What is an impacted tooth?
Impaction is a condition when a tooth fails to erupt the mouth. Eruption of teeth is a continuous process of movement of a tooth from its location of development (inside the gum) to its functional location (above the gum). A tooth that ceases to achieve its functional position is referred to as an impacted tooth. The cessation of eruption can be caused by a physical barrier or ectopic positioning of the tooth. An impacted tooth can be an erupted tooth, a partially erupted tooth or an unerupted tooth. The most commonly impacted teeth are the third molars (wisdom teeth).
What are the symptoms?
Lack of eruption of a tooth is the most frequently associated symptoms of an impacted tooth. It may be associated with crowding and insufficient development of the upper and lower jaw. An erupted impacted tooth generally appears to be angulated or tilted.
In permanent dentition impaction is most commonly seen in mandibular third molars followed by maxillary third molar and maxillary canines. It may also be seen affecting mandibular premolars, maxillary premolars, maxillary central incisors and maxillary lateral incisors. Impaction in deciduous teeth is extremely uncommon and if present it affects the second molars.
The diagnosis of completely unerupted impacted toot can be done using dental radiographs. Generally, impacted teeth can lead to periodontal problems in the neighboring teeth. It can lead to resorption of the adjacent teeth and can predispose the tooth to develop dental caries. The impacted teeth are also susceptible for development of certain types of dental cysts, infections and tumors.
What causes an impacted tooth?
- The local causes for impaction of the tooth include irregular positioning and increased density of overlying bone. It may also be associated with ankylosis of the tooth.
- Soft tissue and bony lesions at the site of the tooth can cause its impaction.
- Dilacerated (curved) roots, lack of space in the dental arch and over retained deciduous teeth are also few of the local factors leading to impaction.
- Trauma to the developing tooth or habits involving tongue, finger or pencil use inside the oral cavity can also lead to impaction.
- The systemic causes associated with impaction in include genetic and environmental factors.
- The postnatal factors include rickets, anemia, tuberculosis, congenital syphilis and malnutrition.
- Endocrine disorders of thyroid, parathyroid, pituitary glands can also lead to impaction of teeth.
- The syndromes associated with impacted teeth include Down’s syndrome, Hurler’s syndrome, osteopetrosis, Cleidocranial dysostosis and cleft palate.
How is an impacted tooth treated?
An impacted tooth can be left untreated followed by long term observations and periodic dental radiographs in few cases. Partially erupted canine and anterior teeth can be orthdontically assisted for their proper eruption using fixed mechanotherapy.
The most commonly recommended treatment for impacted teeth includes surgical removal. The surgical removal of impacted teeth is carried out by transalveolar extractions. Pre-surgical radiographs are necessary to determine the cutting of the bone and position of the incision. The extractions are done under local anesthesia and are followed by analgesics and antibiotics treatment.
The surgical procedures involving third molars should be carefully handled as the possible complications include trismus, dento-alveolar fractures, periodontal damage and tempero- mandibular joint injury.