Campbell B K, Fillingim R B, Lee S, Brao R, Price D D, Neubert J K
Magnolia Orthodontics, Hickory, NC, USA.
Department of Community Dentistry and Behavioral Science, College of Dentistry, University of Florida, Gainesville, FL, USA.
JDR Clin Trans Res. 2017 Jan;2(1):58-65. doi: 10.1177/2380084416675837. Epub 2016 Oct 26.
Temporomandibular joint disorder (TMD) is a complex musculoskeletal disorder that presents with pain, limited jaw opening, and abnormal noises in the temporomandibular joint. Despite the significant impact that TMD has in terms of suffering and financial burden, relatively few new treatments have emerged; therefore, development of novel treatments to treat TMD pain remains a high priority. The rationale of this study was to use a double-blind, vehicle-controlled clinical trial to evaluate the effects of a high-concentration (8%) capsaicin cream on TMD. This is based on the hypothesis that targeting TRP vanilloid subfamily member 1 (TRPV1) for pain control may provide a novel method for pain relief in TMD patients. TRPV1 is primarily expressed on a population of nociceptive-specific neurons and provides a candidate target for the development of pain treatments. Capsaicin is the primary agonist for TRPV1 and has been used previously in relatively low doses (0.025% to 0.075%) as a therapeutic for a variety of pain disorders, including postherpetic neuralgia and osteoarthritis; however, analgesic efficacy remains equivocal. TMD and healthy control subjects were assigned to either an active capsaicin or vehicle control group. The treatments were applied for 2 h and then removed. Quantitative sensory testing (QST) was completed prior to drug application (baseline), 2 h after drug application, and 1 wk later. Perceived pain intensity was measured using a visual analog scale (VAS) following capsaicin or vehicle cream application. Significantly lower pain was reported in the week after application in the capsaicin-treated TMD subjects. For QST measures, there was a decreased thermal pain threshold 2 h after capsaicin application for both the control and TMD groups, but this resolved within a week. Capsaicin had no effect on pressure pain threshold or mechanical sensitivity in both TMD and healthy individuals. This study demonstrates that 8% topical capsaicin therapy is a relatively safe, simple, and effective treatment for patients with TMD. : This study evaluated a novel topical capsaicin therapy for reducing orofacial pain. The results of this study can be used to provide another treatment option for patients with TMD.
颞下颌关节紊乱病（TMD）是一种复杂的肌肉骨骼疾病，表现为疼痛、张口受限以及颞下颌关节出现异常响声。尽管TMD在患者痛苦和经济负担方面影响重大，但新出现的治疗方法相对较少；因此，开发治疗TMD疼痛的新疗法仍然是当务之急。本研究的基本原理是采用双盲、赋形剂对照临床试验，评估高浓度（8%）辣椒素乳膏对TMD的疗效。这基于这样一种假设，即靶向瞬时受体电位香草酸亚家族成员1（TRPV1）来控制疼痛可能为缓解TMD患者的疼痛提供一种新方法。TRPV1主要表达于一群伤害性特异性神经元上，为疼痛治疗的开发提供了一个候选靶点。辣椒素是TRPV1的主要激动剂，此前已以相对低剂量（0.025%至0.075%）用于治疗多种疼痛疾病，包括带状疱疹后神经痛和骨关节炎；然而，镇痛效果仍不明确。TMD患者和健康对照受试者被分配到活性辣椒素组或赋形剂对照组。治疗应用2小时后去除。在药物应用前（基线）、药物应用后2小时以及1周后完成定量感觉测试（QST）。在应用辣椒素或赋形剂乳膏后，使用视觉模拟量表（VAS）测量疼痛强度。在应用辣椒素治疗的TMD受试者中，应用后一周报告的疼痛明显减轻。对于QST测量，辣椒素应用后2小时，对照组和TMD组的热痛阈值均降低，但在一周内恢复。辣椒素对TMD患者和健康个体的压痛阈值或机械敏感性均无影响。本研究表明，8%的局部辣椒素疗法对TMD患者是一种相对安全、简单且有效的治疗方法。：本研究评估了一种新型局部辣椒素疗法减轻口面部疼痛的效果。本研究结果可为TMD患者提供另一种治疗选择。
