Diagnosis is exclusively based on the symptoms and clinical presentation. X-rays may be useful. Pericoronitis can be classified into 3 types depending upon the features present:
Acute. Here all the features are present.
Subacute. The classical symptoms have subsdied but certain signs are still present along with the presence of a sinus tract (parulis).
Chronic. Here, most of the features have subsided but a distinct fistulous tract is present.
Acute pericoronitis is treated with gentle topical use of antiseptic mouthwashes (such as chlorhexidine or oxygenating agents).
Food debris, bacteria or any other irritants under the operculum are diluted and washed out with saline.
Gentle application of 50% trichloroacetic acid to the under-surface of the operculum results in the immediate cessation of pain.
Systemic use of antibiotics such as Metronidazole, 200 - 400mg, 3x daily, for 5 days or Co-Amoxiclav, 375 - 625 mg, 3x daily for 5 days or Erythromicin, 250 - 500 mg, 3x daily for 5 days (if allergic to Penicillins) if there are systemic signs and symptoms.
Alternatively, if the operculum is being traumatised by an upper tooth, this tooth can either be ground down (and taken out of occlusion with the caveat that the tooth may erupt and continue traumatising the operculum) or the tooth is removed. These options may only be a temporary stop-gap and the lower tooth may eventually have to be removed anyway.
Photos of Pericoronits / Operculitis effecting Lower Jaw Wisdom Teeth
Pericoronitis is an inflammatory reaction of the operculum (this is the dense, fibrous flap that covers about 50% of the biting surface of a completely or partially erupted lower jaw wisdom tooth) covering an erupting or impacted tooth, usually the lower wisdom tooth.
Poor oral hygiene
Occlusal trauma to the operculum (i.e. the operculum is bitten on by upper jaw molars)
Gingival (gum) infection
Accumulation of bacteria and food debris beneath an operculum
Reduced body resistance
Redness & swelling of the operculum and gingivæ (gums)