Double-masked research on effect and mechanism of polarized infrared light therapy to temporomandibular disorders (TMD)

选择偏振光照射TMD30例患者(女27例，男3例，年龄11~76岁)的近期疗效。他们的主要主诉是TMJ疼痛或张开和/或咀嚼时的下颌角疼痛等。根据日本颞下颌关节学会提出的标准，将患者分为5组。每次探视期间，对疼痛程度最高的部位进行光照射10min，每次照射周期为2秒~2秒，采用视觉模拟评分法(VAS)测量疼痛程度。用直尺测量最大开口处的切距。对下颌功能障碍和活动受限的主观评估进行评分。结果显示：1)VAS评分明显下降(P&lt；0，01：Wilcoxon符号等级检验)；2)半数患者VAS评分下降50%以上；3)平均最大开口距离增加。4)下颌功能障碍和活动受限评分明显降低(P&lt；0.0I：Wilcoxon符号秩次检验)。5)本病病史较短的I型和II型年轻患者效果最好。II.双掩模研究下光照射治疗的疗效及机制本研究采用双掩模原理评价偏振光照射治疗TMD的疗效。比较第一部分所述假照射的临床反应。并用激光多普勒血流仪测量皮肤血流量和皮肤温度。因此，对于偏振光照射的效果和机理还没有得出明确的结论。为了能够更准确和有效地评估光疗的益处，还需要进一步的随机临床试验。

I.Short-term effects of the polarized light irradiation to TMD30 patients (27 female and 3 males, aged from 11 to 76) were selected. Their chief complaints were TMJ pain or angle of mandible pain on opening and/or chewing, and so on. According to the criteria proposed by Japanese Society for Temporomandibular Joint, patients were classified into five groups. Light irradiation was applied to the most painful area for 10 minutes with 2 seconds on-2 seconds off cycle during each visit.The level pain intensity was measured using Visual Analogue Scale(VAS). Interincisal distance of maximum opening was measured by ruler. Subjective estimates of Jaw Dysfunction and Activity Limitation were scored. The measurements of pre-irradiation, 2nd and 3rd visit were compared.Results were as follows.1)VAS score dropped significantly (P<0,01 : Wilcoxon signed rank test).2)More than 50% reduction of the VAS score was observed among half of patients.3)Average interincisal distance of maximum opening smoothly increased. Pain-free opening revealed the largest increment, and more than 10mm increment was observed among 25% of patients.4)Scores of the Jaw Dysfunction and Activity Limitation were decreased significantly (P<O.0I : Wilcoxon signed rank test).5)The best results were obtained among young Type I and II patients with short history of the present illness.II.Efficacy and mechanism of the light irradiation therapy under double-masked studyThe study was made to assess the efficacy of the polarized light irradiation to TMD by double-masked principle. The clinical responses described part I by sham irradiation was compared. Also, the skin blood flow by laser Doppler flowmetry and the skin temperature were measured. Consequently no definite conclusion can be drawn about the efficacy and mechanism of the polarized light irradiation. Further randomized clinical trials are needed in order to enable the benefits of light therapy to be more precisely and validly evaluated.