Pericoronitis is the inflammation of the gingival tissue surrounding the crown of the partially erupted wisdom tooth or teeth in the jaw. It is more common in lower molars than the upper molars. A gingival tissue flap is seen covering the crown. Decision to whether extract the teeth or tooth or incise the flap lies in the hands of the dentist which depends on various factors. 
Usually third molar erupts upto the age of 29 yrs or more. If the jaw size is small the third molar will put pressure on the remaining adjacent teeth and will try to squeeze in through the little space to erupt. In this process it might get impacted or might erupt completely. If it gets impacted it has a gum tissue flap covering around it or over it. Food particles then accumulate under the flap causing inflammation. Poor oral hygiene will worsen the case.

Main complications:
Pain and swelling
Difficulty in chewing food from that side
Reduced mouth opening
Cheek bite
Difficulty in swallowing
Bleeding from the site.

Three options to manage pericoronitis:
1. Relieving pain
2. Incising the flap
3. Extraction

Relieving the pain
If the tooth will erupt fully on its own and when there is an opposing tooth present, the dentist may take a call on not extracting the tooth or incising the flap. The dentist may decide to manage the case by reliving the pain. 
Treatment: scaling plus curettage , salt water warm gargles, NDAIDS , antibiotics.

Incising the flap
If the patient is in severe pain even after deep scaling curettage and medications and if there is an antagonist tooth present, the flap is incised to get the rid of the inflamed tissue and give a guide path for eruption. Antibiotics are prescribed after the surgery. Patient is educated on keeping the surgical site clean by using antiseptic mouthwash, warm salt water gargles.

Extraction
If the problem persists and the flap grows back again a second surgery is needed. Extracting the tooth usually solves the problem . Usually patient recovers within 7-14 days from pericoronitis. Regular dental visits helps to reduce the chances of pericoronitis .also maintaining oral hygiene and regular scaling at dental clinic helps to prevent inflammation.