Greg Goddard

Chronic myofascial temporomandibular pain is associated with neural abnormalities in the trigeminal and limbic systems

&NA; Myofascial pain of the temporomandibular region (M‐TMD) is a common, but poorly understood chronic disorder. It is unknown whether the condition is a peripheral problem, or a disorder of the central nervous system (CNS). To investigate possible CNS substrates of M‐TMD, we compared the brain morphology of 15 women with M‐TMD to that of 15 age‐ and gender‐matched healthy controls. High‐resolution structural brain and brainstem scans were carried out using magnetic resonance imaging (MRI), and data were analyzed using a voxel‐based morphometry approach. The M‐TMD group evidenced decreased or increased gray matter volume compared to controls in several areas of the trigeminothalamocortical pathway, including brainstem trigeminal sensory nuclei, the thalamus, and the primary somatosensory cortex. In addition, M‐TMD individuals showed increased gray matter volume compared to controls in limbic regions such as the posterior putamen, globus pallidus, and anterior insula. Within the M‐TMD group, jaw pain, pain tolerance, and pain duration were differentially associated with brain and brainstem gray matter volume. Self‐reported pain severity was associated with increased gray matter in the rostral anterior cingulate cortex and posterior cingulate. Sensitivity to pressure algometry was associated with decreased gray matter in the pons, corresponding to the trigeminal sensory nuclei. Longer pain duration was associated with greater gray matter in the posterior cingulate, hippocampus, midbrain, and cerebellum. The pattern of gray matter abnormality found in M‐TMD individuals suggests the involvement of trigeminal and limbic system dysregulation, as well as potential somatotopic reorganization in the putamen, thalamus, and somatosensory cortex.

The short-term effects of acupuncture on myofascial pain patients after clenching.

Aim:  Short‐term pain reduction from acupuncture in chronic myofascial pain subjects was evaluated using an 11‐point (0 to 10) numeric rating scale, visual analog scale (VAS), and pain rating of mechanical pressure on the masseter muscle.

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.

TMD prevalence in rural and urban Native American populations.

ABSTRACT The purpose of this study was to assess the prevalence of TMD in a consecutive sample of 102 subjects from the Native American population living in an urban setting and 90 subjects living in a rural setting. The study utilized a clinical examination and standardized questionnaires. The sample age ranged from five to 84 years of age. The subjects were asked to estimate pain frequency, severity and daily pattern of jaw pain, difficulty in opening, joint clicking, and sleeping problems. Examination was performed on joint, masticatory, and cervical muscles, as well as occlusion. Data was collected and statistically analyzed. Statistically significant differences were found; however, the only statistically significant difference that might have clinical significance was more facial pain in the urban population.

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.

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.

Case Report of Trigeminal Neuralgia Presenting as Odontalgia

A case of trigeminal neuralgia presenting as odontalgia in a 47-year-old female is described. This case shows the difficulty of making a correct diagnosis and how patients can be subjected to unnecessary treatment and continued suffering when a correct diagnosis is not made.

Articular disk displacement of TMJ due to trauma.

One hundred and thirty native American Indian patients undergoing orthodontic treatment for malocclusions were screened for temporomandibular joint (TMJ) abnormalities. These patients were followed over the course of orthodontic treatment and six of these patients suffered a traumatic injury to the TMJ. These six patients who had been previously screened and found to be asymptomatic, developed symptoms. Three were diagnosed with articular disk displacement of the TMJ confirmed by magnetic resonance imaging (MRI).

Comparison of masticatory muscle myofascial pain in patients with and without a chief complaint of headache.

Abstract Objectives: Headaches are a common complaint in temporomandibular disorder (TMD) patients. However, few studies have compared the symptom characteristics between TMD patients with and without a complaint of headache. The aim of this study was to compare subjective symptoms and treatment outcomes between myofascial TMD patients who had a chief complaint of headache and those who did not. Methods: One hundred sixty one patients underwent comprehensive examinations and scored their pre- and post-treatment symptoms on a form (4 items assessing pain intensity and 1 assessing sleeping difficulty). On the basis of the primary diagnosis, patients were divided into two groups: myofascial pain with and without a chief complaint of headache (MPH and MP). Results: Before treatment, patients in the MPH group scored significantly higher with respect to pain intensity and level of sleeping difficulty than did patients in the MP group (jaw/face pain, P  =  0·015; headache, P < 0·001; neck pain, P < 0·001, and difficulty in sleeping, P  =  0·005; Mann-Whitney U-test). Patients in the two groups demonstrated similar treatment outcomes, except for neck pain. Conclusion: Significant differences in symptom characteristics and outcomes were observed between primarily myofascial TMD patients with and without a chief complaint of headache.