Journal of Oral & Facial Pain and Headache, 03/2009

Stomatodynia (burning mouth syndrome) is characterized by a spontaneous, continuous burning pain felt in the oral mucosa typically of anxiodepressive menopausal women. Because there is no obvious organic cause, it is considered a nonspecific pain. This Focus Article proposes a hypothesis based on the following pathophysiological cascade: chronic anxiety or posttraumatic stress leads to a dysregulation of the adrenal production of steroids. One consequence is a decreased or a modified production of some major precursors for the neuroactive steroid synthesis occurring in the skin, mucosa, and nervous system. At menopause, the drastic fall of the other main precursor supply, the gonadal steroids, leads to a brisk alteration of the production of neuroactive steroids. This results in neurodegenerative alterations of small nerve fibers of the oral mucosa and/or some brain areas involved in oral somatic sensations. These neuropathic changes become irreversible and precipitate the burning pain, dysgeusia, and xerostomia associated with stomatodynia, which all involve thin nerve fibers. Keywords: adrenal steroid, burning mouth syndrome, functional pain, gonadal steroid, idiopathic orofacial pain, neuroactive steroids, neuropathic pain, stomatodynia

Aims: To investigate whether any of the pretreatment physical signs, symptoms, and responses on psychological questionnaires would predict treatment outcomes after a standardized temporomandibular disorder (TMD) treatment program. Methods: The care provided to 157 TMD patients was a short course of physical therapy, an occlusal appliance, and over-the-counter nonsteroidal anti-inflammatory drugs (OTC NSAIDs). A multidimensional outcome assessment was performed using six variables. Follow-up data were available on 81.5% of enrolled subjects and elapsed time from initial visit to the two follow-up points was 13 ± 4.7 and 33.6 ± 9.8 months, respectively. Multiple regression analyses were conducted to assess the relationship between 18 predictor variables and the six outcome variables. Results: The results showed that the combination of a higher initial visual analog scale (VAS) pain score plus a lower jaw function interference score was significantly associated with a reduction of VAS pain after treatment (P .05; adjusted R2 = 0.54). Moreover, the combination of a higher initial activity limitation score plus a lower jaw function interference score was associated with a greater reduction of the activity limitation score after treatment (P .05; adjusted R2 = 0.36). None of the other outcomes were found to relate to any of the pretreatment variables. It must be noted that no single variable was a strong predictor and the odds ratios between the above three variables and the predicted outcomes were not robust. Conclusion: The corollary of these results suggests that if a high degree of jaw function interference is present (eg, clicking, locking), then the prognosis of improvement with brief self-directed physical therapy, an occlusal appliance, and OTC NSAID is lower, at least within the time frame of this study. Keywords: multiple logistic regression analysis, physical medicine treatment, predictors, temporomandibular disorders, treatment outcome

Aims: To investigate (1) differences in heart rate variability (HRV) indices between masticatory muscle pain (MMP) patients and pain-free controls at rest, during a stressor condition, and during a post-stressor recovery period, and (2) factors including psychological distress, social environment, and family-of-origin characteristics in the MMP sample compared to a pain-free matched control sample. Methods: Physiological activation and emotional reactivity were assessed in 22 MMP patients and 23 controls during baseline, stressor, and recovery periods. Physiological activity was assessed with frequency domain HRV indices. Emotional reactivity was assessed with the Emotional Assessment Scale. Analytic strategy began with overall 2 x 3 multivariate analyses of variance on physiological data followed by focused contrasts to test specific hypotheses regarding physiological and emotional status. Hypothesized differences between study groups on psychological and social-environmental variables were compared with univariate analyses of variance. Results: The MMP patients showed physiological activation during the baseline period and significantly more physiological activation during the recovery period compared to the controls. This pattern was also present in emotional reactivity between the groups. The emotional and physiological differences between the groups across study periods were more pronounced in pain patients reporting a traumatic stressor. Conclusion: These results provide further evidence of physiological activation and emotional responding in MMP patients that differentiates them from matched pain-free controls. The use of HRV indices to measure physiological functioning quantifies the degree of sympathetic and parasympathetic activation. Study results suggest the use of these HRV indices may improve understanding of the role of excitatory and inhibitory mechanisms in patients with MMP conditions. Keywords: emotional reactivity, heart rate variability, masticatory muscle pain, orofacial pain, self-regulation

Aims: As there is a high correspondence between the experience of trauma and posttraumatic stress disorder (PTSD) symptoms among chronic orofacial pain patients, study objectives included: (1) to document the nature of traumatic experiences and severity of PTSD symptoms among a female sample of orofacial pain patients, (2) to examine the relationship between PTSD symptoms and both pain-related and psychosocial outcomes, and (3) to use structural equation modeling (SEM) to test hypotheses of mediation derived from the Mutual Maintenance Model of chronic pain and PTSD. Methods: The study design was a cross-sectional, retrospective case series of 411 female patients (mean age 41.0, SD 13.1) who were seen at the University of Kentucky Orofacial Pain Center between 1997 and 2007. A series of correlational and SEM analyses were conducted to test study hypotheses. Results: Of the total sample, 23.6% (n = 97) reported PTSD symptoms consistent with a diagnosis of PTSD. Higher PTSD symptom reports were associated significantly (P .01) with the following outcomes: symptoms of psychological and affective distress, life interference due to pain, receipt of punishing responses from one's spouse, limited activity levels, and poor sleep quality. SEM analyses indicated PTSD symptoms likely exert their influence on pain severity through depression and sleep quality. Conclusion: PTSD and depression screening as well as thorough sleep evaluations should be included in the routine assessment for orofacial pain patients and, if appropriate, referrals for treatment of PTSD symptoms should be considered part of the standard of care. Keywords: chronic pain, mutual maintenance, orofacial pain, posttraumatic stress disorder, sleep quality

Aims: To characterize and contrast human sensory and vascular changes produced by topical application of the algesic chemical capsaicin to the glabrous lips and tongue. Methods: Applications of 1% capsaicin or vehicle cream to the glabrous lips and tongue were randomized between two two-trial sessions. The capsaicin trial followed the vehicle trial for each session. Before and 5, 15, and 30 minutes after capsaicin or vehicle cream application, six parameters were recorded from the glabrous lips or the tongue dorsum: (1) burning pain intensity, as measured on a visual analog scale; (2) burning pain area, as indicated by subjects on an orofacial drawing; (3) mechanical sensitivity, as measured by a von Frey filament; (4) visual flare; (5) blood flow and temperature, as measured by laser-Doppler imaging and thermography, respectively; and (6) areas of increased temperature (hot spots), as calculated by a digital tracer from the thermographs. Data were analyzed by ANOVAs and Pearson's correlations. Results: Compared to vehicle application, capsaicin elicited burning pain, increases in blood flow and temperature, but no change in mechanical sensitivity in the glabrous lips or tongue. Greater increases in blood flow and temperature paralleled more intense burning pain and larger areas of perceived pain for the lips compared to the tongue. The location of distinct areas of increased temperature within the orofacial area differed between the capsaicin-lip and capsaicin-tongue trials. Conclusion: The several differences between these responses to noxious stimulation of the glabrous lips and tongue may have implications for examinations of orofacial somatosensory functions. Keywords: capsaicin, laser-Doppler imaging, orofacial pain, thermography

Aims: To investigate the presence of proteinase-activated receptor 2 (PAR2) in the human tooth pulp and to determine whether there are any changes in receptor expression with caries and pain. Methods: Forty-four mandibular first permanent molars were collected from children (n = 36, mean age 9.96 years ± 2.11) requiring dental extractions under general anesthesia. Teeth were categorized as either intact (n = 22) or carious (n = 22). Carious teeth were further subdivided into asymptomatic (n = 10) and painful (n = 12). The coronal pulp was removed and processed for indirect immunofluorescence by using antibodies raised against PAR2 and double labeled with either a neuronal marker (protein gene product 9.5) or both a smooth muscle cell (SMA) and endothelial (UEIL) marker, in order to examine PAR2 presence in both neuronal and vascular tissue. In addition, hemotoxylin and eosin staining was performed to identify pulpal fibroblasts. Results: PAR2 expression was found to be present in pulpal nerve fibers, vascular tissue, and pulpal fibroblasts. PAR2 neuronal expression was not affected by the presence of caries (P > .05) but was significantly less in carious painful teeth than in carious asymptomatic teeth (P .05). No changes in vascular PAR2 expression were found (P > .05); however, the number of PAR2-labeled fibroblast-like cells per mm2 was significantly greater in carious teeth (P .05). Conclusion: These findings indicate that PAR2 receptors and changes in their level of expression may have relevance and clinical importance in nociception. Keywords: caries, human tooth pulp, immunohistochemistry, pain, proteinase-activated receptor 2

This article reports a rare case of a temporomandibular joint (TMJ) chondrosarcoma in a child. Chondrosarcoma is a malignant cartilaginous neoplasm that resembles synovial chondromatosis. In the head and neck region, chondrosarcoma is uncommon, corresponding to 6.4% to 12% of all reported cases. The majority of patients with chondrosarcoma are in the third to fourth decades of life. A Pubmed search showed that 20 TMJ chondrosarcoma cases had been reported up to 2008. The present case was of an 11- year-old girl referred to an Oral Disease Center and presenting with a preauricular swelling on the right side and normal ENT evaluation. The patient was healthy. Discrete pain and mild limitation of mouth opening were observed. A panoramic radiograph as well as computed tomography (CT), ultrasound, and magnetic resonance imaging (MRI) revealed an osteolytic lesion in the right TMJ. The skull base and adjacent spaces were preserved but adjacent anatomic structures were displaced. After an incisional biopsy, the patient underwent high condylectomy. Microscopic findings showed a tumor exhibiting cartilaginous tissue proliferation with celullar pleomorphism, nuclear hyperchromasia, and mixoid changes in the matrix. The immunohistochemical analysis of the expression of Ki-67 and Cyclin B1 proteins (cellular proliferation markers) revealed a very low proliferative cell index. The 3.5 years of clinical and imaging follow-up have shown no evidence of recurrence or metastasis, but signs of myofascial disorders could be observed. It is concluded that cartilaginous lesions in the jaws must be regarded with suspicion, since benign and malignant lesions may show similar clinical features. This case emphasized the importance of interdisciplinary approaches to minimize the possibility of misdiagnosis. Keywords: chondrosarcoma, malignant neoplasm, synovial, temporomandibular joint