Hyperdontia is a condition that causes too many teeth to grow in your mouth. These extra teeth are sometimes called supernumerary teeth. They can grow anywhere in the curved areas where teeth attach to your jaw. This area is known as the dental arches.

The 20 teeth that grow in when you’re a child are known as primary, or deciduous, teeth. The 32 adult teeth that replace them are called permanent teeth. You can have extra primary or permanent teeth with hyperdontia, but extra primary teeth are more common.

The main symptom of hyperdontia is the growth of extra teeth directly behind or close to your usual primary or permanent teeth. These teeth usually appear in adults. They’re twice as common in men than they are in women.

Extra teeth are categorized based on their shape or location in the mouth.

Shapes of extra teeth include:

  • Supplemental. The tooth is shaped similarly to the type of tooth that it grows near.
  • Tuberculate. The tooth has a tube or barrel-like shape.
  • Compound odontoma. The tooth is made up of several small, tooth-like growths near each other.
  • Complex odontoma. Rather than a single tooth, an area of tooth-like tissue grows in a disordered group.
  • Conical, or peg-shaped. The tooth is wide at the base and narrows out near the top, making it look sharp.

Locations of extra teeth include:

  • Paramolar. An extra tooth grows in the back of your mouth, next to one of your molars.
  • Distomolar. An extra tooth grows in line with your other molars, rather than around them.
  • Mesiodens. An extra tooth grows behind or around your incisors, the four flat teeth at the front of your mouth used for biting. This is the most common type of extra tooth in people with hyperdontia.

Hyperdontia usually isn’t painful. However, sometimes the extra teeth can put pressure on your jaw and gums, making them swollen and painful. Overcrowding caused by hyperdontia can also make your permanent teeth look crooked.

The exact cause of hyperdontia is unknown, but it seems to be associated with several hereditary conditions, including:

  • Gardner’s syndrome. A rare genetic disorder that causes skin cysts, skull growths, and colon growths.
  • Ehlers-Danlos syndrome. An inherited condition that causes loose joints that easily dislocate, easily bruised skin, scoliosis, and painful muscles and joints.
  • Fabry disease. This syndrome causes an inability to sweat, painful hands and feet, a red or blue skin rash, and abdominal pain.
  • Cleft palate and lip. These birth defects cause an opening in the roof of the mouth or upper lip, trouble eating or speaking, and ear infections.
  • Cleidocranial dysplasia. This condition causes abnormal development of the skull and collarbone.]

Hyperdontia is easy to diagnose if the extra teeth have already grown in. If they haven’t fully grown in, they’ll still show up on a routine dental X-ray. Your dentist may also use a CT scan to get a more detailed look at your mouth, jaw, and teeth.

While some cases of hyperdontia don’t need treatment, others require removing the extra teeth. Your dentist will also likely recommend removing the extra teeth if you:

  • have an underlying genetic condition causing the extra teeth to appear
  • can’t chew properly or your extra teeth cut your mouth when you chew
  • feel pain or discomfort due to overcrowding
  • have a hard time properly brushing your teeth or flossing because of the extra teeth, which could lead to decay or gum disease
  • feel uncomfortable or self-conscious about the way your extra teeth look

If the extra teeth are starting to affect your dental hygiene or other teeth — like delaying the eruption of permanent teeth — it’s best to remove them as soon as possible. This will help avoid any lasting effects, such as gum disease or crooked teeth.

If the extra teeth only cause you mild discomfort, your dentist may recommend taking nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen (Advil, Motrin) for pain.

Many people with hyperdontia don’t need any treatment. Others may need to have some or all of their extra teeth removed to avoid any other problems. Make sure to tell your doctor about any feelings of pain, discomfort, swelling, or weakness in your mouth if you have hyperdontia.