What is STMJ dysfunction? (Synovial Temporomandibular Joint Dysfunction)
April 04th, 2011
I am often asked “What can you do as a physiotherapist to help a patient who comes into a dental office and says “I have jaw pain… my bite is off… my back teeth won’t touch when I bite down.”
The purpose of this article is to enhance knowledge of TM Joint and soft tissue management to assist dental profession to recognize and treat occlusal dysfunction which is valuable to ensure success in restoring function to the TMJ.
Dr Mariano Rocobado, a world authority on TM joint dysfunction told the Pacific dental conference that success with STM joint dysfunction must be a team approach. The dentists are 50% of the professionals involved because of the influence of occlusion on the TMJ. They have the tools to evaluate and treat teeth and bones. The other 50% of evaluation and treatment, such as measurements of range-of-motion in the cervical spine/ cranium, muscle tests, joint-play tests, postural evaluations, acupuncture & massage therapy are performed by physical therapists.
What is STMJ dysfunction? * Synovial Temporomandibular Joint Dysfunction*
Wikipedia says that “The temporomandibular joint is the jaw joint and is frequently referred to as TMJ. There are two TM Joints, one on either side of the face. In a normal joint they work in balanced unison. Research has shown that TM Joint dysfunction can happen as early as 7 years old.
Anyone every shanked or sliced a golf shot off the tee box? The jaw is affected by similar mechanics. If range of motion is unequal the end result might be deviation towards the tighter or hypomobile side. Like golf the performance can be affected by mood!
ANATOMY: The name is derived from the two bones which form the joint: the upper temporal bone which is part of the cranium (skull), and the lower jaw bone called the mandible. The unique feature of the TM Joint is a biconcave articular disc. The disc is composed of fibrocartilagenous tissue (like the firm and flexible elastic cartilage of the ear) which is positioned between the two convex bones of the condyle and cranium that form the joint. It is one of the only synovial joints in the human body with an articular disc, (It is a thin, oval plate, placed between the condyle of the mandible and the mandibular /glenoid fossa.
It is thicker at its periphery, especially behind, than at its center.
Its upper surface is concavo-convex from before backward, to accommodate itself to the form of the mandibular fossa and the temporal tubercle. Its under surface, in contact with the condyle, is concave.Its circumference is connected to the articular capsule; and in front to the tendon of the Lateral pterygoid.It divides the joint into two cavities, each of which is furnished with a synovial membrane. Therefore the disc divides each joint into two. The lower joint compartment formed by the mandible and the articular disc is involved in rotational movement — this is the initial movement of the jaw when the mouth opens. The upper joint compartment formed by the articular disk and the temporal bone is involved in translational movement — this is the secondary gliding motion of the jaw as it is opened widely.
Palpation of joint:
- You can locate this joint by putting your finger on the triangular structure in front of your ear. Then move your finger just slightly forward and press firmly while you open your jaw all the way and shut it. Alternatively say “NO” and “NEVER” Feel different motions in the TMJ. (You can also feel the joint motion in your ear canal)
- Test occlusion changes with different neck posture. Look down, side flex neck and notice how bite moves from side to side (if does not often upper cervical needs realigned)
- Sit with legs crossed and notice if bite changes
Typical symptoms of STMJ (synovial temporomandibular dysfunction)
- Biting or chewing difficulty or discomfort
- Clicking, popping, or grating sound when opening or closing the mouth.This is NOT normal for any synovial joint?
- Dull, sharp, or aching pain in the face each time you swallow, yawn, talk, or chew,
- Earache (particularly in the morning) – many referrals to Ear, Nose and Throat physicians are because people think they have an ear infection.
- Headache (particularly in the morning)
- Temple/cheek / eye or forehead pain
- Hearing loss
- Migraine (particularly in the morning)
- Jaw pain or tenderness of the jaw
- Reduced ability to open or close the mouth
- Frequent head/neck aches / Neck and shoulder pain
- Sinusitis (can lead to mouth breathers)
What to do if patients come into your office complaining of the above symptoms
Ever find your self saying to patients “Come back in two weeks” Ask yourself ..why wait to start treating pain or wait for pain to hit?
Think about this analogy. The jaw should be treated the same way.
Which is most important finger to the dentist? If the thumb started to make a noise or hurt when you picked up a tool, you would not ignore the situation because it could effect your business and ability to enjoy life.
Think about your golf game. If you start pulling shots to the right and lose consistency, you take your swing to the pro shop. Why do humans procrastinate to get help or change their ways?
Frustration and anxiety will fan the flaming symptoms of a hot joint!
It is my opinion that patients should NOT be sent away. STMJ is progressive in nature therefore patients should be treated immediately. Reduction of pain of muscle origin is often accomplished with a bite guard or night splint. Sometimes ice packs and /or anti-inflammatory medications can be used
The most common disorder of the TMJ is disc displacement. In essence, this is when the articular disc, attached anteriorly to the superior head of the lateral pteygoid muscle and posteriorly to the retrodiscal tissue, moves out from between the condyle and the fossa, so that the mandible and temporal bone contact is made on something other than the articular disc. This, as explained above, is usually very painful, because unlike these adjacent tissues, the central portion of the disc contains no sensory innervation.
In most instances of disorder, the disc is displaced anteriorly upon translation, or the anterior and inferior sliding motion of the condyle forward within the fossa and down the articular eminence. With the invention of MRI ‘s the disc has been seen in 13 different locations.
On opening, a “pop” or “click” can sometimes be heard and usually felt also, indicating the condyle is moving back onto the disk, known as “reducing the joint” (disc displacement with reduction). Upon closing, the condyle will slide off the back of the disc, hence another “click” or “pop” at which point the condyle is posterior to the disc. Upon clenching, the condyle compresses the bilaminar area, and the nerves, arteries and veins against the temporal fossa, causing pain and inflammation
In disc displacement without reduction the disc stays anterior to the condylar head upon opening. Mouth opening is limited and there is no “pop” or “click” sound on opening. (see videos)
Role of the dentist
- Assessment of the teeth occlusion and function of the jaw joints and muscles in functional position. I have always wondered why bite assessment and filing down teeth Is performed lying supine and not sitting which is more functional?
- Education on early intervention if acute not chronic Rest the muscles and joints by eating soft foods.
- Do not chew gum.
- Avoid clenching or tensing. Evaluate stress levels and coping skills honestly. Try relaxation techniques and stress reduction, (Yoga, zumba fitness, dancing and singing),patient education, non-steroidal anti-inflammatory drugs, muscle relaxants or other medications may be indicated in a dose given by a doctor…many patients self medicate
- Avoid biting nails/cuticles/pencils
- Relax muscles with moist heat (1/2 hour at least twice daily). In cases of joint injury, ice packs applied soon after the injury can help reduce swelling.
- See Cathy’s blog http://cathyrussell.extracontactexperts.com
for April 2011 for TMD care
- Improving your posture is the key to reducing neck and headaches. Start with your feet and soles of shoes: uneven wear-spots show the need for correction.
2. Refer to a physiotherapist who will take a detailed history, from birth to present time
3. An exercise program by Dr Mariano Rocabado addresses postural relationships with the head to neck, neck to shoulders and lower jaw to upper jaw. The objective of his home exercise program is for patients to: learn a new postural position, fight the soft tissue memory of the old position, restore the original muscle length-tension relationships, restore normal joint mobility and restore normal body balance. Rocabado advocates the instruction of six fundamental components of activity for treatment of TMJ dysfunction. He recommends that patients complete each activity 6x/session and 6x/day.
The activities are as follows:
1) Rest position of the tongue
a) Make a clucking sound with the tongue x 6
b) Find normal resting position = holding one third of tongue gently against the roof of the mouth just behind the front teeth
c) Diaphragmatically breathe through nose while tongue is in resting position x 6 breaths
2) Control TMJ Rotation on Opening – tongue on roof of mouth and open x 6 reps
3) Mandibular Rhythmic Stabilization – shown in my march blog, apply light resistance to opening, closing, and lateral deviation with the jaw in a resting position holding for 6 seconds (this is key when a patient has instability as this assists with visualization/neuromuscular reeducation)
4) Stabilized Head Flexion = upper cervical flexion (nodding) – facilitate upper cervical flexion as most of these patients have forward head posture resulting in upper cervical extension deviation. Nod head x 15 degrees back and forth 6 x reps.
5) Lower Cervical Retraction – chin tuck x 6 second hold
6) Shoulder Girdle Retraction – pull shoulders back and down – hold x 6 seconds
7) Functional activities like eating ,singing and whistling should them be assessed and changed if necessary
8) Joint mobilization
When the TMJ is restricted joint mobilization can be performed in various directions to improve joint play at the temporomandibular joint.
Expectations of patients
When treating patients with an acute onset or post traumatic injury they are more likely to respond better to physical therapy intervention while patients with a chronic TMD tend to not respond as quickly.
Personally I treat many areas of the body in conjunction with the the jaw because this affects jaw and postural alignment… ie: cranium, palate, cervical spine/related musculature, shoulder girdles, thoracic spine/related musculature, lumbar spine and pelvis
Computerized tomographic scanning holds promise for the future compared to conventional
radiography, as it offers the advantages of greater accuracy in determining the position and possible perforation of the disk, better definition of sclerosis and early ankylosis, and much less radiation.
For more info see www.cyberpt.com/tmj.asp
5 Nov 2008
2. Application of Orthopedic Principles in Evaluation of the
Temporomandibular Joint by MARK H. FRIEDMAN and JOSEPH WEISBERG
Also see you tube videos for TM joint function: