Pericoronitis is a common dental emergency condition that usually found in association with the eruption of lower third molar, the gum tissue around the molar teeth becomes swollen and infected. This condition usually occurs in the late teens or early twenties.

Pericoronitis can develop when wisdom teeth only partially erupt (break through the gum). bacteria accumulate under the flap of tissue around the tooth and cause an infection. In cases of pericoronitis, food or plaque (a bacterial film that remains on teeth after eating) may get caught underneath a flap of gum around the tooth. If it remains there, it can irritate the gum and lead to pericoronitis. If the pericoronitis is severe, the swelling and infection may extend beyond the jaw to the cheeks and neck.

What Are the Symptoms of Pericoronitis?
Symptoms of pericoronitis can include:

Pain
Infection
Swelling in the gum tissue (caused by an accumulation of fluid)
A "bad taste" in the mouth (caused by pus leaking from the gums)
Swelling of the lymph nodes in the neck
Difficulty opening the mouth