混合牙列期身体重心动摇和咬合力的相关性研究

目的：调查混合牙列期身体重心动摇与咬合力之间的关系。方法56名处于Hellman咬合发育Ⅲ期A阶段的健康小学生纳入研究。通过检查咬合平衡中点与中线的距离( X)关系,X≤5 mm被划分为正中组,X>5 mm被划分为偏移组。使用自动姿态分析系统测定了身体平衡相关开闭眼时的重心动摇距离、重心动摇面积。使用牙齿压力感应装置Dental Prescale?测定了咬合接触面积、平均咬合力、最大咬合压力,咬合力和咬合平衡。结果咬合接触面积和咬合力的测试结果男女分别为18.1 mm2、712.2 N和14.1 mm2、541.8 N,差异均具有统计学意义(P<0.05)。咬合平衡中点正中组与偏移组的咬合接触面积、咬合力之间差异具有统计学意义(P <0.05)。咬合平衡中点正中组开、闭眼时期的重心动摇距离、面积明显小于偏移组,咬合平衡与开、闭眼时期的重心动摇距离、面积有关且具有统计学意义(P<0.05)。重心动摇稳定组的咬合接触面积大于动摇组,两者差异具有统计学意义(P<0.05)。结论 Hellman咬合发育Ⅲ期A阶段儿童咬合平衡和人体重心动摇存在相关性,咬合接触面积与身体重心动摇相互影响。     

颞下颌关节紊乱病患者牙合接触特征的研究

目的　研究颞下颌关节紊乱病 (tempromandibulardisorders,TMD)患者的牙合接触特征。方法　应用T ScanII咬合分析仪对 32例TMD患者进行牙尖交错位、前伸及侧方运动的咬合检查并与正常组对照。结果　TMD患者的牙合力中心偏离中线的程度大于对照组 ,闭合时间与牙合分离时间明显较对照组延长 ,早接触出现率明显高于对照组 ,但非工作侧牙合干扰及前伸牙合干扰的出现率与对照组差异无显著性。结论　早接触是与TMD发病有密切关系的牙合因素 ,牙合力中心、闭合时间与牙合分离时间可作为判断TMD病变程度及治疗效果的参考依据。     

The relationship between body balance function and occlusal function during the mixed dentition period

The aim of this study was to investigate the relation between body balance and occlusal balance during the mixed dentition stage. Fifty-six healthy children with Hellman's Dental Age IIIA: (31 boys and 25 girls) with an average age of 8.1 years, were selected from an elementary school. The body balance, distance and area of gravity center movement (GCM) were measured with automatic posture analytical devices. Occlusal abilities were measured with pressure-sensitive sheets (Dental Prescale^®), including occlusal contacts area, average occlusal pressure, maximum occlusal pressure, occlusal force and occlusal balance. Analysis of occlusal balance was determined by separating the middle group (| x | ≤ 5 mm) from the deflection group (| x | > 5 mm) based on the position of occlusal balance center. Similarly, the children were instructed to perform the GCM area of eyes-closed exercise. The first 25% of the participants with the best balance were grouped as the good balance group; and the last 25% with the worse balance were grouped as the bad balance group. Results showed that occlusal contact area and occlusal force of the middle group were more than the deflection group, GCM distance and area of the middle group were less than the deflection group. occlusal contacts area and occlusal force of the good balance group were more than the bad group. Body balance function and occlusal balance function were observed to have mutual influence during Hellman's Dental Age IIIA stage in this study.     

Effects of Occlusal Contact and Its Area on Gravity Fluctuation

Objective:To examine changes in gravity fluctuation caused by experimentally altering the area of occlusal contact.Materials and Methods:Subjects consisted of 15 adult Japanese males with normal stomatognathic function, no missing teeth except for the third molars, and equivalent occlusal contact in the anterior and bilateral posterior regions. Silicon biteplates fabricated for each subject to evaluate gravity fluctuation in relation to changes in occlusal contact area were as follows: RP(−)–OC(+) (entire occlusal surface covered in centric occlusion); RP(+)–OC(+) (entire occlusal surface covered with bite slightly raised); Ant or Pos/RP(+)–OC(+) (anterior or posterior region selectively covered); and RP(+)–OC(−) (only retromolar pads covered, no occlusal coverage).Results:No significant differences in gravity fluctuation were noted between subjects wearing biteplates covering the entire occlusal surface. Subjects wearing biteplates with no occlusal contact showed greater gravity fluctuation than those with occlusal contact. In addition, gravity fluctuation for the Ant/RP(+)–OC(+) group (no occlusal contact in the posterior region) was greater than for RP(+)–OC(+) and Pos/RP(+)–OC(+). However, groups with unilateral occlusal contact in the posterior region exhibited large right and left sway amplitude.Conclusions:These results suggest that occlusal contact, especially posterior occlusal contact, affects gravity fluctuation, and that appropriate occlusion attained by maintaining even occlusal contact in the posterior region is crucial for gravity fluctuation.     

调治疗对改善颞下颌关节紊乱病疼痛症状的疗效评价

目的:探讨调牙合对TMD疼痛症状的疗效。方法:36名有疼痛症状的TMD患者,18例进行调牙合治疗,18例作为对照,进行模拟调牙合。这两组按照病程又分为急性期组和慢性期组。比较治疗前后咬合接触点数和疼痛强度变化,以及咀嚼运动轨迹变化。结果:治疗后,治疗组咬合接触点数显著增加(P<0.05),急性期组即时疼痛无改善(P>0.05),24 h疼痛值明显下降(P<0.05),慢性期组两种痛值均有显著下降(P<0.05)。调牙合治疗对咀嚼运动轨迹的稳定性和形态无显著影响(P>0.05)。结论:建立广泛而稳定的咬合接触关系,对于改善颞下颌关节紊乱病慢性疼痛症状具有明显效果。     

TMD患者咬合接触情况与牙弓宽度的测量分析

目的：通过测量和比较正常人群与TMD患者在牙尖交错位时的咬合接触情况及牙弓宽度情况,探讨这2个解剖特征与TMD发病的相关性。方法：收集120个临床病例分为2组,A组TMD患者50例,B组正常人群（对照组）70例,通过对2组人群的咬合接触情况、牙弓宽度进行测量分析,探讨这2个解剖特征与TMD发病的相关性。结果：牙尖交错位时,TMD患者的无咬合接触牙齿数高于正常人群;牙弓宽度较正常人群窄（P﹤0.05）。结论：TMD发病与咬合接触少,牙弓宽度窄这2个解剖特征有关。     

Occlusion, sternocleidomastoid muscle activity, and body sway: a pilot study in male astronauts

The modifications induced by microgravity on the coordinated patterns of movement of the head, trunk, and limbs are reported on extensively. However, apparently there is little data on the masticatory muscles. In normal gravitational conditions, information from the neck and stomatognathic apparatus play a role in maintaining the body's balance and equilibrium. The current pilot study used normal gravity conditions to investigate the hypothesis of a functional coupling between occlusion and neck muscles and body postural oscillations. The immediate effect of modified occlusal surfaces on the contraction pattern of the sternocleidomastoid muscles during maximum voluntary clenching and on the oscillation of the center of foot pressure was analyzed in 11 male astronauts (aged 31-54 yrs). All subjects were healthy and free from pathologies of the neck and stomatognathic apparatus. Occlusal splints were prepared using impressions of their dental arches. The splints were modeled on the mandibular arch, had only posterior contacts, and were modified to obtain a more symmetric, standardized contraction of the masseter and temporalis muscles during teeth clenching. Surface EMG activity of the sternocleidomastoid muscles was recorded during a maximal voluntary clench with and without the splint. Sternocleidomastoid potentials were standardized as percent of the mean potentials recorded during a maximum contralateral rotation of the head, and the symmetry of the EMG waves of left- and right-side muscles was measured. Body sway was assessed with and without the splint, either with eyes open or closed. The variations of the center of foot pressure were analyzed through bivariate analysis, and the area of the 90% standard ellipse was computed. Within each visual condition (eyes open or closed), the difference between the areas of oscillation measured with and without the splint was computed. Muscular activity was more symmetric with the splint. The area of oscillation of the center of foot pressure was larger without the splint than with the splint, both with eyes open and eyes closed. The modifications, induced by the occlusal splint in the sternocleidomastoid muscles' symmetry, and center of foot pressure differential area with closed eyes, were significantly related (p < 0.05): the larger the increment in muscular symmetry, the smaller the area of oscillation with the splint as compared to without the splint. A functionally more symmetric maxillo-mandibular position resulted in a more symmetric sternocleidomastoid muscle contraction pattern and less body sway. Modifications in the contraction of the masticatory muscles may therefore affect the whole body.     

T-ScanⅢ应用于牙根纵裂患者咬合特征分析的初步研究

目的:探讨牙根纵裂(vertical root fractures,VRF)发生的牙合因素。方法:应用T-ScanⅢ咬合分析仪对8例VRF患者及个别正常牙合者分别进行正中及侧方咬合记录,定量数据牙合力百分比值(tooth occlusal force percent-ages,T-FP)、双侧牙合力百分比值(two sides force percentages,TS-FP)、牙合力不对称指数(asymmetry index of occlusal force,AOF)、闭合时间(occlusion time,OT)、侧方牙合分离时间(disclusion time,DT)采用配对资料的符号秩和检验分析,定性数据早接触、牙合力中心点 (center of force,COF) 位置及偏移方向采用Fisher确切概率法检验分析,检验水准α=0.05,P<0.05差异有统计学意义。结果:VRF组T-FP、AOF、OT、DT大于正常对照组,差异具有统计学意义(P<0.05);2组COF位置差异具有统计学意义(P<0.05),TS-FP、早接触发生率、COF偏移方向差异无统计学意义(P>0.05)。结论:VRF患者全口牙合力分布不均衡,双侧 牙合力分布不对称,牙合接触稳定性差。     

Evaluation of recovery in lip closing pressure and occlusal force and contact area after orthognathic surgery

PurposeThe purpose of this study was to evaluate the relationship between lip closing force, occlusal contact area and occlusal force after orthognathic surgery in skeletal Class III patients.Subjects and methodsThe subjects consisted of 54 patients (28 female and 26 male) diagnosed with mandibular prognathism who underwent sagittal split ramus osteotomy with and without Le Fort I osteotomy. Maximum and minimum lip closing forces, occlusal contact area and occlusal force were measured pre-operatively, 6 months and 1 year post-operative.ResultsMaximum and minimum lip closing forces, occlusal contact area and occlusal force increased with time after surgery, however a significant increase was not found in the occlusal contact area in women. In increased ratio (6 months/pre-operative and 1 year/pre-operative), the maximum lip closing force was significantly correlated with the occlusal contact area (P < 0.0001).ConclusionsThis study suggested that orthognathic surgery could improve the occlusal force, contact area and lip closing force, and an increase ratio in maximum lip closing force was associated with an increased ratio in occlusal contact area.     

Relationship between masticatory function, dental arch width, and bucco-lingual inclination of the first molars

The aim of this study was to clarify the influence of masticatory function on dental arch forms. We evaluated the relationship between the masticatory movement path and occlusal force (as masticatory function) and the dental arch width and first molar bucco-lingual inclination. The subjects were 60 healthy adult females (mean 23.4 years; S.D. 1.6 years) without previous orthodontic treatment or functional abnormalities in the temporomandibular joint. Furthermore, the subjects were divided into a wide group (W-group) and a narrow group (N-group) based on mean maxillary inter-molar width in Japanese females. The masticatory path was recorded using gnathohexagraph system. Maximum occlusal force was measured using a simple type occlusal force meter. And subjects’ arch width and bucco-lingual inclination of the first molars was measured. W-group showed larger arch width and the first molar was more upright on the buccal side compared with N-group. Furthermore, the lateral component of masticatory movement and maximum occlusal force was large in W-group compared with N-group. In the group which strong occlusal force and grinding type mastication had wide arch width and the mandibular first molars upright on the buccal side.     

Comparison of dynamic occlusal contacts during chewing between children with primary dentition and normal adult females

ObjectiveInvestigation of dynamic occlusal contacts when food particles are being pulverized during chewing is of interest for many researchers and clinicians. However, measurement of dynamic occlusal contacts during chewing is difficult, and differences between children and adults have not been established. The purpose of this study is to test the hypothesis that dynamic occlusal contacts of children differ from those of adult females.Subjectsand methods: Thirteen healthy children (4–6 years of age; mean age 5 years, 7 months) and thirteen adult females (18–26 years of age; mean age 20 years, 7 months) with normal occlusion participated in this study. Occlusal contact area (OCA) was estimated with a developed measurement system combining 3-D digitization of tooth shape with 3-D tracking of mandibular movements (1) during the closing stroke, (2) at the maximum closing position (MCP), and (3) during the opening stroke. OCA at static maximum intercuspation (ICP) was also estimated.ResultsAt the MCP, the children's OCA was less than 76.4% of the contact area seen at the ICP. The timing of maximum OCA in children was shifted more towards the opening stroke compared with adults, and the OCA remained greater during opening in children than adults. The occurrence of the MCP was less stable in children than in adults, both between subjects and within subjects.ConclusionsWe conclude that both the amount of OCA and the pattern of occlusal contacts during the occlusal phase of chewing completely differ between children and adult females.     

磨牙症患者（牙合）接触特征的研究

目的 :研究磨牙症患者牙合接触的特征 ,探索牙合因素与磨牙症的关系。方法 :用T -scanII型咬合分析仪对 2 3名磨牙症患者与 13名对照者分别进行正中牙合位、前伸及侧方运动的咬合检查 ,测量闭合接触时间、前伸与侧方牙合分离时间 ,观察平衡侧牙合干扰出现的情况。结果 :磨牙症患者的闭合时间小于对照组 ;侧方牙合分离时间比对照组长 ;与对照组相比多数磨牙症患者出现平衡侧牙合干扰。结论 :平衡侧牙合干扰可能是与磨牙症有密切关系的重要的牙合因素     

Changes in occlusal function after extraction of premolars: 2-year follow-up

Objective:To determine the effects of extraction and the number of teeth extracted on changes in occlusal function by measuring occlusal contact area and force before and after orthodontic treatment with a fixed appliance.Materials and Methods:Female patients treated with a fixed appliance were divided into nonextraction (n = 36), two maxillary premolar extraction (n = 31), and four premolar extraction (n = 18) groups. Bite pressure-sensitive films were used to analyze the occlusal contact area and force. Measurements were performed before treatment (Pre-Tx), immediately afterward (After-Tx), and 2 years later (2Y After-Tx). The data were analyzed using a linear mixed model and the post hoc Bonferroni test.Results:The occlusal contact area and force after treatment decreased significantly compared with Pre-Tx values but were increased 2 years later in all groups. There were no significant differences in occlusal contact area or force during the entire observation period among the three groups (P > .05). The occlusal contact area and force in the nonextraction and two maxillary premolar extraction groups recovered to Pre-Tx levels 2 years later (P > .05). The occlusal contact area in the four premolar extraction group was significantly lower than the Pre-Tx level after 2 years of retention (P < .05).Conclusions:The occlusal contact area and force showed a tendency to decrease immediately after treatment and then gradually increase to pretreatment levels during the observation period. However, the occlusal contact area did not recover fully after 2 years in the four premolar extraction group.     

T-ScanⅡ咬合分析数据作为早期牙隐裂调(牙合)干预指标的应用研究

目的:探讨牙隐裂(cracked tooth syndrome,CTS)患者动态咬合特征,分析其异常(牙合)因素,探索T-Scan Ⅱ咬合力分析系统作为牙隐裂调(牙合)干预指标之一的可行性.方法:T-ScanⅡ咬合力分析系统记录15名早期牙隐裂患者调胎干预前后牙尖交错位(ICP)及左右侧方咬合的过程.定量测定(牙合)接...     

磨牙症患者磨损特征的研究

目的 观察磨牙症患者（牙合）磨损的部位与程度,分析磨牙运动的特征及相关的影响因素。方法 对64名磨牙症患者进行检查及模型分析,对每个牙磨损程度与部位进行评分比较。结果 左右同名牙磨损无差异,上下同名牙磨损不完全相同;尖牙的磨损最严重;侧方磨动所致的磨损远远大于前伸磨动所致的磨损;牙弓的中段磨损最严重。结论 磨牙运动主要以侧方运动为主,以尖牙磨损最严重,尖牙磨损对磨牙症的发生发展是一重要的促进因素。?     

不同咬合接触对单颗后牙种植修复咬合平衡的影响

目的: 研究不同咬合接触方式对咬合平衡指数的影响,为改进种植修复咬合平衡提供依据。方法: 选择2018年12月—2019年12月上海市普陀区眼病牙病防治所行单颗后牙种植修复的患者24例,均采用标准化种植流程,按照修复体与对颌牙将被调整到的咬合接触紧密程度不同,随机分为A、B 2组,分别使用12 μm和20 μm咬合纸进行调整,使咬合纸在修复体和对颌牙咬紧时恰好可以有阻力抽出。应用T-scan咬合力分析仪分别测定修复前及修复当天、3个月、6个月、12个月和18个月牙尖交错位时咬合力分布情况,换算成咬合平衡指数。采用SPSS 21.0软件包对数据进行统计学分析。结果: 2组在修复前咬合平衡指数分别为（-0.389+0.066）和（-0.368+0.055）,修复当天分别为（-0.249+0.069）和（-0.283+0.056）,差异无统计学意义（P>0.05）;修复3个月时分别为（-0.052+0.022）和（-0.169+0.063）,6个月时分别为（-0.025+0.015）和（-0.088+0.045）,12个月时分别为（-0.010+0.008）和（-0.029+0.016）,18个月时分别为（-0.000+0.000）和（-0.006+0.008）,2组咬合平衡指数均呈逐渐增加至0的趋势,A组绝对值远小于B组,但A组的上升幅度远大于B组,差异有统计学意义（P<0.05）。结论: 单颗后牙种植修复能逐渐恢复咬合平衡,选用12 μm咬合纸调整修复体与对颌牙咬合接触紧密程度,能更早获得咬合平衡。     

正常牙尖交错位咬合的T-Scan Ⅱ系统分析

目的:观察正常人群从下颌姿势位向牙尖交错位闭合时咬合接触的情况及其与时间的关系。方法:利用T-Scan Ⅱ扫描系统对30位咬合关系正常,没有肌功能紊乱和颞下颌关节紊乱病的受试者进行咬合检查,记录其咬合力分布情况、咬合接触时间。采用SAS 9.0软件包对数据进行统计学分析。结果:受试者在牙尖交错位状态下记录的两侧咬合力量分布无显著性差异(P=0.3242);受试者牙尖交错位时的咬合力占累积最大力的百分比平均为96.89%,可信区间为90.88%~100%;平均咬合接触时间为(0.2015±0.086)s,两者无相关性(P>0.05)。结论:咬合力中心的位置、牙尖交错位时的咬合力与累积最大力的差值、咬合接触时间均可作为临床上判断咬合是否健康的指标,亦可应用于咬合治疗疗效的评判。     

全口义齿平面前点确定方法的光弹性研究

目的 探讨全口义齿平面前点的确定方法与光弹性效果。方法 选择2015年2月—2017年7月到我院诊治的10例牙列缺失患者作为研究对象,同时制作了由哥特式弓轨迹顶点(义齿A组)、自然咬合法(义齿B组)确定平面前点的全口义齿,测定义齿的咬合指标、光弹性效果与应力情况。结果 调前,义齿A组的咬合接触时间多于义齿B组,左右侧力百分比差值与力中心距离到中线的距离少于义齿B组,对比都有统计学意义(P＜0.05);调后两组上述指标对比都无统计学意义(P＞0.05)。义齿A组与义齿B组测定都显示牙尖工作斜面与平面的夹角呈越向远中越大的趋势,相邻角度差值也有向远中增大的趋势,组间对比无差异(P＞0.05)。义齿A组与义齿B组模型的光弹性材料符合模型实验的基本要求,两组的舌向集中的正中与前伸最大应力值均小于解剖(P＜0.05),在两组对比无差异(P＞0.05)。结论 采用哥特式弓轨迹顶点与自然咬合法确定全口义齿平面前点能维持义齿平衡,其中哥特式弓轨迹顶点确定平面前点的全口义齿的咬合能达到更好的咬合关系。     

咬合重建对大鼠三叉神经节P物质表达影响的研究

目的：研究咬合重建对大鼠三叉神经节P物质（substance P,SP）表达的影响。方法：Wistar雄性大鼠30只,随机分为3个实验组及相应的正常对照组,每组5只。实验组动物间断磨除右上、下颌磨牙牙冠至龈下,有2组分别第3周、第9周停止磨牙,任其自行萌出,恢复咬合关系。双侧三叉神经节（trigeminal ganglia,TG）切片行SP免疫组织化学反应（SABC法）。光镜观察拍片,并用Image Pro Plus5.1图像分析软件进行测定。结果与对照组对照。SPSS10.0软件行统计分析。结果：单侧咀嚼实验组咀嚼侧和非咀嚼侧TG内SP免疫阳性神经元百分比与对照组比较显著降低（P〈0.01,P〈0.05）,其非咀嚼侧明显低于咀嚼侧（P〈0.01）。早期恢复咬合实验组TG内免疫阳性神经元百分比与对照组比较无差别（P〉0.05）,其咀嚼侧与非咀嚼侧比较无差别（P〉0.05）。晚期恢复咬合实验组TG内免疫阳性神经元百分比与对照组比较显著降低（P〈0.01,P〈0.05）,其非咀嚼侧明显低于咀嚼侧（P〈0.05）。结论：早期恢复咬合关系TG内SP表达可恢复正常,晚期恢复咬合关系SP表达不能恢复正常,SP参与了单侧咀嚼引起的颞颌关节病的病理变化过程。     

Periodontal tactile sensation and occlusal loading condition of autotransplanted teeth: A retrospective pilot study

Purpose

The objectives of this retrospective pilot study were: (1) to examine the occlusal properties (periodontal tactile sensation, occlusal force support ability, dynamic tooth mobility, occlusal force, contact area, preferred chewing side and main occluding area) of autotransplanted teeth with no clinical complications after transplantation (postoperative periods from 1 to 7 years).