TMJD

ANATOMY
The mandible is the largest, most mobile and the strongest bone in the head.
The structure consists of a condylar, barrel-shaped joint surface for the temporal mandibular joint.

DETAILED ANATOMY AND MUSCULATURE
The mental protuberance swells on either side of the original site of the symphysis mentis, which makes it, resemble the symphysis pubis. The lateral surfaces have the masseter muscle and 1/8th of the temporalis tendon externally. Internally, they accept the remaining 7/8th of temporalis tendon and both medial and lateral ptergoids. The medial ptergoids mimic the external masseter in form and in function. The lateral ptergoids pronate the jaw. The main muscle that propogates masticatory is the buccanator which attaches to the mandible superior to the obligue line and by the pterigomandibular raphe, plays the vital role (with the tongue) of locating and containing the chewed morsel of food for the teeth to work on.
The internal aspect of the mandibular canal is the entry point of the 5th cranial nerve. Thirty-eight percent of neurological input to the brain comes from the face, mouth and TMJ region.
There are 136 muscles above and below the mandible pivot the jaw, moving it forward as the mouth opens. The total neurological input to the brain from sensory and proprioceptors nerves during mandibular motion acts as a dominant pattern setter for the motor cortex. (in other words, mandibular motion sets the pattern for at least 38% of the motor muscles in the body, particular in the neck, pectoral muscle area of the chest and pelvic regions. Normalizing mandibular and temporomandibular joint function is a wise prerequisite to any attempt at normalizing the neuromuscular mechanisms of the rest of the body.
The mandible has 16 muscle group attachments.
Temporalis
Masseter
Lateral pterigoids
Medial pterigoids
Buccinator
Depressor labi inferioris
Hypoglossus
Myohyoid
Digastric
Platsma
Geniohyoid
Mentalis
Superior pharngeal constrictor
Genioglossus
Orbicularis oris
Depressor anguli oris

The masseter muscle has the greatest contractile strength per fibre out of ant muscle in the body. It is the major pattern setter in mandible movements.
The lateral ptergoids are short, stout and tenacious muscle
The posterior fibres of the temporalis are involved in the TMJ conditions. They play a role in TM joint pain and in muscular contractions headaches, and can contribute to temporal bone imbalance. These fibres are antagonists of the lateral pterigoid muscle. The lateral pterigoids protrude the jaw, the posterior fibres of temporalis retrude it.

MOTION
The mandible is more open to psychological input than any other bone in the head. These inputs from unexpressed aggression, determination, or fear of speaking out, cause changes in mandibular motion that range from subtle to dramatic. For instance, in states of rage the mandible is so muscularly tense that almost all movement is lost. The person can barely separate his teeth to speak.

DIAGNOSTIC CONSIDERATIONS
It is amazing how the rest of the body responds to optimizing of mandibular status. For instance, neck tension and osteoarthritis, respiratory inhibition such as occurs in asthmatic states, and low back pain may all be relieved by normalizing the mandible.

ENERGETICS
The mandible represents both expression and absorption. For over 160,000 generations the mandible has smiled with pleasure, chattered, trembled in moral anxiety, moved sideways while perusing problems, pouted, kissed, seduced, and signaled. Many of these behavior patterns are locked up in our jaws and muscles and play havoc with the TM joint and temporal bones when we are confronted with on going stresses.
Among the energies held in the mandible are:

Identity
The bone associated with the individual’s sense of who he is.

Aggression
Where we display our readiness to fight – prognating the jaw. We lift our upper eyelids and eyebrows, jut our head forward toward the target, clench our teeth and raise our shoulders-----like a cat fanning out its fur.

Determination
We set our jaws out and start to stroke our chins wisely.

Tenacity
We hang on with our nails and teeth; we clench our teeth; we grin and bare it.

Sexuality
Sexuality and sensual movement in the pelvis is natural – but often restricted by fears and conditioning about sensuality and sexuality. If we can not allow natural movement in our pelvis, we transfer the need for movement to the mandible and we talk about our own, or other people’s sexuality. If we can not move either the pelvis or mandible, we begin to armor our belly and begin to become psychotic: we feel nothing at all. Some people may manifest sexual inhibition by becoming tight-lipped, or by pursing their lips. The stiffness of inhibition gets caught as stiffness in the upper neck and TM joints and is acted out as anger.

Sensuality
We evert our lips to suckle, sing, playing the saxophone, to show pleasure and kissing.

Suppression of Tender Emotion
At age five we are told to grow up and don’t cry. The mentalis muscle on the chin, quivers and oscillates attempting to suppress the emotion. The lower lip rotates to cry out like a pout, then retracts to a pencil thin line to “keep it all in.” This leaves a lasting impression on the mandible, the teeth clenching and the TM joints.

Trauma and Dysfunction
The mandible is frequently traumatized. How many scars do you have on your chin? How many dental visits left a mark physical or psychic? Who beat you up? Fist fights. On going stress shocks into bruxism (grinding of the teeth) and the degeneration of the TM joints. Anxiety, stress and aggression alter the physiology of the jaw musculature, temporomandibular joints, and upper neck.

INTERCONNECTEDNESS
The mandible plays a part in sphenoid and temporal status. It may dominate maxillary function by way of the teeth. It is a principle player in most types of headaches. It acts as a strong controller and pattern setter for the neck, upper chest, pelvic girdle, and feet. The position and motility of the mandible is affected by all of the midline structures of the body - the hyoid, sternum, xiphoid process linea alba and symphysis pubis.

LOCATION
The temporals are located posterolateral to the sphenoid, inferior to the parietals and anterior and lateral to the occiput.

SUTURES & ARTICULATION
The temporals present a highly delicate, ballerina –on –points suture with the zygomae; a rolling overlap, or squamous suture with the parietals; a modified and robust interdigitated suture with the occiput; a harmonic (plain) suture with the sphenoid; and an open no contact border with the condylar and basilar portions of the occiput at the cranial base.
The temporals are the most superficial of the four bones that meet the pterion. They are one of three bones that form the asterion.
Each temporal articulates with a maximum of five bones: sphenoid, occiput, parietal, zygomae and the fronal.

DETAILED ANATOMY & MUSCULATURE
The temporals hold the organ of hearing and balance in the inner ear. The CN7 (facial nerve) weaves through the petrous portion, making two right angles. The CN8 (vestibulocochlear nerve) passes through the same foramana, the internal acoustic meatus.
Additional temporal landmarks worth noting include the foramen lacerum (shared with the sphenoid), the jugular foramen (shared with the occiput), the temporomandibular fossa and its saddle joint architecture, and the styloid process (whose attachments form a small but important ingredient in temporal motility).
A variety of muscles can affect temporal status. The sternocleidomastoid and temporalis are the most powerful and important muscles that directly affect the temporals.
Muscles that attach to the temporals consists of the:
• Sternocleidomastoid (SCM)
• Temporalis
• Longissimus capitus
• Splenius capitus

PHYSIOLGY
Each temporal bone rotates around the long axis of the petrous portion.
The temporals are effective “governors” of the sphenoid; think of them as inseparable and mischievous twins. Look you the mandible whenever the temporals are affected and then you have four bones to consider: temporals, the sphenoid, and the mandible.
Styloid and mastoid ligamentous and muscular attachments add further potentially disequilibriating forces. The tugs, tears trituration, and traumas of the teeth, and the action of the muscles of mastication, all affect the temporals. They do this through the temporomandibular joint, the lateral ptergoids, the retrodiscal ligaments, the sphenotemporal ligaments, the stylomandibular ligaments, and the most powerful neck muscles of all, the sternocleidomastoids.

MOTION
The petrous tip is anchored to the posterolateral corner of the body of the sphenoid by the petroclinoid ligament. This structure helps to create the axis of rotation and maintains a pinpoint articulation between the petrous tip and the root of the posterior clinoid process.

ENERGTICS
The temporals are about the balance of life. The heavy scheduling of modern life can remove this balance, our “organizers” serving to over – organize our lives. One symptom of the loss of balance in life is VERTIGO – can be seen as the patient saying, “please pick me up.” The second symptom is “TINNITUS – “I don’t want to hear it anymore!” It is often a symptom with a strong causative emotional component. In tinnitus and deafness, people cut themselves off from the world; through hearing we assimulate our environment, or choose not to. The temporals are often involved in withdrawal.
In psychogenic states especially anger, suppressed rage, anxiety, and tension – play an emphatic role in temporal bone balance. These motions are mediated to the temporals through the temporomandibular joints and SCM and temporalis tension.

TRAUMA & DYSFUNCTION
A person feels quite out – of – sorts when their temporals are faulted. They may suffer from disequilibrium or vertigo and short term memory lapses and short – term emotional problems as well. Temporal disequilibrium is a side effect of automobile whiplash injury.
Schoolteachers all over the world used to punish children by yanking their ears in an abrupt and repeated oscillatory fashion. This strange, obviously instinctive ritual form of punishment (it is probably tens of thousands of years old) may guarantee feelings of malaise and repentance in the unfortunate child by displacing and altering the energetic field of his temporal bones.
The open architecture of the jugular and petrous portions makes the cranial base portion of the temporals susceptible to displacement, especially in low – impact trauma, such as falling onto grass while running, and low – speed whiplash injury.
The seventh cranial nerve CN7 (facial nerve) makes two right angles as it weaves through the petrous portion of the temporals. If the temporal bones displace (due to ongoing stress mediated to them through posture or muscular tension) or lose their inherent mobility, the nerve can be faulted. If the nerve is compressed or put under tension, acute peripheral facial paralysis or “Bell’s Palsy” can result. This serious condition takes three to nine months to heal; with 70 to 90 percent of suffers recovering to a “cosmetically acceptable level. However 16 percent are left with major defects. The highest incidence of Bell’s Palsy occurs in the third trimester, which may be due to altered mediastinal influences upon the cranial base, or increased tension in the sternocleidomastiod muscles or both.
The very short auditory tubes in infants quite readily allow bacterial infections to spread from the nasopharnyx into the inner ears or mastoid air cells. (Breast-feeding can help to reduce ear infections in the newborn by up to 50 percent.) Craniosacral work with children in these cases focuses on draining the space between the ramus of the mandible and the mastoid process of the temporal bone.
Possible treatments in craniosacral work would encompass normalization of the atlanto – occipital joint and gentle upper neck decompression and unwinding to optimize the position and motion of the atlas.

INTERCONNECTEDNESS
The temporals are functionally wedded by the sphenoid and mandible.
The temporal bones connection to the tentorium is immediate and extensive. Temporal faulting always involves the tentorium, which therefore tends to implicate the other bones that attach to the tentorium – sphenoid, occiput, and the other temporal bone. The “core link” means that the sacrum and ilia may also be affected or be affecting the temporals.
Temporal status and motility seem to echo the other main lateral joints of the body, the shoulders and hips. The mastoid processes have an energetic connection to the ishial tuberosities.

TMJ is the most complex joint of the body. It comprises of two temporal bones and our mandible. The mandibular condyle of the mandible fits into the temporal bone. There are three postural muscles that attach to the mastoid of the temporal bone.
TMJ problems are not just an isolated phenomenon of this joint, it ha to do with out posture, how we move, the condition of our teeth and how we chew. It is necessary to have a total health approach. Your dentist should be the head of the team, but your therapist should also work in conjunction with the dentist to normalize the pull of muscles so that this joint can be normalized into its position into the skull.

TEST
There is a test you can do. If you have a problem in the joint that you did not know you have yet because the pain is not there but you maybe slowly and insidiously be wearing down the joint and destroying the disc of the joint.
Place the pad of your index fingers in both ear canals. Right underneath the hole is the TM joint. Listen to the joint for 1) crepitus and grinding. 2) Popping when the opening the jaw and if one of the 3) condyles seeds into the joint at a different time than the other side.
When we open and close our jaw, it should be like a hinge. It moves forward over the eminence. As the jaw opens it translates over the eminence and when we close the jaw it should go back to translate over that eminence and seed into the joint.
If your jaw opens and does not move, the jaw is fixed in that joint. This is not good. The TM joint is bilateral, which means what happens on one side equally happens to the other side.

PATTERNS OF OPENING AND CLOSING
This due to imbalances of the muscles.
First pattern is a “C” opening. This is when you open the mouth on one side and close on the same side.
The second pattern is you open the mouth on one side and close on the other side. You should open and close the mandible simultaneously. If you have pain or popping, grinding or crepitus, your joint is under distress. Notice how much you hear it and how clearly you hear it when you put you fingers in your ears and press slightly down you open and close the mandible.

ROLE OF TRIGGER POINTS PLAY IN MUSCLES
How muscles play a vital role in causing tension in other muscles.
A trigger point is an area of high neurological activity (an area that is sending out high intensity impulses in a muscle). It is sending out these impulses to other muscles which in turn tighten those other muscles. (See TMJ chart).
Let’s take a look at the muscles of the skull. They respond to our head going forward. (posterior suboccipital muscles) Bring you head forward and you can feel a tightening at the base of you skull. This is one of the postural influences. If your head is in front of your shoulders (and it should be in alignment with our shoulder) you are going to get chronic tightness and headache patterns at the base of the skull. These muscles rotate our head backwards when our head moves forward and they can develop trigger points in these muscles.
In these TMJ charts (scroll down), you will see the letter “T” which means “Trigger points” and this is the pain referral area which these trigger points at the base of the skull fire into the temporal area to the temporalis muscle and tightens that muscle. The temporalis muscle has a tendon that comes down and attaches on the cornoid process so as we close the mouth it tightens. This is one of the three muscles that we use to close our jaw. As we open and close our jaw, the masseter muscle may become tighten and develop trigger points that will fire into the temporalis muscle. When you chew, it activates the masseter muscle. If you were to bite down right now, you would feel the muscle bulge out in the cheek. If that muscle is too tight, trigger points can fire up into the temporal area and to the ear. This can leave us with ringing in the ear – tinnitus.
To give you an idea of how important it is to have this joint functioning properly and our jaw aligned properly we have to understand the incredible enervation of nerves. This means that the nerve supply to the jaw and teeth is greater than any other area of the body and one of the most sensitive nerves in the body supplying energy to our teeth. That nerve is called the Trigeminal nerve.
An anatomist has estimated that 70% of the nerve endings or receptors of the body intermingle with this nerve which means it is incredibly sensitive. In an anatomist book, we see how heavily enervated the nerve impulses are. In the upper molars, each tooth has three nerves going into it and most of our teeth have two nerves. How long could you go having a single raspberry seed stuck in your teeth? A day, 2 days, a week? You would probably be nuts by the end of a week. The reason why I ask this question to understand the incredible influences the teeth and mandible has on our overall health. How calm, irritated or intense we are.
The mandible influences the position of the teeth. That is why it must be normalized.

POSTURE AND PELVIS
The pelvis has a lot to do with our posture. When the posture tilts forward, you automatically develop a swayback and the knees lock back in response for the pelvis tilting forward. Another thing you will notice is the head will tilt forward in response to the pelvis tilting forward. So you can see that the position of the mandible is going to change as the position of the pelvis changes. Not just tilting forward or backward but also sideways. If the pelvis tilts to one side, you see people with their shoulders high or low that will influence the position of the mandible.
Notice the (last trigger point chart) Erector Spinae muscle (which means keeping the spine erect) and where it attaches to the pelvis. The Erector Spinae muscle automatically contracts as the pelvis tilts forward. The other attachment of the Erector Spinae muscle is on the mastoid process of the temporal bone. So, the more our pelvis tilts forward, the more that muscle tightens up to the attachment on the mastoid process. It has a tremendous pull down. This is the insertion of the muscle so it actually pulls down. It does two things. It tilts our head back as the pelvis tilts forward and it causes compression of the temporal plate pulling down on this joint. When that happens, it can cause tremendous wearing away of the disc and deterioration of the mandible condyle itself.
The more our pelvis tilts forward, and the more our head goes forward, the more our sub-occipital muscles shorten. And when they shorten, they cause compression and cause all the nerves at the base of our skull to become compressed. These are some of the mechanics that go on when we have our pelvis tilting forward.
Correct posture looking at the Baching chart states the external auditory meatus is in correct alignment to our shoulders (our ears should be over our shoulders.) Most people are tilted forward. Gravity is pushing us forward, down and the force of gravity is 33.5 pounds of pressure per square inch. Just think of it – every square inch of our body is unceasing stress from cradle to grave and is constantly pushing us down and forward. And as that occurs, it is changing the position of our pelvis. Again, when your pelvis goes forward, your knees automatically lock back as the head goes forward. This starts a whole series of muscles tightening, and cervical muscles contracting in our head and neck. The result is more pressure on this joint.
In my therapy program, I release all muscles of chewing – temporalis, masseter, pterigoids, (medial pterygoid helps close our jaw), and tongue muscles. The tongue muscle merges into the styloglossus muscle, which attaches on the styloid process of the temporal bone. Our swallowing muscles, the stylopharyngeus muscle attaches on the styloid process of the temporal bone as well as the muscles that open our jaw, the suprahyoid muscles that will pull our jaw down. We must treat the internal and external muscles that affect that joint.
Again, the Erector Spinae is the most powerful muscle of the body. It attaches to mastoid process so the more postural distortion we are, the more the muscles at the base of the skull – sub – occipitals tighten and the muscles that attach to the mastoid process tighten. These three muscles can produce a powerful force pulling the cranium down and when it pulls the cranium down the upper part of the joint (temporal portion) will be compressed on the mandible.

GAIT
Another thing we have to understand that has an influence on the joint is gait (movement patterns).

Thrusting Forward
As a person thrusts forward, there is a muscle called the lateral pterygoid inside the mouth that protrudes the jaw. When a person thrusts forward, their jaw will feel a tightening at the TM joint. This muscle, the lateral pterygoid tightens and displaces our condyle

Waddle Gait Pattern
We see people walk like a duck. They waddle to both sides and each time they got to the right, the muscles are going to shorten and tighten. On the left, the muscles are going to lengthen and stretch.

Wisp Gait Pattern
If you have a gait pattern where you wisp to one side, (right side) the right side will chronically shorten and tighten and the left side of the joint will open.

LIGAMENTS
Lateral ligaments and the articular capsule can be stretched. These two ligaments help hold the mandible into our skull.
If we have a waddling pattern to one side we shorten and tighten the muscles on the right side.That ligament will stretch, the whole capsule will stretch and will displace our jaw and it will cause the disc (that absorbs shock) in the jaw to responds to forces of torquing and abnormal gait patterns. If left, the disc will be worn away and we can have a grinding bone on bone then we get arthritis. Then the condyle will actually flatten out and deteriorate and the pain will be awful.
It is important that we understand these influences.

TRIGGER POINT CHARTS
Lets look at three muscles that are inside the mandible.
Medial Pterygoid closes our jaw from inside. The trigger point fires into the inner ear, up into the masseter and parts of the temporal area.
The Lateral Pterygoid, which is important in TMJ problems because the superior belly of that muscle attaches to the disc and pulls the disc forward. The trigger points fire into the face, ear, and joint capsule.
The Digastric muscle is extremely important because it helps pull our jaw backward – if you wanted to retract your jaw instead of protruding it. Trigger points in this muscle fire into the mastoid process where the SCM (sternocleidomastoid muscle), Splenius Capitus and Longissimus Capitus (upper portion of Erector Spinae) attach to the mastoid process (Muscles I talked about before).

PAIN REFERRAL CHART
If we take a look at the pain referral chart, of the trigger points that commonly fire around the neck, we notice how many muscles there are. That will give you an idea of how much of a muscular involvement there is in TMJ problems.

TEETH

Sheering
If you have teeth that are sheering off your jaw maybe pulling to one side and your teeth are grinding and sheering. The muscles are doing this.

Worn Away
If you have teeth that are worn away, and you grind your teeth at the right, (bruxism) the teeth are ground down, muscular tension does that.
So the muscles play an extremely vital role.

JOINT CAPSULE
Looking at the chart where the mandible and pelvis is, we can see how tilting can be influenced by muscles and tilting of the pelvis. It is a direct relationship by the position of the pelvis to the position of the mandible.
In the diagram, we see the mandible that sits in the joint. Number 2 is the articular disc and behind the disc we see the retrodiscal ligament that attaches on the back of the capsule that helps stabilize the mandible and the disc.
Lets move to the right diagram and we see how the role of the lateral pterygoid attaches to the front of the disc can contraction this disc forward. Other muscles like the Temporalis can take our mandible and push it superior and backwards. So what happens is the disc starts to move off the mandible and our disc starts riding on our retrodiscal tissues. That can be extremely painful because there are a lot of vascular tissues that supply blood and oxygen to the capsule.
The displacement of the jaw and the disc is a very complex process.

PROGRAM
The Neuromuscular Therapist will design a program to release these muscles and stabilize your pelvis and work in conjunction with your dentist. It is important that your dentist understands the role these muscles and postural muscles are playing – the role and position of the pelvis.
In dentistry, there is a subsection called “Neuromuscular Dentists.” These dentists have been trained to understand the role of position and muscles in TMJD. The book “Neuromuscular Dental Diagnosis and Treatment” written by Robert Jakelson is destine to be a classic in the dentistry field.
These dentists will be making bite splits to take pressure off the joint. It is important that these bite splints are made with the muscles IN THE RELAXED STATE. Many bite splints have been made and are being made in with the muscles in the tense position, and it is that tension in the muscle that has caused the pathology problem. The most effective way is to release the muscles and build the bite splint so the jaw can be in a relaxed position.
Your dentist and therapist should be working together to make sure your jaw is in the most optimum position to relieve your discomfort.

CAUSES
Imbalances of musculature are some of the causes of TMJD but there are others such as:
1) Direct trauma or blow to the jaw.
2) A fracture of the mandible
3) Occlusal malfunctioning
4) Teeth being misshaped
5) Deformities in the jaw itself
6) Arthritis in the jaw.

There can be many causes to this complex problem. That is why I suggest a total health team approach between the therapist and dentist. There can be psychological problems also. The health care team will design for you a program especially for you and your pain pattern. Work together so you can maximize the healing process.
They believe as I believe that part of your healing process should be an educational process.

Please respect that the above images are copyrighted by The St. John Method of Neuromuscular Massage Therapy.