肌位(s)板对颌间关系调整作用的研究

目的:研究肌位(s)板对下颌位置的调整作用.方法:对102例颅颌功能紊乱(CMD)患者均戴用肌位(s)板,戴板后1周、2周、1月各复查1次,以后每月复查1次,共戴板3～6月.记录戴板后是否出现咬合不稳,若有咬合印迹变化者则磨去原有咬合印迹重垫,直至不再变化,待症状消失后去除(s)板,轻咬至肌接触位,记录与颌位是否协调.结果:戴板期间66例患者的咬合印迹始终不变,36例患者出现咬合不稳,经重垫后,咬合板的(s)关系稳定不变.待症状消失后去板.102例患者中,12例表现为肌牙位不一致,其中前牙早接触2例,先天性垂直距离不足1例,牙尖交错位(ICP)偏位9例.结论:肌位(s)板对下颌位置的调整作用是调正肌位,在肌位正常情况下,判断肌牙位是否一致,从而检出ICP异常.     

肌位He板对颌关关系调整作用的研究

目的；研究肌位Ｈｅ板对下颌位置的调整作用。方法；对１０２例颅颌功能紊乱患者均戴用肌位Ｈｅ板，戴板后１周，２周，１月各复查１次，以后每月复查１次，共戴板３－６月，记录载板是否出现咬合不稳，若有咬合印迹变化者则磨去原有咬合印迹重垫，直至不再变化，待症状消失后去除Ｈｅ板，轻咬至肌接触位，记录Ｈｅ与颌位是否协调。     

肌位咬合板对颅颌功能紊乱者下颌运动影响的研究

研究肌位咬合板对颅颌功能紊乱患者下颌运动的影响。方法：采用下颌运动轨迹描记信，记录99例患者戴板前和即刻置入咬合板后自姿势位（MPP）至牙尖交错（ICO）、自然张闭口及最大最快张闭口运动；孪-吞个月后复查（不戴板）。结果：戴板后87．8％CMD患者由MPP闭合至ICO侧后移消失，自然张闭口轨迹一致率由戴板前4％提高到78.8％，最大最快张闭口运动轨迹规则度由15.2％提高至89.9％,速度也显著增加（P＜0.05）.复查显示:咬合正常者MPP至ICP侧后消失,张闭口轨迹一致,速度轨迹规则,速度增加,咬合异常者下颌运动与治疗前相比无变化.结论:肌位咬合板对CMD治疗机理之一是调整异常的下颌运动.     

深覆与颅颌功能紊乱

为探讨深覆的致病机理,对56例伴深覆的颅颌功能紊乱患者从临床,X线摄影。下颌运动及治疗等方面进行了研究,得出结果:①弹响以开口初、闭口末居多(75.61％);髁突以后位居多(76.79％);②有31例临床上表现牙位与肌位不一致;③下颌运动轨迹描记,深覆(牙合)患者自然开闭口及由姿势位闭合至ICO时下颌向后运动的人数显著多于非深覆(牙合)患者,但戴咬合板由姿势位闭合至ICO下颌则呈前上方向运动;④经肌位咬合板治疗,患者症状消失,但牙位与肌位仍不一致.结果提示深覆(牙合)的主要致病机理:①切道斜度大,下颌运动受限、下颌后退导致髁突后位,盘突关系不协调;②导致牙位与肌位不一致,造成关节内微小创伤。肌位咬合板可消除或减轻症状。     

对固定正畸治疗病例的作学评价的临床体会

目的 :通过对正畸治疗结束前患者进行学评价 ,将学的要求引入正畸临床 ,为提高正畸治疗稳定性和减少TMD发病率 ,为正畸临床提供参考。方法 :对矫治结束前的 30例病例进行学分析和评估。矫治病例结束前在关节科医生的指导下对以下指标作分析与评估 :(1)ICP状态下的接触 ,确保ICP的稳定。 (2 )观察RCP与ICP的关系 ,可以是一位的 ,也可以是谐调一致的 ,即RCP滑至ICP是直向前 ,无偏滑 ;(3)观察肌位与牙位 ,即轻咬与重咬颌位一致 ,无偏斜。 (4 )前伸运动时 ,前牙切对切均匀接触 ,后牙无接触或轻接触。 (5 )侧方运动时 ,工作侧有良好的接触 ,无高点 ,非工作侧无接触 ,最好以尖牙引导即尖牙保护。结果 :(1)30例病例中有 9例符合上述 5条学标准 ,拆除矫治器进入保持阶段。 (2 ) 1例患者牙位与肌位不一致 ,5例患者未达到前伸平衡合 ,6例患者未达侧方平衡 ,7例患者存在ICP的不稳定 ,2例患者不符合多项学标准。对上述 2 1例学标准病例采用不同方法处理 :(1)针对问题进一步治疗 ,调整关系 ;(2 )结合垫治疗或采用功能矫治器作保持 :(3)调后拆除矫治器进入保持阶段 ;(4 )应患者强烈要求拆除矫治器进入保持阶段。结论 :对固定正畸治疗病例的作学评价可以提高正畸质量 ,不同的学问题可以     

不同类型咬合板对颞下颌关节紊乱病疼痛患者咀嚼肌肌电的影响

目的:研究松弛型咬合板和稳定型咬合板对急慢性颞下颌关节紊乱病(TMD)疼痛患者颞肌前束(TA)、咬肌(MM)肌电的影响。方法:68例TMD疼痛患者分为急慢性2组,比较分析戴咬合板前和戴咬合板1个月后双侧TA和MM肌电电位。结果:戴板后静息状态下急慢性组患者双侧TA及MM肌电电位均较戴板前明显下降(P<0.05);紧咬状态下急性组戴松弛型咬合板患者双侧TA、MM肌电电位较戴板前明显上升,戴稳定型咬合板患者仅MM肌电电位较戴板前明显上升;慢性组戴松弛型和稳定型咬合板患者MM肌电电位均较戴板前明显上升(P<0.05)。结论:松弛型和稳定型咬合板均对咀嚼肌有松弛作用,松弛型咬合板更能明显缓解TMD急性患者肌紧张。     

重度深覆伴牙列缺损患者的重建

对13例重度深覆(牙合)伴牙列缺损患者(10例兼有颅颌系统功能紊乱症)用肌位咬合垫消除深覆对下颌运动的限制,调整髁突位置,观察2月待(牙合)位稳定,患者自我感觉良好,用铸造支架咬合垫式义齿作(牙合)建修复。(牙合)重建后下颌边缘运动时水平向的位移增大,垂直向的位移减小,息止(牙合)间隙减小,快速开闭口运动速度加快,咀嚼效率提高,肌肉的收缩功能有所改善,说明(牙合)重建修复是成功的,重建了咬合,关节、肌肉的生理平衡。     

在肌力闭合道终点建(牙合)方法的改进

国内外学者认为肌力闭合道终点是建牙合的最适位,作者根据颌位决定牙合的接触状态,上下牙齿尖窝相对可达最稳定颌位的机理,将排有下后牙的牙合托戴入口中,嘱患者下颌处于姿势位时,反复自然咬合,下牙合托上的后牙与上颌堤牙合面反复咬合的印记,即为肌力闭合道终点位。在此位制作的全口义齿患者戴上感觉舒适,临床效果满意,报告如下。一、在肌力闭合道终点建牙合的方法　　作者单位:050081石家庄,解放军52997部队卫生所(贺小红);石家庄和平医院口腔科(刘淑红、贺砚田)　　1.制作牙合托:在上下唇自然闭合的口裂线以下2ｍｍ～3ｍｍ与磨牙后垫中点…     

流体静力牙合垫在TMD诊断和治疗中的应用

目的观察流体静力牙合垫治疗颞下颌关节紊乱病的效果.方法选择5例常规方法治疗效果不明显的颞下颌关节紊乱病患者,先用流体静力牙合垫辅助建立下颌肌位,再制作硬树脂牙合垫保持该位置.结果患者戴流体静力牙合垫一周,大多数症状缓解或消失,治疗后随访1年,疗效稳定.结论流体静力牙合垫可能是一种诊断与治疗颞下颌关节紊乱病的有效辅助装置,有进一步研究的价值.     

儿童替牙期骨性AngleⅢ类错咀嚼肌肌电研究

目的 :研究儿童替牙期骨性AngleⅢ类错与正常的咀嚼肌肌电变化规律。方法 :对 2 0例替牙期AngleⅢ类骨性错儿童及 2 0名正常儿童进行咀嚼肌肌电图检查 ,测量嚼肌深浅层和颞肌前后束在姿势位、牙尖交错咬合位、前伸运动边缘位、后退运动边缘位的肌电活动 ,所得数据进行统计学分析。结果 :骨性安氏Ⅲ类错姿势位嚼肌与颞肌的肌电活动均大于正常 ;牙尖交错咬合位嚼肌、颞肌肌电位均较正常小 ;下颌前伸时颞肌前束肌电显著性高于正常 ;下颌后退时 ,嚼肌显著性高于正常。结论 :替牙期AngleⅢ类骨性错肌电有其特征性 ,提示早期矫治替牙期AngleⅢ类骨性错不仅能解决美观问题 ,更有利于改善咀嚼肌收缩功能 ,减少肌功能对颅面形态的不良影响。     

无牙颌位至最大开口位下颌运动规律的初步探讨

目的：探讨从无牙颌位至最大开口位时下颌颏部及髁突顶部的运动轨迹的规律，分析在无牙颌患者牙尖交错位建He与此运动轨迹的关系。方法：分别对22例无牙颌患者行无牙颌位、牙尖交错位和最大开口位时的头颅侧位X线片拍摄，测定在二三个位置时颏前点、髁突顶点以及相应的面角的改变。结果：颏前部从无牙颌位至牙尖交错位及最大开口位发生向下向后的移位，髁突顶发生向下向前的移位，SNPg角逐渐减小。结论：颏部及髁突从无牙颌位到最大开口位下颌的位置出现旋转性的位移，颏前部及髁突顶部可出现不同的旋转曲线，在此轨迹上有助于帮助确定牙尖交错位建He点。     

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是上下颌牙列之间的静态接触或动态咬合接触关系,以及在口颌系统功能和功能紊乱中控制牙接触的系统各组成成分之间的一种动态的生物学关系。学以咬合研究为中心,探索咬合的生理病理特性及临床应用,理解咬合形态与功能的辩证关系。与颌位是学研究的基本概念,对牙尖交错位、后退接触位、下颌姿势位及正中关系的正确理解在临床工作有重要意义。     

牙合学几个基本概念与研究现状

牙合是上下颌牙列之间的静态接触或动态咬合接触关系,以及在口颌系统功能和功能紊乱中控制牙接触的系统各组成成分之间的一种动态的生物学关系。牙合学以咬合研究为中心,探索咬合的生理病理特性及临床应用,理解咬合形态与功能的辩证关系。牙合与颌位是牙合学研究的基本概念,对牙尖交错位、后退接触位、下颌姿势位及正中关系的正确理解在临床工作有重要意义。     

安氏Ⅱ^1类人群牙尖交错位的平衡与稳定性的分析

目的研究安氏Ⅱ^1类人群肌位到牙位运动过程中的动态咬合接触情况,探讨牙尖交错位的稳定性、肌位一牙位的一致性（平衡性）及其相关的牙胎形态因素。方法对60名未经过正畸治疗的安氏Ⅱ^1类受试者进行检查,采用T-ScanⅡ咬合分析系统记录并分析其肌位到牙位运动过程中的动态骀接触情况,在模型上分析牙殆形态,利用SPSS12．0对数据进行分析。结果①牙尖交错位上的骀力中心点与中线的垂直距离、左右侧殆力差值及骀接触点数目在三次重复测量中均无显著差异;②肌位牙位不调与否的两组间在上下牙弓后段宽度上存在差异;③两组间在Spee曲线深度、Spee曲线流畅性、磨牙近远中向指数等垂直向及矢状向指标上的差异没有统计学意义。结论安氏Ⅱ。类人群具有一定的牙尖交错位的稳定性;肌位牙位的一致性与牙弓后段宽度的协调性有关,而与该人群的垂直向及矢状向的牙殆形态异常无关。     

口腔矫形颌位研究进展与临床应用

提要：口腔矫形颌位通常是用来描述髁突位于舒适的、可重复的、重建牙尖交错牙合时必须依赖的颌位,是患者义齿修复或正畸等口腔治疗后,下颌的生理功能运动颌位。本文从临床操作的角度,及垂直向的关系和髁突位置确定,总结目前争论的几种口腔矫形颌位观点,并认为口腔矫形颌位不是某个单独的点,而是一个可接受的范围,只要能够形成和谐的颌位与牙尖交错牙合关系,牙合能在生理位行使功能,就可以认为矫形颌位的定位是正确的。     

Evaluation of proximal contact strength by postural changes

STATEMENT OF PROBLEM

Proper proximal contact is important for maintaining and stabilizing the dental arch. However, the proximal contact strength (PCS) is not a constant value and can be affected by a variety of factors.

PURPOSE

This study examined the influences of postural changes on the posterior PCS.

MATERIAL AND METHODS

Twelve adults with a normal occlusion and had not undergone prosthetic treatment or proximal restoration were participated in this study. A metal strip was inserted into the proximal surface and removed at a constant velocity. The contact strength was measured in every contact point between canine to second molar in both arches. The PCSs were obtained initially in the upright position, secondly in the supine position and finally in the upright position again. All measurements were repeated after a 2 hour period. Statistical analysis was carried out using the Friedman test (P < .05).

RESULTS

Generally, a decrease in PCS occurred when the posture was changed from the initial upright to supine position, while it increased when the posture was changed from the supine to upright position. A significant change was observed in all areas except for between the canine-first premolar in the maxilla and between the first molarsecond molar in the mandible areas.

CONCLUSION

The posterior PCS, which dentists generally believe to be a static feature of occlusion, is affected significantly by posture.     

The difference between registered natural head position and estimated natural head position in three dimensions

This study determined the intra-rater and inter-rater reliability of re-orientating three-dimensional (3D) facial images into the estimated natural head position. Three-dimensional facial images of 15 pre-surgical class III orthognathic patients were obtained and automatically re-orientated into natural head position (RNHP) using a 3D stereophotogrammetry system and in-house software. Six clinicians were asked to estimate the NHP of these patients (ENHP); they re-estimated five randomly selected 3D images after a 2-week interval. The differences in yaw, roll, pitch, and chin position between RNHP and ENHP were measured. For intra-rater reliability, the intra-class correlation coefficient (ICC) values ranged from 0.55 to 0.77, representing moderate reliability for roll, yaw, pitch, and chin position, while for inter-rater reliability, the ICC values ranged from 0.38 to 0.58, indicating poor to moderate reliability. The median difference between ENHP and RNHP was small for roll and yaw, but larger for pitch. There was a tendency for the clinicians to estimate NHP with the chin tipped more posteriorly (6.3 ± 5.2 mm) compared to RNHP, reducing the severity of the skeletal deformity in the anterior–posterior direction.     

Do occlusal contact areas of maximum closing position during gum chewing and intercuspal position coincide?

Objective

Occlusal contact area (OCA) is most important during the occlusal phase when food particles are being pulverized. OCA is most easily measured statically at the maximum intercuspal position (ICP). However, the assumption of coincidence between dynamic maximum closing position (MCP) and statically determined ICP has not been previously tested. The purpose of this study is to introduce a method of quantifying OCA of all teeth during dynamic mastication to determine whether the OCA at the dynamic MCP during chewing is similar to the statically determined maximum possible OCA.

Design

Thirteen healthy females participated in this study. Morphologic tooth shape data were measured from dental models using an automatic 3D digitizer. Mandibular movement during gum chewing was recorded using an optoelectronic analysis system with 6 degrees of freedom, and ten cycles were selected for analysis. The dynamic OCA was estimated with a measurement system combining 3D tracking of mandibular movements with 3D digitization of tooth shape.

Results

The estimated mean 3D difference between the incisor position at ICP and MCP was 0.129 mm. At the dynamic MCP, the maximum OCA was 98.5% (68.42 mm²) of the maximum possible contact area in the static ICP (69.46 mm²). Both between-subject and within-subject variation were least at the dynamic MCP.

Conclusion

The maximum OCA during chewing is nearly identical to statically determined maximum possible OCA.     

Effects of neuromuscular deprogramming on the head position

Objectives:

The aim of this study was to evaluate the effects of the neuromuscular deprogramming of the mandible on the craniocervical position.

Methods:

Participants (n?=?65) were separated into two groups: 25 untreated controls (10 men and 15 women) and 40 patients (17 men and 23 women) and underwent neuromuscular deprogramming with upper occlusal splints for an average of 6 months and 7 days, before orthodontic treatment. Lateral cephalograms were obtained from each subject in the natural head position (NHP), before and after neuromuscular deprogramming. Craniocervical cephalometric analysis was performed to evaluate craniovertical (NSL/VER), craniocervical (OPT/NSL and CVT/NSL), and cervicohorizontal (OPT/HOR and CVT/HOR) angulation, and the angle of the cervical curvature (OPT/CVT).

Results:

After neuromuscular deprogramming, significant changes in three angles — NSL/VER (P<0·001), OPT/NSL (P<0·001) and CVT/NSL (P<0·001) — were found between the two groups. For the cervical spine position, no significant changes were observed.

Conclusion:

The results indicate that neuromuscular deprogramming using occlusal splint causes significant extension of the head.     

Breathing type and body position effects on sternocleidomastoid and suprahyoid EMG activity

The objective of this study was to determine the effects of breathing type and body position on sternocleidomastoid and suprahyoid electromyographic (EMG) activity. The sample included 18 subjects with upper costal breathing type (study group) and 15 subjects with costo-diaphragmatic breathing type (control group). All individuals had natural dentition and bilateral molar support. EMG recordings at rest and while swallowing saliva were carried out by placing surface electrodes on the left sternocleidomastoid and left suprahyoid muscles. EMG activity was recorded while standing, seated upright, and in the lateral decubitus position. Upper costal breathing type subjects showed a significantly higher suprahyoid EMG activity at rest than costo-diaphragmatic subjects in all body positions studied (mixed model with unstructured covariance matrix). In the lateral decubitus position, both breathing types showed a significantly higher sternocleidomastoid EMG activity at rest and while swallowing saliva. The suprahyoid muscles demonstrated a significantly higher EMG activity at rest as well as in the lateral decubitus position (mixed model with unstructured covariance matrix). These results are relevant because sternocleidomastoid and suprahyoid muscles play an important role in controlling the head posture and mandible dynamics. The neurophysiological mechanisms involved are discussed.