Teeth start to pass through the gums (emerge) during infancy, and again when the primary (baby) teeth are replaced by the permanent teeth.
If a tooth fails to come in or emerges only partially, it is considered to be impacted. This most commonly happens with the wisdom teeth (the third set of molars). They are the last teeth to emerge. They usually come in between the ages of 17 and 21.
An impacted tooth remains stuck in gum tissue or bone for various reasons. The area may be overcrowded so there's no room for the teeth to emerge. For example, the jaw may be too small to fit the wisdom teeth. Teeth may also become twisted, tilted, or displaced as they try to emerge. This results in impacted teeth.
Impacted wisdom teeth are very common. They are often painless and do not cause problems. However, some professionals believe an impacted tooth pushes on the next tooth, which pushes the next tooth. Eventually, this can cause a misalignment of the bite. A partially emerged tooth can trap food, plaque, and other debris in the soft tissue around it, which can lead to inflammation and tenderness of the gums and unpleasant mouth odor. This is called pericoronitis. The retained debris may also lead to the decay on the wisdom tooth or the neighboring tooth.
Unpleasant taste when biting down on or near the area
Visible gap where a tooth did not emerge
Exams and Tests
Your dentist will look for swollen tissue over the area where a tooth has not emerged, or has only partially emerged. The impacted tooth may be pressing on nearby teeth. The gums around the area may show signs of infection such as redness, drainage, and tenderness. As gums swell over impacted wisdom teeth and then drain and tighten, it may feel like the tooth came in and then went back down again.
Dental x-rays confirm the presence of one or more teeth that have not emerged.
No treatment may be needed if the impacted tooth is not causing any problems.
Over-the-counter pain relievers may help if the impacted tooth causes discomfort. Warm salt water (one-half teaspoon of salt in one cup of water) or over-the-counter mouthwashes may be soothing to the gums.
Removal of the tooth (extraction) is the usual treatment for an impacted tooth. This is done in the dentist's office. Most often, it will be done by an oral surgeon. Antibiotics may be prescribed before the extraction if the tooth is infected.
Impacted teeth may cause no problems for some people and may not need treatment. Treatment is usually successful when it does cause symptoms.
Wisdom teeth removed before age 20 often have better results. This is because the roots are not fully developed. This allows for an easier removal and better healing. As a person ages, the roots become longer and curved. Bone becomes more rigid and complications can develop.
Ilona Fotek, DMD, MS, Palm Beach Prosthodontics Dental Associates, West Palm Beach, FL. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.