数字化下颌运动记录及咀嚼肌肌电图在下颌骨肿瘤患者口颌功能评价中的应用

目的 将数字化下颌运动记录与肌电图相结合,观察单侧下颌骨体部及升支肿瘤患者术前、术后下颌运动和咀嚼肌功能临床特点,初步探索运动和咀嚼肌功能的相互关系和产生机制。方法 纳入单侧下颌骨体部及升支病变术前患者6例以及下颌骨单侧病变节段性切除及颌骨重建术后患者3例。采用下颌运动记录系统及表面肌电图系统,采集患者下颌边缘运动、咀嚼运动的运动轨迹,同时记录双侧咬肌、颞肌表面肌电图,采集患者静息、最大力咬合时双侧咬肌、颞肌表面肌电图。在数字化虚拟模型上观测运动轨迹,并分析下颌边缘运动的幅度和方向。分析患者健、患侧静息,最大力咬合,双侧咀嚼时的咀嚼肌电活动特点,计算不对称指数、活动指数。结果 术前患者最大开口度均值为(35.20±6.87) mm,3例患者轻度张口受限,所有患者张口轨迹均偏向患侧。侧向运动中患侧运动平均幅度(10.34±1.27) mm,健侧(6.94±2.41) mm,差异有统计学意义。术后患者最大开口度均值为(30.65±17.32) mm,下颌边缘运动特点与术前患者一致。术前患者最大力咬合时,患侧咬肌肌电活动44.20 (5.70, 197.90) μV]和颞肌的肌电活动中位数42.15 (22.90, 155.00) μV]略低于健侧咬肌45.60 (7.50, 235.40) μV]和健侧颞肌63.30 (44.10, 126.70) μV],咀嚼时未见异常。术后则出现了个性化的改变,部分患者患侧肌电活动减弱,部分患者患侧肌电活动亢进。结论 良、恶性肿瘤及手术均可造成下颌运动和双侧咬肌和颞肌的肌电活动异常。

Application of digital mandibular movement record and masticatory muscle electromyography in the evaluation of stomatognathic function in patients with mandibular tumor

Objective: 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.Methods: 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. Results: 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.Conclusion: 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.