Lower back gum swollen
Swelling behind the last lower molar may involve a wisdom tooth, trapped food, infection, or local trauma.
The short answer
The lower back gum may partly cover an erupting third molar, creating a flap where plaque and food collect. Other causes include a periodontal pocket, ulcer, cheek trauma, a decayed neighbouring tooth, or a jaw infection.
What is the direct answer?
What does this question mean?
A dentist checks the gum flap, tooth position, bite, drainage, tenderness, and mouth opening, often using an X-ray to see the wisdom tooth and adjacent roots. The treatment depends on whether the source is local irritation, decay, or infection.
What can you do next?
Rinse gently with warm salt water if comfortable, keep the area clean with a small soft brush, and choose soft foods. Do not puncture the swelling or place aspirin directly on the gum.
When should you seek dental care?
Urgent care is needed for fever, spreading facial or neck swelling, difficulty opening the mouth, swallowing, or breathing. Recurrent swelling behind a molar also needs dental assessment.
What should you ask the dentist?
Ask whether a wisdom tooth is involved, whether food is trapped under a gum flap, and whether cleaning, drainage, restoration, or extraction is indicated.
Frequently asked questions
Can home care replace diagnosis?
Home care can reduce irritation or discomfort, but it cannot identify or remove every dental cause.
What should I take to the appointment?
Bring your medicines, relevant health history, and a clear description of when the symptom or concern began.