Pericoronitis is an infection of the gum flap overlying partially erupted molars, most commonly the wisdom teeth. Food and plaque are trapped under the gum causing inflammation, swelling, and pain. Secondary cellulitis of the surrounding soft tissues can develop.
Soams JV, Southam JC. Oral Pathology. 3rd Ed. Oxford: Oxford University Press, 1998;51-70.
Douglass AB, Douglass JM. Common dental emergencies. Am Fam Physician. 2003. 67(3):511-6.