颞下颌关节骨性部分的测量和分析

本文观察测量并分析了颞下颌关节的形态结构,建立了能较客观反映该关节形态的15项指标的正常值。用3项特征指数,即关节窝指数、关节结节指数和髁突指数,能较好地反映该关节的几何形态,并表达其功能部位的相互关系,以及用频数分布曲线反映其分布规律。本文认为,男性的颞下颌关节显著大于女性,而左、右侧之间,有无咬(牙合)组之间的差别均不显著。本文结果可为该关节的临床研究、病变分析乃至人工颞下颌关节的设计,提供形态学依据。     

用于分析面形态与颞下颌关节生物力学关系的三维有限元模型的建立

目的为研究(牙合)面形态变化对颞下颌关节应力影响的规律,建立包括下颌牙列(牙合)面形态及双侧髁突的三维有限元模型.方法尸头1具,平行于眶耳平面作CT扫描,获取下颌骨几何参数;取石膏模型,以三维扫描仪对牙列(牙合)面扫描(精度0.5mm);将石膏模型参数与CT参数换算到同一坐标系下,在髁突上方设均厚类关节盘,关节盘顶及下颌角作约束设计,经划分网格生成有限元模型.结果建立了包括双侧髁突、类关节盘及下颌牙列在内的用于分析咬合与颞下颌关节关系的三维有限元模型.结论采用本方法可建立研究(牙合)面形态与颞下颌关节应力关系的三维有限元模型.     

骨性Ⅲ类儿童前牵引后颞下颌关节改变的相关性分析

背景：前牵引治疗能有效改变儿童骨性Ⅲ类错(牙合)患者的颅颌面结构关系,同时也改变了颞下颌关节结构。但是关于前牵引颞下颌关节改变和颅颌面变化的相关性,尚无确切研究结果。目的：分析儿童骨性Ⅲ类错(牙合)患者前牵引矫治前后牙颌面改变与颞下颌关节改变的相关性,探讨前牵引矫治对儿童颞下颌关节的影响。方法：上颌前方牵引矫治儿童骨性Ⅲ类错(牙合)29例,男16例,女13例,年龄8-11岁,对前牵引矫治前后牙颌面和颞下颌关节的改变进行头影测量分析、坐标系统定位测量分析,数据分析采用配对t检验和Mann-Whitney检验及Pearson相关性分析。结果与结论：前牵引治疗前后骨骼矢状方向发生明显改变,颞下颌关节窝和髁状突在X轴改变明显,在Y轴改变不明显,颞下颌关节后间隙明显减小;相关性分析发现,颞下颌关节与牙颌面结构改变之间存在中等相关关系。结果表明,前牵引矫治后,牙颌面与颞下颌关节结构均有明显改变,且颞下颌关节骨改建与牙颌面改变之间存在中等相关关系,但没有密切相关关系。     

不同功能位颞下颌关节盘影像解剖学研究进展

颞下颌关节 (temporomandibularjointTMJ)是人体颌面部稳定而灵活的左右联动关节。CT、MRI等影像技术的广泛应用 ,促进了颞下颌关节动态解剖的发展。本文就不同功能位颞下颌关节盘的解剖及影像解剖文献作一综述。1　关节盘的解剖1.1　关节盘的形态闭口齿正中咬合位关节盘多为椭圆形 ,有上、下两面 ,其形态分别与关节窝和髁突相适合。上面与关节窝接触 ,从后向前分为三段 ,后端形突、中段形凹、前端较平。下面与髁突邻接 ,分两段 ,后段与髁突的关节面接触 ,呈凹型 ,前段向下凸。关节盘周缘与关节囊相连 ,同时 ,盘内侧、外侧分别与髁突的…     

咬合接触对颞下颌关节生物力学影响的有限元研究

目的建立用于研究咬合接触与颞下颌关节生物力学关系的三维有限元模型,并设计不同的工况来分析不同咬合接触情况下颞下颌关节应力的变化规律。方法尸体头颅1具,平行于眶耳平面作CT扫描;取石膏模型,以三维扫描仪对牙列(牙合)面扫描;将石膏模型扫描参数与CT扫描参数换算到同一坐标系下,在髁突上方设均厚的类关节盘,关节盘顶及下颌角作约束设计,经划分网格生成有限元模型。工况一:左侧下颌不同牙位咬合接触面加载;工况二:在包括左侧下颌第二磨牙的颞下颌关节三维有限元模型上,设计下颌第二磨牙牙尖交错(牙合)、远中方向和颊侧方向三种加载部位的工况,研究不同工况下双侧髁突处应力分布变化的规律。结果(1)建立了包括双侧髁突、类关节盘及下颌牙列在内的用于分析咬合与颞下颌关节关系的三维有限元模型。(2)咬合加载牙位不同,双侧髁突应力效应不同,髁突外、中、前、顶等处为承受较高压强的区域。(3)咬合加载部位牙面承载形态不同,双侧髁突应力效应也不同,其变化包括应力性质和应力的分布特点等方面,远中加载和颊侧加载时分别可致加载侧髁突内极和加载对侧髁突内极应力集中。结论咬合接触部位及方向变化可影响髁突应力分布。     

中国全新世女性颞下颌关节尺寸的时代变化*

目的：研究中国全新世女性颞下颌关节测量性状的时代变异问题。方法：对中国北方地区新石器时代 （47 例）、青铜铁器时代（112 例） 和近代（26 例） 成年女性13 项颞下颌关节测量性状进行测量, 并运用 SPSS19.0 软件对各时代测量性状数据进行平均值计算和不同时代间差异的假设检验。结果：髁突、冠突在全新世 厚度变薄,髁突的变薄主要在新石器- 青铜铁器时代,冠突的变薄主要在青铜铁器- 近代。髁突面积在全新世缩小, 尤其在青铜铁器时代- 近代缩小的幅度更大。下颌窝深度在全新世变化不大。髁突面积/ 下颌窝面积缩小,其变化 主要发生在新石器- 青铜铁器时代。结论：全新世女性颞下颌关节仍在进化,女性颞下颌关节的演变特点与男性 颞下颌关节有相似之处,也有差异。     

3 种不同髁突头部形态全颞下颌关节假体的生物力学研究

目的 对个性化聚醚醚酮(polyetheretherketone, PEEK)全颞下颌关节假体进行三维建模,通过有限元分析 3 种不同髁突头部形态(原型、80% 原型及圆柱形)假体的应力分布特征,评估 3 种不同髁突头部形态对 PEEK 全颞 下颌关节假体稳定性、关节运动以及关节窝的影响。 方法 建立颅颌面及 PEEK 全颞下颌关节假体有限元分析模 型Ⅰ、Ⅱ、Ⅲ,分析在牙尖交错位、切 颌位、左侧磨牙颌位及右侧磨牙颌位 4 种不同咬合条件下,关节窝假体、髁突 假体、钛钉最大应力,下颌骨应力、应变分布,以及 3 种模型的最大位移。 结果 3 种模型 PEEK 全关节假体及螺钉 的最大应力分别为 35. 22、16. 73 MPa,均低于其材料的屈服强度;模型Ⅰ、Ⅱ、Ⅲ下颌骨最大应力分别为 41. 47、42. 84、 56. 92 MPa,应变分别为 3. 896×10-3 、2. 175×10-3 、4. 641×10-3 。 3 种模型的最大位移为 209. 0 μm,位于模型Ⅲ的左侧下 颌角处。 结论 3 种不同髁突头部形态的个性化 PEEK 全颞下颌关节假体均显示出较为均匀的应力应变分布,但髁 突头部形态为 80% 原型假体的力学效果更好。 研究结果为 PEEK 全颞下颌关节的设计提供一定理论依据。     

髁突骨折术中颞下颌关节盘复位有限元模型的建立与初步分析

目的：建立正常的颞下颌关节有限元模型和髁突骨折切复内固定手术模型,为颞下颌关节系统的生物力学研究提供数字平台。方法获取正常颞下颌关节CT和MRI扫描图像数据,使用Mimics、Geomagic、ANSYS等软件建立颞下颌关节三维有限元模型和髁突骨折外科手术模型并进行初步的生物力学分析,以验证模型的有效性。结果建立了颞下颌关节系统的三维有限元模型和髁突骨折外科模型具有良好的生物形态。结论根据CT、MRI影像和解剖参数,利用医学影像三维建模软件Mimics以及逆向工程软件Geomagic Stadio可以精确、可行地构建颞下颌关节系统的表面网格模型,并在有限元分析软件Ansys中构建颞下颌关节系统的三维有限元模型。该模型还原了TMJ的生物力学环境。     

计算机辅助三维重建下的颞下颌关节形态发生

目的:观察颞下颌关节的形态发生,初探形态变化与组织分化的联系.方法:光镜下观察并描记胎儿期颞下颌关节窝、关节盘、髁状突及Meckel软骨组织学图像,PC机行三维重建.结果:颞骨关节面从中线向侧方逐渐沉积,覆盖原始髁突始基;软骨始基的下后缘改建迅速,稍后软骨中血管长入,并常与其上方颞骨软骨内成骨同时出现;骨化区初现于Meckel软骨下缘开始扭曲处.结论:胎儿期颞下颌关节各部分外形不断改变,与组织分化关系密切.     

颞下颌关节三维动态磁共振成像研究及生物力学分析

目的通过在多层面二维动态MR成像上获取颞下颌关节组织的运动数据,构建颞下颌关节的三维动态模型,并进行初步生物力学分析。方法 MRI检查采用GE Signa 1.5T TwinSpeed超导型磁共振扫描仪。选取2例无症状男性志愿者行颞下颌关节MRI检查,将图像数据导入Mimics软件,构建颞下颌关节的三维模型,动态分析张口幅度和关节盘横径的量化关系。结果建立的颞下颌关节三维动态模型清晰显示三维动态盘髁关系及关节盘在动态过程中的形态变化;志愿者1张口/关节盘横径拟合直线为:y=-0.03x+14.44,相关系数R2=0.591,志愿者2相关拟合直线为:y=-0.061x+13.48,相关系数R2=0.306,志愿者张口位置与关节盘横径变化具有直线趋势,关节盘横径随着张口幅度的加大而呈现减小的趋势,颞下颌关节盘对于髁突的包绕程度与张口幅度呈反比。颞下颌关节盘纵径厚度在张口活动中后带外份及中带内份的变化幅度最大。结论通过颞下颌关节二维动态MR成像数据可构建三维动态模型立体动态地观察颞下颌关节运动,可直观、准确显示颞下颌关节盘髁关系,可作为颞下颌关节二维静态MR成像的有益补充,弥补常规MRI检查的局限。     

RECENT ADVANCES IN THE MOLECULAR BASIS OF PATHOGEN RECOGNITION AND HOST RESPONSES IN THE URINARY TRACT

The interactions between pathogenic bacteria and their hosts are dynamic and multifaceted. The presence of bacterial pathogens at mucosal surfaces triggers a vigorous inflammatory response that is essential for controlling the replication and spread of the intruder. However, inflammation also damages host tissue, and thus its induction must be tightly regulated. The molecular mechanisms underlying the stimulation of an inflammatory response by pathogenic bacteria have been elusive. The urinary tract infection (UTI) model system has been a powerful tool for understanding the interactions between cells of the innate host defense system, as well as the bacterial factors and host receptors involved in eliciting host cell activation. This article will discuss several recent findings that enhance our understanding of inflammatory effector mechanisms and pathogen recognition in the context of a mucosal surface.     

Using sensitivity analysis to validate the predictions of a biomechanical model of bite forces.

Biomechanical modelling has become a very popular technique for investigating functional anatomy. Modern computer simulation packages make producing such models straightforward and it is tempting to take the results produced at face value. However the predictions of a simulation are only valid when both the model and the input parameters are accurate and little work has been done to verify this. In this paper a model of the human jaw is produced and a sensitivity analysis is performed to validate the results. The model is built using the ADAMS multibody dynamic simulation package incorporating the major occlusive muscles of mastication (temporalis, masseter, medial and lateral pterygoids) as well as a highly mobile temporomandibular joint. This model is used to predict the peak three-dimensional bite forces at each teeth location, joint reaction forces, and the contributions made by each individual muscle. The results for occlusive bite-force (1080N at M1) match those previously published suggesting the model is valid. The sensitivity analysis was performed by sampling the input parameters from likely ranges and running the simulation many times rather than using single, best estimate values. This analysis shows that the magnitudes of the peak retractive forces on the lower teeth were highly sensitive to the chosen origin (and hence fibre direction) of the temporalis and masseter muscles as well as the laxity of the TMJ. Peak protrusive force was also sensitive to the masseter origin. These result shows that the model is insufficiently complex to estimate these values reliably although the much lower sensitivity values obtained for the bite forces in the other directions and also for the joint reaction forces suggest that these predictions are sound. Without the sensitivity analysis it would not have been possible to identify these weaknesses which strongly supports the use of sensitivity analysis as a validation technique for biomechanical modelling.     

EXPLORING THE VALIDITY AND PREDICTIVE POWER OF AN EXTENDED VOLUNTEER FUNCTIONS INVENTORY WITHIN THE CONTEXT OF EPISODIC SKILLED VOLUNTEERING BY RETIREES

The current study examined the structure of the volunteer functions inventory within a sample of older individuals (N = 187). The career items were replaced with items examining the concept of continuity of work, a potentially more useful and relevant concept for this population. Factor analysis supported a four factor solution, with values, social and continuity emerging as single factors and enhancement and protective items loading together on a single factor. Understanding items did not load highly on any factor. The values and continuity functions were the only dimensions to emerge as predictors of intention to volunteer. This research has important implications for understanding the motivation of older adults to engage in contemporary volunteering settings.     

Modeling the biomechanics of articular eminence function in anthropoid primates

One of the most prominent features of the cranial component of the temporomandibular joint (TMJ) is the articular eminence (AE). This bar of bone is the primary surface upon which the condyle translates and rotates during movements of the mandible, and is therefore the primary point at which forces are transmitted from the mandible to the cranium during loading of the masticatory apparatus. The shape of the AE is highly variable across primates, and the raised eminence of humans has often been considered a defining feature of the human TMJ, yet few data exist to address whether this variation is functionally significant. This study used a broad interspecific sample of anthropoid primates to elaborate upon and test the predictions of a previously proposed model of AE function. This model suggests that AE inclination acts to resist non-normal forces at the TMJ, thereby maximizing bite forces (BFs). AE inclination was predicted to covary with two specific features of the masticatory apparatus: height of the TMJ above the occlusal plane; and inclination of the masticatory muscles. A correlate of this model is that taxa utilizing more resistant food objects should also exhibit relatively more inclined AEs. Results of the correlation analyses found that AE inclination is strongly correlated with height of the TMJ above the occlusal plane, but less so with inclination of the masticatory muscles. Furthermore, pairwise comparisons of closely related taxa with documented dietary differences found that the AE is consistently more inclined in taxa that utilize more resistant food items. These data preliminarily suggest that variation in AE morphology across anthropoid primates is functionally related to maximizing BFs, and add to the growing dataset of masticatory morphologies linked to feeding behavior.     

Dose-dependent sustained local release of dexamethasone from biodegradable thermosensitive hydrogel of PEG-PLGA-PEG triblock copolymers in the possible prevention of TMJ re-ankylosis (Arakeri's TMJ release technique)

Temporomandibular joint (TMJ) ankylosis is a devastating anatomico-pathological condition which severely affects the quality of human health. Over the last 70 years various treatments have been described to treat this distressing condition. But no single method has uniformly produced successful results. Although various surgical techniques have been improved periodically, the treatment results remain inefficient due to its recurrence as TMJ re-adhesion. Since recurrence remains as a problem in many cases, the TMJ ankylosis presents a major therapeutic challenge in head and neck surgery. The re-ankylosis is a unique phenomenon that so far has defied a full and logical explanation, based upon biological and mechanical factors that are linked together in a coherent fashion. Many factors have been implicated in the development of re-adhesion following TMJ surgery. But still the mechanism by which the TMJ re-adhesion develops is unclear. Hence, TMJ ankylosis demands an alternative effective treatment modality to prevent its recurrence as re-ankylosis. This paper postulates some critical biological factors responsible for re-ankylosis based on which a novel treatment modality is also proposed.     

Relationship between sex, age, and the minimum thickness of the roof of the glenoid fossa in normal temporomandibular joints

This autopsy study investigates the minimum thickness of the roof of the glenoid fossa of grossly normal temporomandibular joints (TMJ) and correlates this to gender and age. This study was based on 49 TMJ specimens collected from 26 male and 23 female cadavers whose mean age at death was 73.8 years (range=50-96). No information was available about TMJ symptoms before death. A digital micrometer was used to measure the minimum thickness of the glenoid fossae. Comparisons were made based on gender and age. The mean value for the minimum roof thickness of all joint specimens examined was 0.8 mm. Mean values for male and female specimens were 0.8 and 0.7 mm, respectively, which were not significantly different. In addition, no age-related differences were observed. The average thickness was 0.7 mm for individuals in their fifties, 0.8 mm for those in their sixties and seventies, 0.6 mm for those in their eighties, and 0.8 mm for individuals in their nineties. Although these data indicate that the minimum thickness of the glenoid fossa of the TMJ is not significantly correlated with sex or age in patients 50 years of age and older, they nonetheless provide additional information about normal TMJ anatomy, particularly with regard to our knowledge of joint remodeling and function in the disease and non-disease states. Thickness of the glenoid fossa has also been implicated as a factor in facial trauma involving superior displacement of the mandibular condyle into the middle cranial fossa. The thickness of the glenoid fossa is also of potential interest during surgeries involving the glenoid fossa, such as TMJ arthroplasty or joint reconstruction.     

BRIDGING THE GAP: SIMILARITY AND DIFFERENCE BETWEEN PSYCHOANALYTIC AND SYSTEMIC THERAPEUTIC ORIENTATIONS

ABSTRACT In recent times much has been made of integrative tendencies and common ground between therapeutic orientations, previously locked into highly oppositional frames. This is evident in the rapprochement between psychoanalysis and cognitive-behavioural therapy in adult mental health. It is a trend that is also evident in the shifting relationship between systemic and psychoanalytic orientations. This paper begins with an overview of factors influencing the wider integrative ethos before considering the specific circumstance of the relationship between systemic family therapy and psychoanalysis. The paper considers both the past history of oppositionality between the two orientations as well as some current developments that might facilitate a more creative dialogue. Particular attention is paid to issues of similarity and difference between the therapeutic relationship in systemic family therapy and the psychoanalytic framework of the transference/countertransference. Implications for therapeutic technique are explored. The aim is not to minimize difference but to encourage cross-fertilization between these therapeutic orientations in the interest of patients/families who may benefit from an integrated response.     

Mice deficient in biglycan and fibromodulin as a model for temporomandibular joint osteoarthritis

The temporomandibular joint (TMJ) within the craniofacial complex is unique. In humans, the TMJ can become diseased resulting in severe and disabling pain. There are no cures for TMJ disease at this time. Animal models of TMJ disease are scarce, but some exist, and they are described in this paper. We present in greater detail one animal model that is deficient in two extracellular matrix (ECM) proteoglycans, biglycan (BGN) and fibromodulin (FMOD). Doubly deficient BGN/FMOD mice develop premature TMJ osteoarthritis (OA). In order to explore the mechanistic basis of TMJ-OA, tissues from the condyle of mutant mice were examined for their relative capacity to differentiate and undergo apoptosis. Our data show that there is a redistribution of the critical ECM protein, type II collagen, in mutant mice compared with controls. Mutant mice also have increased apoptosis of the chondrocytes embedded in the articular cartilage. We speculate that the overall imbalance in apoptosis may be the cellular basis for the abnormal production of structural ECM proteins. The abnormal production of the ECM could, in turn, lead to premature erosion and degradation of the articular surface resulting in TMJ-OA. These data underscore the importance of the ECM in controlling the structural integrity of the TMJ.