Gum swollen over back molar
Swelling over a back molar can come from trapped plaque, an erupting wisdom tooth, trauma or infection and needs cause-based care.
The short answer
A swollen flap or lump over a back molar may be inflamed gum around an erupting wisdom tooth, trapped food, trauma, decay or an abscess, so the cause needs examination. Pain, bad taste, pus, fever or limited opening makes infection more concerning.
What is the gum pocket over an erupting wisdom tooth?
The tissue behind or over a molar is gingiva, and partly erupted wisdom teeth can leave a pocket called an operculum where bacteria and food collect. Similar swelling can arise from the tooth pulp, periodontal tissues or a cheek-biting injury.
How can you care for a swollen gum over a molar?
Rinse gently with warm water, brush the area with a soft brush and avoid picking, squeezing or placing chemicals on the swelling. Arrange a dental examination because treatment may involve cleaning under the gum flap, restoring or removing a tooth, or treating an abscess.
When does swelling over a molar need prompt care?
Seek prompt care for increasing pain, pus, fever, facial swelling, a foul taste or difficulty opening the mouth. Go urgently for swelling that affects swallowing or breathing, or spreads into the face or neck.
Is the swelling from the wisdom tooth or the molar?
Ask whether the swelling is around an erupting wisdom tooth or comes from the molar itself, and whether an X-ray is needed. Ask how the area will be cleaned and whether the tooth can be maintained, restored or should be removed.
Frequently asked questions
Can a wisdom tooth cause gum swelling?
Yes. A partially erupted wisdom tooth can trap food and bacteria beneath a gum flap.
Will the swelling disappear by itself?
It may settle temporarily, but recurrence or infection requires assessment of the tooth and surrounding gum.
Who wrote this page
This library is published by Dental Nation, a licensed dental group practising in the United Arab Emirates. Pages are written and overseen by the same clinical team that treats patients in our clinics, and are held to a fixed editorial standard for safety and accuracy.
This page is patient education, not medical advice, and cannot replace an examination. Anything urgent — facial swelling, trauma, uncontrolled bleeding or severe pain — needs a dentist or emergency care now.