This study aims to evaluate the effect of Nd:YAG laser therapy (NdLT) on postoperative pain, swelling, and trismus after mandibular third molar (M3) surgery. Three hundred patients were randomly divided into the Nd group (n = 100), medication group (n = 100), and Nd+medication (Nd+m) group (n = 100). The WHARFE classification system was used to assess surgical difficulty. After surgery, the Nd group was irradiated by the Nd:YAG laser in very long-pulsed mode (VLP, pulse duration 1 ms, 20 Hz, 4 W, R21-C3) in 6 regions of the extraction socket with a total energy of 300 J. For the medication group, dexamethasone 0.75 mg and loxoprofen 60 mg were prescribed immediately and every 12 h thereafter for 3 days. The Nd+m group received both treatments mentioned above. Pain assessment was performed at 6, 24, 48, and 72 h postoperatively using the visual analog scale (VAS). Swelling was evaluated by changes in the distance from (1) the tragus to the labial commissure, (2) the tragus to the pogonion, and (3) the mandibular angle to the lateral canthus preoperatively and 72 h postoperatively. Trismus was assessed by the change in maximum mouth opening. Groups Nd and Nd+m had lower VAS scores at 6 h, 24 h, and 48 h (F = 13.80, p = 0.00), but the difference between the two groups was not significant (F = 1.34, p = 0.11). However, no significant difference was observed at 72 h (p = 0.10). There was no significant difference in swelling or trismus among the three groups (p > 0.05). NdLT is an effective approach to improve complications after M3 surgery.

本研究旨在评估 Nd:YAG 激光治疗 (NdLT) 对下颌第三磨牙 (M3) 手术后疼痛、肿胀和牙关紧闭的影响。 300 名患者被随机分为 Nd 组 ( n = 100)、药物组 ( n = 100) 和 Nd+药物 (Nd+m) 组 ( n = 100)。 WHARFE分类系统用于评估手术难度。术后，Nd组用Nd:YAG激光以超长脉冲模式（VLP，脉冲持续时间1 ms，20 Hz，4 W，R21-C3）照射拔牙窝的6个区域，总能量为300 J。对于药物组，立即给予地塞米松 0.75 mg 和洛索洛芬 60 mg，此后每 12 小时一次，持续 3 天。 Nd+m组接受上述两种治疗。使用视觉模拟量表（VAS）在术后 6、24、48 和 72 小时进行疼痛评估。通过术前和术后 72 小时（1）耳屏到唇连合、（2）耳屏到颏前点、（3）下颌角到外眦的距离的变化来评估肿胀。通过最大张口度的变化来评估牙关紧闭。 Nd组和Nd+m组在6小时、24小时和48小时时的VAS评分较低（ F = 13.80， p = 0.00），但两组之间差异不显着（ F = 1.34， p = 0.11）。然而，72 小时时没有观察到显着差异（ p = 0.10）。三组间肿胀或牙关紧闭程度无显着差异（ p >0.05）。 NdLT是改善M3术后并发症的有效方法。