Wang J, Chen J P, Wang Y, Xu X L, Guo C B
Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital Stomatology, Beijing 100081, China.
Beijing Da Xue Xue Bao Yi Xue Ban. 2019 Jun 18;51(3):571-578. doi: 10.19723/j.issn.1671-167X.2019.03.029.
To study the clinical characteristics of mandibular movement and masticatory muscle function in preoperative and postoperative patients with unilateral mandibular tumors in the region of mandibular body and ramus by combining digital mandibular movement records with electromyography, and to preliminarily explore the relationship and mechanism between movement and masticatory muscle function.
Six preoperative patients with tumor in unilateral body and ramus of mandible were included, and three postoperative patients with unilateral segmental resection and reconstruction of mandibular bone were included. The mandibular movement recording system and surface electromyography system were used to collect the movement trajectory of the patients' mandibular marginal movement and chewing movement, and the surface electromyography of bilateral masseter and temporalis was recorded concurrently. The surface electromyography of bilateral masseter and temporalis was collected when the patients were at relaxation and at maximal voluntary clenching (MVC). The motion trajectory was observed on the digital virtual model, and the motion amplitude and direction of mandibular marginal movements were analyzed. The characteristics of masticatory electromyogram (EMG) activity in affected and unaffected sides at relaxation, MVC and bilateral mastication were analyzed, and the asymmetry indexes and activity indexes were calculated.
The preoperative mean maximum opening of the patients was (35.20±6.87) mm. Three patients had mild mouth opening limitation, and all the patients' mouth opening trajectory was skewed to the affected side. During lateral movements, the mean range of motion of the affected side [(10.34±1.27) mm] and that of the healthy side [(6.94±2.41) mm] were significantly different. The maximum opening of the postoperative patients was (30.65±17.32) mm, and the mandibular marginal movement characteristics were consistent with those of the patients before surgery. During MVC in the preoperative patients, the median EMG activities of the masseter muscle [44.20 (5.70, 197.90) μV] and the temporalis muscle [42.15 (22.90, 155.00) μV] on the affected side were slightly lower than those of the masseter [45.60 (7.50, 235.40) μV] and the temporalis muscle [63.30 (44.10, 126.70) μV] on the healthy side. In the postoperative patients, individualized changes occurred. Some patients suffered from weakened electromyographic activity on the affected side, while some other ones showed hyperelectromyographic activity on the affected side.
Both benign and malignant tumors as well as their surgery can cause abnormal mandibular movements and change of electromyographic activity of bilateral masseter and temporalis muscles.
通过将数字化下颌运动记录与肌电图相结合，研究下颌体和升支区域单侧下颌肿瘤患者术前和术后的下颌运动及咀嚼肌功能的临床特征，并初步探讨运动与咀嚼肌功能之间的关系及机制。
纳入6例单侧下颌体和升支肿瘤术前患者，以及3例单侧下颌骨节段性切除并重建术后患者。使用下颌运动记录系统和表面肌电图系统收集患者下颌边缘运动和咀嚼运动的轨迹，并同步记录双侧咬肌和颞肌的表面肌电图。在患者放松和最大自主紧咬（MVC）时收集双侧咬肌和颞肌的表面肌电图。在数字虚拟模型上观察运动轨迹，分析下颌边缘运动的运动幅度和方向。分析放松、MVC和双侧咀嚼时患侧和健侧咀嚼肌电图（EMG）活动的特征，并计算不对称指数和活动指数。
术前患者平均最大开口度为（35.20±6.87）mm。3例患者有轻度开口受限，所有患者的开口轨迹均向患侧偏斜。在侧方运动时，患侧平均运动范围[（10.34±1.27）mm]与健侧[（6.94±2.41）mm]有显著差异。术后患者最大开口度为（30.65±17.32）mm，下颌边缘运动特征与术前患者一致。术前患者在MVC时，患侧咬肌肌电图活动中位数[44.20（5.70，197.90）μV]和颞肌肌电图活动中位数[42.15（22.90，155.00）μV]略低于健侧咬肌[45.60（7.50，235.40）μV]和颞肌[63.30（44.10，126.70）μV]。术后患者出现个体化变化。部分患者患侧肌电图活动减弱，而部分患者患侧肌电图活动增强。
良性和恶性肿瘤及其手术均可导致下颌运动异常以及双侧咬肌和颞肌肌电图活动改变。
