Temporomandibular Disorder or TMD is a broad term referring to problems with the jaws and their functioning.  It is commonly referred to as “TMJ”.  This system is very complex and problems are caused by a variety of factors. 

The temporomandibular system consists of three basic components: the temporomandibular joint itself, the teeth, and the neuromuscular system.

TMJ– This is the term that is often used to describe TMD, but it specifically refers to the joints that work your lower jaw, or mandible.  Neither joint works alone…..when your jaw functions, both joints will be working.  There is also a small cartilage disc between the lower jaw and the skull within the joint.  When healthy, the disc acts as a sort of “shock absorber” for the joint.

Teeth–  The teeth are like the third leg of a tripod, the TMJ’s being the other two legs.  The alignment of your bite and the functioning of the TMJ’s are intimately connected.  Problems in any of the three areas may effect the other two.

Neuromuscular– This system is made up of the nerves and muscles which work the temporomandibular system.  These nerves and muscles move only the lower jaw (mandible) since only it moves during functional movements (i.e. eating).  The nerves transmit the messages for the muscles to move the jaw and also send pain signals to the brain.

Common Signs and Symptoms

Signs and symptoms can include some or all of the following:

• Jaw pain and/or stiffness

• Headaches

• Vague tooth soreness or toothaches

• Sensitive teeth

• Painful or tender jaw joint

• Difficulty opening jaw

• Pain and fatigue when eating hard or chewy foods

• Clicks, pops, or grinding sound in jaw joint

• Ear pain

• Cervical tension and pain

• Tooth wear

• Awareness of grinding/clenching teeth while sleeping or awake (bruxism)

Temporomandibular disorders come in many forms and varying degrees of severity.  Basically, TMD is a problem when you either experience pain and/or loss of jaw function.  Loss of function can range from mild jaw stiffness to being unable to open the barely at all.

Common Causes of TMD

TMD rarely has one single cause.  Any of the following factors may contribute to TMD.  Each patient presents with an individual combination of factors that are determined during history taking and clinical exam.

Trauma—Acute trauma to the jaw can cause damage to the muscles and/or joint.  The acute pain and loss of function usually responds well to conservative treatment, but trauma to the joint can lead to chronic damage which may eventually contribute to a TMD problem at a later time.

Bruxism— This refers to a non-functional grinding and clenching of the teeth.  Some do this while awake, but more often it is done while sleeping.  Bruxism is the most common factor found in TMD.

Malocclusion—This term essentially means “bad bite”.  This occurs when the teeth do not bite together in harmony with the shape and position of the joints, thus leading to pressure on the joints.

Ergonomic—Your job and how you do it can contribute to TMD and related problems, usually due to poor posture while sitting.

Treatment Of TMJ

Treatment plans for TMD are as varied as the patients that present with it.  It is very important to realize that the goal of TMD treatment is to minimize pain and establish a return to function.. TMD conditions are typically not “cured”, but are managed.  Often damage to the joint itself cannot be reversed, but the body can heal it enough to return to function without pain.  Common treatments include the following.

Physical therapy—Therapy for TMD can include everything from treatments to relax the muscles of the jaw, to joint mobilization techniques, to exercise programs to establish better overall posture.

Splints/ night guards— These are designed to protect the teeth from further wear.  Splints will also reduce the severity of grinding at night to allow the muscles to rest and help protect the joint from further stress.

Rest—The jaw must rest to heal.  Gum chewing, biting fingernails, and clenching the teeth while awake are but a few habits to avoid.  Avoiding crunchy or chewy foods during treatment will also help. 

Medication—Pain relievers and/or muscle relaxants may be prescribed or purchased and in some cases serve as useful adjuncts to other treatments.

Moist heat—Heat is often very helpful for the sore muscles of TMD.  The heat promotes blood flow which aids in healing.

TMJ Specialist

Eric G.M. Roth, PT, CMPT, MPT
Physical Therapist

Kingston clinic / 297-7050