This candle signifies the light we wish to shine on the
knowledge needed, to continue our struggle against our
pain, suffering and injustices...Please, don't let the light go
A LIFETIME OF MOTION:
TEMPOROMANDIBULAR JOINTS
Every bend of the knee, blink of the eye or movement of the mandible depends on biochemical conversations between motor and sensory neurons and muscle cells. Adding to the complexity of these conversations, regulatory molecules (hormones, growth factors and cytokines) provide signals to control the metabolism of cartilage, bone, ligament and muscle cells as found in the temporomandibular joint.
If we become "conversationally impaired," like the 25 million older Americans afflicted with osteoporosis, the 10 million adults suffering with chronic facial pain or the millions of seniors with osteoarthritis, we seek compassion, understanding and expert diagnosis and treatment from our dental and medical health care providers.
In some instances, the conversationally impaired synovial joints of our bodies are repaired or replaced by mechanical surgical solutions when they become worn or diseased. In 1992, about 123,000 complete hip replacements and 100,000 complete knee replacements were performed at a cost of about $5 billion a year.
Our challenge in dentistry is to understand the fundamental biology and the unique clinical problems associated with the bilateral synovial joints that articulate the cranial temporal bone and the mandibular bone--a bilateral hinge for the lower jaw.
Temporomandibular joint diseases and disorders spring from problems with the interaction of the sensory and motor neurons (the specific neuromuscular junctions associated with craniofacial muscles of masticatio) and the cell-cell communications within and between cartilage, bone, ligament and muscle cells. TM disorders encompass a broad spectrum of candidate diseases and disorders. These range from inherited gene misspellings (osteogenesis imperfecta, chondrodysplasias) to acquired degenerative processes such as osteoporosis, arthritis and diabetic neuropathies.
The TMJ is actually two bilateral synovial joints formed by the mandibular condyles fitting into the glenoid fossa of the temporal bone (Figure 1). Separating these two opposing bones from direct contact is the interposed articular disk (meniscus). The articular portion of the disk or meniscus is composed of dense fibrous connective tissue, devoid of nerves or vessels. In contrast, the posterior portion of the disk is vascularized and innervated. The disk is attached to the mandibular condyle both medially and laterally by the collateral ligaments. These ligaments permit rotational movement of the disk on the condyle during the openings and closings of the mouth. The condyle disk complex moves out of the glenoid fossa during extended mouth opening (Figure 2).
Facilitating the many subtle movements of these joints is lubrication provided by the synovial fluid (enriched with hyaluronic acid). This fluid serves as a medium for buffering contractile, compression and lateral forces, and for transporting nutrients to and waste products from the articular surfaces.
The TMJ is not a typical synovial joint. Its condylar cartilage articular surfaces are lined with dense fibrous connective tissue rather than hyaline cartilage, as is the case with knee synovial joints. In contrast with hyaline cartilage, fibrous connective tissue has a different molecular composition and structure and different physical properties (a greater ability to repair itself, for example). These differences suggest that the TMJ's ability to manage inherited and acquired degenerative diseases or physical injuries may differ from that of other skeletal synovial joints.
Movements and stabilization of the TMJs are achieved by a group of six principal skeletal muscles of mastication. These muscles are responsible for elevating the mandible (mouth closing), depressing the mandible (mouth opening), protruding the mandible and stabilizing the mandibular condyle and disk during various functions. The mastication muscles are involved in a variety of functional behaviors--talking, swallowing and chewing--as well as aberrant behaviors such as bruxism, which includes grinding, clenching and empty-mouth chewing motions.
Recently, after all these years, two dentists (Drs. Gary Hack and Gwendolyn Dunn) from the University of Maryland Dental School reported a previously undescribed muscle, which by location should be involved in mastication. The "new" muscle extends from behind the eye to the maxillary bone. When confirmed, it will be called sphenomandibularis.
The trigeminal cranial nerve supplies the motor innervation of the muscles of mastication as well as sensory innervation to the oral structures and face. Neurons from the trigeminal as well as the facial, hypoglossal and vagus cranial nerves share the same neuron pool as neurons from the upper cervical spine. The biochemical conversations between motor neurons and muscle cells serve to maintain the functional integrity of the neuromuscular junction. The convergence of the trigeminal and cervical nerves is a potentially significant anatomic and physiological explanation for the source of referred pain from the cervical to the trigeminal region. As health professionals we need to be aware of this common referral pattern when considering a hypothesis or differential diagnosis. We need to consider this pattern before settling on a therapeutic strategy to address the signs and symptoms of chronic facial pain with or without inherited or acquired TM diseases and disorders.
Treating TM disorders remains a difficult challenge for clinical dentistry and medicine. Chronic facial pain affects about 10 million adults. Of these, nearly 7 million have pain mainly centered on the masticatory muscles and/or TMJ. Other common symptoms can include limited movement or locking of the jaw, painful sounds when moving the jaw, a major perceived change in the articulation between the maxillary and mandibular dentition and a radiating pain in the face, neck or shoulders.
These symptoms do not appear to have one common cause. Rather, they seem to present a heterogeneous group of conditions with overlapping signs and symptoms. Conventional dental X-rays and transcranial radiographs generally are not useful in developing a tentative diagnosis for TM diseases and disorders. Other imaging techniques usually are required when osteoarthritis is suspected and when chronic pain is not reduced over time. These other imaging techniques include arthrography (synovial joint X-rays using a radiopaque dye), magnetic resonance imaging, or MRI, and tomography (sequential and serial X-ray images of tissue at a precise depth).
THE NEED FOR DIAGNOSTIC CRITERIA
Unfortunately, there remains a lack of a scientific knowledge on the etiology and pathogenesis of TM diseases and disorders. Their epidemiology in the entire American population is incomplete. For example, how can we identify and segregate osteoarthritis associated a TM problem from rheumatoid arthritis and other systemic diseases? How can we identify patients at risk of developing TM diseases and disorders? And how can we prevent these signs and symptoms of the disease process?
As yet, randomized clinical trials have not been applied to establish clinical guidelines for diagnosis and treatment. In the absence of such scientific guidelines, a number of approaches have been offered to define the problem. For example, the International Headache Society listed TM diseases and disorders in its 11th diagnostic classification and divided them into disorders of the craniofacial bones including the mandible, TMJ disorders and masticatory muscle disorders. As the demand for specific diagnostic criteria and treatment outcome data increased, other organizations published more extensive classification guidelines. Their intent was to establish more specific diagnostic criteria.
The following definition, clinical presentation and prevalence data are from the 1993 American Academy of Orofacial Pain TMD guidelines:
There is little consensus today on the most favorable diagnostic classification schema because they all appear to be based on signs and symptoms rather than cause (etiology) and epidemiologic information. More carefully designed population studies will yield prevalence data and more precise specific disease categories. This will result in improved classification and possibly more precise terminology for TM diseases and disorders.
CONTRIBUTING FACTORS
Many factors can disturb the physiological balance among the various components aiding mandibular movements. One complication is differentiating between an abnormality that causes the problem and an abnormality results from adaptation to the problem. The available evidence suggests that the main causes of TM diseases and disorders are inherited gene mutations, acquired diseases (arthritis, neoplasia, osteoporosis, diabetes), trauma and anatomical, pathophysiological and psychosocial factors.
Examples of trauma include blows from a fist or object that injures the mandible and the TMJ. Injuries also may result while eating, talking on the telephone with the head in an awkward position, yawning, singing, prolonged mouth opening and extended stretching (as may occur in a long dental appointment). Such injuries can result in an internal derangement of the joint (dislocated jaw, displaced disk or injury to the condyle) and cause TM disorders.
Anatomical factors contributing to TM problems include inherited defects expressed in the craniofacial skeleton, neurological tissues, dentition and musculature. For example, several craniofacial syndromes present mandibulofacial dysmorphogenesis, bilateral asymmetry of the mandiblular condyles and congenital absence of the ramus of the mandible.
Childhood injuries may be the source of structural factors that influence the TMJ's synovial joint structure and function. Malocclusions also have been cited as either primary or secondary causes of TM diseases and disorders.
| " It is increasingly apparent that most complex human diseases and disorders reflect an exquisite set of interactions between human behavioral, environmental and biological factors. " |
Human behavioral sciences suggest that psychosocial factors may be related to TM problems. It is increasingly apparent that most complex human diseases and disorders reflect an exquisite set of interactions between human behavioral, environmental and biological factors. Understanding these interrelationships should improve how we promote health, reduce disease and enhance diagnosis and treatment. Further, patients with chronic facial pain often adopt compensatory behaviors--protracted teeth clenching, teeth grinding and various mandibular or mouth movements.
TREATMENT
Despite our limited knowledge of cause and pathogenesis, much has been done to improve our management of TM diseases and disorders. TMD management is traced in the written record to the ancient Egyptians and their manual setting of jaw dislocations. In the late 19th century, Annandale was one of the first surgeons to reposition the articular disk. And in the early 20th century, Pringle performed one of the first menisectomies. In 1934, Costen published his treatise on the improvement of TM conditions by altering occlusion. His work stimulated interest in occlusal techniques to provide optimal dental treatment including TMD treatment.
Thereafter, the profession became increasingly aware of the importance of the masticatory musculature, dental occlusion and emotional factors, occlusal therapy, bioelectric instrumentation, orthodontic treatment, trigger point injections, chronic pain management, TMJ prosthetic devices, and behavioral and educational approaches.
In a Technology Assessment Conference for TMJ sponsored by the National Institutes of Health and held in May 1966, the panel categorized all TMD treatments as either conservative/reversible or irreversible.
The panel recommended that conservative/reversible treatments always be pursued first. Because most patients do not have severe, degenerative TMD, these conservative treatments usually will be sufficient. Conservative treatments do not invade the tissues of the jaw, face or joint and are as simple as possible. They provide temporary relief of pain and muscle spasms but do not "cure" TMD. Self-care practices such as a soft foods diet, application of heat or ice packs and avoidance or reduction of extreme jaw movements (wide yawning, loud singing, gum chewing) are potentially useful in reducing or eliminating TMD symptoms.
Also useful are physical therapy approaches to muscle stretching and relaxing, the use of short-term muscle relaxants and anti-inflammatory drugs, and behavioral and educational techniques for reducing stress. Prosthetic plastic splints or bite plates that fit over the upper and lower teeth can also help reduce masticatory muscle tension that comes from clenching and grinding.
In connection with conservative therapies, the conference panel also suggested additional research:
The conference panel observed that these procedures were indicated only in a very small percentage of patients. Patients, the panel noted, should be made fully aware of the reasons for the treatment, the risks involved and other types of treatment available. There is a need for careful, well-designed randomized clinical trials to compare these procedures with reversible treatments and to determine their long-term efficacy, the panel said. Patients who have already undergone surgery should be informed that the probability of success decreases with each additional intervention.
| " The Food and Drug administration in late 1990 issued a safety alert and device recall for the TMJ prostheses made after 1976 when Congress enacted the Medical Device Amendment. Before 1976, most medical devices did not have to be proven safe or effective to be sold. " |
TMJ prosthetic devices have been used surgically for many years. These devices include:
Unfortunately, these materials were found to fragment under the physical forces within the TMJ environment, producing microscopic fragments or particles during TMJ loading and function. Thereafter, it was learned that these polymer materials are not degraded by tissue enzymes (for example, metalloproteases), resulting in many complications. These complications include foreign body giant cell reactions, foreign particle migration to adjacent tissues, chronic pain, lymphadenopathy, severe osteoarthritis-like pathology, overt bone resorption, connective tissue degradation, Sj�gren's-like autoimmune disease, perforation into the middle cranial fossa and persistent immunological dysfunctions.
The Food and Drug administration in late 1990 issued a safety alert and device recall for the TMJ prostheses made after 1976 when Congress enacted the Medical Device Amendment. Before 1976, most medical devices did not have to be proven safe or effective to be sold. Even after that, manufacturers could market devices with little FDA scrutiny if they claimed they were similar to pre-1976 devices. Reacting to problems with the synthetic polymer TMJ devices, the FDA now has criteria for these devices that are more stringent than for any other joint in the body. Also, the agency has not approved any TMJ total joint prosthesis.
Using drug therapy to manage chronic pain associated with TMD was the subject of an excellent review by Dr. D. DeNucci and colleagues in the May 1996 issue of JADA.
Drugs may be useful particularly in managing the early symptoms of a TMD. Drug therapy often can be the primary approach to treating chronic pain or to inhibiting inflammatory processes that may contribute to TMD. The medications are similar to those used for other painful musculoskeletal conditions, including short-term treatment with non-steroidal anti-inflammatory drugs and muscle relaxants for pain of muscle origin. For less- well-characterized pain, regular administration of antidepressants may be useful. Opiates are all too often administered to patients with chronic pain for long periods, despite long-standing concern about their tendency to cause dependence. There are a few well-controlled studies of drugs for managing chronic orofacial pain. Clinicians must weigh the risk of side effects against potential benefits.
In its recommendations, the conference panel noted that universally accepted, scientifically based guidelines for diagnosing and managing TMDs are not available. Consequently, practitioners sometimes have attempted to respond to patient needs various as yet unproven diagnostic and therapeutic approaches.
Concerns about the sensitivity, specificity, safety and overall efficacy of these approahess--as well as the potential for harm--led the panel to recommend new, well-designed studies to assess the accuracy, reliability and relative effectiveness of currently used diagnostic tools and treatments. Well-designed and controlled clinical trials using a significantly large, randomized patient population have not been accomplished as yet. In addition, the panel strongly encouraged professional education to ensure proper and safe practices in treating TMDs, including the psychological and social aspects of these TMD problems.
A number of scientific opportunities are now apparent. These new research avenues can actually mimic cellular, molecular and developmental biology advances by producing new biomaterials through tissue and genetic engineering. Enter the new field of "biomimetics." Together, advances in imaging techniques, non-opiate drugs and fundamental immunology promise potentially exciting advances in the future management of TMDs.
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TMJD_SAFE_HAVEN_4_LIFE_ISSUES · TMJ SUPPORT GROUP
This TMJD Support Group is intended to be a Safe Haven and provide a place where people with TMJ pain can come and offer and receive support from people who know what they are going through. This is not a medical group and we do not have medical degrees or medical backgrounds. However, with the variety of members in here, there is bound to be someone who has been there and done that and can answer your questions.
This group is in memory of Debbie Ward whom suffered from TMJD & died of unknown causes.
There are many types of members with TMJD. Some have been treated medically, some treated with various splint therapies and physical therapies as well as some with surgical treatments ranging from Arthroscopy to full jaw joint replacements. Everyone with any degree of TMJD or has a family member that deals with it is welcome to join and offer and receive support that we all so badly need to get through each day with the pain we have to live with.
It is YOUR place to cry, scream or vent on the pain you are dealing with and how it is affecting your life and the lives of your loved ones. The group is MODERATED to avoid the unsolicited advertisements and spam. We are all in pain and do not need to have to deal with that too.
TMJ SURGERY FAMILY!.
A Great Place to Share Information! This site is for sharing and is not a substitute for the advise of your physician/oral surgeon. Please consult with your health care professional.
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