Jeffrey P. Okeson

Cerebral activation during thermal stimulation of patients who have burning mouth disorder: an fMRI study.

Abstract The pathophysiology of burning mouth disorder (BMD) is not clearly understood, but central neuropathic mechanisms are thought to be involved. The aim of this study was to gain insight into the pathophysiology associated with BMD by using functional magnetic resonance imaging (fMRI). Areas of brain activation following thermal stimulation of the trigeminal nerve of eight female patients with BMD (mean age 49.1 ± 10.1) were mapped using fMRI and compared with those of eight matched pain‐free volunteers (mean age 50.3 ± 12.3). Qualitative and quantitative differences in brain activation patterns between the two study groups were demonstrated. BMD patients displayed greater fractional signal changes in the right anterior cingulate cortex (BA 32/24) and bilateral precuneus than did controls (p < 0.005). The control group showed larger fractional signal changes in the bilateral thalamus, right middle frontal gyrus, right pre‐central gyrus, left lingual gyrus, and cerebellum than did the BMD patients (p < 0.005). In addition, BMD patients had less volumetric activation throughout the entire brain compared to the control group. Overall, BMD patients displayed brain activation patterns similar to those of patients with other neuropathic pain conditions and appear to process thermal painful stimulation to the trigeminal nerve qualitatively and quantitatively different than pain‐free individuals. These findings suggest that brain hypoactivity may be an important feature in the pathophysiology of BMD.

Long-term treatment of disk-interference disorders of the temporomandibular joint with anterior repositioning occlusal splints

Forty patients with three different types of symptomatic disk-interference disorders were treated with anterior repositioning splint therapy for 8 weeks. At the end of that period 80% of the patients were free of joint sound and pain. Each patients splint was then gradually modified until the patients original occlusal condition was reestablished. Each patient was then allowed to function in that position. The patients were reevaluated an average of 2 1/2 years later. Seventy-five percent of the patients had no joint pain and 66% had a return of joint sounds. Sixty-six percent of the patients did not find the need to seek additional treatment for jaw pain and dysfunction.

psychological and physiological parameters of masticatory muscle pain

&NA; The objective of this research was to identify the psychological and physiological variables that differentiate persons reporting masticatory muscle pain (MMP) from normal controls (NC). This study examined the characteristics of 35 MMP patients in comparison to 35 age‐, sex‐, and weight‐matched NCs. All subjects completed a series of standardized questionnaires prior to undergoing a laboratory evaluation consisting of a psychosocial stressor and pressure pain stimulation at multiple body sites. During the evaluation, subjects’ emotional and physiological responses (heart rate, blood pressure, respiration, skin temperature, and muscle activity) were monitored. Results indicated that persons with MMP reported greater fatigue, disturbed sleep, depression, anxiety, menstrual symptoms, and less self‐deception (P’s<0.05) than matched controls. At rest, MMPs had lower end tidal carbon dioxide levels (P<0.04) and lower diastolic blood pressures than the NCs (P<0.02). During laboratory challenge, both groups responded to the standard stressor with significant physiological activity and emotional responding consistent with an acute stress response (P<0.01), but there were no differences between the MMPs and NCs. Muscle pain patients reported lower pressure pain thresholds than did NCs at the right/left masseter and right temporalis sites (P’s<0.05); there were no differences in pressure pain thresholds between MMPs and NCs for the left temporalis (P<0.07) and right/left middle finger sites (P’s>0.93). These results are discussed in terms of the psychological and physiological processes that may account for the development of muscle pain in the masticatory system.

Current terminology and diagnostic classification schemes

This article reviews the current terminology and classification schemes available for temporomandibular disorders. The origin of each term is presented, and the classification schemes that have been offered for temporomandibular disorders are briefly reviewed. Several important classifications are presented in more detail, with mention of advantages and disadvantages. Final recommendations are provided for future direction in the area of classification schemes.

Differential Diagnosis of Temporomandibular Disorders and Other Orofacial Pain Disorders

There are many types of pain conditions that are felt in the orofacial structures. Most of the conditions treated by the dentist are associated with the teeth, periodontal structures, and associated mucosal tissues. This article focuses on the differential diagnosis of other common pain conditions the dentist will likely face, such as temporomandibular disorders, neuropathic pain disorders, and common headaches; and the clinical presentation of each. Controlling or reducing pain can be accomplished by controlling perpetuating factors such as parafunctional habits and by some simple behavioral modifications. Finally, this article offers some simple treatment considerations.

Psychological and sleep quality differences between chronic daily headache and temporomandibular disorders patients

The aim of this study was to investigate whether chronic daily headache (CDH) and temporomandibular disorders (TMD) patients present with different psychological and sleep quality characteristics. Sixty-seven patients diagnosed with CDH, according to classification criteria from Silberstein et al., were matched by age and sex with 67 patients who had a primary diagnosis of myofascial pain (MP) and 67 patients with a primary diagnosis of TMJ intracapsular pain (IC) according to the Research Diagnostic Criteria for TMD. The CDH group was comprised of three mutually exclusive diagnostic groups: chronic migraine (n = 35); chronic tension-type headache (n = 26); ‘other CDH’ (n = 6). All patients completed a battery of psychological and sleep quality questionnaires. All CDH subgroups showed similar psychological and sleep quality profiles. Pain intensity and duration were controlled in the multivariate analyses (MANCOVA) by treating them as covariates. The CDH and MP groups revealed higher levels of psychological distress than the IC group on most psychological domains. The MP group also revealed numerically higher levels of psychological distress in most psychological domains than the CDH group, although these differences were generally not significant. We did not find significant differences between the three groups on post traumatic stress symptoms either. Sleep quality was significantly worse in the MP group than in the CDH and IC groups. These results are discussed in the context of multimodal patient evaluation and treatments that are often necessary for successful clinical management.

Craniomandibular disorders and headaches

Three hundred patients were questioned regarding frequency of headache pain. One hundred forty-one patients were seeking treatment at the University of Kentucky College of Dentistry TMJ Clinic for CMD. A comparison group of 159 was selected from persons being screened for routine dental needs. The following findings regarding incidence and frequency of headache pain were observed: 1. The incidence of headache pain was twice as high in the CMD group than in the comparison group (p less than .001). 2. Of the persons in each group reporting the occurrence of headaches, the frequency of headaches in the CMD group was significantly higher (44%) than in the comparison group (p less than .001). Thirty-three patients with headache pain were treated for a 4-week period with occlusal splint therapy. Patients were questioned regarding the number of headaches per week they had before and after occlusal splint therapy. The following results were observed: 1. Twenty-one (63.6%) patients showed a decrease in the frequency of their headaches. 2. Ten (30.3%) patients showed complete remission of headaches. 3. No patient showed an increase in the frequency of headaches. 4. As a group the average number of headaches per week before treatment was 5.06; after occlusal splint therapy the average number of headaches per week was 2.15 (p less than .001).

The classification of orofacial pains.

This article highlights the process of making the proper orofacial pain diagnosis. A classification is presented based on the clinical characteristics of the pain complaint and the structure by which it emanates. It is meant to serve as a road map for the clinician, which will help him or her establish the correct diagnosis, thereby allowing the selection of the proper treatment.

Reduction of pain and EMG activity in the masseter region by trapezius trigger point injection

In this open, uncontrolled trial, 20 patients with upper trapezius muscle trigger point pain and ipsilateral masseter muscle pain received a single trigger point injection of 2% lidocaine solution (without epinephrine) in the upper trapezius muscle. Following the trapezius injection, there was a significant (P < 0.001) reduction in pain intensity ratings for pain in the masseter region. In addition, there was a significant (P < 0.03) reduction in EMG activity in the masseter muscle. Overall, however, a significant relationship between EMG activity in the masseter and the self-report of pain was not found with the present data set. These clinical findings support the contention that sources of deep pain can produce heterotopic sensory and motor changes in distant anatomical regions.

Oromandibular dystonia revisited: a review and a unique case.

Oromandibular dystonia (OD) is a focal dystonia whereby repetitive or sustained spasms of the masticatory, facial, or lingual muscles result in involuntary, and possibly painful jaw opening, closing, deflecting, retruding, or a combination of the above. 1-3,4 There have been numerous publications since the French neurologist Henry Meige published this condition in 1910. Nevertheless, OD is often misdiagnosed and subsequently patients are managed incorrectly by dentists. The diagnosis of dystonia and the distinction between the different focal types are purely clinical and can be affected by several factors, including the circumstances of the examination, the psychologic status of the patient, and the attitude of the observer. The diagnosis of OD may well challenge 6 the astute clinician. This is primarily due to the numerous forms and severities in the presentation of OD. In particular, the diagnosis is elusive in selected patients with unrecognized triggers, presenting during periods of quiescence. There is an absence of a gold standard (a diagnostic test or biomarker) for validity of the diagnosis, and therefore the different types of focal dystonia cannot be assessed. 8 Misdiagnosis commonly includes temporomandibular disorders (TMD) such as bruxism or spontaneous condylar disloca tion, hemimasticatory or hemifacial spasms, 13