Journal of Oral & Facial Pain and Headache, 03/2005

Aims: To describe the course of reported musculoskeletal pain in the temporomandibular region and other signs and symptoms of temporomandibular disorders (TMD) as well as psychological distress over the course of pregnancy and 1 year postpartum. Methods: Women with musculoskeletal orofacial pain (n = 19) and pain-free comparison subjects (n = 16) in the first trimester of pregnancy were selected through records review from the population of a large health maintenance organization. Subjects completed a self-administered questionnaire assessing pain, depression, and somatic symptoms; provided a sample of whole unstimulated saliva; and underwent a standardized clinical examination during the third, sixth, and ninth months of pregnancy and 1 year postpartum. Results: At baseline (third month of pregnancy), 16 of the 19 patients with musculoskeletal orofacial pain met criteria for an RDC/TMD diagnosis. Reported musculoskeletal orofacial pain diminished significantly during the second or third trimester of pregnancy and increased again postpartum. Measures of mandibular opening increased over pregnancy in both cases and comparison subjects and remained high postpartum. Depression and somatic symptoms changed little over the course of pregnancy but were substantially lowered at 1 year postpartum for both groups. As expected, subjects with pain had higher levels of palpation pain, diminished mandibular range of motion, and higher levels of psychological distress compared to subjects without orofacial pain. Conclusion: Musculoskeletal orofacial pain and related symptoms appear to improve over the course of pregnancy. This improvement occurs in the presence of increased joint laxity and is not paralleled by improvements in psychological distress. Thus, it was concluded that the improvement in pain is most likely associated with the dramatic hormonal changes occurring during pregnancy. Keywords: hormones, pain, pregnancy, psychological distress, temporomandibular disorders

Aims: To investigate the responses of the hypothalamus-pituitary-adrenocortical and sympathetic-adrenal-medullary systems to experimentally induced psychological stress in patients with myofascial pain. Methods: To characterize the features of these systems, temporal variations in plasma cortisol, adrenaline, and noradrenaline concentrations in response to psychological stress were measured in 20 patients with myofascial pain and in 20 healthy controls. Results: The concentrations of plasma cortisol, adrenaline, and noradrenaline in response to psychological stress were significantly higher in the pain patients than in the healthy controls. Furthermore, although the plasma cortisol, adrenaline, and noradrenaline concentrations were significantly increased from the basal levels in both groups, the rate of recovery from these levels was significantly slower in patients than in healthy controls. Conclusion: These results suggest that both the sympathetic-adrenal-medullary and hypothalamic-pituitary-adrenocortical systems are more highly activated in response to psychological stress in patients with myofascial pain than in healthy individuals. Keywords: myofascial pain, psychological stress, cortisol, adrenaline, noradrenaline

Aims: To evaluate whether smoking influences the presence and/or development of signs and symptoms of temporomandibular disorders (TMD) among adults. Methods: A random sample of subjects 35, 50, and 65 years of age was drawn from the general population and examined with the aid of a questionnaire and a clinical examination. Within the sample, smokers were identified based on reported current smoking and nonsmokers were matched to the smokers based on age, gender, educational level, area of residence, and number of teeth. In total, 268 subjects were matched (134 pairs). Six years after the baseline examination, 122 matched pairs were re-examined. Results: Mild symptoms of TMD were reported by approximately 30% of the sample both at baseline and at the follow-up examination 6 years later. Pain in the jaws and/or more severe symptoms of TMD were reported by approximately 15% on both occasions. No significant differences between smokers and nonsmokers were found regarding symptoms of TMD. In both examinations, mild signs (dysfunction index I) were found in approximately 40% of the sample and moderate to severe signs (dysfunction index II to III) in approximately 20%; no statistically significant differences were found between smokers and nonsmokers. No significant differences were found between smokers and nonsmokers regarding the course of symptoms or signs of TMD during the study period. Conclusion: Smoking is not a factor related to the presence or development of signs and symptoms of TMD. Keywords: bruxism, epidemiology, headaches, orofacial pain, smoking, tobacco

Aims: Since occlusal variables such as overbite and overjet have been thought to be associated with temporomandibular disorders (TMD), and joint sounds are some of the most prevalent signs of TMD, the aim of this study was to determine whether overbite and overjet are risk factors for temporomandibular joint (TMJ) sounds. Methods: A population-based cross-sectional study of 3,033 subjects (age range, 10 to 75 years; 53% female) was conducted in Germany. Overbite/overjet, reproducible reciprocal clicking (RRC) during open-close jaw movements that did not occur in the protrusive jaw position, and joint crepitus were assessed according to the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD). Results: When age and gender were controlled for, high or low values of overbite and overjet were not associated with a greater risk of RRC and crepitus as compared to a reference category of a normal overbite and overjet of 2 to 3 mm (multiple logistic regression; odds ratios 0.7 to 1.3; P > .05 for all). Conclusion: This study showed that higher or lower overbite or overjet jaw relationships, even extreme values, are not risk factors for TMJ sounds as assessed by clinical examination. Keywords: crepitus, disc displacement, overbite, overjet, temporomandibular disorders

Aims: To examine whether any signs and symptoms of temporomandibular disorders were significantly associated with masseter muscle activity levels during sleep. Methods: One hundred three healthy adult subjects (age range, 22 to 32 years) participated in the study. They were asked to fill out questionnaires, undergo a calibrated clinical examination of their jaws and teeth, and perform 6 consecutive nightly masseter electromyographic (EMG) recordings with a portable EMG recording system in their home. The EMG data were considered dependent variables, while the questionnaire and examination data were considered independent variables. Multiple stepwise linear regression analysis was utilized to assess possible associations between these variables. Results: Both gender and joint sound scores were significantly related to the duration of EMG activity. None of the other independent variables were found to be related to any of the muscle activity variables. Conclusion: The results suggest that both gender and clicking are significantly related to duration of masseter EMG activity during sleep. Keywords: bruxism, electromyography, joint clicking, masseter muscle, temporomandibular disorders

Aims: To evaluate a newly developed semi-automatic computerbased method to analyze the objectivity of the Bruxcore Bruxism-Monitoring Device (BBMD) by assessing the interrater reliability. The capability of the BBMD to differentiate between sleep bruxers (SB) and healthy controls was also verified by estimating the sensitivity, specificity, and predictive values. Methods: Forty-eight SB and 21 controls took part in this investigation. After a detailed clinical dental examination, each participant received a BBMD to be worn for 5 consecutive nights. The BBMDs were then scanned and rated by 2 independent examiners using the new method, which counted the abraded area in pixels. Interrater reliability was assessed by intraclass correlation coefficient (ICC) analyses. Results: The analyses showed a very high interrater reliability of ICC = 0.99, and comparison of the mean pixel scores revealed values that were approximately 8 times higher for the SB than for the controls. With a selected pixel score cutoff point of 2900, a sensitivity of 79.2% and a specificity of 95.2% were found. The clinical diagnosis was correctly predicted in 97.4% of the SB and 66.7% of the controls. Conclusion: The results support the assumption that the newly developed analyzing method for the assessment of the BBMD is a clinically suitable, objective, and applicable method that seems to be able to differentiate between SB and a healthy control sample. These data, however, need to be confirmed in further investigations using polysomnographic recordings. Keywords: abrasion, clinical assessment, reliability, sleep bruxism

Aims: To use the human blink reflex (BR) to explore possible neuropathic pain mechanisms in patients with atypical odontalgia (AO). Methods: In 13 AO patients, the BR was elicited using a concentric electrode and recorded bilaterally with surface electromyographic (EMG) electrodes on both orbicularis oculi muscles. Electrical stimuli were applied to the skin above branches of the V1, V2, and V3 nerves and to the V branch contralateral to the painful branch. Sensory and pain thresholds were determined. The BR examination of the painful V branch was repeated during a capsaicin pain-provocation test. The data were analyzed with nonparametric statistics. Results: The BR responses (R2 and R3) evoked by stimulation of V3 were significantly smaller than the BR responses evoked by stimulation of V1 and V2 (P .004). There were no differences in BR (R2 or R3) between the painful and nonpainful sides (P > .569), and the BR (R2 and R3) was not significantly modulated by experimental pain (P > .080). The sensory thresholds were significantly lower on the painful side compared to the nonpainful side (P = .014). The pain thresholds were not different between sides (P > .910). Conclusion: No major differences between the V nociceptive pathways on the right and left sides were found in a relatively small group of AO patients. Future studies that compare BRs in AO patients and healthy volunteers are needed to provide further knowledge on the pain mechanisms in AO. Keywords: atypical odontalgia, blink reflex, capsaicin, pain, trigeminal nociception

Aims: To investigate the presence of vanilloid receptor 1 (TRPV1) in human dental pulp and to correlate any expression with caries and pain. Methods: Permanent mandibular first molars were collected and categorized as intact or grossly carious. Grossly carious teeth were further categorized as carious asymptomatic or carious painful samples. Coronal pulps were removed and processed for indirect immunofluorescence using antibodies raised against TRPV1 and a neuronal marker, either protein gene product 9.5 or alpha-smooth muscle actin, in conjunction with Ulex europaeus agglutinin 1 lectin to fully label the pulp vasculature. Results: Analysis revealed that TRPV1 labeling was not confined to pulpal nerve fibers. TRPV1 was also consistently expressed within pulp microvasculature. Expression of neuronal TRPV1 was significantly increased throughout the pulp in grossly carious samples (P .05). No significant differences were found between carious asymptomatic and carious painful samples. A significant increase in vascular TRPV1 expression was observed in arterioles present in the midcoronal pulp in carious painful compared with carious asymptomatic samples (mean area ± SEM [%] of TRPV1 to vascular labeling; 6.48% ± 4.5% for carious asymptomatic teeth, n = 9; 31.21% ± 9.6% for carious painful teeth, n = 9; P = .02). Conclusion: Expression of TRPV1 in pulpal nerve fibers undergoes marked changes with caries. This may be of relevance in the development of pulpal inflammation, but its relationship to dental pain is still unclear. However, vascular TRPV1 expression does appear to be positively correlated with dental pain, thus providing new insights into symptomatic pulpitis. Keywords: blood vessels, inflammation, pain, tooth pulp, vanilloid receptor 1

Occipital neuralgia is an extracranial pain that may be confused with other headaches. It can be attributed to multiple causes. The authors report the case of a 55-year-old woman suffering from right occipital neuralgia secondary to respiratory tract infection that began 6 days before the pain started. The patient suffered from a sharp and burning pain with paroxysms in the right occipital region and at the top of the right ear. Sensation was decreased in the affected area, and hypersensitivity to touch and cold water was also noted. Tinel's sign was present, and local anesthetic block produced pain relief. The combination of gabapentin and amitriptyline did not provide significant pain relief but led to marked adverse effects. Carbamazepine (300 mg/d) was required for pain control. A month later the patient appeared totally painfree. The treatment was continued for 3 months, and the patient remained pain-free over a subsequent follow-up period of more than 6 months. Thus, in the case of occipital pain, a careful assessment of symptoms and a thorough history are necessary to obtain the correct diagnosis and to choose the appropriate treatment plan. Keywords: head and neck, infection, occipital nerves, occipital neuralgia, respiratory tract