Swollen gum lower back mouth

A swollen lower back gum may surround a partly erupted wisdom tooth, trap food under a gum flap, or reflect infection from a nearby molar.

A gum flap can create a pericoronal pocket around an erupting third molar. Plaque, food, decay, or root infection can inflame it.

Rinse gently, brush with a small soft brush, and clean between teeth without forcing tools under the flap.

Seek prompt care for recurrent swelling, pus, fever, restricted opening, or painful swallowing. Facial or breathing symptoms are urgent.

Ask whether the wisdom tooth, gum flap, cavity, or neighbouring tooth is responsible and whether imaging is needed.