macrodontia, such as in some Chinese populations, although a consensus is harder to come by with small samples of individuals per country or geographic area. A number of organizations do assert that males tend to have macrodontia more than females though, no matter the cause. Macrodontia is linked genetically where other conditions are present, as mentioned with KBG syndrome or other developmental disabilities, but isolated cases of macrodontia in individuals with no other conditions are just that -- isolated. Overall, macrodontia is considered rare and case studies are not widespread.

For those who have macrodontia, is it common to have pain or to need treatment? Or is it mostly just a physical peculiarity that can be left alone?

Complications and Care

Physical appearance is one of the most obvious complications of macrodontia but something less apparent is what happens inside the face and jaw of people who have uneven teeth. When one or more teeth are outsized (or undersized as in the case of microdontia, where smaller than normal teeth develop), a person's bite may be uneven, leading to jaw and joint disorders, as well as pain in the face and skull area. These maxillofacial concerns can cause mild, acute pain or long-term, extreme pain and should be treated. Chewing also can be less effective depending on the location of the oversized tooth, or macrodont, which can lead to digestive problems if food is not properly or completely broken down before swallowing. Always consult with a dental professional or pediatrician if macrodontia is developing as a child grows or is suspected.

Differences in size and rough surfaces sometimes found in those with macrodontia also can lead to problems with effective cleaning and cavities. Gum care in these instances is especially important in order to prevent pockets where teeth and gums aren't matching up with adjacent teeth.

Scaling back the tooth size or extracting the tooth are options for treating or correcting macrodontia. Reducing teeth size -- or stripping -- can be done to some extent but sometimes only minimally. Replacing the natural tooth with a prosthesis or artificial tooth -- or teeth in the case of multiple macrodonts -- allows for very even matching with the normal-sized natural teeth [source: Cameron and Widmer].

In some cases, macrodontia will not cause pain or interfere with chewing or hygiene, and it may not even be very apparent depending on the location of the outsized tooth. And, even when prominent, sometimes the peculiarity adds to the singularity and attractiveness of a person's smile, especially in a loved one.

More information on teeth of all shapes and sizes follows.

Lots More Information

Sources

Cameron, Angus and Widmer, Richard. "Handbook of Pediatric Dentistry, Second Edition." Elsevier Limited. 2003.
Chussid, Steven. "Abnormalities of the Teeth." Columbia.edu. 2011. (Nov. 23, 2011) http://www.columbia.edu/itc/hs/dental/d7710/client_edit/dental_anomalies.pdf
Langland, Olaf, E., et al. "Principles of Dental Imaging." Lippincott Williams and Wilkins. 2002.
Maegawa, G.H.B., et al. "Clinical Variability in KBG Syndrome: Report of Three Unrelated Families." American Journal of Medical Genetics Part A, Wiley.com. Sept. 21, 2004. (Nov. 25, 2011) http://onlinelibrary.wiley.com/doi/10.1002/ajmg.a.30293/full
National Institutes of Health (NIH). "Bilateral Macrodontia of Mandibular Second Premolars: A Case Report." NIH.gov. Jan. 2001. (Nov. 18, 2011) http://www.ncbi.nlm.nih.gov/pubmed/11309876
Rajendran, R. and Sivapathasundharam B., eds. "Shafer's Textbook of Oral Pathology, Sixth Edition." Elsevier. 2009.
Wilford, John Noble. "Human Teeth, Small Already, Keep on Shrinking." NYTimes.com. Aug. 30, 1988. (Nov. 5, 2011) http://www.nytimes.com/1988/08/30/science/human-teeth-small-already-keep-on-shrinking.html?pagewanted=all&src=pm
Yang, Cindy. "Case Based Pediatrics for Medical Students and Residents: Pediatric Dental Basics." University of Hawaii, Hawaii.edu. March 2003. (Nov. 24, 2011) http://www.hawaii.edu/medicine/pediatrics/pedtext/s01c12.html