TMJ facts & research: how common TMD is, who it affects, and what the evidence says

A jaw epidemic nobody is talking about

Your jaw opens and closes around 2,000 times a day. For roughly one in three adults, that simple motion comes with a click, an ache, a pop, or a pain that radiates into the head, neck, and ears. Studies estimate about 31% of adults live with a temporomandibular disorder, and modeling suggests the figure could approach 44% by 2050. Women are about 1.75× more likely to be affected than men, and most never get proper care.

TMJ, TMD, TMJD: three letters, one stubborn confusion

TMJ — Temporomandibular Joint

Two of them, actually — one in front of each ear, where your lower jaw meets your skull. Everyone has TMJs. Yours are working right now, opening and closing every time you talk, chew, or yawn.

TMD — Temporomandibular Disorders

An umbrella term for any condition causing pain or dysfunction in the jaw joint and the muscles that control it. Headaches, jaw clicking, locking, ear fullness, neck tension — if it traces back to that joint or those muscles, it lives under TMD.

TMJD — Temporomandibular Joint Disorder

Often used interchangeably with TMD, though some clinicians use TMJD specifically when the joint itself (cartilage, disc, bone) is involved — versus muscle-driven pain. In everyday use, TMD and TMJD mean the same thing.

Global prevalence: it's everywhere, some places more than others

A 2025 meta-analysis pooling dozens of studies found temporomandibular disorders on every continent, with the highest pooled rates in Europe and the lowest in North America.

The pain isn't equal-opportunity

Across pooled data, women are affected substantially more often than men — about 36.7% versus 26.7%, a 1.75-fold difference.

A young person's condition

Unusually for a chronic pain condition, TMD peaks in early-to-mid adulthood rather than old age.

It rarely shows up just as jaw pain

Muscle pain, joint sounds, and headache dominate how TMD actually presents.

Why perimenopause makes it worse

Sex hormones influence TMD risk: estrogen and relaxin both act on joint tissue and pain sensitivity. Risk is elevated up to 3.2× during reproductive years, about 64% of women report symptoms worsening through perimenopause, and roughly 41% continue to have elevated symptoms after menopause.

United States, unevenly affected

US facial-pain prevalence varies by region, running higher in Appalachia and the Mountain West and lower across the Plains. (Illustrative, anchored to NHIS regional facial-pain patterns.)

It takes years to get a name for it

The path to a TMD diagnosis is long: patients see an average of 4.6 providers over roughly 3.2 years, and about 68% are initially misdiagnosed.

TMD rarely travels alone

TMD commonly co-occurs with headache, sleep, and mood conditions.

A condition that falls into an insurance gap

TMD care sits between medical and dental coverage. US treatment costs run into the billions annually (about $4B), with average out-of-pocket spending near $2,400 per year.

It's growing

Estimated and projected TMD prevalence has risen steadily and is modeled to continue climbing toward 2050.

Where this came from

1. NIDCR (2018). Prevalence of TMJD and its Signs and Symptoms. National Institute of Dental and Craniofacial Research.
2. Valesan et al. (2021). Prevalence of temporomandibular joint disorders: a systematic review and meta-analysis. Clin Oral Investig 25, 441–453.
3. Alqutaibi, Almashraqi et al. (2025). Global prevalence of temporomandibular disorders: a systematic review and meta-analysis. J Oral & Facial Pain Headache 39(2):48–65.
4. Zieliński et al. (2025). Quo Vadis Temporomandibular Disorders? By 2050, the Global Prevalence of TMD May Approach 44%. J Clin Med 14, 4414.
5. LeResche L. (1997). Epidemiology of temporomandibular disorders: implications for the investigation of etiologic factors. Crit Rev Oral Biol Med 8(3):291-305.
6. Liou et al. (2023). Bidirectional Associations of Temporomandibular Joint Disorders with Major Depressive and Anxiety Disorders. J Evid Based Dent Pract 23:101860.
7. Al-Jewair, Shibeika, Ohrbach (2021). Temporomandibular Disorders and Their Association with Sleep Disorders in Adults: A Systematic Review. J Oral Facial Pain Headache 35:41–53.
8. Slade GD, Durham J (2018). Prevalence, Impact, and Costs of Treatment for Temporomandibular Disorders. NASEM commissioned paper.
9. Macfarlane TV et al. (2002). Oro-facial pain in the community: prevalence and associated impact. Community Dent Oral Epidemiol 30:52–60.
10. Gonçalves DA et al. (2010). Headache and symptoms of temporomandibular disorder: an epidemiological study. Headache 50:231–241.