Why Does My Jaw Hurt on One Side?

You wake up and the jaw hurts on one side. Or maybe you notice a click every time you open your mouth wide — but only on the left. Or you have been dealing with a dull, nagging pain near your ear for weeks, and you cannot quite figure out why.

One-sided jaw pain is more common than most people realize. And while it can feel alarming, it is usually something that can be explained — and treated — once you understand what is going on.

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The anatomy behind the pain

The jaw is one of the most frequently used joints in your body. You use it for talking, chewing, yawning, swallowing — hundreds of times a day. Connecting your lower jaw to your skull, just in front of each ear, are two small but remarkably complex structures called the temporomandibular joints (TMJ). One on the left, one on the right — and they work together as a team. When one side starts to have problems, the whole system feels it.

Pain that affects only one side is actually the more common presentation. When both sides hurt equally, it often points to systemic conditions like arthritis or whole-body bruxism. But unilateral jaw pain — pain on just one side — tends to point to more localised issues: one affected joint, one troubled tooth, or one overworked group of muscles.

Common causes of one-sided jaw pain

1. TMJ Disorder (TMD)

This is the most common cause of persistent, one-sided jaw pain.¹ Because you have a TMJ on each side of your face, problems can develop in just one joint while the other stays completely fine — which is exactly why the pain lands on just one side. Common signs include:

•       Clicking or popping when you open or close your mouth

•       Pain near your ear, cheek, or temple — on one side

•       Jaw stiffness in the morning, or difficulty opening fully

•       Pain that worsen when chewing hard foods

•       Referred pain into the neck, shoulder, or as headaches

Research shows that over 70% of patients with chronic unilateral TMD consistently chew on the same side⁴ — and over time, that overloads the joint on that side.

2. Bruxism (teeth grinding and clenching)

Bruxism is the involuntary grinding or clenching of teeth — most often during sleep. If you grind unevenly or clench harder on one side, that TMJ takes more load. Over time, this leads to inflammation, disc displacement, and persistent one-sided pain. ¹

3. Dental issues on one side

Sometimes the pain is not from the joint at all — it is from a tooth. Possible culprits include:

•       A cracked or fractured tooth — sharp pain when biting

•       A dental abscess or infection — throbbing pain, sometimes with swelling

•       An impacted wisdom tooth — deep ache at the back of the jaw

•       A high filling or crown — even a slightly uneven bite throws extra force onto that joint.

4. Muscle tension and stress

Stress is a surprisingly common driver of jaw pain. When we are anxious or tense, many of us clench our jaw without noticing. The muscles around the jaw respond to emotional stress just like the muscles in your shoulders and neck.²

5. Injury or trauma

A knock to the jaw can strain the ligaments, muscles, or joint capsule on one side. Symptoms sometimes develop days or weeks after the initial injury as inflammation builds up slowly.

6. Referred pain from other structures

Not all jaw pain originates in the jaw. Ear infections, sinusitis, and neck-related headaches are all known to mimic one-sided jaw pain through the trigeminal nerve. [3]to the neck, shoulder, or as headaches

When should you see a professional?

Not every jaw ache needs an urgent visit. But see a dental professional sooner rather than later if:

•       Pain lasts more than a few days and does not improve with rest

•       Jaw pain is accompanied by swelling, fever, or difficulty swallowing

•       You cannot open your mouth fully, or it locks

•       Pain is progressively getting worse

•       You notice changes in how your teeth come together

What Can Help?

Treatment depends on the cause — which is why a proper assessment comes first. Common approaches include:

•       Custom occlusal splint : worn overnight to cushion the joint and protect teeth from grinding

A custom-fitted mandibular advancement device (MAD) can hold the lower jaw slightly forward during sleep to keep the airway open. Image Source: Modern Dental Laboratory Hong Kong

•       Mandibular advancement device (MAD): if snoring or sleep apnea is contributing to the grinding and joint stress

A custom-fitted mandibular advancement device (MAD) can hold the lower jaw slightly forward during sleep to keep the airway open. Image Source: Modern Dental Laboratory Hong Kong

•       Physiotherapy: exercises and manual therapy for the jaw muscles and neck

•       Dental treatment: addressing tooth problems — infection, fracture, or an uneven bite

•       Lifestyle changes: reducing stress, avoiding hard foods during a flare, being aware of chewing habits

Frequently asked questions(FAQ)

Q: Why does my jaw only hurt on one side?

A: Because you have two separate TMJs, problems can develop in just one. One-sided jaw pain usually points to a localised issue — a specific joint problem, a dental problem on that side, or the habit of chewing or clenching more heavily on one side. ⁴

Q: Can stress really cause jaw pain?

A: Yes. Emotional stress commonly leads to jaw clenching — either during the day or during sleep — which overloads the joint and surrounding muscles. ²

Q: Will it go away on its own?

A: Sometimes mild cases resolve with rest, soft food, and stress reduction. But if pain persists beyond a week or two, or is affecting your sleep or daily eating, get a professional assessment. Untreated TMD can progress to more persistent joint changes that are harder to manage.

Q: Is jaw pain related to my snoring?

A: It can be. Snoring and sleep apnea can trigger the jaw to clench repeatedly overnight — a protective reflex that also causes bruxism and TMJ overloading. If your jaw pain tends to be worst in the morning, this connection is worth exploring with your dentist. ³

This article is produced by the Education Team of the Modern Dental Global Foundation. MDGF is a non-profit dental charity and education. This content is for informational purposes only and does not constitute individual medical or dental advice. Please consult a qualified dental professional for personal guidance.

References [1] Gauer RL, Semidey MJ. Diagnosis and treatment of temporomandibular disorders. Am Fam Physician. 2015;91(6):378–386. PMID:25822556

[2] Ferrillo M et al. Pain management and rehabilitation for temporomandibular disorders: a systematic review. Int J Environ Res Public Health. 2022;19(7):4302. doi:10.3390/ijerph19074302

[3] Rodrigues Conti PC et al. Headaches and orofacial pain: their relationship with sleep disorders. J Appl Oral Sci. 2023;31:e20230027. doi:10.1590/1678-7757-2023-0027

[4] Meeder W et al. Jaw biodynamic data for 24 patients with chronic unilateral temporomandibular disorder. Sci Data. 2017;4:170168. doi:10.1038/sdata.2017.168

[5] Natu VP et al. Temporomandibular disorder symptoms and their association with quality of life, emotional states and sleep quality in South-East Asian youths. J Oral Rehabil. 2018;45(10):756–763. doi:10.1111/joor.12692