Condition
Move the jaw
Shown on the patient's left. Colour and values are geometry in this model only: how much a branch's path lengthens, or how close bone comes to it. They are not measured nerve pressure. Branches marked schematic are drawn on landmarks, not traced from a dataset.
Painful areaWorking muscleNerve: low → high stretch or closenessColoured areas are schematic.
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What studies report for this condition
Conditions
- Healthy jaw Reference
- In the study groups cited, average maximum opening was about 41–43 mm and average maximum sideways movement about 12 mm, with wide variation between people. The joint rotates and slides forward together from the start of opening; it is not a simple hinge.[22][61][39]
- Jaw-muscle pain Myalgia
- Pain in the chewing muscles, at the temple and the cheek, that changes with jaw use. It often comes and goes: over five years about a third of cases persisted, a third went away and a third recurred.[59][69]
- Jaw-joint pain Arthralgia
- Pain in the joint itself, just in front of the ear, that changes with jaw movement. Diagnosis is made by a clinician after examining the joint.[69]
- Clicking Disc displacement with reduction
- The cartilage disc sits in front of the joint when the mouth is closed and slips back into place as it opens, which can be heard as a click. Clicking is the most common jaw-joint sign on examination in adults, and is usually painless and stable over time.[77][51][69]
- Closed lock Disc displacement without reduction, with limited opening
- The disc stays in front of the condyle and does not slip back. In the type shown here it restricts the joint's forward translation, so opening is limited and the chin turns toward that side. A jaw that suddenly locks, or opening that keeps getting smaller, needs a dentist or doctor.[69]
- Clenching Bruxism (awake or sleep)
- Repeated or sustained jaw-muscle activity, awake or asleep, such as clenching, grinding, or bracing the jaw without the teeth touching. The model colours the working muscles; it does not show tooth contact. An international consensus describes bruxism as a behaviour rather than a disease: in otherwise healthy people it may have no consequence.[41]
- Jaw held forward Mandibular advancement device
- For diagnosed obstructive sleep apnoea, a sleep physician may prescribe a custom mouthguard that holds the lower jaw forward during sleep to keep the throat more open. Response varies between people. Guidelines call for a qualified dentist to fit and adjust it, a follow-up sleep test, and continued follow-up with both the physician and the dentist, because jaw pain is common early and the bite shifts with years of use.[58][17][55]
Findings by topic
Jaw joint
From the start of opening, the joint both rotates and slides forward; no pure hinge phase was found.[39]
Applies to: Healthy jaw
About three in ten adults show signs of a jaw-joint disorder on a standard examination; clicking is the most common.[77]
Applies to: Clicking
In patients whose jaw pain caused little impairment, managed with advice and self-care, muscle-pain diagnoses fell sharply over 2–3 years, while painless clicking stayed about the same.[46]
One clinic cohort without an untreated comparison group.
Applies to: Clicking, Jaw-muscle pain
In a study of 40 untreated patients with a non-reducing disc followed for 2.5 years, about three in four were symptom-free or improved; a quarter did not improve or needed treatment.[37]
One observational cohort.
Applies to: Closed lock
Jaw and joint pain is more common in the first weeks of wearing an advancement device and is usually temporary.[17][40]
The newest meta-analysis rated the certainty of this evidence very low.
Applies to: Jaw held forward
Jaw-joint signs before treatment are not, on their own, a routine reason to avoid an advancement device; they are a reason for the dentist to monitor the joint.[2]
Applies to: Jaw held forward
Chewing muscles
An international consensus defines bruxism as muscle activity that can be a risk factor, harmless, or possibly protective, rather than a disorder in itself.[41]
Applies to: Clenching
People who report clenching or grinding more often have jaw-muscle pain, and in a large cohort self-reported jaw habits, including clenching and grinding, predicted new jaw disorders.[43][74]
Self-report, not measured muscle activity.
Applies to: Clenching
In sleep-laboratory recordings, the study did not detect more night-time jaw-muscle activity in people with jaw-muscle pain than in people without it.[60][44]
Applies to: Clenching, Jaw-muscle pain
Trigeminal nerve
The auriculotemporal nerve, a branch of the mandibular division of the trigeminal nerve, supplies the jaw joint and the skin of the temple and ear. In dissections it runs close to the condylar neck and the joint, and its roots vary (one to five).[36][32]
Anatomy: 16 dissected specimens, and a systematic review of the nerve's variations.
Applies to: Healthy jaw, Jaw-muscle pain, Jaw-joint pain, Clicking, Closed lock
In 18 joints from autopsies, two joints with a displaced disc had the auriculotemporal nerve almost touching the inner side of the condyle, and one joint with excessive condylar movement showed compression of the masseteric nerve. The authors proposed that the joint could mechanically irritate nearby nerves.[30]
A proposed mechanism from a small anatomical study. We found no clinical study showing that nerve entrapment causes jaw pain.
Applies to: Clicking, Closed lock, Jaw-joint pain
Pain from the jaw joint and chewing muscles is carried by trigeminal nerve fibres to the brainstem. Reviews describe how these signals can be amplified in the periphery and the brainstem, and how deep and skin inputs converge on the same neurones, which may explain why jaw pain spreads and is felt in other places.[70][11]
Narrative reviews, largely of animal studies: mechanisms, not a diagnostic test.
Applies to: Jaw-muscle pain, Jaw-joint pain
We found no evidence that jaw disorders cause trigeminal neuralgia. It is classified separately, and in its commonest (primary) form contact between a blood vessel and the trigeminal nerve root inside the skull plays an important role.[13][6]
Diagnostic classification and the European neurology guideline.
Applies to: Jaw-muscle pain, Jaw-joint pain, Clicking, Closed lock, Clenching
Head and face
Headache attributed to a jaw disorder is a diagnosis in the international headache classification. A clinician makes it after examining the jaw and excluding other explanations; it cannot be settled from symptoms alone.[29][68]
Applies to: Jaw-muscle pain, Jaw-joint pain
Migraine, tension-type headache and chronic headache were more common in people with painful jaw disorders.[62]
One-time snapshot studies, so they cannot show which comes first. The review rated the certainty of this evidence very low to low.
Applies to: Jaw-muscle pain, Jaw-joint pain
People with migraine more often had a jaw disorder, and people with a jaw disorder more often had migraine.[16]
Odds ratios 6.1 and 2.6, pooled from cross-sectional studies: this shows the two occur together, not which causes which.
Applies to: Jaw-muscle pain, Jaw-joint pain
In a large cohort of people who started without a jaw disorder, existing migraine and frequent headache predicted developing one later.[76]
One cohort, from one study group. It shows order in time, not cause.
Applies to: Jaw-muscle pain
Over 11 years, jaw-muscle pain at the start was associated with higher odds of later tension-type headache. Jaw-joint pain showed no clear association with it, and neither showed a consistent association with later migraine.[4]
Muscle pain: odds ratio 2.1 (95% CI 1.2–3.8). Joint pain: 0.4 (0.1–1.3). One population cohort, 530 people at follow-up.
Applies to: Jaw-muscle pain, Jaw-joint pain
Painless clicking has not been shown to go with headache. Only two studies looked.[62]
Applies to: Clicking
In women with jaw-muscle pain, pressing tender spots in jaw and neck muscles reproduced familiar pain and spread it over a larger area than in healthy women.[19]
One small blinded study, 25 patients and 25 controls.
Applies to: Jaw-muscle pain
Splints and jaw physiotherapy have uncertain effects on headache. In one trial, adding a splint to counselling gave no clear extra benefit.[12][15]
The meta-analysis rated certainty low to very low.
Applies to: Jaw-muscle pain, Clenching
Ear
Tinnitus and jaw disorders often occur together: the odds of tinnitus were about four times higher with a jaw disorder, and the odds of a jaw disorder about four times higher with tinnitus.[3][50]
Odds ratios 3.9 and 4.2 from 34 observational studies, with high heterogeneity and mostly self-reported tinnitus. This shows co-occurrence, not cause.
Applies to: Jaw-muscle pain, Jaw-joint pain
In a five-year population study, a tender jaw joint at the start was associated with a higher risk of a later tinnitus diagnosis.[8]
Adjusted risk ratio 2.4 (95% CI 1.6–3.7). One observational cohort, not yet replicated.
Applies to: Jaw-joint pain
Ear symptoms are commonly reported with jaw disorders: a feeling of fullness most often, then ear pain, ringing and dizziness.[56]
Applies to: Jaw-muscle pain, Jaw-joint pain
Studies with hearing tests did not consistently find hearing loss in people with jaw disorders and ear complaints. That cannot rule it out for any one person: new hearing changes should be assessed, and sudden hearing loss needs urgent medical care.[27][21]
Small studies.
Applies to: Jaw-muscle pain, Jaw-joint pain
In a randomised trial of 80 people with chronic tinnitus and a jaw disorder and/or oral habits, diagnosed after a multidisciplinary assessment, an orofacial programme (advice, jaw physiotherapy and, where indicated, a splint) improved one of two tinnitus scores compared with delayed treatment.[78]
Tinnitus that changes with jaw movement does not on its own mean jaw treatment will help.
Applies to: Jaw-muscle pain
In one population study, tinnitus was associated with tender muscles and joints; no clear association was detected with clicking or limited opening.[7]
The patient group was small (30).
Applies to: Clicking, Closed lock
A small ligament connects the jaw-joint disc region to a middle-ear bone. Anatomy studies describe it; none show that it causes ear symptoms.[65][49]
Applies to: Clicking, Closed lock
Teeth and bite
Across about 40 bite features studied, no consistent, clinically meaningful association with jaw disorders was found.[47]
Applies to: Jaw-muscle pain, Jaw-joint pain, Clicking, Closed lock
A few extreme bite features are more common in jaw disorders but explain little, and some may result from joint changes rather than cause them.[57]
Applies to: Jaw-muscle pain, Jaw-joint pain, Clicking, Closed lock
Grinding teeth down to "balance the bite" has not been shown to treat or prevent jaw disorders.[35]
The Cochrane review (6 trials) was withdrawn in 2016 as out of date; we found no later trial that reverses it.
Applies to: Jaw-muscle pain, Jaw-joint pain
In a 20-year cohort, orthodontic treatment was not associated with either more or fewer jaw disorders.[42]
Applies to: Jaw-muscle pain, Jaw-joint pain, Clicking, Closed lock
For hard splints, the current Cochrane review (57 trials) could not reach firm conclusions.[73]
All evidence rated very low certainty.
Applies to: Jaw-muscle pain, Jaw-joint pain, Clicking
Among teeth that already have cracks, cracks were more often painful in people who reported clenching or grinding.[28]
Applies to: Clenching
In an exploratory study of 32 young adults, those with marked tooth wear showed no more sleep jaw-muscle activity than matched controls.[31]
Applies to: Clenching
Years of wearing an advancement device gradually change how the teeth meet, and the change had not levelled off by the end of follow-up. Long-term skeletal change was small.[55][26]
Applies to: Jaw held forward
Neck and shoulders
Jaw and head move together: opening, closing and chewing are accompanied by head movement.[18]
Applies to: Healthy jaw
People with jaw disorders report more neck disability, and greater jaw disability goes with greater neck disability.[14]
Observational studies; they cannot show which causes which.
Applies to: Jaw-muscle pain, Jaw-joint pain
Adults with neck pain had higher odds of a jaw disorder (odds ratio about 3.6).[9]
Cross-sectional studies; the review rated certainty very low.
Applies to: Jaw-muscle pain
After whiplash, jaw pain was reported by about 19–27% of people, against 6% of controls.[25]
Applies to: Jaw-muscle pain, Jaw-joint pain
Breathing and sleep
Custom devices that hold the jaw forward reduce breathing pauses compared with no treatment, though CPAP reduces them more. How well a device works varies from person to person.[38][72][54]
Applies to: Jaw held forward
The sleep-medicine and dental-sleep-medicine guideline recommends that sleep physicians consider prescribing an oral appliance, rather than no treatment, for adults with obstructive sleep apnoea who cannot tolerate CPAP or prefer an alternative.[58]
A "standard", the guideline's stronger level of recommendation, on moderate-quality evidence.
Applies to: Jaw held forward
The same guideline suggests a custom, adjustable device fitted by a qualified dentist, dental oversight of side effects, follow-up sleep testing, and periodic visits with both the physician and the dentist.[58]
These are weaker "guideline"-level recommendations.
Applies to: Jaw held forward
In a one-month crossover trial, daytime sleepiness improved about as much with a device as with CPAP; people reported wearing the device for more hours per night.[54]
Applies to: Jaw held forward
Night-time jaw-muscle episodes usually follow a brief arousal from sleep.[33]
Applies to: Clenching
A 2024 meta-analysis did not detect higher odds of sleep bruxism in people with sleep apnoea.[10]
Odds ratio 1.23, 95% CI 0.47–3.20: the interval is wide and allows a substantially higher or lower risk.
Applies to: Clenching
In a prospective cohort, self-rated sleep quality worsened in the months before painful jaw disorders first appeared, and symptoms suggestive of sleep apnoea predicted them.[67][66]
Sleep was self-rated and apnoea was judged from symptoms, not a sleep study.
Applies to: Jaw-muscle pain, Jaw-joint pain
Pain elsewhere in the body
Painful jaw disorders often occur alongside other chronic pain conditions, such as fibromyalgia, low back pain and headache. This shows overlap, not cause.[75]
Cross-sectional analysis within a large prospective cohort.
Applies to: Jaw-muscle pain, Jaw-joint pain
In pooled studies, about three in four people with fibromyalgia met criteria for a jaw disorder, mostly the muscle type.[79]
Applies to: Jaw-muscle pain
Higher pain sensitivity on testing modestly predicted new jaw disorders.[23]
Applies to: Jaw-muscle pain
Mood and stress
In prospective data, psychological stress, low mood and reporting many physical symptoms elsewhere in the body came before new jaw disorders.[20][5]
This is about what predicts jaw disorders. No study we found tested whether jaw position causes depression.
Applies to: Jaw-muscle pain, Jaw-joint pain
Digestion
Irritable bowel syndrome and reflux are more common in people with jaw disorders. One genetic study suggested an effect of reflux on jaw disorders; it did not find one in the other direction.[1][24]
Applies to: Jaw-muscle pain, Jaw-joint pain
Posture and balance
A meta-analysis did not detect a difference in craniocervical position or neck alignment between people with and without jaw disorders. Earlier reviews called the relationship unclear because the studies were of low quality.[14][52][63]
Applies to: Jaw-muscle pain, Jaw-joint pain, Clicking, Closed lock
Reviews did not find that the bite or jaw position predictably changes body posture or standing balance.[45][53]
Applies to: Jaw held forward, Jaw-muscle pain, Jaw-joint pain, Clicking, Closed lock
A controlled study did not detect differences in posture or balance measures in people with a pain-free displaced jaw disc on one side.[64]
21 participants and 21 controls.
Applies to: Clicking, Closed lock
Eyes and vision
A few small studies measured eye focusing (convergence and accommodation) with the jaw in different positions or after wearing a splint, and reported differences. None shows that jaw problems damage eyesight or that jaw treatment improves vision.[71][48][34]
A 30-person comparison of a repositioning appliance with no appliance; a 100-person case-control study, whose authors note the tests were hard to reproduce; and an uncontrolled study of 42 splint wearers, whose 6-month improvement showed no further significant change at a year.
Applies to: Jaw-muscle pain, Jaw-joint pain, Clicking, Closed lock, Clenching