Wisdom Tooth - Partial Eruption

Partial Eruption

Sometimes the wisdom tooth fails to erupt completely through the gum bed and the gum at the back of the wisdom tooth extends over the biting surface, forming a soft tissue flap or lid around the tooth called an operculum. Teeth covered by an operculum can be difficult to clean with a toothbrush. Additional cleaning techniques can include using a needle-less plastic syringe to vigorously wash the tooth with moderately pressured water or to softly wash it with hydrogen peroxide.

However, debris and bacteria can easily accumulate under an operculum, which may cause pericoronitis, a common infection problem in young adults with partial impactions that is often exacerbated by occlusion with opposing third or second molars. Common symptoms include a swelling and redness of the gum around the eruption site, difficulty in opening the mouth, a bad odor or taste in the mouth, and pain in the general area which may also run down the entire lower jaw or possibly the neck. Untreated pericoronitis can progress to a much more severe infection.

If the operculum does not disappear, recommended treatment is extraction of the wisdom tooth. An alternative treatment involving removal of the operculum, called operculectomy, has been advocated. There is a high risk of permanent or temporary numbness of the tongue due to damage of the nerve with this treatment and it is no longer recommended as a standard treatment in oral surgery.

Chronic inflammation in the gingival tissue of the partially erupted third-molar, i.e. chronic pericoronitis, may be the etiology for the development of paradental cyst, an inflammatory odentogenic cyst.