What is hyperdontia?

Hyperdontia is an oral condition characterized by having an excess number of teeth. The standard number of primary teeth is 20 and the standard number of permanent teeth is 32.
Primary teeth are the first set of teeth that erupt in a person's mouth, generally by the age of 36 months of age, and are shed by the time the person is about 12 years old. The permanent teeth then take the place of the primary teeth and usually erupt completely by the time the person reaches 21 years of age.
A person who develops more than 20 primary teeth or more than 32 permanent teeth has hyperdontia. The additional teeth are referred to as supernumerary teeth. Supernumerary teeth can occur in any part of the dental arch, but the most common supernumerary teeth are permanent, anterior incisors, in the maxillary (upper) arch.
- After maxillary incisors, maxillary and mandibular (lower arch) fourth molars are the next most common supernumerary teeth. These generally appear as extra impacted wisdom teeth.
- An extra maxillary incisor is called a mesiodens, and an extra fourth molar is referred to as a distodens or distomolar. Extra primary teeth present at or shortly after birth are called natal teeth.
What is the main cause of hyperdontia?
The cause of hyperdontia is not entirely clear. It is believed that there may be a genetic factor in hyperdontia consisting of an autosomal dominant trait with low penetrance (only sometimes producing supernumerary teeth in a carrier of the mutated gene).
Other possible causes are environmental factors and overactivity of the dental lamina during tooth development. The dental lamina is a zone of cells that initiates the formation of the tooth germ, which forms the tooth.
What are risk factors for hyperdontia?
When a person does develop multiple supernumerary teeth, it often is associated with a variety of conditions or syndromes, such as:

SLIDESHOW
Mouth Problems: TMJ, Canker Sores, Painful Gums and More See SlideshowHow common is hyperdontia?
The prevalence of hyperdontia is between 1% and 4% of the population with a male-to-female ratio of 2:1; the majority of cases are limited to a single tooth. There have been reported cases of over 30 supernumerary teeth in one person, but such large numbers are rare.
What is the best treatment for hyperdontia?
It is important to detect, evaluate, and treat supernumerary teeth as soon as possible since the additional teeth will present both cosmetic and functional problems for the affected individual. As a majority of supernumerary teeth cause clinical problems, treatment generally consists of the removal of the teeth when possible.
What is the prognosis of hyperdontia?
Supernumerary teeth may cause a delayed eruption of adjacent teeth or significant crowding that will often require orthodontic treatment to correct. If retained, the teeth can lead to the development of cysts or tumors. It is generally not necessary to remove natal teeth unless the supernumerary teeth are loose and present a risk for aspiration due to passage into the lung.
Neville, Brad W., et al. Oral and Maxillofacial Pathology, Second Ed. St. Louis: Saunders, 2001.
Pereira, M. N., et al. "Multiple hyperdontia: Report of an unusual case." American Journal of Orthodontics and Dentofacial Orthopedics 140.4 (2011): 580-584.
Top Hyperdontia Related Articles
Caring for Teeth With Braces or Retainers
People who have braces or retainers must take special care when cleaning their teeth. They must floss and brush regularly and avoid eating hard and chewy foods. It's important to wear a mouth guard when playing sports to avoid dental injuries.Cleft Palate and Cleft Lip
Cleft palate and cleft lip are facial and oral defects that occur early in pregnancy. A cleft lip is a split of the two sides of the upper lip, and a cleft palate is a split in the roof of the mouth. Cleft lip the fourth most common birth defect in the U.S. Repair of a cleft palate or cleft lip may require multiple surgeries.Cyst
Cysts are sac-like structures that may be filled with gas, liquid, or solid materials. Cysts may produce symptoms and signs depending on their location. Treatment of a cyst depends upon what caused the cyst in the first place.What Does It Mean When You Dream About Your Teeth Falling Out and Crumbling?
Teeth often represent our strengths, abilities, and pride. Dreaming about your teeth falling out may represent fears of being powerless. You may have bizarre dreams about either losing one of your teeth or all. The dreams could probably indicate your inability to hold things together in life or fears or anxieties you’re battling with.Ehlers-Danlos Syndrome
Ehlers-Danlos syndromes are genetic disorders that include symptoms such as loose joints, tissue weakness, easy bruising, and skin that stretches easily. There are seven types of Ehlers-Danlos syndromes: classical type, hypermobility type, vascular type, kyphoscoliosis type, arthrochalsia type, dermatosparaxis type, and tenascin-X deficient type. Treatment for Ehlers-Danlos syndrome depends on which symptoms and signs are present.Genetic Diseases
The definition of a genetic disease is a disorder or condition caused by abnormalities in a person's genome. Some types of genetic inheritance include single inheritance, including cystic fibrosis, sickle cell anemia, Marfan syndrome, and hemochromatosis. Other types of genetic diseases include multifactorial inheritance. Still other types of genetic diseases include chromosome abnormalities (for example, Turner syndrome, and Klinefelter syndrome), and mitochondrial inheritance (for example, epilepsy and dementia).Is a Mouthguard Good for Your Teeth?
Mouthguards or mouth protectors are coverings worn over teeth. They protect your teeth from injuries. A mouthguard acts as a cushion to minimize the impact of trauma or a blow to the face. Thus, they lower the risk of broken teeth and injuries to the lips, tongue, face, or jaw.Painful Teeth Conditions
Got aching teeth? Your pain may be coming from somewhere other than your choppers.Protect Your Teeth: 19 Bad Dental Habits to Avoid
Bad dental habits can wreck your teeth. Teeth grinding, chewing on ice, playing sports without a mouth guard, and eating and drinking sugary foods and drinks are just a few bad habits that are bad for teeth. Giving nighttime baby bottles, opening things with your teeth, and chewing on pencils can also damage teeth and tissues in the mouth. Drinking red wine and white wine can erode enamel and stain teeth. Smoking, tobacco use, drinking coffee can all lead to tooth stains. Binge eating disorder leads to the consumption of large amounts of sugary food, which can lead to tooth decay. Purging exposes teeth to acids that can wear down enamel.Teeth and Gum Care
With proper teeth and gum care, it's possible to ward off tooth decay and gum disease. It's essential to brush twice a day, floss once a day, eat right, and visit the dentist every six months for a dental check-up.Teeth Grinding (Bruxism)
Bruxism is the medical term for teeth grinding. Bruxism may be caused by stress or anxiety and often happens during sleep. Symptoms and signs include jaw pain, headache, and abnormalities in your teeth. Treatment may involve practicing stress-management techniques, cutting back on caffeine and alcohol, avoiding gum chewing, training oneself not to grind the teeth, and wearing a mouth guard.Teeth Picture
The teeth are the hardest substances in the human body. See a picture of the Teeth and learn more about the health topic.Teething
Teething in babies typically starts between 4 and 10 months of age. Symptoms and signs of cutting teeth include rash, drooling, decreased sleeping, fussiness, bringing the hands to the mouth, and rubbing the cheek or ear. Acetaminophen and ibuprofen may be used to treat teething pain. Do not give aspirin to babies or children due to a condition called Reye's syndrome, which can be deadly.Teeth, Gums and Health
Is your mouth healthy? Teeth and gums can warn you about diseases like diabetes, anemia, and osteoporosis. Find out why gum disease is often found in people with rheumatoid arthritis, and why tooth loss and kidney disease may be linked.Wisdom Teeth
Wisdom teeth are the third set of molars that people get in their late teens or early twenties. Impacted wisdom teeth that only partially erupt allow for an opening for bacteria to enter around the tooth and cause an infection, which results in pain, swelling, jaw stiffness, and general illness. Before your wisdom teeth are pulled, the teeth and the surrounding tissue will be numbed with a local anesthetic. Recovery from wisdom tooth removal depends upon the difficulty of the extraction.