Masuda swelling
Back-mouth swelling can involve a wisdom-tooth gum flap, a tooth-root infection, or nearby soft tissue.
The short answer
A swelling near the back of the mouth may involve a wisdom-tooth gum flap, a tooth-root infection, salivary tissue, or another soft-tissue condition.
Why can a wisdom tooth cause swelling under a gum flap?
A partially erupted third molar can have an operculum that traps food and bacteria. Swelling beside another tooth may arise when pulpal inflammation spreads through the root.
What can you do at home for swelling near a wisdom tooth?
Clean gently, rinse with warm salt water, avoid squeezing the lump, and use pain medicine only as directed for you.
When is mouth swelling an urgent dental problem?
Seek urgent dental care for fever, pus, increasing swelling, facial asymmetry, or limited opening; get emergency help for breathing or swallowing difficulty.
What should you ask about swelling near the back tooth?
Ask whether the cause is a wisdom tooth, gum, salivary tissue, or root, and whether examination or radiography is needed.
Frequently asked questions
Can I pop the lump?
No, squeezing or puncturing can injure tissue and spread contamination.
What is the main next step?
Clean gently, rinse with warm salt water, avoid squeezing the lump, and use pain medicine only as directed for you.
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.