Jaw Swelling: Causes and When to Seek Treatment

What a swollen jaw can mean

The jaw region is packed with structures that can swell: teeth and gums, the jawbone (mandible and maxilla), lymph nodes, salivary glands, the jaw joint and muscles. Where the swelling sits, whether it hurts, and whether it changes with eating are the strongest clues.

Lower jaw swelling

Tooth abscess

A dental abscess is a pocket of pus from tooth decay, a cracked tooth or gum disease. A lower molar abscess causes a throbbing toothache, pain on biting, swelling of the gum and lower jaw, a bad taste and sometimes fever. Swelling may extend along the jaw edge or under the jaw.

Infected wisdom tooth

When a lower wisdom tooth partly breaks through the gum, food and bacteria get trapped under the gum flap. This pericoronitis causes pain at the back of the jaw, swelling, difficulty opening the mouth and a bad taste. It is most common between ages 17 and 25.

Swollen lymph nodes

Lymph nodes under the jaw and along its edge swell during infections of the throat, teeth, gums, tongue or scalp. They feel like soft, tender, movable peas or grapes. They usually shrink within 2 to 3 weeks. See swollen lymph nodes. A node that is hard, painless, fixed in place, or growing for more than a few weeks needs checking for lymphoma or cancer spread.

Submandibular salivary gland problems

The submandibular gland sits under the lower jaw. A stone in its duct blocks saliva, so the gland swells and aches when you eat or even think about food, then slowly goes down. If the blocked gland becomes infected, it stays swollen, red and painful, and pus may appear under the tongue. See salivary gland stones and sialoadenitis.

Upper jaw swelling

• Upper tooth abscess: swelling of the gum, cheek and sometimes the lower eyelid. Infection near the eye needs urgent care because it can spread to the eye socket.
• Sinus infection: pressure and swelling over the cheek with a blocked nose, often with upper toothache.
• Parotid gland swelling: the parotid sits in front of the ear and over the angle of the jaw. Mumps causes painful swelling on one or both sides with fever. Bacterial parotitis affects older, dehydrated people after surgery or illness.

Other causes of jaw swelling

• Injury: bruising or a fracture of the jaw, especially if teeth no longer fit together or the chin is numb.
• Jaw joint disorders: TMJ inflammation can cause swelling in front of the ear with clicking and pain on chewing.
• Cysts: dental cysts and skin cysts such as epidermoid cysts.
• Bone infection (osteomyelitis): rare; follows dental infection or radiation and causes deep pain, swelling and numbness.
• Medication-related osteonecrosis of the jaw: exposed bone and swelling in people on certain osteoporosis or cancer bone medicines.
• Tumors: benign jaw tumors (such as ameloblastoma) or salivary gland tumors usually grow slowly and painlessly. Oral and lymph node cancers are less common causes.
• Allergic reaction or angioedema: rapid swelling of lips, face and tongue.

Ludwig angina: the emergency to know

Ludwig angina is a rapidly spreading infection of the floor of the mouth, usually from a lower molar. It causes firm, board-like swelling under the chin on both sides, raises the tongue, and can block the airway within hours. Drooling, a muffled voice, trouble swallowing and breathing difficulty mean you should call 911 or your local emergency number.

When to seek treatment for jaw swelling

See a dentist or doctor the same day if a swollen jaw comes with toothache, fever, a bad taste or trouble opening your mouth. Dental infections do not heal by themselves; antibiotics alone usually only delay the problem. Book a routine appointment for a painless lump that lasts more than 2 to 3 weeks, or swelling that comes and goes with meals.

How the cause is found

Your dentist or doctor will examine the teeth, gums, floor of the mouth, salivary duct openings and neck nodes, and check how wide you can open your mouth. Tests may include:

• dental x-rays to find an abscess or impacted tooth
• ultrasound of a gland or lymph node
• CT scan for deep neck infections, fractures or suspected tumors
• blood tests for infection or mumps
• a fine-needle biopsy of a persistent lump

Treatment of jaw swelling

• Dental abscess: drainage of pus, then root canal treatment or tooth extraction. Antibiotics are added if the infection is spreading or you have a fever.
• Pericoronitis: cleaning under the gum flap, salt-water rinses, sometimes antibiotics, and wisdom tooth removal if it keeps recurring.
• Salivary stones: hydration, warm compresses, gland massage and sour sweets to boost saliva flow. Stones that do not pass are removed by a minor procedure.
• Salivary infection: fluids, warm compresses, antibiotics.
• Lymph nodes: treat the underlying infection; investigate persistent nodes.
• Fractures: soft diet or surgical fixation.

Home care while you wait to be seen

• Take acetaminophen (paracetamol) or ibuprofen, following the label dose.
• Rinse with warm salt water several times a day.
• Use a cold compress on the outside of the face for 15 minutes at a time in the first 24 hours after injury; use warm compresses for salivary swelling.
• Do not apply heat to a suspected dental abscess, which may encourage it to spread outward.
• Keep drinking fluids.

Frequently asked questions

What causes swelling on one side of the jaw?

The most common causes on one side are a tooth abscess, an infected wisdom tooth, a swollen lymph node, or a blocked or infected salivary gland. Injury and jaw joint problems are other causes. Swelling with toothache or fever usually points to a dental infection that needs prompt treatment.

Can a tooth infection make your jaw swell?

Yes. An abscess spreads pus into the surrounding bone and soft tissue, causing swelling of the gum, cheek or jaw. It needs a dentist to drain it and treat the tooth. Seek emergency care if swelling spreads to the neck, under the tongue or near the eye.

Why does my jaw swell when I eat?

Swelling that appears with meals and goes down afterward is typical of a salivary stone blocking the gland duct. Saliva builds up behind the blockage when the gland is stimulated. Drinking plenty, sucking sour sweets and gland massage can help, but see a doctor or dentist.

How long does jaw swelling last?

With treatment, swelling from a dental abscess usually settles within 3 to 5 days. A swollen lymph node from an infection can take 2 to 3 weeks to shrink. Swelling after an injury improves over 1 to 2 weeks. Persistent swelling needs investigation.

Should I go to the ER for a swollen jaw?

Go to the ER if swelling makes it hard to breathe, swallow or speak, spreads to the neck or under the tongue, or comes with high fever and trouble opening the mouth. Otherwise, see a dentist or doctor the same day for a painful swollen jaw.