What is Pericoronitis?

Pericoronitis is a condition with an aetiology that is almost always associated with tooth impaction, and especially with impacted wisdom teeth.

The third molar teeth, better known as wisdom teeth, start to erupt at the age of 17 and the eruption of all four teeth is usually completed by the age of 24. Sometimes, depending on the size and structural characteristics of the jaw bones and the rest of the teeth, there is not enough room in the back of the mouth for the wisdom teeth to erupt normally.

If there is a problem, a wisdom tooth may:

• Fail completely to erupt, remaining under the gums.
• Erupt only partially, with part of the chewing surface still covered by the gums.
• Erupt almost completely, but in an abnormal angle.

Complete or partial failure to erupt is referred as ‘tooth impaction’ and the affected 3rd molars as ‘impacted wisdom teeth’. Generally, a pericoronitis infection will be caused by:

• Gum flap infection. In case of a partially erupted wisdom tooth, part of the tooth is exposed, but part of it remains covered by a flap of gum tissue. Food particles and other debris may get trapped under this flap of gums and cause an initial inflammation. The decomposition of food particles, in combination with poor oral hygiene that allows the accumulation of dental plaque and tartar, promotes the growth of bacteria and the development of an infection. Even if the patient has good oral hygiene, it's not easy to clean under the flap with a toothbrush, so inflammation and infection can easily develop.
• Trauma. Several incidents of pericoronitis are caused by a minor trauma of the gums around a tooth. Gum flaps over a partially impacted tooth are usually already inflamed. The same occurs around and over a wisdom tooth that is still completely under the gums because the tooth puts tension on the gums that cover it. The inflamed tissue is more susceptible to minor injuries during chewing either from food components or the opposing teeth. If the lower gum flap is already inflamed and swollen, the upper tooth may bite down on it, causing additional irritation and swelling, and causing the development of pericoronitis.

Other factors which are considered that predispose to pericoronitis are emotional stress, fatigue, upper respiratory tract infections, second trimester of pregnancy and menstruation.

Pericoronitis may affect any tooth that has eruption problems and becomes impacted, but since impaction is a very rare condition in the rest of the teeth, it most often occurs with the wisdom teeth, most commonly those of the lower jaw. Pericoronitis is a main cause of wisdom tooth pain.

Symptoms of pericoronitis can include:

• Pain
• Swollen gum tissue in the area of the affected tooth. It can be difficult to bite down comfortably without catching the swollen tissue between your teeth. It can progress to become a knob-like mass of tissue that is very painful when you chew or open and close your mouth.
• Bad breath (caused by the trapped food and bacteria under the gum flap)
• Jaw stiffness
• Discharge of pus from the gum near the tooth
• A bad smell or taste in the mouth (caused by pus leaking from the gums)

More serious symptoms include:

• Severe throbbing pain.
• Swollen lymph nodes under the chin in the neck.
• Muscle spasms in the jaw
• Swelling on the affected side of the face
• Difficulty opening the mouth.
• Fever.
• Dysphagia. Difficulty in swelling food.

Pericoronitis is easy to diagnose during a clinical examination. In most cases the swelling of the gum tissues around an impacted tooth is a clear and very obvious sign of pericoronitis. The gums are red, swollen or draining fluid or pus.

If pericoronitis is caused by a partially erupted or impacted tooth then the dentist will usually take an X-ray to determine the exact position, size, alignment, and orientation of the tooth and decide about the treatment accordingly.

The dentist will also look for other symptoms that may indicate that the swelling and infection has spread beyond the jaw to the cheeks and neck. In severe cases of pericoronitis the infection may spread into surrounding tissues, developing to cellulitis, a very serious, often life-threatening infection that must be treated quickly to prevent further spread and possible swelling of the airway.

Depending on the etiology, symptoms, and severity of pericoronitis the dentist may recommend a combination of the following treatments:

• Improvement of oral hygiene to keep the area clean.
• Frequent rinsing with warm salt water to sooth the patient. External application of heat should be avoided since it promotes spread of infection towards the facial skin.
• Soft diet to avoid further irritation of the gum tissue.
• Analgesics for temporary pain relief.
• Antibiotic therapy (usually penicillin).
• Excision of the pericoronal flap of gum tissue (if the dentist decides to not extract the tooth immediately).
• Drainage, if an abscess has developed.
• Extraction of the impacted tooth (to eliminate the causative factor of pericoronitis). The removal of the tooth is better to be scheduled after the infection is under control, to prevent it from spreading.
• The most severe cases when the swelling and infection has spread to the neck may need to be treated in a hospital with intravenous antibiotics.

Usually, the symptoms of pericoronitis can be relieved with conservative treatment in about one week. However, if the tooth is partially impacted and food and bacteria keep building up under the gum, pericoronitis will more than likely return. The only permanent solution for the treatment of pericoronitis is the extraction of the impacted wisdom tooth.

The only thing a patient with an impacted tooth can do to prevent pericoronitis is to take extra care for the oral hygiene around that tooth, and try to avoid injuring the area with hard foods. Unfortunately there is not much that can be done to prevent the impaction of a tooth. Many dentists suggest that wisdom teeth should be extracted right after their eruption, because they will cause problems sooner or later. However not all dentists agree with this approach.