beta-endorphin and Facial-Pain

The non-steroidal anti-inflammatory drugs (NSAIDs) are among the most widely used classes of drugs for the management of acute and chronic pain in dentistry. Their therapeutic efficacy and toxicity are well-documented and provide evidence that NSAIDs generally provide an acceptable therapeutic ratio of pain relief with fewer adverse effects than the opioid-mild analgesic combination drugs that they have largely replaced for most dental applications. The great many studies done with the oral surgery model of acute pain indicate that a single dose of an NSAID is more effective than combinations of aspirin or acetaminophen plus an opioid, with fewer side-effects, thus making it preferable for ambulatory patients. The combination of an NSAID with an opioid generally results in marginal analgesic activity but with an increased incidence of side-effects, which limits its use to patients in whom the NSAID alone results in inadequate analgesia. The selective COX-2 inhibitors hold promise for clinical efficacy with less toxicity from chronic administration and may prove advantageous for the relief of chronic orofacial pain. The use of repeated doses of NSAIDs for chronic orofacial pain should be re-evaluated in light of a lack of documented efficacy and the potential for serious gastrointestinal and renal toxicity with repeated dosing.

Topics: Analgesics, Opioid; Anti-Inflammatory Agents, Non-Steroidal; beta-Endorphin; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Cyclooxygenase Inhibitors; Drug Combinations; Edema; Facial Pain; Humans; Isoenzymes; Ketorolac; Membrane Proteins; Periodontitis; Prostaglandin-Endoperoxide Synthases; Temporomandibular Joint Disorders; Toothache

This study focused on the relationship between the HPA axis function and the heat pain threshold in the orofacial region upon cold pressor (CP) stimulation.. Ten healthy male individuals participated in this study. CP stimulation was applied to each participant, and their peripheral blood was collected 5 min before, during and 5, 15, 30, 45, 60 min after receiving CP. In addition, 5 of those 10 participants were selected at random and they experienced a mock CP trial on different days. The heat pain thresholds on the facial skin about 10mm anterior to the right external auditory canal (trigeminal V2 region) in each subject were simultaneously recorded 5 min before and 5, 30, 60 min after CP stimulation. The blood pressure and heart rate were continuously monitored throughout the course of the CP and mock trials using an electric blood pressure meter.. Significant increases in the plasma concentration of cortisol, beta-endorphin and ACTH were induced by CP stimulation, while no significant increases were observed under the mock trial conditions. The blood pressure and heart rate showed concomitant increases during CP stimulation. In addition, the heat pain threshold in the orofacial region significantly increased after receiving CP stimulation. These results suggest that CP stimulation activated the HPA axis thereby increasing the heat pain threshold in the orofacial region in healthy individuals.. This observed pain threshold increase might be due to the activation of an endogenous opioid system, such as increase in the circulating beta-endorphin levels.

Topics: Adrenocorticotropic Hormone; Adult; beta-Endorphin; Blood Pressure; Cold Temperature; Face; Facial Pain; Heart Rate; Hot Temperature; Humans; Hydrocortisone; Hypothalamo-Hypophyseal System; Male; Maxillary Nerve; Mouth; Pain Threshold; Physical Stimulation; Pituitary-Adrenal System; Time Factors

The clinical efficacy, side effect liability, and hormonal effects of two prototypic pharmacologic agents were evaluated for the management of chronic myogenous facial pain in a double-blind, randomized, controlled clinical trial. Thirty-nine subjects (35 women,. 4 men) with daily or near-daily orofacial pain of at least 3 months' duration and tenderness to palpation of masticatory muscles participated. Patients were randomly allocated to one of four treatments: placebo, diazepam, ibuprofen, or the combination of diazepam and ibuprofen. Pain, mood, muscle tenderness, maximal interincisal opening, and plasma levels of beta-endorphin were measured following 2-week baseline and 4-week treatment periods. Pain, as measured by a visual analog scale, was significantly decreased in the diazepam and diazepam plus ibuprofen groups but not for the ibuprofen or placebo groups. Analysis of variance showed a significant drug effect for diazepam but not for ibuprofen, indicating that pain relief was attributable to diazepam. No significant changes were noted in muscle tenderness, interincisal opening, or plasma beta-endorphin level. This study supports the efficacy of diazepam in the short-term management of chronic orofacial muscle pain. The lack of effect following administration of an anti-inflammatory analgesic suggests that inflammation is not the basis for chronic muscle pain in the orofacial region, and that the analgesic effect of such medications is not sufficient for pain relief in this condition.

Topics: Adult; Analysis of Variance; Anti-Anxiety Agents; Anti-Inflammatory Agents, Non-Steroidal; beta-Endorphin; Diazepam; Double-Blind Method; Drug Therapy, Combination; Evaluation Studies as Topic; Facial Pain; Female; Humans; Ibuprofen; Male; Pain Measurement; Statistics, Nonparametric; Temporomandibular Joint Dysfunction Syndrome

The mechanisms of relief from persistent pain after temporomandibular joint (TMJ) surgery are not well studied. It was hypothesized that if persistent pain is relieved by TMJ surgery, up-regulated parts of the central nervous system will be desensitized and the neuroendocrine opioid release will decrease back to normal levels. Eleven female patients with a mean age of 47.4±19.4 years and with TMJ pain due to chronic closed lock were examined before and 6-24 months after TMJ discectomy. The effects on plasma β-endorphin levels, pain intensity, and pain thresholds were analyzed. Plasma β-endorphin levels (P=0.032), pain at rest (P=0.003), and movement-evoked pain (P=0.008) were all significantly reduced at follow-up. The reduction in plasma β-endorphin levels correlated with a reduction in maximum pain intensity (P=0.024) and with a longer time after surgery (P=0.041). Seven out of eight patients who reported a substantial reduction in maximum pain intensity presented a decrease in β-endorphin levels in the plasma. In conclusion, this pilot study showed a significant reduction in plasma β-endorphin levels and pain intensity at 6-24 months after TMJ surgery; plasma β-endorphin levels were correlated with time after surgery. However, the results must be interpreted with caution since this was a single-centre observational study with a small sample size. If replicated in larger sample sets, the measurement of β-endorphin levels may be of prognostic value for the treatment outcome.

Topics: Adolescent; Adult; Aged; beta-Endorphin; Facial Pain; Female; Humans; Middle Aged; Pain Management; Pain Measurement; Pain Threshold; Pilot Projects; Prospective Studies; Radiography, Panoramic; Temporomandibular Joint Disorders; Treatment Outcome

Acupuncture applied at myofascial trigger points (MTrPs) of distant anatomical regions, to reduce pain in a patient's area of primary complaint, is one strategy that is available to manage myofascial pain. However, the endogenous opioid-mediated analgesic mechanism of distant acupuncture associated with pain control is still unclear. This aims of this study were to evaluate the changes in enkephalin and β-endorphin in serum, spinal cord, dorsal root ganglion (DRG) and muscle induced by acupuncture at distant myofascial trigger spots (MTrSs, similar to human MTrPs) in rabbits, to explore its underlying remote analgesic mechanism.. Acupuncture at MTrSs of a distant muscle (gastrocnemius) was performed either for one session or five daily sessions in rabbits. The levels of enkephalin and β-endorphin in proximal muscle (biceps femoris), serum, DRGs and spinal cords (L5-S2) were then determined by immunoassay immediately and 5 days after treatment.. Immediately after treatment, acupuncture comprising both one dose and five doses significantly enhanced spinal enkephalin expression and serum β-endorphin levels (p<0.05). However, only five-dose acupuncture significantly enhanced the β-endorphin levels in the biceps femoris and DRGs (p<0.05), while 1-dose acupuncture did not (p>0.05). Furthermore, 5 days after treatment, significantly increased levels of spinal enkephalin and serum β-endorphin persisted in animals that received 5-dose acupuncture (p<0.05).. This study demonstrates that interactions within the endogenous opioid system may be involved in the remote effects of acupuncture treatment and could be a potential analgesic mechanism underlying MTrP pain management.

Topics: Acupuncture Points; Acupuncture Therapy; Animals; beta-Endorphin; Enkephalins; Facial Pain; Ganglia, Spinal; Male; Muscle, Skeletal; Pain Management; Rabbits; Trigger Points

Evidence strongly supports that low-level laser therapy (LLLT) is an effective physical modality for the treatment of pain associated with myofascial trigger points (MTrP). However, the effect of laser fluence (energy intensity in J/cm(2)) on biochemical regulation related to pain is unclear. To better understand the biochemical mechanisms modulated by high- and low-fluence LLLT at myofascial trigger spots (MTrSs; similar to human MTrPs) in skeletal muscles of rabbits, the levels of β-endorphin (β-ep), substance P (SP), tumor necrosis factor-α (TNF-α), and cyclooxygenase-2 (COX-2) were investigated in this study. New Zealand rabbits (2.5-3.0 kg in weight) were used in this study. High-fluence LLLT (27 J/cm(2)), low-fluence LLLT (4.5 J/cm(2)), or sham operations were applied on MTrSs of biceps femoris of rabbits for five sessions (one session per day). Effects of LLLT at two different fluences on biceps femoris, dorsal root ganglion (DRG), and serum were determined by β-ep, SP, TNF-α, and COX-2 immunoassays. LLLT irradiation with fluences of 4.5 and 27 J/cm(2) at MTrSs can significantly reduce SP level in DRG. LLLT with lower fluence of 4.5 J/cm(2) exerted lower levels of TNF-α and COX-2 expression in laser-treated muscle, but LLLT with higher fluence of 27 J/cm(2) elevated the levels of β-ep in serum, DRG, and muscle. This study demonstrated fluence-dependent biochemical effects of LLLT in an animal model on management of myofascial pain. The findings can contribute to the development of dosage guideline for LLLT for treating MTrP-induced pain.

Topics: Animals; beta-Endorphin; Cyclooxygenase 2; Facial Pain; Ganglia, Spinal; Lasers, Semiconductor; Low-Level Light Therapy; Male; Muscle, Skeletal; Rabbits; Substance P; Treatment Outcome; Tumor Necrosis Factor-alpha

Patients with limited jaw opening and movement-evoked pain from the temporomandibular joint have moderate to severe pain that may be relieved by surgery. The purpose of this study was to investigate if the preoperative state is associated with alterations in plasma β-endorphin (βE) levels and pain thresholds.. Eighteen female patients with painful unilateral temporomandibular joint and 18 age-matched healthy women participated. After blood sampling for analysis of plasma βE levels, pressure pain thresholds over the masseter muscles and index fingers were recorded with an electronic algometer. Electrical detection and pain thresholds were recorded with the PainMatcher (Cefar Medical AB, Lund, Sweden) device. Nonparametric statistics, ie, Mann-Whitney U test and Spearman correlation test, was used for statistical analyses.. The patients showed higher plasma βE levels (P = .013) and lower pressure pain thresholds over the masseter muscle at the painful side (P = .041) and bilaterally over the index fingers compared with the controls (P < .05 for all comparisons). High plasma βE levels correlated to increased electrical detection thresholds (n = 36, r = 0.347, P = .038).. This study showed that patients with limited jaw opening and movement-evoked pain from the temporomandibular joint had significantly higher plasma βE levels and lower pressure pain thresholds in the orofacial area and at remote sites compared with pain-free, healthy, age-matched controls. An increased level of βE seems insufficient to inhibit pain and central sensitization. Further studies are warranted to elucidate the relation between βE and pain thresholds secondary to stress, inflammation, and discectomy.

Topics: Adult; Aged; Arthralgia; beta-Endorphin; Case-Control Studies; Facial Pain; Female; Humans; Matched-Pair Analysis; Middle Aged; Pain Threshold; Range of Motion, Articular; Reference Values; Severity of Illness Index; Temporomandibular Joint Disorders

To investigate the presence of endogenous beta-endorphin, an opioid, in the synovial lavage fluid of the temporomandibular joint (TMJ), and to compare the concentration of 3-endorphin in patients with closed lock with that in symptom-free subjects.. Thirty-eight patients (38 joints) with closed lock diagnosed on the basis of the results of clinical examination and magnetic resonance imaging (MRI) and 11 healthy volunteers (19 joints) were examined. Samples of lavage fluid were obtained prior to arthrocentesis by washing the joint with saline. Samples were assayed for beta-endorphin by an enzyme immunoassay, and concentrations of protein were measured by a bicinchoninic acid assay. Subjective pain was assessed by patients using a visual analog scale. Bone changes in the condyle were assessed by MRI, and synovitis was assessed on the basis of arthroscopic findings.. beta-endorphin was present in the synovial fluid of the TMJ, and the concentration was significantly higher in patients with closed lock of the TMJ compared to symptom-free volunteers. The beta-endorphin levels were not, however, significantly correlated with clinical parameters in the patients.. The study results support recent findings that some opioids and their receptors exist not only within the central nervous system but also in the TMJ region, and that opioid concentrations are higher in patients with pain and dysfunction of the TMJ.

Topics: Adolescent; Adult; Aged; beta-Endorphin; Case-Control Studies; Facial Pain; Female; Humans; Immunoenzyme Techniques; Indicators and Reagents; Joint Dislocations; Male; Mandibular Condyle; Middle Aged; Pain Measurement; Quinolines; Sex Factors; Statistics, Nonparametric; Synovial Fluid; Synovitis; Temporomandibular Joint Disorders

Previously reported differences in sensitivity to experimental pain stimuli between the sexes, as well as between temporomandibular disorder (TMD) patients and healthy control subjects, may be attributable in part to group differences in two pain modulatory mechanisms: the baroreceptor reflex arc and the endogenous opioid system. Twenty-two pain-free (PF) men, 20 PF women and 20 women with TMD underwent two testing sessions in which heat pain and ischemic arm pain threshold and tolerance were measured during both sessions, but followed relaxation during one session and laboratory stress tasks during the other. Blood pressure (BP) and plasma -endorphin (E) concentration were measured during a baseline rest and during the stress or relaxation periods. PF men's threshold and tolerance for heat pain, but not for ischemic pain, exceeded that of PF women's during both sessions. PF women and TMD women did not differ in sensitivity to either pain modality; however, significantly lower ischemic pain threshold (IPTh) was linked to oral contraceptive use in PF women but not TMD patients. In the men alone, higher baseline systolic BP (SBP) was correlated with higher heat pain threshold on both days and heat pain tolerance on the stress day. Conversely, in TMD women, higher baseline SBP was correlated with lower ischemic pain tolerance (IPTol) on both days; BP and pain sensitivity were not related in PF women. In men, but not in PF or TMD women, stress systolic and diastolic BP were positively correlated with heat pain threshold and tolerance and higher diastolic reactivity to stress were correlated with higher heat pain and IPTh and tolerance. On the stress day, higher baseline E level was strongly associated with higher IPTol in PF women but marginally associated with lower IPTol in TMD women. Thus, it appears that a BP-related analgesic mechanism (probably baroreceptor-mediated) predominates in PF men, while an endogenous opioid mechanism predominates in PF women. Stress enhances the expression of these central mechanisms. Female TMDs appear unable to effectively engage normal pain-inhibitory systems; opioid receptor desensitization and/or downregulation are probably implicated, because TMDs' production of E appears normal.

Topics: Adult; Arm; beta-Endorphin; Blood Pressure; Facial Pain; Female; Hot Temperature; Humans; Ischemia; Male; Pain Threshold; Sex Characteristics; Stress, Psychological; Temporomandibular Joint Disorders