Journal of orofacial pain最新文献

Aims: To (A) evaluate test-retest reliability of vibrotactile sensitivity in the masseter muscle and (B) test if (1) the vibration threshold is decreased after experimental tooth clenching, (2) intense vibrations exacerbate pain after tooth clenching, (3) pain and fatigue are increased after tooth clenching, and (4) pressure pain thresholds are decreased after tooth clenching.

Methods: In part A, 25 healthy female volunteers (mean age: 42 ± 12 years) participated, and 16 healthy females (mean age 32 ± 10 years) participated in three 60-minute sessions, each with 24- and 48-hour follow-ups in part B. Participants were randomly assigned tooth-clenching exercises with clenching levels of 10%, 20%, or 40% of maximal voluntary clenching. A Vibrameter applied to the right masseter muscle measured perceived intensity of vibration and perceived discomfort, which were assessed on 0-50-100 numeric rating scales. An electronic algometer measured pressure pain threshold (PPT). Two 0- to 100-mm visual analog scales measured pain intensity (VASpain) and fatigue (VASfatigue). Measurements were made on the right masseter muscle. Interclass correlation coefficient (ICC) was used to calculate test-retest reliability of VT measurements. Outcome variables were tested with two-way ANOVAs for repeated measures and Dunnett's post-hoc test.

Results: Moderate long-term (ICC 0.59) and good short-term (ICC 0.92) reliability was found for VT on the masseter muscle. Clenching level had no main effect on perceived intensity of vibration; time effects (P < .05) were only observed at 40 minutes (Dunnett's test: P < .01). Clenching level and time had no effect on perceived discomfort. Only time effects were significant for PPT (P < .01), with reductions at 50 and 60 minutes compared to baseline (Dunnett's test: P < .05). Clenching level and time had main effects for VASpain and VASfatigue (P < .001).

Conclusion: Experimental tooth clenching appears to evoke moderate levels of pain and fatigue and short-lasting hyperalgesia to mechanical stimulation, but not proprioceptive allodynia. The absence of proprioceptive allodynia does not necessarily exclude delayed onset muscle soreness (DOMS) but warrants further studies on the clinical manifestations of DOMS in jaw muscles.

Aims: To characterize pain related to primary burning mouth syndrome (BMS) in terms of intensity, interference, and distress caused by the pain, as well as factors influencing the pain across a period of 2 weeks, and to study the use of coping and management strategies on a daily basis.

Methods: Fifty-two female patients with primary BMS completed a 2-week pain diary. Pain intensity, interference, distress, and mood on a 0 to 10 numeric rating scale (NRS), as well as pain amplifying and alleviating factors, were recorded three times a day. The use of treatments (medication or other means) and coping strategies were recorded at the end of each day. Coefficient of variation, repeated measures analysis of variance, and correlative methods were used to assess the between- and within-subject variation, pain patterns, and associations between various pain scores.

Results: The overall mean pain intensity score of the 14 diary days was 3.1 (SD: 1.7); there was considerable variation in pain intensity between patients. Most patients experienced intermittent pain. On average, pain intensity increased from the morning to the evening. Intercorrelations between pain intensity, interference, distress, and mood were high, varying between rs = .75 and rs = .93 (P < .001). Pungent or hot food or beverages, stress, and tiredness were the most frequently mentioned pain-amplifying factors. The corresponding pain-alleviating factors were eating, sucking pastilles, drinking cold beverages, and relaxation. Thirty (58%) patients used pain medication and 35% reported using other means to alleviate their BMS pain. There was large variation in the use of coping strategies -between subjects.

Conclusion: There were considerable differences in pain, in factors influencing the pain, and in pain behavior across BMS patients. This indicates that patient information and education as well as treatment of BMS pain should be individualized.

Aims: To determine the contribution of a wide range of factors to care-seeking behavior in orofacial pain patients, expressed as (A) decision to seek care and (B) number of health care practitioners visited.

Methods: Subjects with orofacial pain complaints were recruited in seven TMD clinics and from a nonclinical population sample. They received a questionnaire including a wide range of possible predictors. To study which predictive variables were associated with the decision to seek care and with the number of health care practitioners visited, multiple regression models were built.

Results: Two hundred three persons with orofacial pain participated in the study. Of these participants, 169 (140 females) had visited at least one health care practitioner (care seekers), while the other 34 persons (25 females) did not (non-care seekers). The decision to seek care was not only associated with the pain intensity (P < .05), but, in women, also with fear of jaw movements (P < .01): Women with more fear of jaw movements were more likely to seek care. Pain intensity and disability were not associated with the number of health care practitioners visited. Instead, the main predictors were catastrophizing (P = .004) and the use of painkillers (P = .008).

Conclusions: Pain intensity and fear of jaw movements play an important role in the decision to seek care for orofacial pain. The continuous search for help is associated with catastrophizing and the use of painkillers.

Aims: To investigate nociceptive behavior and the immunoreactivity of microglia and phosphorylated-p38 (p-p38) mitogen-activated protein kinase (MAPK) following intracisternal administration of SB203580, a p38 MAPK inhibitor, or minocycline, a microglia inhibitor, in rats with temporomandibular joint (TMJ) inflammation.

Methods: The number of nociceptive behavioral responses was recorded for nine successive 5-minute intervals following formalin injections into the left TMJ. SB203580 or minocycline was administered intracisternally 2 hours prior to the formalin injection. Statistical analysis used one-way analysis of variance followed by least significant difference post-hoc analysis.

Results: The intra-articular injection of formalin increased the expression of p-p38 MAPK in the ipsilateral medullary dorsal horn. Most of the p-p38 MAPK co-localized with OX42, a microglial marker, but not with GFAP, an astrocyte marker. Intracisternal injections of SB203580 (0.5, 1, or 5 Μg) attenuated the number of nociceptive behavioral responses and the expression of p-p38 MAPK in the medullary dorsal horn. Intracisternal injections of minocycline (25 or 50 Μg) also attenuated the responses and the expression of OX42 and p-p38 MAPK in the medullary dorsal horn.

Conclusion: These findings suggest that p38 MAPK in microglia plays an important role in the central processing of inflammatory TMJ nociception in rats. The data further indicate that a targeted blockade of the microglial p38 MAPK pathway is a potentially important new treatment strategy for inflammatory TMJ nociception.

Aims: To study the effect of estrogen deficiency and altered temporomandibular joint loading on the histomorphology of condylar cartilage and on the expression of types II and X collagen and matrix metalloproteinase-3 (MMP-3).

Methods: Thirty-six female rats were divided into four groups: ovariectomized rats on a normal diet, nonovariectomized control rats on a normal diet, ovariectomized rats on a soft diet, and nonovariectomized control rats on a soft diet. Ovariectomy was performed at the age of 60 days. Repeated-measures ANOVA was used to analyze the data.

Results: The condylar cartilage in the ovariectomized normal diet group showed a significantly higher number of cells than in the nonovariectomized control rats (P < .001). The proportional amount of MMP-3 expression was significantly higher in the ovariectomized rats than in the nonovariectomized control rats in both diet groups (P < .001). The area covered by types II and X collagen was significantly higher in the experimental groups than in the control groups (P < .01).

Conclusion: Condylar cartilage is sensitive to both estrogen level and dietary loading.

Aims: To analyze the influence of frequency, intensity, and duration of temporomandibular disorders (TMD), headaches, and neckshoulder pain (NSP) on Sami women's daily life. A further aim was to analyze the relationship between these symptoms and age.

Methods: All 751 Sami women 21 to 70 years old registered in either the Swedish Sami Parliament's electoral register or registered as reindeer owners or herders and living north of the Arctic Circle in Sweden were sent a questionnaire regarding TMD symptoms, NSP, and headaches. In total, 487 women (65%) participated. The questionnaire focused on symptom frequency, duration, and intensity and whether these symptoms influenced activities of daily life. The symptom's interference with daily life activities was measured, respectively, with a numerical rating scale (NRS). The statistical analyses included multiple logistic regression analysis and Chi-square test. A P value < .05 was considered statistically significant.

Results: Seventeen percent of the women reported that symptoms in the jaw-face region to some degree disturbed their daily life, and for 6%, the interference was significant (≥ 5 on NRS). Duration of jaw pain, troublesome impaired jaw opening, and neck pain, together with a low education level, affected reports of whether symptoms of TMD influenced daily life. Almost half of the study population reported that headaches had a negative impact on their life. A similar pattern was reported for NSP. The prevalence of frequent and troublesome symptoms of TMD and headaches, but not NSP, showed a declining trend with age.

Conclusion: TMD symptoms, headaches, and NSP negatively influence many Sami women's daily life. Factors related to pain had the greatest influence when these Sami women rated the related impairment.

Aims: To describe the cause, clinical signs, and symptoms of patients presenting to a tertiary care center with iatrogenic lesions to the mandibular branches of the trigeminal nerve.

Methods: Pain history, pain scores using the visual analog scale, and mechanosensory testing results were recorded from 93 patients with iatrogenic lingual nerve injuries (LNI) and 90 patients with iatrogenic inferior alveolar nerve injuries (IANI). Results were analyzed using the SPSS statistical software. Chi-square tests were applied for nonparametric testing of frequencies, where P ⋜ .05 indicated statistical significance. Appropriate correlations were also carried out between certain data sets.

Results: Significantly more females were referred than males (P < .05). Overall, third molar surgery (TMS) caused 73% of LNI, followed by local anesthesia (LA) (17%). More diverse procedures caused IANI, including TMS (60%), LA (19%), implants (18%), and endodontics (8%). Approximately 70% of patients presented with neuropathic pain coincident with anesthesia and÷or paresthesia. Neuropathy was demonstrable in all patients with varying degrees of loss of mechanosensory function, paresthesia, dysesthesia, allodynia, and hyperalgesia. Functionally, IANI and LNI patients mostly had problems with speech and eating, where speech was affected amongst significantly more patients with LNI (P < .001). Sleep, brushing teeth, and drinking were significantly more problematic for IANI patients (P < .05, P < .001, and P < .0001, respectively).

Conclusion: Neuropathic pain, as well as anesthesia, frequently occurs following iatrogenic trigeminal nerve injury similar to other posttraumatic sensory nerve injuries. This must be acknowledged by clinicians as a relatively common problem and informed consent appropriately formulated for patients at risk of trigeminal nerve injuries in relation to dentistry requires revision.

Aims: To examine the effect of decreased estrogen level and altered diet hardness on condylar cartilage morphology of the rat temporomandibular joint (TMJ) and on the expression of condylar cartilage estrogen receptor alpha (ERa) and matrix metalloproteinase-8 (MMP-8).

Methods: A total of 36 female rats was divided into four groups: ovariectomized rats fed a normal diet, non-ovariectomized controls fed a normal diet, ovariectomized rats fed a soft diet, and non-ovariectomized controls fed a soft diet. Ovariectomy was performed at the age of 60 days. Seven days after the operation, the rats were sacrificed. Repeated measures ANOVA and Duncan's multiple comparison tests were used for statistical analysis.

Results: The ovariectomized rats had thicker cartilage layers than the controls, both in the normal diet and soft diet groups. The thinnest cartilage layers were found in the control rats fed with the soft diet. The thickness of the chondroblastic layer was significantly higher (P < .001) in the normal-diet rats than in the soft-diet rats in both ovariectomized and non-ovariectomized groups. The thickness of the proliferative layer was significantly higher (P < .001) in the ovariectomized soft-diet rats than in the soft-diet control rats. The proportional amount of ERa was statistically significantly higher (P < .001) in the condylar cartilage of the ovariectomized rats than in the non-ovariectomized control rats both in the normal- and soft-diet groups. The proportional amount of ERa was statistically significantly higher (P < .001) in the ovariectomized normal-diet rats than in the ovariectomized soft-diet rats. The proportional number of MMP-8-positive cells was statistically significantly higher (P < .001) in the condylar cartilage of ovariectomized rats fed the soft diet than in non-ovariectomized control rats fed the soft diet. Control rats fed with the normal diet had a higher proportional amount of MMP-8 positive cells than control rats fed with the soft diet (P < .05).

Conclusion: The rat TMJ condylar cartilage is sensitive to changes in estrogen levels and altered diet hardness.