A supernumerary tooth is any extra tooth that grows beyond the normal set of 20 baby teeth or 32 permanent teeth. The condition, also called hyperdontia, affects roughly 2% of the population. Most people have just one extra tooth, but some develop several. These additional teeth can appear anywhere in the mouth, though they show up most often in the upper jaw.
Where Extra Teeth Appear
Supernumerary teeth are classified by where they grow and what they look like. The most common type is called a mesiodens, an extra tooth that develops right between the two upper front teeth. A mesiodens is often small and peg-shaped, and it can sit behind or between the front teeth, sometimes staying buried in the bone entirely.
Extra teeth that develop next to the molars in the back of the mouth are called paramolars. They grow on the cheek side or tongue side of a molar and may have an unusual, smaller shape compared to the molars beside them. A distomolar is an extra tooth that forms behind the very last molar, essentially a “fourth molar” at the back of the arch.
Some supernumerary teeth look perfectly normal. These are called supplemental teeth because they match the size and shape of the teeth around them. A supplemental tooth next to your lateral incisor, for instance, might look like a duplicate of that tooth. Others are rudimentary, meaning they’re smaller, oddly shaped, or underdeveloped compared to normal teeth.
Why Extra Teeth Develop
The exact cause isn’t fully understood, but the leading theory involves the dental lamina, the strip of tissue in the jaw that gives rise to tooth buds during fetal development. In hyperdontia, this tissue appears to be overactive, producing one or more additional tooth buds that go on to develop into fully formed (or partially formed) teeth. Genetics play a clear role: supernumerary teeth tend to run in families, and several genetic conditions are strongly associated with them.
Cleidocranial dysostosis is a rare inherited condition that affects bone development throughout the body, including the skull, collarbones, and jaws. People with this condition often develop multiple supernumerary teeth along with delayed eruption of their permanent teeth. Gardner syndrome, another inherited disorder, involves intestinal polyps, bone growths on the facial bones, and skin cysts. Roughly 30% of people with Gardner syndrome develop extra teeth. Cleft lip and palate is also associated with a higher rate of supernumerary teeth, particularly near the cleft site. Less commonly, conditions like Ellis-van Creveld syndrome, Nance-Horan syndrome, and Rubinstein-Taybi syndrome are linked to extra teeth as well.
Most supernumerary teeth, however, occur in people who have no underlying syndrome at all.
Problems They Can Cause
Extra teeth are not always harmless bystanders. One large study found that nearly 89% of supernumerary teeth caused at least one complication. The most frequent issue is displacement of neighboring teeth: the extra tooth physically pushes adjacent teeth out of their normal position, which occurred in about 56% of cases in that study. Delayed eruption of permanent teeth is the next most common problem, affecting around half of cases. When a supernumerary tooth sits in the path of a developing permanent tooth, it can block that tooth from coming in on schedule or at all.
Other complications include gaps between the front teeth (diastema), rotation of adjacent teeth, crowding, and retention of baby teeth that should have fallen out. In rare cases, the sac of tissue around an unerupted supernumerary tooth can enlarge into a fluid-filled cyst called a follicular cyst. Root resorption, where the extra tooth gradually damages the roots of neighboring teeth, is uncommon but possible.
How Supernumerary Teeth Are Found
Many supernumerary teeth are discovered by accident during a routine dental X-ray, especially when the extra tooth is still buried in the jawbone. A panoramic X-ray, the wide image that captures your entire mouth in one shot, is typically the first tool used. Smaller periapical X-rays can also reveal extra teeth in a specific area. However, because these are flat, two-dimensional images, overlapping structures in the jaw can sometimes hide a supernumerary tooth or make its exact position hard to pin down.
When a dentist needs a more precise picture, particularly before planning surgery, cone beam computed tomography (CBCT) is the preferred option. This 3D scan uses a lower radiation dose than a traditional CT scan and produces detailed, multi-angle views of the jaw. CBCT shows exactly where the extra tooth sits in relation to neighboring teeth, nerves, and bone, which allows for more accurate surgical planning and less risk of damaging surrounding structures during removal.
When Removal Is Recommended
Not every supernumerary tooth needs to come out. If the extra tooth has erupted into the mouth, the surrounding teeth have come in normally, there’s no crowding or cosmetic concern, and no cyst or other pathology is present, your dentist may recommend simply monitoring it with periodic X-rays.
Removal is recommended when the extra tooth is:
- Blocking a permanent tooth from erupting on time
- Displacing or rotating neighboring teeth
- Creating hygiene problems by making an area too tight to brush or floss, increasing the risk of cavities
- Associated with a cyst or other pathology visible on imaging
- Interfering with orthodontic treatment that’s planned or underway
- Compromising bone grafting or implant placement
- Causing cosmetic concerns, such as a visible gap between the front teeth
Timing Matters for Children
When a supernumerary tooth is found in a child, timing of removal can significantly affect the outcome. The American Academy of Pediatric Dentistry recommends extracting an unerupted supernumerary during the early mixed dentition stage, around ages 6 to 7. At that point, the permanent tooth’s crown has fully formed but the root is still shorter than the crown, so the tooth retains enough natural eruptive force to come in on its own after the obstruction is removed.
Waiting too long reduces the chance that the blocked permanent tooth will erupt without help. If the root of the permanent tooth has already fully developed by the time the supernumerary is removed, orthodontic treatment or surgical exposure may be needed to guide the tooth into place.
What Recovery Looks Like
Recovery from supernumerary tooth extraction follows the same general timeline as any tooth extraction. The first two days require the most care. You’ll leave the gauze in place for a few hours to let a blood clot form in the socket, then rest for at least 24 hours. During this window, avoid using straws, spitting, rinsing vigorously, or drinking hot liquids, all of which can dislodge the clot and slow healing. Keeping your head slightly elevated when lying down helps reduce swelling.
A follow-up appointment is typically scheduled about two weeks after the procedure so your dentist can check that the site is healing properly. If the supernumerary tooth was deeply impacted in bone, the extraction is more involved (closer to a surgical removal like a wisdom tooth extraction), and full healing may take several weeks. Signs that something isn’t right include severe pain that radiates to the ear, or drainage from the wound with a foul taste or smell.
For children whose permanent tooth was being blocked, the exciting part comes after recovery. In many cases, the permanent tooth begins moving into position on its own within several months of the supernumerary tooth’s removal, especially when the extraction was timed during early mixed dentition.