齒顎矯正治療期間，裝置調整後之疼痛常是患者和醫師最大的困擾。而近期
，低能量雷射用於臨床止痛療效上，有其正面意義。故本研究之目的是要評 估低能量雷射對減輕齒顎矯正裝置調整後疼痛之療效。實驗對象為 47 名志願 參加研究的牙科學生；將橡皮 separator 放置於四個象限之各被選定小臼齒的 近遠心接觸面來引起矯正疼痛；再將功率 50mw 的鎵─砷半導體雷射（波長 904nm ）之光纖頭置於頰側牙齦緣下四公厘處照射之。同一受測者，各顆牙 齒照射時間長短為 30 秒（安慰劑組）、 30 秒、 60 秒、 90 秒；雷射照射前 後均以「視覺類比尺度」（ Visual Analogue Scale─V.A.S. ）評估受測者的疼 痛程度；實驗連續進行五天，再以統計學方法來評估實驗結果。在每日治療 前後 V.A.S. 差值的中位值（ median ）的比較中；照射雷射 90 秒的牙齒在第 二、第三天雖比其他三組的牙齒明顯有較高的中位值，但其他天的比較中，
並沒有相同的現象。此外，由無母數分析得知，在第五天的照射前後差的比 較中， 90 秒組有最大的止痛效果，且有統計學上的差異（ p<0.001 ）。但在 其他天的比較結果中，並無統計學上的一致差異來證明照射組比安慰劑組有 較大的止痛療效。故根據本研究得知，低能量雷射對齒顎矯正調整後疼痛的 後期具有立即抒解疼痛的療效且以照射 90 秒效果較佳，但仍無法完全排除安 慰劑的效應。
低能量雷射對減輕齒顎矯正疼痛之臨床評估
Postadjustment pain has been the big problem that bothered the patients and the orthodontists during the pe riod of orthodontic treatment. Recently, low-power laser therapy has been shown to produce the analgesic effect in clinical application. The purpose of this study was to evaluate the efficacy of using low-power las er in reducing orthodontic pain. Forty-seven voluntary dental students were included in this study. Elastom eric separators were placed at the proximal contacts in each quadrant to induce orthodontic pain. The tip of a 50 mW Gallium-Arsenic (904 nm) semiconductor laser probe was placed at the buccal gingiva and direct ed at the area, 4 mm gingivally from the gingival margin.
Three different treatment durations of 30, 60, 90 seconds and one placebo treatment of 30 seconds we re performed within each subject. Visual Analogue Scale (V.A.S.) was used to quantify the intensity of the pain perceived by the subjects before and after laser applications for each day. All the testing procedure wa s proceeded for five days. The results were analyzed statistically. In comparing with the median scores of V.A.S. difference in other groups, before and after laser therapy, those in the treatment group of 90 seconds laser application showed lower level of pain in the second and third days. However, there wasn't the similar tendency of the analgesic effect in the comparisons of those above in other days. On the other hand, the data was processed with the nonparametrically statistical analysis. There was the significantly maximal analgesic efficacy statistically with the 90 seconds radiation of laser application, in the difference between the pre-treatment and post-treatment scores of the fifth day. (P<0.001) Nevertheless, there weren't co ncomitant significant difference statistically between the treatment and placebo groups in other analyses to prove that the treatment could alleviate the orthodontic pain absolutely. According to this study, the orthod ontic postadjustment pain could be reduced immediately by the low-power laser therapy in the late stage, a nd the treatment duration of 90 seconds was the better choice in the analgesic purpose. However, the place bo effect could not be excluded completely.
Clinical Evaluation of Using Low-Power Laser to Reduce Orthodontic Pain
