The temporomandibular joint is susceptible to many of the conditions that affect other joints in the body, including ankylosis, arthritis, trauma, dislocations, developmental anomalies, and neoplasia.
Most cases of TMJ, however, are not so simple. Deep-space infections with resulting trismus or neoplams about the joint may mimic TMJ dysfunction. Muscle pain can sometimes be associated with trigger points in muscle tissue. These trigger points can be localized by digital palpation, both intraorally and extraorally. This is known as Myofascial pain syndrome.
Any dysfunction of the muscles may cause the teeth to occlude (bite) with each other incorrectly;if teeth are traumatized by this, they may become sensitive, demonstrating one of the many interplays between muscle, joint, and tooth.
In a healthy joint, the surfaces in contact with one another (bone and cartilage) do not have any receptors to transmit the feeling of pain. The pain therefore originates from one of the surrounding soft tissues. When receptors from one of these areas are triggered, the pain causes a reflex to limit the mandible's movement. Furthermore, inflammation of the joints can cause constant pain, even without movement of the jaw.
Due to close proximity of the ear to the temporomandibular joint, TMJ pain can often be confused with ear pain. The pain may be referred in around half of all patients and experienced as otalgia (earache). Conversely, TMD is an important possible cause of secondary otalgia. Treatment of TMD may then significantly reduce symptoms of otalgia and tinnitus, as well as atypical facial pain. Despite some of these findings, some researchers question whether TMD therapy can reduce symptoms in the ear, and there is currently an ongoing debate to settle the controversy.
The dysfunction involved is most often in regards to the relationship between the condyle of the mandible and the disc. The sounds produced by this dysfunction are usually described as a "click" or a "pop" when a single sound is heard and as "crepitation" or "crepitus" when there are multiple, rough sounds.
Over-opening the jaw beyond its range for the individual or unusually aggressive or repetitive sliding of the jaw sideways (laterally) or forward (protrusive). These movements may also be due to parafunctional habits or a malalignment of the jaw or dentition. This may be due to:
Some recent studies have demonstrated a statistical relation between bipolar disorder and temporomandibular joint disorder
An alternative approach is for pain modification, for which off-label use of low-doses of Tricyclic antidepressant that have anti-muscarinic properties (e.g. Amitriptyline or the less sedative Nortriptyline) generally prove more effective.
An approach to eliminating para-functional habits involves the taking of a detailed history and careful physical examination. The medical history should be designed to reveal duration of illness and symptoms, previous treatment and effects, contributing medical findings, history of facial trauma, and a search for habits that may have produced or enhanced symptoms. Particular attention should be directed in identifying perverse jaw habits, such as clenching or teeth grinding, lip or cheek biting, or positioning of the lower jaw in an edge-to-edge bite. All of the above strain the muscles of mastication (chewing) and results in jaw pain. Palpation of these muscles will cause a painful response.
Treatment is oriented to eliminating oral habits, physical therapy to the masticatory muscles, and alleviating bad posture of the head and neck. A flat-plane full-coverage oral appliance, e.g. a non-repositioning stabilization splint, often is helpful to control bruxism and take stress off the temporomandibular joint, although some individuals may bite harder on it, resulting in a worsening of their conditions. The anterior splint, with contact at the front teeth only, may then prove helpful.
According to the National Institute of Dental and Craniofacial Research (NIDCR) of the National Institutes of Health (NIH), TMJ treatments should be reversible whenever possible. That means that the treatment should not cause permanent changes to the jaw or teeth. Examples of reversible treatments are:
What may be concluded is that there are various treatment modalities which a well-trained experienced dentist may employ to relieve symptoms and improve joint function. They include:
Attempts in the last decade to develop surgical treatments based on MRI and CAT scans now receive less attention. These techniques are reserved for the most recalcitrant cases where other therapeutic modalities have changed. Exercise protocols, habit control, and splinting should be the first line of approach, leaving oral surgery as a last resort. Certainly a focus on other possible causes of facial pain and jaw immobility and dysfunction should be the initial consideration of the examining oral-facial pain specialist, oral surgeon or health professional. One option for oral surgery, is to manipulate the jaw under general anaesthetic and wash out the joint with a saline and anti-inflammatory solution in a procedure known as arthrocentesis. In some cases, this will reduce the inflammatory process.
New temporomandibular joint dysfunction syndrome genetics research from Rice University, Department of Bioengineering described.
Mar 03, 2008; Fresh data on temporomandibular joint dysfunction syndrome are presented in the report 'The effects of protein-coated surfaces on...
Data on temporomandibular joint dysfunction syndrome therapy detailed by researchers at Tehran University of Medical Sciences.(Report)
Mar 17, 2010; Scientists discuss in 'Treatment of temporomandibular joint ankylosis: gap and interpositional arthroplasty with temporalis...
Research on temporomandibular joint dysfunction syndrome animal studies published by scientists at University of Minnesota.
Mar 11, 2010; Scientists discuss in 'NMDA receptor blockade reduces temporomandibular joint-evoked activity of trigeminal subnucleus caudalis...
New Temporomandibular Joint Dysfunction Syndrome Study Findings Have Been Reported by Researchers at Clemson University.(Report)
May 30, 2011; Scientists discuss in "The region-dependent biphasic viscoelastic properties of human temporomandibular joint discs under...