正畸与正颌联合治疗成人骨性反殆后咀嚼肌肌电变化

目的：检查对比分析成人骨性反he正畸与正颌手术联合矫治前后的主要口咀嚼肌肌电，揭示正畸与正颌手术联合矫治后咀嚼肌功能的变化规律方法：20名正畸与正颌手术联合治疗的成人骨性反he患者，利用肌电图仪测试治疗前后咬肌、颞肌前束、二腹肌前腹在功能活动中肌电变化结果：正畸与正颌手术联合矫治对咬肌、颞肌前束、二腹肌前腹的功能活动均有不同程度的影响，其中对咬肌的功能影响最明显：结论：正畸与正颌手术联合治疗成人骨性反he．咀嚼肌的异常肌张力多数得到纠正，但咀嚼肌的功能未能得到满意的恢复，咀嚼肌的功能恢复是一个复杂而长期的过程．还需要较长的功能锻炼恢复期。     

正畸与正颌联合治疗成人骨性反后咀嚼肌肌电变化

目的 :检查对比分析成人骨性反牙合正畸与正颌手术联合矫治前后的主要咀嚼肌肌电 ,揭示正畸与正颌手术联合矫治后咀嚼肌功能的变化规律。方法 :2 0名正畸与正颌手术联合治疗的成人骨性反牙合患者 ,利用肌电图仪测试治疗前后咬肌、颞肌前束、二腹肌前腹在功能活动中肌电变化。结果 :正畸与正颌手术联合矫治对咬肌、颞肌前束、二腹肌前腹的功能活动均有不同程度的影响 ,其中对咬肌的功能影响最明显。结论 :正畸与正颌手术联合治疗成人骨性反牙合 ,咀嚼肌的异常肌张力多数得到纠正 ,但咀嚼肌的功能未能得到满意的恢复 ,咀嚼肌的功能恢复是一个复杂而长期的过程 ,还需要较长的功能锻炼恢复期     

正畸-正颌联合治疗成人骨性Ⅲ类错(牙合)研究进展

成人严重骨性Ⅲ类错(牙合)是临床上骨性错(牙合)畸形最为常见的一种,不仅存在牙性问题,同时还伴有颌骨形态、位置的异常,严重影响患者面部美观、口颌功能及心理健康.正畸-正颌联合治疗是行之有效的手段.本文从正畸-正颌联合治疗适应证选择、手术时机、对软硬组织侧貌及稳定性的影响等方面做一综述.     

正畸-正颌手术联合矫治骨性开(牙合)的长期稳定性研究

目的 研究正畸-正颌手术联合矫治骨性开15年后的骨性以及牙性变化.方法 本研究样本为10例成年骨性开患者,所有患者均采用正畸-正颌手术联合矫治.上颌采用了Le Fort I型截骨术,下颌采用了双侧升支矢状劈开截骨术(BSSO).选择患者在正畸治疗前(T1)、治疗后(T2)以及正颌手术后平均15年(T3)的头颅侧位片进行...     

成人骨性安氏Ⅱ类1分类错(牙合)的正颌-正畸联合治疗

目的采用正畸-正颌手术联合治疗骨性安氏Ⅱ类Ⅰ分类错(牙合)患者,介绍手术前后正畸及术前的准备工作.方法11例成人骨性安氏Ⅱ类Ⅰ分类错(牙合)患者,均经术前正畸-正颌手术-术后正畸的治疗过程.手术前后正畸目的是矫正上下颌前牙前突,排齐牙列,协调上下牙弓,平整牙(牙合)曲线,建立正颌术后良好的咬合关系.术前准备包括术前电脑模拟手术、模型外科、(牙合)板制作.结果11例患者建立了良好的咬合关系及协调的上下颌骨关系,面容美观改善.结论骨性错(牙合)畸形患者采用正畸-正颌联合治疗,能获得功能和美观的满意效果,术前正畸、电脑模拟手术、模型外科、(牙合)板制作及术后正畸,每一操作步骤的精确到位均十分重要.     

成人骨性Ⅲ类错(牙合)畸形的正畸正颌联合治疗研究进展

骨性Ⅲ类错(牙合)是临床常见的发育畸形,同时存在牙性与骨性关系异常,严重影响患者面部美观,咬合功能,社会交往甚至心理健康。对于严重的骨性Ⅲ类错(牙合),正畸掩饰治疗结果往往不尽如人意,而正畸-正颌联合治疗能够有效改善面形和咬合关系,多取得了满意的效果。正畸-正颌联合治疗随着外科技术的发展衍生出了传统模式、手术优先模式以及手术提前模式等多种方法,本综述旨在对现有治疗骨性Ⅲ类错(牙合)的正畸-正颌联合治疗进行一系统阐述,并分析对比不同正畸-正颌联合治疗模式的疗效与术后稳定性,以期为成人骨性Ⅲ类的临床规范治疗提供理论参考。     

成人骨性Ⅰ类错(牙合)双颌前突的正颌-正畸联合治疗

目的采用正畸-正颌手术联合治疗成人骨性Ⅰ类错[牙合]前突患者，以期取得面貌及咬合关系的改善。方法选择10例成人骨性Ⅰ类错[牙合]双颌前突患者，通过术前正畸-正颌手术-术后正畸的联合治疗。对治疗前后的头颅侧位片进行测量分析。结果建立良好的上下颌咬合关系，面型改善；SNA、SNB显著减小。结论成人Ⅰ类骨性错[牙合]畸形患者采用正颌-正畸联合治疗，能快速地、有效地获得满意的咬[牙合]功能及侧貌效果。     

Effect of unilateral posterior crossbite on the electromyographic activity of human masticatory muscles.

Studies dealing with the electromyographic activity of masticatory muscles in patients with unilateral posterior crossbite are infrequent. The purpose of this study was to assess the electromyographic pattern of masticatory muscles at rest position, during swallowing, and during mastication, in 30 subjects with right posterior crossbite and to compare them to 30 normocclusive subjects. The 2 groups were matched according to age, gender, skeletal Class I, and mesofacial growth pattern. Electromyographic activity of right and left anterior temporalis, posterior temporalis, masseter, and anterior digastric muscles was recorded at rest position, while swallowing water, and while chewing. Disposable bipolar surface electrodes were used in both groups. Data were compared between groups and between right and left sides within each group. The results revealed that the posterior temporalis of the non-crossbite side was more active than that of the same side in subjects with crossbite at rest position and during swallowing. The activity of both anterior digastrics was higher in the crossbite subjects during swallowing. During chewing the right masseter muscle was less active in the crossbite patients than in normocclusive subjects. The results obtained during chewing indicate a bilateral masticatory pattern in both groups.     

The influence of crossbite on the coordinated electromyographic activity of human masticatory muscles during mastication

The analysis of the masticatory muscle activity in subjects with altered occlusal relationships could provide useful data of the functional impact of morphological discrepancies. Thirty subjects aged 16-18 years, with a sound, full permanent dentition, bilateral angle class I, and an overjet and overbite between 2 and 5 mm, were examined. The control group (10 male, 10 female) had no crossbite, while the crossbite group (four male, six female) had a posterior unilateral crossbite (five on the left side, five on the right side). The electromyographic activity of the left and right masseter and temporalis anterior muscles was recorded during 15 s of unilateral (left and right) chewing of gum, and expressed as a percentage of the maximum voluntary clench on cotton rolls. For each subject, the masticatory frequency, the confidence ellipse of the simultaneous differential left-right masseter and temporal activity (Lissajous figure), and an index of muscular symmetry, were computed to assess muscular coordination. In the crossbite subjects, the four analysed muscles appeared to contract with altered and asymmetric patterns. A large variability was found, and the confidence ellipses calculated for the chewing tests performed on the crossed sides were not significant, while the confidence ellipses of the uncrossed side chewing were different from the ellipses computed in the normal occlusion group. The altered occlusal relationship influenced the coordination of the masticatory muscles during chewing on both sides. The functional alteration was more apparent when the side with the altered morphology was directly involved, i.e. when chewing was performed on the crossbite side.     

Orthodontic intervention combined with myofunctional therapy increases electromyographic activity of masticatory muscles in patients with skeletal unilateral posterior crossbite

Objective. The aim of this study was to evaluate the electromyographic activity of both the temporalis and masseter muscles and the mastication type of patients with skeletal unilateral posterior crossbite before and after orthodontic treatment and speech therapy. Methods. A total of 14 patients with skeletal unilateral posterior crossbite (eight females and six males), between 6–13 years of age, underwent electromyographic evaluation of their masseter and temporalis muscles in mandibular rest, habitual mastication and isometry. The subjects were assessed with regard to mastication type before and after orthodontic treatment and speech therapy. The data obtained during mandibular rest and habitual mastication were normalized in terms of the mean values of isometry. The Student's t-test was used for paired samples to compare the mean values of electromyographic activity (p < 0.05). Results. The masseters during habitual mastication presented higher electromyographic activity after both treatments (p = 0.0458). There was no significant difference between the contralateral masseters in terms of mandibular rest or habitual mastication before or after either treatment (p > 0.05). During habitual mastication, after the treatments, the temporalis muscle on the malocclusion side showed higher electromyographic activity than the contralateral side (p = 0.0263). Prior to therapy, all of the patients exhibited chronic unilateral mastication (n = 14) and 13 patients exhibited bilateral mastication after treatment. Conclusions. Orthodontic intervention combined with myofunctional therapy in patients with skeletal unilateral posterior crossbite provided an increase in the electromyographic activity of the masseter and temporalis muscles during mandibular rest and habitual mastication, with predominantly bilateral mastication.     

Influence of surgical orthodontic treatment on masticatory function in skeletal Class III patients

Skeletal Class III patients exhibit malocclusion characterised by Angle Class III and anterior crossbite, and their occlusion shows total or partially lateral crossbite of the posterior teeth. Most patients exhibit lower bite force and muscle activity than non‐affected subjects. While orthognathic surgery may help improve masticatory function in these patients, its effects have not been fully elucidated. The aims of the study were to evaluate jaw movement and the electromyographic (EMG) activity of masticatory muscles before and after orthognathic treatment in skeletal Class III patients in comparison with control subjects with normal occlusion. Jaw movement variables and EMG data were recorded in 14 female patients with skeletal Class III malocclusion and 15 female controls with good occlusion. Significant changes in jaw movement, from a chopping to a grinding pattern, were observed after orthognathic treatment (closing angle P < 0·01; cycle width P < 0·01), rendering jaw movement in the patient group similar to that of the control group. However, the grinding pattern in the patient group was not as broad as that of controls. The activity indexes, indicating the relative contributions of the masseter and temporalis muscles (where a negative value corresponds to relatively more temporalis activity and vice versa) changed from negative to positive after treatment (P < 0·05), becoming similar to those of control subjects. Our findings suggest that orthognathic treatment in skeletal Class III patients improves the masticatory chewing pattern and muscle activity. However, the chewing pattern remains incomplete compared with controls.     

单侧后牙反(牙合)患者的咀嚼肌肌电图分析

目的: 通过对单侧后牙反(牙合)患者咀嚼肌肌电检查,分析单侧后牙反(牙合)对咀嚼功能的影响.方法:用肌电图仪记录20 例(男11 例,女 9 例)单侧后牙反(牙合)患者和20 例(男10 例,女10 例)正常对照组在下颌姿势位、紧咬和双侧咀嚼时咬肌和颞肌前束的肌电数据.计算咬肌的活动不对称指数(ASMM)和颞肌前束的活动不对称指数(ASTA),然后进行统计学分析.结果:在紧咬和双侧咀嚼时,单侧后牙反(牙合)组咬肌和颞肌前束肌电值明显低于对照组(P＜0.05),反(牙合)侧明显低于非反(牙合)侧;单侧后牙反(牙合)组与对照组ASMM和ASTA在紧咬和双侧咀嚼时有显著性差异(P＜0.05);单个后牙反(牙合)组与多个后牙反(牙合)组ASMM和ASTA在紧咬和双侧咀嚼时有显著性差异(P＜0.05).结论:单侧后牙反(牙合)对咀嚼肌功能有明显的影响,应对其进行积极治疗.     

Impact of dental and skeletal movements on the facial profile within the framework of orthodontic and surgical treatments

The impact of dental and skeletal movements on the soft tissues during orthodontic and surgical treatments is widely known. Most studies are limited to examining the repercussions of a dental or skeletal movement on a given soft tissue point. The uniqueness of the present study, carried out on 95 patients, lies in the examination of the impact of movements of various landmarks--2 dental points (incision superius and incision inferius) and 4 skeletal points (anterior nasal spine, point A, point B, andpogonion)--on 7 soft tissue landmarks (from the tip of the nose to soft tissue pogonion). The study was carried out with the purpose of providing a simple, practical, and accurate tool for clinical use to assist in treatment planning. This article outlines the main aspects of the tool while specifying its limitations and error margins.     

Reliability of electromyographic activity vs. bite-force from human masticatory muscles

The reproducibility of electromyographic (EMG) activity in relation to static bite-force from masticatory muscles for a given biting situation is largely unknown. Our aim was to evaluate the reliability of EMG activity in relation to static bite-force in humans. Eighty-four subjects produced five unilateral static bites of different forces at different biting positions on molars and incisors, at two separate sessions, and the surface EMG activities were recorded from temporalis, masseter, and suprahyoid muscles bilaterally. Intraclass correlation coefficients (ICCs) were determined, and an ICC of ≥ 0.60 indicated good reliability of these slopes. The ICCs for jaw-closing muscles during molar biting were: temporalis muscles, ipsilateral 0.58-0.93 and contralateral 0.88-0.91; and masseter muscles, ipsilateral 0.75-0.86 and contralateral 0.69-0.88. The ICCs for jaw-closing muscles during incisor biting were: temporalis muscles, ipsilateral 0.56-0.81 and contralateral 0.34-0.86; and masseter muscles, ipsilateral 0.65-0.78 and contralateral 0.59-0.80. For the suprahyoid muscles the 95% CIs were mostly wide and most included zero. The slopes of the EMG activity vs. bite-force for a given biting situation were reliable for temporalis and masseter muscles. These results support the use of these outcome measurements for the estimation and validation of mechanical models of the masticatory system.     

Electromyography of the perioral and masticatory muscles in orthodontic patients with atypical swallowing

Subjects with an open bite and an atypical swallowing pattern before (n=20) and after (n=10) orthodontic treatment and subjects with a normal swallowing pattern (n=15) were examined. The electromyographic (EMG) activity of the upper and lower lips in the region of the modiolus and of the mentalis, masseter and temporal muscles was evaluated during the swallowing of saliva and of water and after the chewing of peanuts as well as during maximal biting in intercuspal position.During swallowing the atypical swallowers exhibited larger EMG activities of the perioral muscles and smaller EMG activities of the masticatory muscles than the control subjects. During maximal biting in intercuspal position, major EMG activity of the masseter and temporal muscles and minor EMG activity of the perioral muscles were recorded in both groups. No normalization of the electromyographic swallowing pattern could be observed during orthodontic treatment (closure of the open bite).