During the infancy years, primary (baby) teeth emerge through the gums. Around age 6, these teeth start to shed and adult teeth grow in.
In some cases, permanent teeth erupt abnormally, which can result in complications later on. For example, when a tooth does not emerge or only grows in partially, it is considered an impacted tooth.
Surgical removal or exposure of an impacted tooth is typically necessary to reduce the chance of dental crowding and other issues.
The primary cause of an impacted tooth is due to overcrowded teeth in the dental arch. If your jaw is too small, your teeth may grow in crooked and overlap because there is not enough room.
Other possible causes of an impacted tooth include:
Impaction most commonly affects the wisdom teeth (third molars) and canines in the upper jaw (maxillary canines).
Wisdom teeth, also referred to as third molars, erupt behind the 12-year-molars (second molars) about five to nine years later.
Between 16 and 20 years of age, most people undergo wisdom tooth removal surgery because the teeth do not grow in properly. Third molars can grow in at various angles, even horizontally, because jawbones usually aren't large enough for them to erupt normally.
If you have a small jaw, you are more likely to have impacted wisdom teeth. Serious oral infections and cysts can form if an impacted wisdom tooth is not removed.
Canines in the upper jaw are the second most common teeth to become impacted. These teeth are essential because they help you rip and tear food. Because of this, dentists do not typically extract them. Instead, they use treatments that help them erupt normally.
Many times, impacted teeth do not cause any obvious symptoms. However, the longer a tooth is impacted, the more likely these following symptoms will arise:
Serious complications are not likely if your dentist removes an impacted tooth. Although, if it isn't removed, serious dental infections, chronic mouth discomfort, plaque buildup, and nerve damage are possible. Other potential complications include:
A tooth abscess forms due to a bacterial infection from the long-term buildup of pus inside the gums and teeth. Throbbing and pain near the affected tooth often accompany an abscess.
Gingivitis is a mild form of gum disease that causes inflammation in the gingival tissues without bone loss. This form of gum disease is reversible and treated during professional teeth cleanings. If it is left untreated, periodontal disease can form, which is a nonreversible gum disease that causes permanent bone loss.
Treatment may not be necessary if an impacted tooth is not causing problems. Although, in most cases, a dentist or oral surgeon should remove impacted wisdom teeth by age 20 if they are not growing in properly.
If the impacted tooth is in the front of your mouth, you may benefit from orthodontic treatment. Braces, for example, can help move the tooth into the proper position.
An impacted back tooth will need to be surgically exposed. There are two types of oral surgery used to expose impacted teeth, including:
During an open eruption procedure, your dentist or oral surgeon will surgically uncover the crown of the impacted tooth under the gums. The tooth is left exposed to the oral cavity and is surrounded by the soft tissue of the palate or labial mucosa (inside lining of the lips). From here, the dentist can directly visualize the tooth following exposure, allowing for proper eruption.
During a closed eruption procedure, your dentist or orthodontist will surgically expose the tooth under the gums. Then, they will place an orthodontic attachment and replace the overlying mucosa.
Lastly, a chain extends from the attachment through the mucosa, allowing the dentist to place traction on the tooth and simulate normal tooth eruption. This procedure is lengthy but may be necessary for impacted incisors and other front teeth.
Gupta, Seema, and Nikhil Marwah. “Impacted Supernumerary Teeth-Early or Delayed Intervention: Decision Making Dilemma?” International Journal of Clinical Pediatric Dentistry, Jaypee Brothers Medical Publishers, Sept. 2012, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4155876/.
“Impacted Tooth: MedlinePlus Medical Encyclopedia.” MedlinePlus, U.S. National Library of Medicine, https://medlineplus.gov/ency/article/001057.htm.