Adult people usually have 32 permanent teeth and children have 20 baby teeth. Despite the fact that extra teeth in the mouth are quite rare, they affect 0.15-4% of the population. This condition is called hyperdontia and these extra teeth are called supernumerary teeth. Hyperdontia can occur in everyone but it is more often associated with people who have Gardner's syndrome, Down's syndrome, or those born with a cleft lip. In adult men, supernumerary teeth occur twice as often as in adult women. In this article, we will tell you everything you should know about supernumerary teeth.

Types

Supernumerary teeth can develop in any part of the mouth but they tend to grow among permanent teeth. They can be found among baby teeth and it’s more difficult to identify them since they are similar to other teeth and are in the correct position. A clinical examination at the dentist or an X-ray can discover supernumerary teeth. Despite the fact that hyperdontia usually looks like one extra tooth, sometimes there are several teeth that appear individually or in groups. In rare cases, up to 30 supernumerary teeth may develop in a mouth. Types of supernumerary teeth include:

1. Conical

This is the most common type found among permanent teeth. They have a normal root and appear near the central incisors, possibly displacing them.

2. Tuberculate

They are barrel-shaped and hidden in the gums. They have abnormal roots and rarely erupt. They are located in the sky near the central incisors and can block the eruption of these teeth.

3. Supplemental

This is the most common type of extra baby teeth. They usually appear near the lateral incisors. 

4. Molariform

They have a complete root and look like premolars. They usually appear near molars.

Causes and risk factors

The reasons for the appearance of supernumerary teeth are unknown. However, factors that may contribute to their appearance include genetics, hyperactivity of the dental lamina (cells that initiate tooth development), diseases, and atavism (reappearance of a trait no longer characteristic of evolution). Environmental factors, which can cause hyperdontia are not yet known. Conditions associated with supernumerary teeth include:

1. Cleft lip and palate

Over 22% of patients with cleft lip or palate develop supernumerary teeth.

2. Cleidocranial dysplasia

This condition influences the growth of bones and teeth. The risk of developing abnormal teeth in patients with cleidocranial dysplasia is from 5-22% percent.

3. Down syndrome

This is a genetic disease that is also known as trisomy 21.

4.  Ehler-Danlos syndrome

This is a group of hereditary connective tissue diseases.

5. Gardner's syndrome

This genetic syndrome promotes the formation of colorectal polyps and raises the risk of colorectal cancer.

Complications

Supernumerary teeth can cause different dental problems. Some of them present only cosmetic issues while others interfere with normal oral function and health. Some of the dental problems supernumerary teeth can lead to include tooth impaction, misalignment of permanent teeth, issues with proper chewing, the formation of oral cysts or tumors, the eruption of teeth into the nasal cavity and problems with bone graft for an implant.

Treatments

It is important to identify and treat hyperdontia as soon as possible. Treatment usually includes excess teeth removal, which is usually performed under local or general anesthesia. In some cases, supernumerary teeth should be removed only in pieces. Before the procedure, you should discuss the risks and benefits of removing extra teeth with your dentist. The reality is that the removal may increase the likelihood of a rupture of a nerve or blood vessel in your mouth.

If supernumerary teeth are found in a child, they should be removes as soon as possible. If left untreated, hyperdontia can lead to vearious problems with teeth alignment. You can also consult with an orthodontist in these cases. To remove supernumerary teeth that are fused to permanent teeth, a root canal treatment is required to treat tooth pulp and the surrounding tissue.