Hans Jürgen Schindler - Occlusal Splints for Painful Craniomandibular Dysfunction

Diagnoses and Classifications

To address the lack of standardized diagnostic and classificatory criteria for differentiating myoarthropathies, internationally renowned experts presented a new system of diagnosis and classification in 1992 16 that, despite some shortcomings, quickly gained a high degree of international recognition. The name of the system—Research Diagnostic Criteria for Temporomandibular Disorders, RDC/TMD for short—indicates that it was originally developed for clinical trials for research purposes. However, it was soon applied in daily practice, often in a less strict form. RDC/TMD enables diagnostic measures and diagnoses to be standardized in a field previously characterized by inaccurate information and systems that were not comparable to each other. In 2014, the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) were published as a further refinement. 17 In both systems, diagnostics and classification are spread over two areas, which are designated as Axis I and Axis II.

Axis I

Axis I covers the somatic diagnoses ( Table 1-1). These are based on information provided by the patient who is consulting a dentist with symptoms affecting the masticatory system and on the results of the clinical examination. The results of a clinical examination are not sufficient to make the somatic diagnoses. What is more decisive is what the patient tells the dentist when complaining of pain, limited mouth opening, or loud noises in the TMJs. The DC/TMD, like the RDC/TMD, distinguishes between pain-related and pain-unrelated diagnoses that arise during the assessment of a patient.

Table 1-1 Somatic diagnoses of the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) and the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD), which are not compatible with each other

However, as the category-based diagnoses have no implications for therapy, it is usually sufficient in working practice to make the following diagnostic distinctions:

Myalgia (of the relevant muscle or muscles)

Arthralgia (of one or both TMJs)

(Anterior) position (displacement) of the articular disc (with or without reduction)

Limitation of the mandibular range of movement (maximum mouth opening)

It should be stressed that a patient who, for instance, exhibits tender masseter muscles on palpation of masticatory muscles during a routine functional assessment but finds that the muscles never hurt during daily functioning would not be given a diagnosis of “myalgia of both masseters” but merely “sensitivity on palpation of both masseters.”

Axis II

Axis II comprises (mostly pain-related) psychosocial parameters, such as depression, anxiety, distress, negative stress management strategies, tendency to somatization, catastrophizing, and impairment in activities of daily living. It is currently regarded as the diagnostic standard to take into account the patient’s pain-associated psychosocial well-being. To do this, it is helpful to use validated filtered questionnaires (see chapter 2). The psychosocial findings, like the somatic diagnoses, have direct and distinctive implications for treatment.

Diagnostics

History taking

Taking a CMD-related history forms the essential basis of the diagnostic process. It is a self-contained dental service and is regarded as more important than the subsequent clinical examination of the patient. 18 History taking consists of a medical interview tailored to the particular case history of a patient. To standardize patient details, it is also advisable to use validated filtered questionnaires for assessing the psychosocial impairment of patients suffering from pain.

Immediately before first contact with the treating clinician, it is a good idea for (potential) CMD patients to complete a questionnaire about any functional impairments in their masticatory system; this also contains questions about nonpainful findings. For most patients, however, pain plays an important, if not the major, role. The official definition of pain from the International Association for the Study of Pain (IASP) is “an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage.” 19

The subsequent discussion of a patient’s pain history picks up relevant answers in the questionnaire and should cover the following areas:

Main complaints

Localization of the pain

Onset of the pain

Duration of the pain

Frequency of the pain

Quality of the pain

Intensity of the pain

Factors influencing the pain

Accompanying symptoms

Previous treatments

Patient’s expectation of treatment

Patients should also be asked about psychosocial stress factors before and at the time their pain starts. An appropriate way of assessing the degree of emotional stress is to approach the matter via an “imaginary third person,” which often makes it easier for patients to cope with the conversation taking an unexpected turn. For instance, the dentist might say: “A lot of patients who have the same kind of symptoms say that … Is that your experience as well?”

The use of other diagnostic record forms, which patients complete in the dental practice or at home before or after their first dentist-patient contact, is suitable for diagnosing patients with persistent orofacial pain. Pains of this kind are not long-lasting acute pains, but they obey their own rules, which is why more intensive diagnostic investigation is required.

The following tools have proved valuable:

Pain questionnaire

Graded Chronic Pain Scale (GCPS) 20

Depression anxiety stress scales (eg, the German DASS 21 )

It is particularly important to ask patients about any pains that are localized outside the facial area. Patients who consult their dentist will not normally mention pain occurring outside the jaw region unless they are asked. However, recognition of localized pain or widespread pain makes a big difference to the treatment strategy as well as the prognosis. Patients can even be given this part of the form to complete before the first consultation. To help them record any such pain, the questionnaire includes the outlines of a human figure seen from the front, back, and both sides. Patients are asked to mark all the topographic regions in which they typically experience pain. The result from a clinical point of view is that the pain drawings often provide more information than that obtained from panoramic radiographs in CMD patients. If anything, there is a risk with imaging that normal variations are erroneously interpreted as being linked to clinical signs and symptoms.

A pain history enables a working diagnosis to be made, which is confirmed in many cases during the subsequent examination, but it may also be modified to some extent.