• Confusion and Uncertainty Regarding ″TMJ″ and Dental Occlusion
When I left my dental training, like many dentists even today, I lacked a clear understanding of dental occlusion and temporomandibular disorders (TMDs). My early concepts of my responsibility to my patients was mostly about teeth and gums. During the past 35 years that my practice has been devoted to non-surgical management of TMDs, I’ve talked to many dentists regarding their understanding of these disorders. Nearly universally, most dentists recognize and acknowledge that there was a black hole in their dental education related to the subjects of TMDs and dental occlusion. Most dentists will readily acknowledge being quite uncertain and confused about what TMDs are, let alone how to manage them.
The masticatory musculoskeletal system is unquestionably the most elegant and functionally complex joint system in the human body. One of several factors that make it so complex is the presence of teeth and the role of the dental occlusion as it affects both the muscles, as well as its effect on the position and function of the temporomandibular joints. There is no other joint system in the human body in which a structure comparable to the teeth affects the joint and its function as occurs in the masticatory system. It is because of the role of the dental occlusion on the function of the masticatory system that the management of the health and treatment of this system is the primary professional responsibility of the dental profession.
And even though understanding of the function of this system has increased enormously in the past 30+ years, this understanding has not “trickled down” to dental curricula. There has been little improvement in dental education reflecting our increased understanding of the anatomy, physiology, and function of this amazing joint system.
An orthopedic surgeon, Robert B. Salter, MD, in his textbook titled, “Disorders and Injuries of the Musculoskeletal System”, stated that, “to understand the abnormal, we must first understand the normal”. The simple logic of that statement is that to be able to understand TMDs (abnormal function – dysfunction – of the system), we must first understand the normal function of the system. This is where dental education has failed our profession and where dentists need to begin in gaining an understanding of TMDs and dental occlusion — to understand the physiologic requirement of normal function of this system. This body of knowledge is what is nearly totally absent in dental professional training, both at the doctoral and the post-doctoral levels.
Many dentists, due to limited training and recognition of their limited understanding, would prefer to not assume responsibility for treatment of these disorders. However, it is the professional responsibility of every dentist to identify the early signs of these disorders. If your level of understanding is limited, you should, at a minimum, have a protocol in place in your office for screening patients for the earliest signs of TMD. (See “Screening for TMDs in Dental Practice“) It will then be important to identify a professional colleague who does provide treatment, to develop a professional relationship with them, and to refer these patients.
Frequently such referrals are sent to oral surgeons. It should be said, however, that most oral surgeons do not provide non-surgical care for TMDs. Less than 5% of patients with a TMD are candidates for surgery. And non-surgical management can be very effective for 95% of patients if done with knowledge, skill, and experience. Identification of these disorders in their incipient stage, and early treatment, assures the best possible prognosis.
• Dentistry’s Responsibility Regarding Temporomandibular Disorders
The masticatory system, as with other joint systems, is biologically classified as a musculoskeletal system. It is made up of the muscles of mastication, and the temporomandibular joints, as well as the teeth and dental occlusion. It constitutes a highly unique joint system that is both structurally and functionally complex, as compared to other joint systems of the human body. It is, without doubt, the most structurally and functionally complex joint system in the human body.
The masticatory system, and therefore the management of temporomandibular disorders (TMDs), is primarily the responsibility of the dental profession. The primary reason this is true is that there is no other joint system in the human body that has a structure comparable to the teeth that can so profoundly affect both the structure and function of the related joints, as well as the function of the muscles that move those joints. If this was not true, and if the masticatory system was comparable to other joint systems of the human body, this responsibility of the dental profession would not exist and other professionals who deal with musculoskeletal disorders of other joint systems would be entirely capable of complete management of the disorders of the masticatory system.
Given this reality, it is important to appreciate that there is almost no training in dental curricula at any level, doctoral or post-doctoral, that prepares members of the dental profession to provide full and adequate care for patient who have this need. Although the knowledge that is now available is certainly adequate for definitive management of most TMDs, that knowledge has not “trickled down” to the dental educational system at any level. As a result, most dental graduates, at both the doctoral and post-doctoral levels will readily acknowledge feeling quite uncertain and under-prepared to definitively manage these conditions in their patients.
Because TMDs are included in a larger group of conditions known broadly as “orofacial pain,” masticatory musculoskeletal pain of the jaw system (TMD) is often thought of as being synonymous, in most respects, with other types of pain in the oral and facial region. However, there is a very significant difference between masticatory pain and other types of orofacial pain.With many other types of orofacial pain, neurovascular and neuropathing pain, the underlying cause of the pain frequently cannot be directly addressed and, thus, treatment of the pain (reduction of symptoms) is the best that can be hoped for. An example of this would be neuropathic pain, which is generally treated with medications, and little more can be done to affect the cause of the pain.
With masticatory musculoskeletal pain, not only can we treat the symptoms, in the vast majority of these conditions we can directly address the underlying causes. In doing so, we can frequently stop the repetitive exacerbations for which these disorders are known. However, to do so requires a thorough understanding of the anatomy, physiology, and functional requirements for a healthy masticatory system, as well as what is required to restore physiologic homeostasis to the system. This is what has historically been absent from dental training and remains so to this day. There is a general erroneous impression throughout the dental profession and elsewhere that something called “TMJ” is a single discrete disorder. Given the virtual absence of training regarding these conditions, such a misunderstanding is not surprising. The term “TMJ” (or more appropriately, “TMDs”) is a broad, generic term, covering a wide variation of musculoskeletal disorders of the masticatory system and may include relatively minor, usually easily treated conditions that involve only the muscles of mastication. However, at the other extreme are conditions that involve both the muscles and the temporomandibular joints, which at times may require rather complex treatment strategies if definitive care is to be provided.
• Meeting The Challenge of Dentistry’s Responsibility
Patients presenting for treatment of a temporomandibular disorder often report one or more of the following:
• Early signs and/or symptoms of their condition have been present for 6 months or longer.
• Early signs and/or symptoms of their condition were not recognized by their dentist.
• If their dentist recognized the early signs, or if the patient brought these to the attention of the dentist, the dentist may have dismissed a condition that was demonstrating the potential to worsen over time.
• If their dentist recognized the need to initiate treatment, the treatment was perhaps inadequate to intercede sufficiently or was, in some cases, clearly inappropriate. Remember “no training”.
• Referral to a knowledgeable dentist with more extensive experience was deferred until the condition was more advanced and more difficult to treat definitively, making the prognosis for an adequate resolution much in question.
It is undoubtedly unrealistic to expect every dentist to become proficient in the treatment of all forms of temporomandibular disorders. Because of the wide variation in these conditions and the sometimes subtle signs that can differentiate a mild condition from one that has the potential to become more problematic, most dentists simply would not have enough opportunity in their practices to develop the necessary diagnostic judgment nor to learn the appropriate skills required to consistently provide effective management.
A realistic expectation would be for every practicing dentist to learn to do a screening history and a screening examination on every patient on a regular basis and to be able to make a reasonable distinction between TMDs that are within their personal level of knowledge and skill and those that should be treated by someone with more expert knowledge, skill, and experience.
Learning to do an adequate screening history and exam is easily within the capabilities of both dentists and dental hygienists. Dental hygienists are perhaps best positioned in a general practice to recognize these conditions, even when the indicators are occult. With a relatively brief training protocol and the opportunity to apply what they have learned, dental hygienists may represent the best hope to meet the challenge of early recognition of TMDs, thus hopefully insuring that they be treated. See “Screening for TMDs in Dental Practice“.
However, until organized dentistry, dental licensing boards, and leaders in dental education do more than give lip service to this responsibility and community need, it seems unlikely that many dentists will take it upon themselves to rise to the challenge of meeting the public need for a higher standard of care for temporomandibular disorders.
• What You Can Do to Meet the Challenge in Your Dental Practice
In an editorial in the March, 1990 issue of JADA, Dr. William Wathen stated, “There are three basic question for a dentist to consider when presented with a “TMJ” patient in their practice:
1) Do I want to treat the disorder,
2) How far am I willing and capable of going with the treatment
3) Do I want to treat this particular patient?”
He then commented, “The first and third questions are relatively easy to answer. The second question demands cautious reflection.
Many dentists will prefer to continue practicing pretty much the way they are currently and would just as soon let someone else treat patients who may present with signs and symptoms of TMD. There will be some dentists who would like to treat TMD patients whose problem does not exceed their knowledge and skill level in this area. A very small number of dentists may want to accept the challenge to become skilled in treating more complex TMD patients. The choice is a personal one but, as Dr. Wathen suggests, each dentist should realistically consider his or her own level of knowledge and skill in this area.
• Introducing TMD Screening Into Your Practice
Whatever your personal decision, for all practicing dentists the starting point in meeting your professional responsibility would be to introduce a screening procedure into your practice. See “Screening for TMDs in Dental Practice“.
It is recommended that you copy the history and exam form on both sides of a single piece of paper, then cut the page along the dividing line. This will give you two forms with a history questionnaire on one side and an exam form on the opposite side.
We recommend that each patient who presents for their routine recall and prophylaxis be asked by the receptionist to complete the screening questionnaire. Then the form would be transferred to either the dentist or the dental hygienist, whoever would see the patient next. Based on the responses to the screening questionnaire, (as described on the Interpretation of Screening Questionnaire and Exam Form), a determination can be made as to whether a comprehensive evaluation is indicated.
The hygienist can easily be trained to assess the results of the questionnaire, based on the Interpretation Form, mentioned above. And can also be trained to do a screening examination. When the dentist is called to evaluate the patient, the hygienist can bring any significant findings to the attention of the dentist. At that point, the dentist would be able to decide whether he/she would do a comprehensive TMD evaluation, or whether to refer the patient to a colleague who has more knowledge and experience with TMD assessment and treatment.
• Distinguishing Between Types of TMDs (“Simple” to “Complex”)
On the page, “TMD Diagnostic Categories“, TMDs are divided into seven broad categories, with guidelines to help determine the patient type. To most effectively use the guidelines presented on this page, a comprehensive history and exam will need to have been done. However, whether or not you choose to do comprehensive TMD evaluations, reading and understanding the content of this page will help you better assess your own personal level of knowledge and skill regarding TMD management and to make appropriate choices about whether to attempt treatment.
• TMD Considerations for Physical Therapists
The objective of comprehensive TMD management is not only relief of pain, but rehabilitation; a return of the entire masticatory apparatus to optimum physiologic function, or as near to that as is possible in an individual case. The rationale for such an approach is to minimize the likelihood of exacerbations and chronicity, which are known to be common in TMD.
The masticatory apparatus is unique in a number of ways among joints systems in the human body, but principally by virtue of the presence of teeth as a significant influence on joint position and function and on muscle function. If it were not for this fact, there would be no unique role for the dental profession in the management of these disorders and health care professionals who manage other musculoskeletal disorders would be quite capable of total management of masticatory musculoskeletal pain and dysfunction.
Ironically, dental curricula provide little or no training in TMD management and, therefore, most dentists will readily acknowledge having only limited understanding of these disorders and what is required in their management. It should b no surprise, therefore, that dentists typically have little or no understanding or appreciation of the highly important role that physical medicine (physical therapy) can play in comprehensive TMD management, especially when based on a rehabilitation model.
Conversely, it can also be said that most therapists who provide some type of physical or manual therapy typically have little understanding or appreciation of the importance of the dental role in management of these disorders. This lack of understanding and appreciation on the part of each of these professional groups of the value of the other’s role is one of the greatest barriers to achieving truly comprehensive care for most TMD patients.
Dentists who use a strictly dental approach in treating TMD patients will have seen some degree of symptomatic relief in many of the patients they have treated but will almost certainly have had some patients who have not responded well to this type of treatment. Likewise, many therapists will have had a similar experience; standard protocols will have provided significant relief of symptoms in some patients and others will have responded poorly or may have experienced short-term relief but symptoms may have had a tendency to recur chronically. Frequently these patients will be written off by both dentists and therapists as being “stressed” or relegated to some other generic diagnostic category. Often the explanation for their inadequate response may be that, although the therapy being provided was appropriate, alone it was inadequate for this particular patient’s needs. There is no doubt that “stress” and other factors can at times significantly complicate treatment. But the significance of appropriate and effective “dental” therapy combined with well-executed physical medicine must not be overlooked for the vast majority of TMD patients by either professional group
Patients with relatively mild TMD symptoms that have not become chronic may experience symptomatic relief from any of several approaches to treatment. It is the chronic or otherwise difficult patient, in particular, who is more likely to require a coordinated interdisciplinary approach to achieve significant and lasting results. When the benefits of interdisciplinary care for the difficult patient is recognized by both the dentist and the physical medicine therapist, the value of utilizing an integrated interdisciplinary approach in most, if not all, patients in achieving predictable and lasting results becomes obvious.
It is not possible to describe the dental role in detail in this context. However, some general comments follow that should be helpful as an introduction. For those therapists who intend to focus a significant portion of their professional activities on TMD management, it is recommended that you become more knowledgeable in the dental role and develop a working relationship with at least one dentist who is knowledgeable, skilled, and experienced in non-surgical TMD management. Therapists who recognize that they will probably have infrequent opportunities to treat TMD patients may find it worthwhile, both in terms of their own time and the patient’s best interest, to refer these patients to a therapist who has developed the requisite knowledge, skill, and experience to be consistently effective in providing necessary care.
• The Dental Role
In other joint systems of the human body, there is no structure comparable to the teeth that has the potential to directly influence the position, structure and function of the joint or the function of muscles that move the joint. In the masticatory apparatus, a hierarchy exists in the interplay between teeth, joints, and muscles and the fit of the teeth always dominates; i.e. people with teeth always close their mouth where the teeth fit together best, whether or not that is structurally appropriate for the temporomandibular joints or functionally appropriate for the muscles of mastication. The mechanism that produces this consistent “best fit” closure of the jaw is a neuromuscular engram that is programmed by the fit of the teeth. Without this mechanism, normal functional jaw usage such as eating and talking would result in the teeth clashing together.
There are a number of ways in which the fit of the teeth may be detrimental to both joints and muscles. However, eliminating the teeth altogether would not be appropriate, either. Both joint and muscles require the support of the teeth to function appropriately. Fortunately, as is true in other areas of the body, when one or more factors in the dental occlusion contributes to strain in the other components of the masticatory mechanism, there is a capability of adaptation and accommodation that tends to minimize the occurrence of pain and dysfunction in response to these adverse effects from the bite. When musculoskeletal pain and dysfunction do develop, they are known generically as Temporomandibular Disorders.
When the body’s threshold of adaptation and accommodation has been exceeded and pain/dysfunction has been the result, the most predictable means of promoting a return of the masticatory mechanism to normal physiologic homeostasis is, first, to to eliminate or mask, on a temporary basis, the potentially detrimental aspects of the way the teeth come together. The second objective is to provide those elements of an optimum bite that promote optimum physiologic response. This can be done by means of a properly designed and appropriately adjusted intraoral occlusal appliance (splint).
An occlusal appliance (splint) should be seen as a tool to be used in achieving these objectives. As is true with any tool, its effective implementation is a direct consequence of the knowledge, skill, and experience of the person using it. In other words, any piece of plastic fitted to the teeth does not necessarily represent effective “splint” therapy. Because of the lack of training in TMD management in dental curricula, effective use of intraoral appliances in the broad spectrum of TM disorder is not common. Most dentists have, at most, a very limited understanding of what this simple piece of plastic is intended to accomplish or how to use it effectively toward that end.
It is common practice for dentists to instruct patients to wear an appliance only at night as a “night guard” or a “bruxism splint”. Although this may produce some degree of symptom reduction in some patients, and may be appropriate in some circumstances, this approach will not be adequate if the intent of treatment is to achieve not only symptomatic relief but rehabilitation of physiologic function. The reason is that part time wear of an occlusal appliance can not address in a definitive manner the effect on the joints and muscles of possible detrimental discrepancies in the dental occlusion. When appliance therapy is undertaken, there should be, on the part of the dentist, a clear and conscious awareness of the treatment objectives, based on a careful history and a thorough examination. These treatment objectives and their consequences should be communicated to the patient and discussed prior to treatment. In some patients, wear of an appliance only at night will be entirely inadequate to relieve the condition that is producing the pain and may be the primary reason for a less than adequate response to physical medicine therapy as well. Knowledge, skill, and experience in appliance therapy on the part of the dentist and appropriate physical medicine protocols on the part of the therapist is the best assurance of achieving consistent, predictable outcomes in comprehensive TMD management.
• Manual Manipulation of the Temporomandibular Joint
(Addendum for Chiropractors, Osteopaths, and Physical Therapists)
The unique anatomy of the temporomandibular joints, the widely varying types of dysfunctions that can occur in this joint system, and the over-riding influence of the fit of the dental occlusion on the mechanics and position of the temporomandibular joints makes this joint system profoundly distinctive with respect to the appropriateness of aggressive manual manipulation. If a doctor or therapist 1) is not intimately acquainted with the complex anatomy of these joints and the wide variation of potential dysfunctional condition, 2) is not fully acquainted with the effect of the dental occlusion on joint position and function, and 3) is not completely confident of the specific diagnosis in an individual patient with joint dysfunction, aggressive manual manipulation of the temporomandibular joint is contraindicated due to the potential for compounding the condition for which the manipulative therapy is ostensibly being provided. Gentl mobilization, if it appears to be productive, may be another matter.
Conditions of the temporomandibular joints involving internal derangement without reduction, which may potentially benefit from manual manipulation, are subject to almost immediate relapse due to the effect of the dental occlusion on condylar position. If manual manipulation, in the opinion of the therapist, would be appropriate, it should always be done in conjunction with a dentist who is highly knowledgeable, skilled, and experienced in TMD management and the patient must, at the time of the manipulation, be wearing an occlusal appliance (splint) that can be utilized to support the mandible in the corrected condylar position following a successful manipulation and the appliance would need to be modified in an appropriate manner immediately following the manipulation to assure proper support for the joint in the corrected position.
An ongoing working relationship, involving regular communication and good rapport between the dentist and the manipulative therapist is essential.
• Chiropractic Involvement in TMD Management
The following statements are taken from the excellent manual and video tape, “Whiplash and TMJ Injuries – Examination and Diagnosis” by Dennis P. Steigerwald, D.C.
“The chiropractic, medical and osteopathic professions frequently see whiplash victims in a portal-of-entry capacity. The increasing recognition of TMD occurring secondary to whiplash has caused particular problems for these portal-of-entry doctors who do not specialize in treatment of TMD. Unfortunately, the main body of doctors treating TMD as a specialty are most frequently separate in concept, education and techniques from those who specialize in the treatment of whiplash patients. This division frequently makes timely and effective identification, referral, and treatment of the whiplash-induced TMD difficult, resulting in increased joint damage and chronic pain. The resolution of this problem will require a paradigm shift for both populations of doctors. Bridging the gap between the portal-of-entry doctors and the TMD specialist will greatly facilitate the effective treatment of the whiplash induced TMD. By identifying and referring the TMD patient early on in the pathogenesis of the disorder, the portal-of-entry doctor can provide this essential ingredient.”
“The injured temporomandibular joint frequently produce symptoms peripheral to themselves and frequently exert a noxious influence upon paraspinal tissues. The may be a result of altered head, neck, and jaw posturing or a result of central nervous system effect caused by neurological irritations set up by the inflamed temporomandibular joints. In any case, these influences may extend the time of necessary treatment to the spinal injuries as the temporomandibular joints, once injured, can act as a perpetuator of pain/dysfunction in the paraspinal tissues.”
“The posture, movement and anatomic relationships of the component parts of the temporomandibular joints are defined by the soft tissue elements of this system and gravity, except when the teeth are in occlusion. This is important to understand as this represents the vast majority of the time. This is not to understate the influence of the teeth on the system as occlusal influences during full Intercuspation of the teeth (maximum contact between the upper and lower dental arches) produces a defining and somewhat inescapable influence on the relational architecture of these joints. The “close packed” position of this joint systemis, in fact, a function of the size, shape, position, presence or absence of teeth when full Intercuspation (maximum tooth contact is attempted.”
“As inflmmation of the temporomandibular joints is frequently a prominent part of the dysfunctional process, manipulation is not advised while signs of acute inflammation are present other thn for acute disc or joint dislocation. I recommend referral tyo an experienced practitioner for this service.”
“Certain common practices in treating whiplash patients may have to be modified or even avoided if a temporomandibular joint injury has been diagnosed. These include:
1. Application of mandibular harness cervical traction.
2. Use of cervical collars.
3. Cervical manipulation involving mandibular contact should be avoided if temporomandibular joint injury has been identified.
4. Placement of the patient in the prone position, resulting in pressure on the injured temporomandibular joints, should be minimized.”