TMJ

DISORDERS

U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES

National Institutes of Health
CONTENTS

WHAT IS THE 

TEMPOROMANDIBULAR JOINT? 2

WHAT ARE 

TMJ DISORDERS? 4

WHAT CAUSES 

TMJ DISORDERS? 6

WHAT ARE THE 

SIGNS AND SYMPTOMS? 7

HOW ARE TMJ 

DISORDERS DIAGNOSED? 8

HOW ARE TMJ 

DISORDERS TREATED? 9

IF YOU THINK YOU 

HAVE A TMJ DISORDER... 14

15 RESEARCH

16 HOPE FOR THE FUTURE
1

TMJ DISORDERS

Temporomandibular joint and muscle 

disorders, commonly called “TMJ,” are a 

group of conditions that cause pain and 

dysfunction in the jaw joint and the muscles 

that control jaw movement. We don’t know 

for certain how many people have TMJ 

disorders, but some estimates suggest that 

over 10 million Americans are affected. The 

condition appears to be more common in 

women than men.

For most people, pain in the area of the 

jaw joint or muscles does not signal a 

serious problem. Generally, discomfort 

from these conditions is occasional and 

temporary, often occurring in cycles. The 

pain eventually goes away with little or no 

treatment. Some people, however, develop 

significant, long-term symptoms.

If you have questions about TMJ disorders, 

you are not alone. Researchers, too, are 

looking for answers to what causes these 

conditions and what the best treatments are. 

Until we have scientific evidence for safe and 

effective treatments, it’s important to avoid, 

when possible, procedures that can cause 

permanent changes in your bite or jaw. This 

booklet provides information you should know 

if you have been told by a dentist or physician 

that you have a TMJ disorder.
2

WHAT IS THE 

TEMPOROMANDIBULAR JOINT?

The temporomandibular joint connects the 

lower jaw, called the mandible, to the bone at 

the side of the head—the temporal bone. If 

you place your fingers just in front of your ears 

and open your mouth, you can feel the joints. 

Because these joints are flexible, the jaw can 

move smoothly up and down and side to side, 

enabling us to talk, chew and yawn. Muscles 

attached to and surrounding the jaw joint 

control its position and movement.

When we open our mouths, the rounded ends 

of the lower jaw, called condyles, glide along 

the joint socket of the temporal bone. The 

condyles slide back to their original position 

when we close our mouths. To keep this 

motion smooth, a soft disc lies between the 

condyle and the temporal bone. This disc 

absorbs shocks to the jaw joint from chewing 

and other movements.

The temporomandibular joint is different from 

the body’s other joints. The combination 

of hinge and sliding motions makes this 

joint among the most complicated in the 

body. Also, the tissues that make up the 

temporomandibular joint differ from other loadbearing joints, like the knee or hip. Because of 

its complex movement and unique makeup, the 

jaw joint and its controlling muscles can pose 

a tremendous challenge to both patients and 

health care providers when problems arise. 
3

OPEN

Temporal muscle covering 

temporal bone

Disc

Condyle

Masseter muscle

Mandible

CLOSED
4

WHAT ARE 

TMJ DISORDERS?

Disorders of the jaw joint and chewing 

muscles—and how people respond to them—

vary widely. Researchers generally agree that 

the conditions fall into three main categories:

1 Myofascial pain involves discomfort or 

pain in the muscles that control jaw function.

2 Internal derangement of the joint involves 

a displaced disc, dislocated jaw, or injury to 

the condyle.

3 Arthritis refers to a group of degenerative/

inflammatory joint disorders that can affect 

the temporomandibular joint.

A person may have one or more of these 

conditions at the same time. Some people 

have other health problems that co-exist 

with TMJ disorders, such as chronic 

fatigue syndrome, sleep disturbances or 

fibromyalgia, a painful condition that affects 

muscles and other soft tissues throughout 

the body. These disorders share some 

common symptoms, which suggests 

that they may share similar underlying 

mechanisms of disease. However, it is not 

known whether they have a common cause.
5

Rheumatic disease, such as arthritis, may 

also affect the temporomandibular joint as 

a secondary condition. Rheumatic diseases 

refer to a large group of disorders that cause 

pain, inflammation, and stiffness in the joints, 

muscles, and bone. Arthritis and some TMJ 

disorders involve inflammation of the tissues 

that line the joints. The exact relationship 

between these conditions is not known.

How jaw joint and muscle disorders 

progress is not clear. Symptoms worsen 

and ease over time, but what causes these 

changes is not known. Most people have 

relatively mild forms of the disorder. Their 

symptoms improve significantly, or disappear 

spontaneously, within weeks or months. 

For others, the condition causes long-term, 

persistent, and debilitating pain.

 TMJ
6

WHAT CAUSES 

TMJ DISORDERS?

Trauma to the jaw or temoromandibular joint 

plays a role in some TMJ disorders. But for 

most jaw joint and muscle problems, scientists 

don’t know the causes. Because the condition 

is more common in women than in men, 

scientists are exploring a possible link between 

female hormones and TMJ disorders.

For many people, symptoms seem to start 

without obvious reason. Research disputes the 

popular belief that a bad bite or orthodontic 

braces can trigger TMJ disorders.

There is no scientific proof that sounds—

such as clicking—in the jaw joint lead 

to serious problems. In fact, jaw sounds 

are common in the general population. 

Jaw noises alone, without pain or limited 

jaw movement, do not indicate a TMJ 

disorder and do not warrant treatment.
7

WHAT ARE THE 

SIGNS AND SYMPTOMS?

A variety of symptoms may be linked to 

TMJ disorders. Pain, particularly in the 

chewing muscles and/or jaw joint, is the 

most common symptom. Other likely 

symptoms include:

n radiating pain in the face, jaw, or neck,

n jaw muscle stiffness,

n limited movement or locking of the jaw,

n painful clicking, popping or grating in 

n a change in the way the upper and lower 

 TMJ
8

HOW ARE TMJ 

DISORDERS DIAGNOSED?

There is no widely accepted, standard test 

now available to correctly diagnose TMJ 

disorders. Because the exact causes and 

symptoms are not clear, identifying these 

disorders can be difficult and confusing. 

Currently, health care providers note the 

patient’s description of symptoms, take a 

detailed medical and dental history, and 

examine problem areas, including the head, 

neck, face, and jaw. Imaging studies may 

also be recommended.

You may want to consult your doctor to 

rule out other known causes of pain. Facial 

pain can be a symptom of many conditions, 

such as sinus or ear infections, various 

types of headaches, and facial neuralgias 

(nerve-related facial pain). Ruling out these 

problems first helps in identifying TMJ 

disorders. 
9

HOW ARE TMJ 

DISORDERS TREATED?

Because more studies are needed on the 

safety and effectiveness of most treatments 

for jaw joint and muscle disorders, experts 

strongly recommend using the most 

conservative, reversible treatments possible. 

Conservative treatments do not invade the 

tissues of the face, jaw, or joint, or involve 

surgery. Reversible treatments do not cause 

permanent changes in the structure or position 

of the jaw or teeth. Even when TMJ disorders 

have become persistent, most patients still do 

not need aggressive types of treatment.

Conservative Treatments

Because the most common jaw joint and 

muscle problems are temporary and do not 

get worse, simple treatment may be all that is 

necessary to relieve discomfort.

Self-Care Practices

There are steps you can take that may be 

helpful in easing symptoms, such as:

n eating soft foods, 

n applying ice packs,

n avoiding extreme jaw movements 

n learning techniques for 

 TMJ
10

n practicing gentle jaw stretching and relaxing 

Pain Medications

For many people with TMJ disorders, shortterm use of over-the-counter pain medicines 

or nonsteroidal anti-inflammatory drugs 

(NSAIDs), such as ibuprofen, may provide 

temporary relief from jaw discomfort. When 

necessary, your dentist or physician can 

prescribe stronger pain or anti-inflammatory 

medications, muscle relaxants, or antidepressants to help ease symptoms.

Stabilization Splints

Your physician or dentist may recommend an 

oral appliance, also called a stabilization splint 

or bite guard, which is a plastic guard that 

fits over the upper or lower teeth. Stabilization 

splints are the most widely used treatments for 

TMJ disorders. Studies of their effectiveness 

in providing pain relief, however, have 

been inconclusive. If a stabilization splint is 

recommended, it should be used only for a 

short time and should not cause permanent 

changes in the bite. If a splint causes or 

increases pain, or affects your bite, stop using 

it and see your health care provider.
11

The conservative, reversible treatments 

described are useful for temporary relief of 

pain – they are not cures for TMJ disorders. 

If symptoms continue over time, come back 

often, or worsen, tell your doctor.

Botox

Botox® (botulinum toxin type A) is a 

drug made from the same bacterium that 

causes food poisoning. Used in small 

doses, Botox injections can actually help 

alleviate some health problems and have 

been approved by the Food and Drug 

Administration (FDA) for certain disorders. 

However, Botox is currently not approved 

by the FDA for use in TMJ disorders. 

Results from recent clinical studies are 

inconclusive regarding the effectiveness of 

Botox for treatment of chronic TMJ disorders. 

Additional research is under way to learn 

how Botox specifically affects jaw muscles 

and their nerves. The findings will help determine if this drug may be useful in treating 

TMJ disorders. 

 TMJ
12

Irreversible Treatments

Irreversible treatments that have not been 

proven to be effective – and may make 

the problem worse – include orthodontics 

to change the bite; crown and bridge 

work to balance the bite; grinding down 

teeth to bring the bite into balance, called 

“occlusal adjustment”; and repositioning 

splints, also called orthotics, which 

permanently alter the bite.

Surgery

Other types of treatments, such as surgical 

procedures, invade the tissues. Surgical 

treatments are controversial, often irreversible, 

and should be avoided where possible. 

There have been no long-term clinical trials to 

study the safety and effectiveness of surgical 

treatments for TMJ disorders. Nor are there 

standards to identify people who would most 

likely benefit from surgery. Failure to respond 

to conservative treatments, for example, 

does not automatically mean that surgery is 

necessary. If surgery is recommended, be 

sure to have the doctor explain to you, in 

words you can understand, the reason for the 

treatment, the risks involved, and other types 

of treatment that may be available.
13

Implants

Surgical replacement of jaw joints with 

artificial implants may cause severe pain 

and permanent jaw damage. Some of these 

devices may fail to function properly or may 

break apart in the jaw over time. 

If you have already had temporomandibular 

joint surgery, be very cautious about 

considering additional operations. Persons 

undergoing multiple surgeries on the jaw joint 

generally have a poor outlook for normal, 

pain-free joint function. Before undergoing 

any surgery on the jaw joint, it is extremely 

important to get other independent opinions 

and to fully understand the risks.

The U.S. Food and Drug Administration 

(FDA) monitors the safety and effectiveness 

of medical devices implanted in the body, 

including artificial jaw joint implants. 

Patients and their health care providers can 

report serious problems with TMJ implants to 

the FDA through MedWatch at 

http://www.fda.gov/medwatch or telephone 

toll-free at 1-800-332-1088.

 TMJ
14

IF YOU THINK YOU 

HAVE A TMJ DISORDER...

Remember that for most people, discomfort 

from TMJ disorders will eventually go away 

on its own. Simple self-care practices 

are often effective in easing symptoms. If 

treatment is needed, it should be based on 

a reasonable diagnosis, be conservative 

and reversible, and be customized to your 

special needs. Avoid treatments that can 

cause permanent changes in the bite or jaw. 

If irreversible treatments are recommended, 

be sure to get a reliable, independent 

second opinion.

Because there is no certified specialty for 

TMJ disorders in either dentistry or medicine, 

finding the right care can be difficult. Look 

for a health care provider who understands 

musculoskeletal disorders (affecting muscle, 

bone and joints) and who is trained in treating 

pain conditions. Pain clinics in hospitals and 

universities are often a good source of advice, 

particularly when pain continues over time 

and interferes with daily life. Complex cases, 

often marked by prolonged, persistent and 

severe pain; jaw dysfunction; co-existing 

conditions; and diminished quality of life, 

likely require a team of experts from various 

fields, such as neurology, rheumatology, pain 

management and others, to diagnose and 

treat this condition. 
15

RESEARCH

The National Institute of Dental and 

Craniofacial Research (NIDCR), one of the 

National Institutes of Health (NIH), leads the 

federal research effort on temporomandibular 

joint and muscle disorders. In a landmark 

study, NIDCR is tracking healthy people over 

time to identify risk factors that contribute 

to the development of these conditions. 

Preliminary results from this study have 

identified a series of clinical, psychological, 

sensory, genetic and nervous system factors 

that may increase the risk of having chronic 

TMJ disorders. These new findings expand 

our scientific understanding of the onset and 

natural course of TMJ disorders and may lead 

to new diagnostic and treatment approaches.

Additionally, researchers are using data from 

a TMJ implant registry and repository that 

collected health information from patients who 

received implants and from those who had 

implants removed. Recent studies using the 

data have helped researchers plan for new pain 

medication trials and other research projects.

Pain Studies

Because pain is the major symptom of these 

conditions, NIH scientists are conducting a 

wide range of studies to better understand 

the pain process, including:

n understanding the nature of facial pain in TMJ 

 TMJ
16

n exploring differences between men and women 

n pinpointing factors that lead to chronic or 

n examining the effects of stressors, such as noise,

cold and physical stress, on pain symptoms in 

patients with TMJ disorders to learn how lifestyle 

adjustments can decrease pain,

n identifying medications, or combinations of

medications and conservative treatments, that 

will provide effective chronic pain relief,

n investigating possible links between osteoarthritis 

Replacement Parts

Research is also under way to grow human 

tissue in the laboratory to replace damaged 

cartilage in the jaw joint. Other studies are 

aimed at developing safer, more life-like 

materials to be used for repairing or replacing 

diseased temporomandibular joints, discs, and 

chewing muscles.

HOPE FOR THE FUTURE

The challenges posed by TMJ disorders 

span the research spectrum, from causes to 

diagnosis through treatment and prevention. 

Researchers throughout the health sciences 

are working together not only to gain a better 

understanding of the temporomandibular 

joint and muscle disease process, but also to 

improve quality of life for people affected by 

these disorders. 
TMJ DISORDERS is produced and distributed by the 

National Institute of Dental and Craniofacial Research 

in partnership with the Office of Research on Women’s 

Health, components of the National Institutes of Health 

(NIH) in Bethesda, Maryland.

For additional copies of this pamphlet contact:

National Institute of Dental and Craniofacial Research

National Oral Health Information Clearinghouse

1 NOHIC Way

Bethesda, MD 20892-3500 

1–866–232–4528

http://www.nidcr.nih.gov

This publication is not copyrighted. 

Make as many photocopies as you need.

NIH Publication No. 13-3487 August 2013

NIH...Turning Discovery Into Health ®