TMJ Pain Temporomandibular Joint Pain

The temporomandibular joint (TMJ) is the most regularly used joint in the human body. the TMJ, connects the upper and lower jawbones which allows the jaw to open, move back and forth and sideways. It opens and closes about 1500 to 2000 times a day and is also instrumental in several functional movements such as chewing, swallowing, breathing, talking, or yawning. Because the TMJ is a very regularly used joint, its bone, muscle or cartilage may deteriorate over time, leading to disorders of the TMJ.

If you cover your ears with your palms, your thumbs will be on the base of your skull called the occiput. Your palms and fingers will lie across your temporal bones, and the heels of your hands will rest on the angle of your jaw called the mandible. The temporal bone and mandible interact at the temporomandibular joint called the tmj for short. You can locate this joint by lightly placing two fingers directly in front of your ears and open and close your mouth.

Temporomandibular joint disorders, or TMD, are common in adults; as many as one third of adults report having one or more symptoms, which include jaw or neck pain, headaches, and clicking, popping or grating noises within the joint. The joint has a capsule that contains an articular disc and surrounding muscles have a nerve supply which is thought to be the primary source of pain in TMJ disorders.

The cause of tmj pain, in most cases, is not clear. Some are thought to be joint capsule inflammation or damage and muscle pain or spasm may be caused by abnormal occlusion, teeth grinding (bruxism), teeth clenching, lip biting, stress, anxiety, or abnormalities of the disc in the joint.

The temporomandibular joint has been linked to different parts of the body, particularly the neck. Some suggest that posture training may be a positive impact on the muscles because a proper posture can play a relevant role in the relationship between the temporomandibular joint and the rest of the body. It appears that an intimate functional relationship exists between the jaw (mandibular) and the head and neck systems. Patients with temporomandibular disorders often report symptoms of neck pain. Furthermore, some studies have investigated the relationship between neck symptoms noting that mouth opening is always accompanied by head and neck extension and mouth closing by head and neck flexion. These studies suggest that functional jaw movements use mandibular, head, and neck movements involving the temporomandibular joint, the atlanto-occipital joints between the head and neck, and the lower joints of the neck. The studies have noted the contribution of the upper part of the neck, particularly the atlanto-occipital joint, for proper positioning of the TMJ.

Temporomandibular disorder (TMD) is a term that refers to 1 or more conditions that adversely affect the temporomandibular joint or the surrounding masticatory (chewing) musculature. In general, TMD symptoms consist of pain at rest and/or during jaw function, limited range or disturbances of mandibular motion, and noises from within the temporomandibular joint (TMJ). The most common and general categorization of TMD is to separate it into muscle disorders (myofascial disorders that affect the masticatory musculature) or TMJ articular disorders (those that directly affect the TMJ itself like arthritis). It should be noted that both muscle and joint problems can exist at the same time.

Patients with TMD who hold their heads farther forward relative to the shoulders (forward head posture) have a high probability of experiencing symptom improvement as a result of posture training and being provided with self-management instructions.

Poor neck posture is widespread in the general population and appears to be an adaptive, self-perpetuating trait that most people lack the cognitive ability or desire to correct by themselves. Many practitioners have speculated that poor posture may have a negative effect on temporomandibular, or TMD, symptoms and treatment outcome.

Forward head posture is the most common form of poor posture and is assumed by many authors to be related to a multitude of myofascial pain disorders. With this posture, the head’s center of gravity is forward of the spine’s weight-bearing axis, which increases the strain within the posterior cervical muscles, ligaments and joints. Studies have demonstrated that when the head is positioned forward, the upper trapezius muscle activity is significantly higher than it is when the head is in normal alignment and indicates that the patient is more likely have pain from overusing the muscles.

It has been demonstrated that neck muscle activity influences masticatory muscle activity. The additional demand that is placed on the neck by the forward head posture alters the masticatory system so that people are more susceptible to tmj muscle strain, spasm and pain. Posture training usually involves posture exercises performed repetitively to stretch structures that poor posture tends to shorten, strengthen structures that poor posture tends to weaken and create an awareness of the desirable posture.

Related to the neck and posture, a study in the Journal of the Canadian Dental Association, September 2008, Vol. 74, No. 7 "This web-based survey provides the first evidence that chronic pain in jaw muscles and other symptoms of TMD are associated with long-term, heavy use of computers. However, the great majority of people with these symptoms probably also suffer from pain in the shoulder and neck."

In the journal Clinics (Sao Paulo). 2009 January; 64(1): 35–39. It is stated, "Our results suggest a close relationship between body posture and temporomandibular disorder, though it is not possible to determine whether postural deviations are the cause or the result of the disorder. Hence, postural evaluation could be an important component in the overall approach to providing accurate prevention and treatment in the management of patients with temporomandibular disorder."

Also, relating to the neck, whiplash injury has also been associated with tmj pain. The mechanism is not clear, however, in Dynamic Behavior of the Temporomandibular Joint in 198 Frontiers in Whiplash Trauma N. Yoganandana nd F.A. Pintar (Eds.) IOS Press, 2000, indicate that it is mostly related to the neck. It is stated, "Positioning of a headrest very close to the head would provide a clear means of preventing mouth opening." The authors indicate that mouth opening is observed during whiplash, but it does not exceed the physiological limits. The authors state "...TMJ dysfunction is more likely due to post-crash neuromuscular changes and/or pain referral of a cervicogenic [neck] nature." Their reference to headrest positioning is noted to prevent jaw opening and it is also recommended to help prevent whiplash and this is why I highly recommend an add on headrest for vehicles with poorly rated headrests, like the Car Seat Head Support. So if you have neck or tmj problems, this device can help prevent further injury in the event of a rear end auto collision.

In the Journal of the American Dental Association, Vol. 138, August 2007, "One in three people who are exposed to whiplash trauma, which induces neck symptoms, is at risk of developing delayed TMJ pain and dysfunction with onset during the year after the accident." It is well-known that trauma results in injury and pain. Clenching can be considered a form of microtrauma that results in pain. Third molar removal may involve wide opening of the mouth, application of considerable forces to the mandible, and, if performed under general anesthesia, a reduction in a subject’s protective mechanisms. Any of these could result in trauma to the TMJ or the muscles of mastication.

There is also an association to suggest that anxiety, stress, and other emotional disturbances may worsen TMJ disorders, especially in patients who experience chronic pain. There is also a high prevalence of tmj disorders among females as compared to males and the relationship is thought to be of a hormonal nature.

In a recent study in BMC Ear Nose Throat Disord. 2011 May 25;11(1):5. Signs and symptoms of temporomandibular joint disorders related to the degree of mouth opening and hearing loss. TMJ signs and symptoms were more common and severe in females than males. TMJ disorders severity is correlated with the degree of mouth opening and the number of aural symptoms. The absence or presence of mild TMJ are associated with normal audiograms while moderate and severe TMJ are related to hearing loss in median and low tones respectively. Bruxism, joint ankylosis, joint pain and ear itching were more common in TMJ than non-TMJ patients. The study further noted, Furthermore, every movement of the neck or jaw exerts tension on the carotid sheath, increasing the endolymphatic pressure of the hair cells in the cochlea via impedance of the saccus endolymphaticus’ pressure-regulating mechanism, causing tinnitus and vertigo.

Although there is no clear method of treatment, we next explore methods for TMJ Pain Relief.