Supernumerary teeth are extra teeth that develop in a person’s mouth. The normal number of teeth in the human jaw is 20 primary, or deciduous, teeth and 32 permanent teeth. A person with hyperdontia, the condition in which a person develops extra teeth, may develop more teeth than normal even though the extra teeth may never erupt. These extra teeth can cause dental crowding, can fuse with permanent teeth, and can prevent the normal eruption of permanent teeth. Supernumerary teeth can be detected using a dental X-ray and in many cases have to be extracted.
The development of supernumerary teeth may come as a result of an extra tooth bud in the dental lamina, the tissue that forms tooth buds, or because a tooth bud splits during the first stages of tooth development. It is not known why these extra teeth develop in a person’s mouth, but they often accompany other genetic disorders such Gardner’s Syndrome, a disorder in which the growth of different structures such as numerous colon polyps, bony tumors in the skull, and extra teeth can be symptoms. Some dentists cite genetic disorders as a cause for development, while others cite environmental issues. The role of the environment on the development of supernumerary teeth is currently under research.
Even though the extra teeth may never erupt, they can cause a host of problems for the patient with hyperdontia. For example, the extra teeth can be positioned such that permanent teeth are displaced or fail to erupt at the normal time. The extra teeth may also erupt and may be abnormally placed or abnormally shaped and therefore prone to cavities and decay. For example, mesiodens are supernumerary teeth that can grow in between the normal incisors. In addition, extra teeth may also occur between the molars.
To help prevent or correct the problems associated with supernumerary teeth, a dentist may have to extract them. Extraction is typically done under local or general anesthesia, depending on the severity of the problem. In some cases, a dentist may have to cut the tooth and remove it in sections. If the goal of the extraction is to allow the permanent teeth a place to grow, the dentist may also have to ensure the space left is wide enough for permanent teeth to erupt. In addition, orthodontic methods may have to be put in place for the remaining teeth to grow in proper alignment.
