Journal of Oral & Facial Pain and Headache, 04/1996

Seventeen patients with neuropathic orofacial pain are presented with reference to precipitating events, pain descriptions, response to treatment, and other aspects of their histories and clinical presentation. Stellate ganglion blocks were done on 14 patients. Ten of 14 patients reported temporary relief of pain with stellate ganglion blocks. Five of these patients noted more prolonged improvement in pain, two reported no change, and two experienced a temporary increase in pain. It is argued that sympathetically maintained pain involving orofacial locat ons does occur and that stellate ganglion blocks may benefit a subgroup of these patients. It is noted that current diagnostic categories are inadequate to describe a subgroup of these patients. New categories are suggested, and further study is recommended.

The analgesic properties of salmon calcitonin for the treatment of atypical facial pain (AFP) were investigated. An initial open-label trial of salmon calcitonin in subjects with refractory AFP was follwed with a randomized, double-blind, placebo-controlled crossover trial of salmon calcitonin in the management of AFP. Salmon calcitonin (100 IU in 1 mL saline) was administered in an open-label fashion to 13 subjects with refractory AFP five times per week for 6 weeks. In the subsequent randomized investigation, salmon calcitonin (100 IU in 1 mL saline) or placebo (1 mL saline) was delivered three times per week for 3 weeks, with a 1-week washout prior to crossover. The percentage of subjects dropping ot (57%) exceeded that reported in other pain studies using calcitonin. Tgherefore, it was imperative to halt the study for ethical reasons. There was no difference in outcome measures (P > .05) in subjects administered either active drug or placebo, and a high incidence of side effects led to dropout in subjects taking salmon calcitonin. Although salmon calcitonin may have analgesic properties, it is not efficacious for AFP, largely because of the side effects.

Although there are reasons to believe that temporomandibular disorders and other facial pain conditions would have a major impact on the quality of patients' lives, only a small number of studies have attempted to address this in a systematic way. In this study, data on pain and its consequences were assessed for 121 patients making their first visit to a craniofacial pain research unit. The extent to which musculoskeletal and neurologically based facial pain compromised the quality of life was measured using the Oral Health Impact Profile, a recently developed index of the functional and psychosocial outcomes of oral conditions. The data indicated that facial pain had a substantial impact on daily life and that its most common outcomes were psychologic. When compared with a nonpain population, the extent of this impact was striking. There was a four-fold increase in functional problems such as difficulty chewing foods and a nine-fold increase in reports of depression. As anticipated, scores on the Oral Health Impact Profile were associated with the characteristics of the pain and diagnostic subgroups.

Pain-pressure thresholds are routinely used in orofacial pain research to record tenderness in masticatory muscles. This method is employed to stimulate deep tissue afferents, which are thought to be at least partially responsible for pain in temporomandibular disorders. Like other psychophysical measurements, however, this technique must stimulate cutaneous tissues before stimulating deeper tissues. This study examined 39 asymptomatic volunteers to quantify the effect of cutaneous sensory afferents on pain-pressure thresholds. In a randomized, double-blind fashion, pain-pressure thresholds were recorded at four facial sites fore and after subjects received intradermal local anesthetic or a dry needle stick. Pain-pressure thresholds were significantly elevated after local anesthetic (P .0001), suggesting that cutaneous tissues contribute significantly to the pain-pressure threshold. The authors discuss potentially important roles of cutaneous tissues in the assessment of deeper tissues and offer two theories of how the skin may be an important link in the assessment of temporomandibular disorders.

The hypothesis of this short-term study was that repeated episodes of clenching at submaximal bite force levels can induce a progressive increase in pain and tenderness in masticatory muscles. On each day for 5 consecutive days, 10 women clenched on a bite force transducer for 15 minutes at 25% of their maximal bite force. The development of pain, tenderness, and unpleasantness in the masticatory muscles was evaluated with use of 10-cm visual analog scales (VAS) and the McGill Pain Questionnaire (MPQ), Pain detection thresholds (PDT) and pain tolderance thresholds (PTT) to percutaneous pressure stimuli were measured in the masseter and anterior temporalis muscles. Maximal voluntary bite force to brief clenches were assessed. The results showed moderate levels of pain (mean ± SE; 5.3 ± 1.0), tenderness (5.2 ± 1.0), unpleasantness (5.8 ± 0.8), and MPQ scores (16.4 ± 4.9) immediately after the submaximal clenching task on the first day. The following days, the clenching tasks did not increase these scores; in contrast, there were significant decreases on day 5 in both pain intensity (-49.8% ± 14.6%), tenderness (-46.1% ± 14.2%), unpleasantness (-50.4% ± 8.5%), and MPQ scores (-45.8% ± 13.3%) (P .05) when compared to day 1. The clenching procedure failed to induce a progressive increase in pain and tenderness in the masticatory muscles during 5 days. None of the evaluated parameters from this study suggested the start of a vicious cycle.

A visual analog pain scale and scalar responses to 13 pain/symptom indicator Symptom Checklist-90-Revised (SCL-90-R) questions were used to assess symptom prevalence and pain severity in 43 chronic orofacial muscle pain patients and 40 control subjects. The orofacial muscle pain group reported pain in an axial skeletal distribution; neurocognitive, gastrogenitourinary, and musculoskeletal symptoms; infectious events at or preceding onset; similar symptoms in sexual partners; and low prevalence of trauma. Sudden onset was reported by 30.2% of pain patients. Strong associations were found between chronic orofacial muscle pain and (1) onset-related infectiouslike events (67.4%); (2) a higher prevalence of history of respiratory and gastrogenitourinary infectious events; and (3) high prevalences of similar pain symptoms in long-term sexual partners. The sCL-90-R somatization scores (> 62) had a higher prevalence in the chronic pain group. No prevalence differences or associations with pain/symptom indicators were found for depression or anxiety dimension scores. These data suggest that patients with recurrent systemic infectious events have a higher prevalence of reporting of chronic orofacial muscle pain compared with control subjects, and these infectious events are associated with the onset of chronic orofacial muscle pain in 67% of patient

The simultaneous contribution of 11 occlusal factors, dental attrition severity, orthodontic history, trauma (motor vehicle accident [MVA] and non-MVA), and age in defining two independent large populations of females diagnosed with five mutually exclusive temporomandibular disorders was tested through multiple step-wise logistic regression analysis. Non-MVA trauma was significant in both groups in defining disc displacement (DD) with and without reduction, and osteoarthrosis (OA) (both primary and following DD). Anterior open bite was also a significant factor in defining OA in both groups. Much smaller contributions were also made by missing teeth in one of the populations with OA following DD, and by retruded contact position-intercuspal position slide lengths and overjet in one of the primary OA populations. Motor vehicle accident trauma was significant in defining myofascial pain (MP) in both populations, and laterotrusive attition mildly defined MP in one population. Only a minority of total variance was explained: 6% to 8% of DD with reduction; 10% to 14% of DD without reduction; 11% to 20% of OA following DD; 17% to 38% of primary OA; and 4% to 10% of MP. Non-MVA trauma was the major defining feature of the temporomandibular joint intracapsular disorders, and MVA trauma explained a very small percentage of the MP patients. Implications are discussed and recommendations are made for future research.

The rate of abrasion of dental surfaces during short periods of time is difficult to measure clinically, but one quantifiable method is the use of the Bruxcore bruxism monitoring device. The aim of this study was to estimate the interobserver and intraobserver variation in the Bruxcore system using different reading methods. Fifteen volunteers used individually fabricated Bruxcore devices during 4 consecutive nights, and this procedure was repeated after 6 weeks. The abraded areas of the 30 Bruxcore devices were measured by two observers on two occasions and with three methods: microscope without a reference scale; microscope with a reference scale; and a computer-aided system. Intraobserver variation was small (5%), but interobserver variation was statistically significant for all three methods. The computer-aided system was superior to the other two methods. The interaction between Bruxcore values and observers was statistically significant for the microscope methods but not for the computer method. This was a desired property, indicating stability of the computer-aided method over the range of Bruxcore values observed. Small measurement errors, independent of the size of the measurements, can be expected using a trained observer and a computer-aided method for reading the Bruxcore bruxism monitoring device.