TMJ Pain Types: Myofascial Pain and Arthralgia Explained

The temporomandibular joint (TMJ) connects the lower jaw to the skull just in front of each ear, and it is one of the most-used joints in the body — working every time we talk, chew or yawn. TMJ disorders (TMD) are problems with this joint, the chewing muscles, or both, and they are a very common cause of face and jaw pain.

Two of the most frequent diagnoses are myofascial pain (aching in the chewing muscles, often with tender "trigger points") and arthralgia (pain actually inside the joint). Telling muscle pain apart from joint pain matters because each responds to different treatment.

Key Concepts

• Myofascial pain: dull aching in the masseter or temporalis muscles, worsened by chewing or stress-related clenching. Pressing the muscle reproduces the ache; it may come with referral (pain felt in the teeth or temple) or with limited opening if the muscle goes into spasm.
• Arthralgia: pain localised to the joint itself, in front of the ear, that gets worse with jaw movement, chewing or pressing on the joint. Unlike arthritis, it does not require visible joint degeneration.
• Normal jaw opening: the gap between the upper and lower front teeth (interincisal opening) is normally 40–50 mm. Below about 35 mm with pain suggests a real restriction.
• Other TMD types: disc displacement (the cushioning disc slips, causing clicks or locking) and degenerative joint disease (worn joint surfaces, causing grating sounds called crepitus).

How It Works

1. Myofascial pain starts when chewing muscles are overworked — night-time grinding, daytime clenching or prolonged wide opening at the dentist. Overworked fibres develop trigger points: tight knots that ache and refer pain elsewhere.
2. Arthralgia arises when the joint capsule or the tissues behind the disc become inflamed or overloaded, so every jaw movement stretches the sore tissue and hurts.
3. Stress, poor sleep and bad posture amplify both, because tense neck and shoulder muscles pull the jaw into a strained position and lower the pain threshold.

Worked Example

A patient reports jaw pain rated 8 out of 10. Her interincisal opening measures 28 mm, which is 40 − 28 = 12 mm below the lower end of normal — a clear restriction. Pressing her masseter muscle reproduces the exact ache, but the joint itself is not tender, pointing to myofascial pain rather than arthralgia. After four weeks of a night guard, jaw exercises and stress management, her pain drops to 3 out of 10. Improvement = (8 − 3) ÷ 8 = 0.625, about a 63 percent reduction, and her opening improves to 38 mm.

Common Misconceptions

• "A clicking jaw always means disease." Painless clicking alone is extremely common and usually harmless; pain, locking or limited opening are what make it a disorder.
• "TMJ problems always need surgery." The vast majority improve with conservative care — self-care, physiotherapy, splints and stress management. Surgery is reserved for rare severe cases.
• "Only older people get jaw joint problems." TMD peaks in young and middle-aged adults, especially women aged 20–40, and is often linked to stress and clenching.

Real-World Applications

• Dentists use the standardised DC/TMD examination to classify the pain as muscular or joint-based before recommending any treatment.
• Conservative management — soft diet, warm compresses, habit counselling, occlusal splints and physiotherapy — resolves most cases without drugs or surgery.
• Recognising myofascial referral pain prevents unnecessary root canals: pain "in the teeth" that actually comes from the masseter needs muscle treatment, not drilling.

To summarise, myofascial pain is aching, tender chewing muscles often driven by clenching, while arthralgia is pain inside the joint worsened by movement. Both are diagnosed clinically, both usually settle with conservative care, and distinguishing them keeps treatment — and the patient — on the right track.