My back molar gum is swollen

Swelling behind a back molar can come from trapped food, gum inflammation, an erupting wisdom tooth, or infection around the tooth.

The swollen area is usually the gingiva over or beside a molar, often where cleaning is difficult. If a wisdom tooth is only partly through the gum, a flap called an operculum can trap plaque and food and become inflamed.

Rinse gently with warm salt water, brush the accessible tooth surfaces, and use an interdental brush to dislodge food without forcing it into the tissue. Do not cut the gum, apply heat, or place aspirin or concentrated chemicals on the swelling; a clinician may clean under the flap, treat the tooth, or discuss removal when indicated.

Arrange prompt dental care for worsening pain, pus, bad taste, fever, difficulty chewing, or swelling that lasts beyond brief irritation. Seek urgent care if swelling spreads into the face or neck, or if swallowing, breathing, or opening the mouth becomes difficult.

Ask whether the molar has decay, a cracked cusp, a gum pocket, or inflammation around a wisdom tooth, and whether an X-ray shows its roots and position. Ask whether cleaning, a filling, root-canal treatment, gum care, or extraction addresses the actual cause.