Temporomandibular disorders and science: a response to the critics.

This article was prepared by the above authors and submitted to members of the TMD academic community for their endorsement. A total of 120 people signed an endorsement; their names are available on request.

Temporomandibular disorders and science: a response to the critics.

This article was prepared and submitted to members of the TMD academic community for their endorsement. A total of 120 people signed an endorsement; their names are available on request.

Current status of diagnostic procedures for temporomandibular disorders.

Temporomandibular disorders encompass a group of musculoskeletal conditions that involve the joints, the masticatory musculature, or both. In any given patient, there may be several overlapping TM disorders, an orofacial pain condition mimicking a TM disorder or a concomitant TMD and non-TM disorder. The differential diagnosis becomes extremely important.

Role of electronic devices in diagnosis of temporomandibular disorders.

The role of electronic devices in the diagnosis of TMD raises the critical question of whether the clinician can gain diagnostically relevant information from them. This is of serious concern in view of the sparse, unreplicated and invalidated scientific evidence linking the use of such devices to TMD diagnosis and subsequent therapy. Until such time as scientific studies, using blinded evaluations to compare TMD patients and controls, demonstrate acceptable levels of reliability, validity, sensitivity and specificity, as well as positive and negative predictive values, the use of such devices will continue to have questionable diagnostic validity and, therefore, will continue to be considered experimental. Thus, clinicians should carefully consider the diagnostic and therapeutic consequences of using electronic devices prior to adding them to their dental armamentarium.

Reliability and validity of diagnostic modalities for temporomandibular disorders.

Temporomandibular disorders (TMD) encompass a group of musculoskeletal conditions that involve the temporomandibular joint (TMJ) or joints, the masticatory musculature, or both. These conditions are typically characterized by pain in the pre-auricular area that is usually aggravated by chewing or other jaw function and is often accompanied, either singly or in combination, by limitation of jaw movement, joint sounds, palpable muscle tenderness, or joint soreness. As with most other musculoskeletal conditions, the diagnostic "gold standard" for TMD is based upon an evaluation of the patient's history and clinical examination, supplemented, when appropriate, by TM joint imaging. It is against this "gold standard" that the reliability and validity of diagnostic modalities must be compared. With regard to electronic devices, several reviews of the scientific literature have concluded that the diagnostic reliability, validity, sensitivity, and specificity of such devices in the diagnosis of TMD have not been established. In addition, although clinical examination of the dentition may provide useful diagnostic information for some conditions, specific occlusal relationships have poor sensitivity and specificity when related to the presence or absence of TMD. TMJ imaging, when indicated, is useful in the detection of pathology within the joint, provided that validated criteria are applied to an analysis of the image. However, the assessment of condylar position as a diagnostic criterion for TMD has very poor reliability and validity.

Clinical decision making for temporomandibular disorders.

Temporomandibular Disorders (TMD) encompass a number of clinical problems that involve the masticatory musculature, the temporomandibular joint (TMJ), or both. In any given patient, there exists the possibility of several overlapping TM disorders, an orofacial pain condition mimicking a TMD, or a concomitant TMD and non-TMD disorder. Since differential diagnosis involves the determination of which diseases or disorders a patient is suffering from by systematically contrasting the clinical characteristics, differentiation from among multiple possible conditions complicates the diagnostic process, which often must be approached with a certain degree of uncertainty. In addition, the therapeutic decisions that emanate from the diagnostic process have their own predictive uncertainties. These uncertainties can be ameliorated by coupling available clinical research data with structured clinical problem solving methods during the diagnostic-therapeutic decision making process. It is within this context that this article includes a discussion of the rationale for why the clinician should use decision making methods for TMD, a review of previous attempts at developing decision models for TMD, a discussion of the diagnosis of TMD with particular emphasis on the reliability and validity of their diagnostic criteria, a summary of the efficacy of therapeutic modalities and their application to treatment decisions, a sample decision tree analysis of a TM disorder, and some general recommendations for dental education.

Restoration of the vertical dimension of occlusion in the severely worn dentition.

The guidelines presented in this article for diagnosis and treatment of extreme tooth wear are not meant to be all inclusive. Every patient has unique treatment needs, and all of these needs may not be addressed specifically in this article. We believe, however, that careful adherence to the guidelines presented should facilitate a successful treatment of most if not all patients with moderate or severe tooth wear. The general guidelines for treatment of these patients include the following: 1. A comprehensive examination, including a thorough medical and dental history, orofacial and dental clinical examination, dental radiographs, TMD screening history and examination, impressions and jaw relation records for mounting casts in a semi-adjustable articulator, 2. A diagnostic wax-up and diagnostic occlusal adjustment on additional or duplicated mounted casts, 3. Careful planning and consultation regarding the need for preparatory treatment. Careful integration and sequencing of the different areas of treatment needed to enhance the finished result, 4. Discussion with the patient of the different treatment alternatives and sequences possible for his or her individual case, with presentation of advantages and disadvantages and prognosis for each, 5. Finally, careful execution of the agreed upon treatment plan by the dentist. Although not specifically mentioned, treatment success requires a highly motivated patient and skilled dental laboratory technicians. These "treatment partners" should be included in the planning stages of treatment as early as possible to enhance the possibility of having a successful treatment result.

The dilemma of scientific knowledge versus clinical management of temporomandibular disorders.

The dilemma of scientific knowledge versus clinical management of TMD is discussed by focus on five questions; (1) What is scientific evidence and how is it transmitted? (2) What important evidence is lacking in the field of TMD? (3) What clinical concepts have been challenged by the scientific evidence? (4) Why is there adherence to concepts that appear to conflict with the evidence? (5) How does the clinician provide patient care in the face of uncertainty while retaining scientific integrity? It is concluded that no fundamental reason for a dilemma between scientific evidence and clinical practice need exist provided that (1) clinical investigators use appropriate research protocols and report results in refereed scientific journals and (2) dentists are familiar with the requirements of sound scientific evidence, interpret this evidence and its clinical implications, and apply it to the care of TMD patients.

Relationship of occlusal vertical dimension to the health of the masticatory system.

Changes in occlusal vertical dimension have been claimed to cause masticatory system disorders. Early articles on this subject were mainly limited to clinical case reports, and the more recent clinical studies have been flawed by the lack of control groups, blind evaluation, and by poor definition of criteria for evaluating the health of the masticatory system. Research with humans and animals has shown that if increases in occlusal vertical dimension are not extreme and the appliance used covers most of the dentition, there is a good possibility of adaptation. Current scientific knowledge does not support the hypothesis that moderate changes in occlusal vertical dimension are detrimental to the masticatory system.

Electronic technology for clinical prosthodontics.

A review of the literature on electrodiagnostic devices indicates that current studies have not substantiated claims regarding the utility of these devices in clinical dentistry. Research design problems, such as inadequate control subjects and use of inappropriate statistical tests, limit the conclusions that can be drawn from the results of these studies. Further research, including measurements of sensitivity and specificity, is needed in order to indicate the diagnostic utility of jaw tracking or electromyography in clinical dentistry.

Variability of closest speaking space compared with interocclusal distance in dentulous subjects.

Variability of closest speaking space was compared with that of interocclusal distance in 30 dentulous subjects to the nearest 0.1 mm on the screen of a mandibular kinesiograph. Postural rest position was elicited by the subjects saying /M/ and relaxing the jaw. Closest speaking space was defined as the vertical difference in the position of the mandible from the immediate end of rapid counting from 60 to 66 to centric occlusion. The two variables were measured in random order 20 times each. The subjects were examined for two data collecting sessions. The variance of the closest speaking space was smaller than the variance for interocclusal distance for 26 of 30 subjects. The difference between the mean variances was statistically significant, p greater than 0.1 (t 3 and t 3.41, df 29).

Evaluation of temporomandibular joint sounds. Diagnostic analysis and clinical implications.

This literature review and survey highlights the controversies surrounding the significance of joint sounds in general, the problems and pitfalls of joint sound analysis and interpretation, and the degree of importance given peripheral and temporomandibular joint sounds by physicians and dentists. The instrumentation and devices currently proposed for use in the detection and interpretation of joint sounds may not meet the standards of validity, reliability, sensitivity, and specificity, and as pointed out by one investigator, "The only objectivity currently associated with these instruments is their ability to record sounds of undetermined origin." In addition, no solid evidence is available that these particular sounds, when detected, are both repeatable over time and distinctly characteristic for particular disorders or significant pathologic changes. Some degree of caution should be used, therefore, when interpreting joint sounds in the absence of significant signs and symptoms of temporomandibular disorders. The clinical significance of these same sounds may become more or less apparent relative to the information obtained in a comprehensive temporomandibular disorder evaluation and examination including both subjective and objective pain assessments, mandibular range of motion measurements, and the interpretation of radiologic findings.