Charles McNeill

Management of temporomandibular disorders: Concepts and controversies

STATEMENT OF PROBLEM Controversy continues in the area of epidemiology, etiology, diagnosis, and management of temporomandibular disorders (TMD). The field is replete with testimonials and clinical opinion, but it has been lacking in scientific foundation. PURPOSE This article reviews the recent temporomandibular disorder and orofacial pain literature and summarizes the concepts published in the 1993 and 1996 American Academy of Orofacial Pain guidelines. Temporomandibular disorders rarely occur as single entities but rather as multiple problems with overlapping symptoms. CLINICAL SIGNIFICANCE The multicausal nature of these problems and the number of conditions with similar signs and symptoms demand an effective differential diagnostic process. Diagnostic criteria are used from an operational standpoint to establish specific diagnoses based on a multiaxial diagnostic model. CONCLUSION Because little is known about the natural course of the various classifications of temporomandibular disorders, and because most treatment approaches are reported to be equally effective, a conservative, noninvasive management program is endorsed. The emphasis is on a medical multidisciplinary model similar to ones used for other musculoskeletal disorders that involve the patient in the physical and behavioral management of his or her own problem. This article concludes that a majority of temporomandibular disorder patients achieve good relief of symptoms with noninvasive reversible therapy.

History and evolution of TMD concepts.

Historically the field of temporomandibular disorders (TMD) has been based on testimonials, clinical opinion, and blind faith rather than on science. Reparative procedures to the joints, jaws, or occlusal surfaces of the teeth to develop idealized structural relationships that may be required for dental health and function are less likely to be required for the management of chronic musculoskeletal disorders. Because of the concerns of many people today regarding professional credibility and intellectual honesty, the need for a scientific foundation to support the various belief systems is of paramount importance. In fact, therapeutic approaches for TMD are undergoing a major evolution away from the traditional mechanistic dental concepts of the past to the more current biopsychosocial medical concepts that emphasize multidisciplinary approaches. Recent advances in the understanding of pain mechanisms and management of chronic pain have improved long-term treatment outcome. The emphasis is on treatment that involves the patient in the physical and behavioral management of their own problem. The majority of patients with TMD achieve good relief of their symptoms with noninvasive, conservative therapy.

Reproducibility of Visual Analog Scale (VAS) Pain Scores to Mechanical Pressure

Abstract This study tested the reproducibility of visual analog scale (VAS) pain scores to measure changes in masseter muscle pain evoked by maximally tolerable mechanical stimulation over a short time period in healthy subjects. This study also evaluated gender differences in reproducibility of VAS scores to mechanical stimulation. Ten healthy female and eight healthy male individuals participated in this study. The recordings of VAS pain scores to an identical mechanical pressure on the masseter muscle were performed at three different sessions (T1, T2, and T3). The subjects rated their pain on a VAS to a maximally tolerable stimulus that was recorded on an algometer at the first session. The algometer pressure reading was recorded for each subject and then used to duplicate the same identical mechanical stimulus at each of the three sessions. This identical pressure was repeated in the same marked spot at six minutes and after 30 minutes. The subjects rated the pain on a VAS to this identical stimulus at each session. There was no significant difference in VAS pain scores of all subjects at T1, T2, and T3. There was no significant difference in reproducibility of VAS pain scores in females compared to males. Intraclass correlation coefficients were 0.811 on the right masseter and 0.844 on the left masseter. VAS pain scores to mechanical stimulation were reproducible over a short time period. Gender did not affect the reproducibility. This previously unreported method of measuring pain to repeated identical mechanical stimulation appears to have potential for both clinical and research application.

Comparison of Subjective Symptoms of Temporomandibular Disorders in Young Patients by Age and Gender

Abstract The authors assessed the subjective symptoms of temporomandibular disorders (TMDs) in 167 young patients using self-reported forms, with five ratings for pain intensity and six ratings for difficulty in activities of daily living (ADL), to compare TMD symptoms according to gender and three age groups: group 1: 6- to 12-year-olds (juvenile); group 2: 13- to 15-year-olds (early adolescent); group 3: 16- to 18-year-olds (late adolescent). No significant gender differences were found in the symptoms among the groups, except for headache and neck pain in group 3. Pain intensity and tightness in the jaw/face, headache, and neck pain, as well as the ADL-related difficulty in prolonged jaw opening, eating soft/hard foods, and sleeping significantly differed among the groups (p<0.01, Kruskal–Wallis test). Therefore, late adolescent patients with TMDs have higher pain intensity in the orofacial region and greater difficulty in ADL than do early adolescent and juvenile patients with TMDs.

The assessment of trapezius muscle symptoms of patients with temporomandibular disorders by the use of liquid crystal thermography.

OBJECTIVE To test the hypothesis that neuromuscular symptoms of patients with temporomandibular disorders that occur in the upper back and neck can be evaluated by recording the temperature patterns in the skin overlying the muscles. STUDY DESIGN Liquid crystal contact thermography was evaluated on patients with temporomandibular disorders to demonstrate temperature changes in the muscles of the neck and upper back. The study consisted of 22 patients with temporomandibular disorders and 22 normal controls. RESULTS The mean right-versus-left-side temperature difference of the control group was 0.13 degree C whereas the patient group showed a difference of 0.78 degree C. Of the 22 patients with temporomandibular disorders, 21 (95.5%) showed an increased temperature over the trapezius muscle on the symptomatic side. CONCLUSIONS These findings indicate that thermography may be useful in the diagnosis of myofascial symptoms that may be associated with temporomandibular disorders.

Comparison of patients with orofacial pain of different diagnostic categories.

Abstract The authors compared the pain intensity and difficulty experienced in performing activities of daily living (ADL) among 237 patients with orofacial pain. The patients underwent comprehensive examinations and recorded their subjective symptoms on a form (five items for pain intensity and six for ADL-related difficulty). On the basis of the primary diagnosis, the patients were divided into the temporomandibular joint dysfunction (TMJ), myofascial pain (MP), neuropathic pain (NP), and fibromyalgia (FM) groups. The intensity of pain in the jaw/face, tightness in the jaw/face, pain in the neck, and toothache significantly differed among the groups (p<0.01, Kruskal-Wallis test). Compared to other patients, the FM and NP groups reported greater pain intensity, whereas those in the TMJ group reported lesser pain intensity. The ADL-related difficulty was not significantly different among the groups. Thus, compared to pain due to joint-related disorders, myalgic and neuropathic pain seem to be of higher intensity.

Comparison of subjective symptoms among three diagnostic subgroups of adolescents with temporomandibular disorders.

AIM To compare subjective symptoms among three diagnostic subgroups of young patients with temporomandibular disorders (TMDs). DESIGN We comprehensively examined 121 patients with TMDs (age ≤20 years; 90 female patients and 31 male patients) who completed self-reported forms for assessing subjective symptoms, which consisted of five items on pain intensity in the orofacial region and six items on the level of difficulty in activities of daily living (ADL) (rating scale, 0-10). They were divided into three diagnostic subgroups: temporomandibular joint (TMJ) problem (JT) group, masticatory muscle pain (MM) group, and the group with a combination of TMJ problems and masticatory muscle pain (JM group). Their symptoms were compared using the Kruskal-Wallis and Mann-Whitney U-tests. RESULTS The intensity of jaw or face tightness and difficulty in talking and yawning were not significantly different among the groups. However, the MM and JM groups had a significantly higher rating for jaw or face pain, headache, neck pain, tooth pain, and difficulty in eating soft foods (P < 0.01). CONCLUSIONS Young patients with MM or JM report more intense pain in the orofacial region and have more difficulties in ADL than those with JT problems alone.