功能性下颌偏斜青春期模型大鼠髁突软骨中血管内皮细胞生长因子的表达

背景：对于功能性下颌偏斜是否会导致骨性的下颌偏斜以及发生功能性下颌偏斜后下颌骨的生长方式是否会发生改变,目前尚存在争议。血管内皮细胞生长因子能够使内皮细胞的渗透性增加、刺激血管内皮细胞的有丝分裂、促进血管生成以及调节骨的形成。 目的：探索大鼠功能性下颌偏斜对其髁突软骨中血管内皮细胞生长因子表达的影响及意义。 方法：选4周龄雄性SD大鼠60只,随机分为对照组(n=20)和实验组(n=40)。实验组大鼠佩戴作者所在课题组自制镍铬合金上前牙冠套,使下颌发生功能性左偏(2.1±0.3) mm,模拟功能性下颌偏斜。 结果与结论：造模后7-28 d功能性下颌偏斜模型大鼠髁突软骨矢状向后部区域偏斜侧血管内皮细胞生长因子的阳性细胞数量较非偏斜侧减少;造模后14-28 d功能性下颌偏斜模型大鼠髁突软骨矢状向中部及冠状向中部区域偏斜侧血管内皮细胞生长因子的阳性细胞数量较非偏斜侧减少,但与对照组接近;造模后14-28 d功能性下颌偏斜模型大鼠髁突软骨冠状向外部区域偏斜侧血管内皮细胞生长因子的阳性细胞数量较非偏斜侧和对照组减少。说明青春期大鼠发生功能性的下颌偏斜后,双侧髁突软骨中的血管内皮细胞生长因子表达存在差异,导致软骨内的成骨活动发生变化,进而可能使大鼠下颌骨的正常生长发育受到影响,提示应尽早矫治功能性下颌偏斜。     

微支抗种植体及不同矫治力作用下髁突软骨中核心结合因子a1的表达

背景：近年来微支抗种植体以其操作简单、创伤小、支抗强等优点被正畸医生广泛应用于口腔正畸临床,但鲜见用于Ⅱ类颌间的牵引。 目的：以微种植体为支抗,探讨不同矫治力促兔下颌前导后髁突软骨中核心结合因子a1蛋白的表达及与髁突改建的影响。 方法：8 周龄健康新西兰大耳白兔随机分为实验组和对照组,实验组根据矫治力的不同分为100 g、200 g、300 g和 400 g组。实验组动物以微型螺钉种植体为支抗,对兔下颌进行Ⅱ类颌间牵引。实验后4周取材,检测髁突软骨中Cbfa1的表达。 结果与结论：下颌持续牵引后,髁突后区各层的厚度明显高于髁突中前部。与对照组相比随矫治力的增加髁突各层厚度增加,髁突软骨中Cbfa1表达也明显增加,至200 g时达到峰值,而后随矫治力的增加,髁突各层厚度逐渐变薄,髁突软骨中Cbfa1表达也逐渐降低(P < 0.05),提示矫治力能影响髁突软骨中Cbfa1的表达,说明适宜的矫治力作用有利于髁突软骨的改建。     

大鼠髁突软骨细胞凋亡与胰岛素样生长因子1的影响

背景：胰岛素样生长因子1参与了髁突软骨生长与改建,是软骨发育关键因子。 目的：探索胰岛素样生长因子1对体外培养大鼠髁突软骨细胞凋亡的作用,以及对凋亡相关因子Bcl-2和Bax mRNA及蛋白表达变化的影响。 方法：体外培养并鉴定出生后1,28 d大鼠髁突软骨细胞后,将每个年龄组的髁突软骨细胞分别分为实验组和对照组。饥饿培养24 h后,实验组加入100 μg/L重组大鼠胰岛素样生长因子1细胞因子孵育48 h,对照组正常培养。 结果与结论：与对照组相比,实验组加入重组胰岛素样生长因子1后,髁突软骨细胞数量增多,增殖速度显著增加(P < 0.05)。实时PCR和Western blot检测显示,加入重组胰岛素样生长因子1培养48 h后,各组髁突软骨细胞中bcl-2 mRNA和蛋白表达增加,bax mRNA和蛋白表达减少(P < 0.05)。 提示胰岛素样生长因子1可以促进新出生及青春期大鼠髁突软骨细胞增殖,抑制其凋亡,并可能通过Bcl-2和Bax介导抑制凋亡。     

颞下颌关节盘前移位对髁状突软骨中纤溶酶原激活剂系统表达的影响

目的研究颞下颌关节盘前移位对关节软骨组织中尿激酶型纤溶酶原激活剂（uPA）系统的影响.方法24只日本大耳白兔在不打开关节囊的情况下建立右侧颞下颌关节盘前移位动物模型,分别于术后4、1、2、4、8d和12周各处死4只动物.常规HE染色观察髁突软骨的形态学变化,并以原位杂交法检测髁突软骨细胞中uPA和纤溶酶原激活剂抑制剂-1（PAI-1）的基因表达变化.结果术后髁突受力区出现一过性的软骨变薄、各层排列紊乱等病理变化.uPA和PAI-1基因转录水平在术后即开始上调,至2周时达到最高水平,至12周时基本恢复至正常水平,与髁突软骨的适应性改建相一致.结论颞下颌关节盘前移位后,关节软骨内uPA系统的变化与关节软骨的适应性改建密切相关.     

周期性张应力促进兔髁状突软骨细胞的增殖

背景：髁状突是下颌最重要的生长区之一,终生具有生长改建能力。在体内条件下,细胞力学的功能研究因其所处生理环境的复杂性、刺激因素传导的不定向性、实验条件的不易控制性而很难得到满意结果,应力刺激对髁状突软骨细胞的直接影响需要进一步行体外研究。 目的：观察周期性张应力对体外培养兔髁状突软骨细胞生长增殖的影响。 方法：体外分离培养及鉴定兔髁状突软骨细胞,在细胞培养至第3代时使用细胞加力装置对细胞施加强度为10%,频率为6循环/min的周期性张应力,作用时间分别为1,6,12和24 h,并设置未加力组作为对照。应用流式细胞仪检测细胞生长周期,应用MTT法分析细胞的增殖活性。 结果与结论：在周期性张应力下,髁状突软骨细胞流式细胞仪检测结果显示在加力6 h和12 h,加力组细胞生长周期开始有显著性变化,在24 h达到实验最大值,差异有显著性意义(P < 0.01)。MTT检测结果示细胞生长活跃,在6,12 h与对照组有明显变化,在24 h达到实验最大值,差异有显著性意义(P < 0.01)。提示周期性张应力可明显促进髁状突细胞增殖,在24 h内具有持续促进作用。 中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程全文链接：     

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.     

下颌骨单侧前上牵引对大鼠颞下颌关节的影响

目的建一种下颌骨单侧前上牵引的大鼠动物模型,以模拟正畸不对称牵引治疗和关节外因素造成的颞下颌关节病,并研究其颞下颌关节盘和髁状突受力后表面超微结构的改变。方法利用外科手术方法在24只SD大鼠左侧下颌角与同侧颧弓前区置入镍钛拉簧,手术不破坏关节区。对照组8只,在下颌角和颧弓区分别用钢丝结扎,但不放置弹簧。弹簧施加的牵引力分别为120g和40g,使下颌骨受到前上方向的持续牵引力,在手术后3、7、14、28d安乐死法处死动物。关节盘和髁状突进行扫描电镜检查。结果本实验成功建立了下颌骨偏移导致颞下颌关节改变的大鼠动物模型。相对于对照组,实验组的加力侧和对照侧颞下颌关节均有不同程度的病理变化。关节盘病变较轻,髁状突病变以轻力组对照侧为重。结论下颌骨单侧前上牵引的大鼠动物模型可以部分模拟关节外不对称因素造成的颞下颌关节改建和病变：包括嚼肌功能紊乱、单侧的颌面肌肉挛缩、疤痕收缩以及正畸不对称牵引治疗等。     

兔髁状突骨上组织Ⅲ型胶原的免疫组织化学研究

采用免疫组织化学方法对兔髁状突骨上组织中Ⅲ型胶原的研究发现，正常对照组Ⅲ型胶原含量较少，主要分布在肥大层浅层的软骨细胞胞浆及胞膜上，一些区域无阳性表达；拔除一侧下颌磨牙后２周、１月和３月时，Ⅲ型胶原的含量均有不同程度的增加，非拔牙侧的表达稍多。提示颞下颌关节的功能负荷改变后，髁状突的软骨发生改建，Ⅲ型胶原参与其改建和修复的过程。     

关节腔注射医用臭氧对早期颞下颌骨关节炎模型大鼠髁突组织学的影响

背景：在临床以及动物实验中均已证实关节腔内注射医用臭氧可有效改善颞下颌关节炎的症状，减缓疾病的发展，但注射医用臭氧的最理想浓度及其范围仍有争议。目的：观察颞下颌关节腔内注射不同质量浓度医用臭氧对颞下颌骨关节炎大鼠髁突软骨的影响。方法：从42只SD大鼠中随机抽取6只作为健康对照组，剩余大鼠采用关节腔内一次性注射碘乙酸钠法建立颞下颌骨关节炎模型，在建模成功的36只大鼠中选择6只作为模型参照组，其余的30只为20,30,40 mg/L医用臭氧组，每组10只。建模成功后医用臭氧组大鼠关节腔内分别注射质量浓度为20,30,40 mg/L医用臭氧，每周1次，连续注射3周，模型参照组和健康对照组分别注射等体积生理盐水，末次注射后1周，取单侧颞下颌关节组织，ELISA法检测髁突软骨中血管内皮生长因子水平，并取另一侧颞下颌关节组织进行苏木精-伊红染色和番红O-固绿染色，应用改良Mankin’s评分法评价颞下颌关节组织病理变化程度。结果与结论：(1)与健康对照组相比，模型参照组、医用臭氧20,30,40 mg/L组大鼠髁突软骨中血管内皮生长因水平显著升高(P <0.05)；与模型参照组、医用臭氧40...     

甲状旁腺激素干预兔下颌骨髁突高位骨折游离复位后的软骨愈合

文题释义：甲状旁腺激素：是一种钙磷调节激素和骨改建调节激素。它可以改善骨小梁的显微结构,提高骨量及骨强度,临床上主要用于治疗绝经后妇女骨质疏松症,促进骨折的愈合。甲状旁腺激素对骨和软骨的再生有着双向调节作用,在持续性高剂量作用下,它可导致骨吸收;间断性低剂量作用下,它可促进骨和软骨增殖再生。 髁突游离骨折：髁突是颌面部骨折好发的部位,临床上将下颌骨髁突骨折分为髁突头部、髁突颈、髁突颈下或髁突基部骨折。髁突高位骨折时,易发生附着于髁突的翼外肌剥脱使其成为游离骨块,复位固定术后可能出现骨愈合不良甚至髁突吸收。 背景：下颌骨髁突高位骨折常伴有软骨的损伤,同时由于附着于髁突的肌肉发生撕脱而成为游离骨块,如何在加快骨愈合同时加快软骨的愈合一直是临床上面临的困难和挑战。 目的：探讨甲状旁腺激素在兔髁突高位骨折游离复位后对髁突软骨愈合的影响。方法：将48只新西兰大耳兔建立髁突高位骨折游离复位固定实验模型,随机分为实验组及对照组,每组24只。术后实验组隔日皮下注射甲状旁腺激素 20 μg/kg,对照组注射生理盐水1 mL;分别在术后1,2,3,4周时处死,取下颌骨髁突标本行组织形态学研究,免疫组织化学和PCR检测髁突软骨中Sox9和基质金属蛋白酶13的表达。实验方案经贵州医科大学动物实验伦理委员会批准(批准号为1700456)。结果与结论：①番红O-固绿染色及苏木精-伊红染色显示实验组中软骨骨折区的软骨细胞数量及软骨基质沉积都较对照组多;②免疫组织化学显示各时期的实验组Sox9因子的表达强度均强于对照组(术后1-3周P < 0.05);实验组基质金属蛋白酶13表达在术后1,2,3周显著低于对照组(P < 0.05);③各时期实验组Sox9 mRNA的表达量均高于对照组(术后1-3周P < 0.05);实验组中基质金属蛋白酶13 mRNA的表达量低于对照组(术后1-3周P < 0.05);④结果说明,间歇性皮下注射甲状旁腺激素,可上调Sox9、抑制早期基质金属蛋白酶13的表达,促进间充质干细胞向软骨转化,加快修复软骨损伤。 ORCID: 0000-0003-0144-4677(谢柳琴) 中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程     

Double mandibular foramen leading to the accessory canal on the mandibular ramus

Purpose

The knowledge of the variation in the mandibular foramen and canal is clinically significant in surgical procedures of the mandible. This study aims to evaluate the anatomical characteristics of double mandibular foramen leading to the accessory canal on the mandibular ramus using cone beam CT.

Methods

The sagittal, cross-sectional, and three-dimensional images of cone beam CT data from 446 patients were evaluated in the presence of double mandibular foramen and the accessory canal passing through the foramen. The accessory canals were classified into two types according to the configuration (forward and retromolar type), and the location of double mandibular foramen was recorded.

Results

The eight double mandibular foramina leading to the accessory canals were observed in six patients out of 446 patients (1.35 % of population). Regarding the configuration of the accessory canal, there were two forward types and six retromolar types. All double mandibular foramina were located above the mandibular foramina on the medial aspect of the mandibular ramus.

Conclusion

Three-dimensional images of cone beam CT data are useful in confirming the presence of double mandibular foramen leading to the accessory canal. The variation may cause failure in the routine mandibular nerve block anesthesia and it is often vulnerable during surgical procedures involving the mandibular ramus. Also, double mandibular foramen is considered as an easy route for tumor cell to spread following the radiotherapy. Therefore, the variation should be carefully investigated using reconstructed cone beam CT images in planning of dental surgery or radiotherapy in the mandible.     

Modelling of mandibular movement

In this paper, the authors presented a novel method to reconstruct individual mandible movement in three dimensions by a virtual articulator system. The system provides a synchronized 3D mandibular movement that faithfully reappear one's natural occlusion movements--sagittal border, lateral, and open-close movements. Movement trajectories are approximated by cubic or high-degree curves modelling. During the whole process, X-ray exposure on human is avoided. The authors apply the optimal methodology to approach the collected samples of movements in order to generate specific occlusion curves and surfaces. The system provides a novel method of mimicking occlusion of individuals. It is a useful tool for recording dynamic movements of an individual in both pre- and post-surgery and also for predicting surgical outcomes.     

Magnetic resonance imaging findings of true bifid mandibular condyle with duplicated mandibular fossa

Bifid mandibular condyle (BMC) is a rare asymptomatic morphological alteration with no predilection for age group or gender. Its morphology varies from a shallow groove to two condylar heads with separate necks, oriented mediolaterally or anteroposteriorly. This report describes an unusual case of anteroposterior bifid condyle in a 39-year-old female patient with the main complaint of mouth-opening limitation and a deviation of the mandible to the left side. Magnetic resonance imaging (MRI) findings revealed a bifid condyle on the left side and duplicated mandibular fossa, with the articular disc over the anterior head. The MRI images in the open-mouth position revealed minimal movement of the condyle. Despite the increased number of mediolateral bifid mandibular condyle cases described in the literature, none of previously reported cases of BMC included an anteroposterior bifid condyle case with two distinct mandibular fossa.     

Human mandibular prenatal growth: bivariate and multivariate growth allometry comparing different mandibular dimensions

Summary Mandibular growth was studied in 36 human fetuses (both sexes) ranging from 13 to 37 weeks of gestation by bivariate and multivariate analyses (bivariate allometry and principal components analysis, PCA). Several mandibular dimensions were measured and correlated with fetal weight. Considering the different mandibular dimensions in sequence of increasing component weights, PCA agreed with bivariate analysis. No mandibular dimension was considered to increase in isometric relationship. PCA showed the following distances with negative allometry: caput mandibulæ-gnathion (both sides), gonion-processus coronoideus (both sides), caput mandibulæ-processus coronoideus (both sides) and gonion-gnathion (right side). On the other hand, the following dimensions grew with positive allometry: goniongnathion (left side) and symphyseal height (both sides). PCA and bivariate analysis showed higher growth rates for the gonion-processus coronoideus distance and symphyseal height on the right side than on the left. All other mandibular dimensions presented more elevated growth rates on the left than on the right side. During the second and third trimesters of prenatal life the mandibular growth was allometrical; the mandibular body grew with more intensity than the ramus in both length and height. The greatest growth rate was found for the height at the symphysis. The angulus mandibulæ presented a negative and slight correlation with the other linear dimensions of the mandible during prenatal life.Abbreviations CM-Gn Caput mandibulæ-gnathion - Go-PC Gonion-processus coronoideus - Go-Gn Gonion-gnathion - CM-PC Caput mandibulæ-processus coronoideus - SH Symphyseal height - AM Angulus mandibulae     

Biomechanical aspects of mandibular growth

The subject of this study was to analyse how functional parameters of stomatognathic systems are influenced by growth. For this purpose, two cephalometric radiographs of 65 patients with class-II-relation treated with functional appliances were superimposed on the occlusal plane. The two patient groups consisted of 32 open bite and 33 deep bite cases. The direction of the condylar growth significantly differed for both cases. Nevertheless the hypothesis could be confirmed that the original functional structure was hardly affected by growth.     

下颌管与下颌后牙的位置关系及临床意义

目的: 为下颌牙种植术等临床口腔外科提供解剖学基础。方法：选取新鲜下颌骨标本10例、成人全牙下颌骨标本18例和20名全牙志愿者,分别暴露出下牙槽神经血管束、下颌管与下颌后牙牙根和CT连续扫描后进行三维重建。观察下牙槽神经、血管的排列关系,用游标卡尺和CT三维重建工作站分别测量下颌后牙牙根至下颌管上壁的距离。结果：下颌管自牙槽窝下方走行,其舌侧骨板较厚;下颌管内的下牙槽血管位于下牙槽神经上方。下颌磨牙的远中根至下颌管的距离均较近中根近。在标本及影像上的第1前磨牙、第2前磨牙、第1磨牙、第2磨牙、第3磨牙牙根至下颌管上壁的距离分别为(8.36±2.34)　mm和(8.42±2.42)mm、(7.36±2.21)mm和(7.52±2.18)mm、(3.22±1.40)mm和(3.36±1.85)mm、(2.96±1.54)mm和(2.84±1.55)mm、(3.64±1.72)mm和(3.88±1.76)mm。结论：（1）下颌后牙至下颌管的距离以第2磨牙最近,由近及远依次为第2磨牙、第1磨牙、第3磨牙、第2前磨牙和第1前磨牙。（2）对选择适宜长度的牙种植体,避免牙种植体损伤下牙槽神经等具有重要意义。     

下颌角整形术对下颌骨应力以及颞下颌关节功能的影响

目的分析基于东方经典美丽分析面罩的下颌角整形术对人体下颌骨及颞颌关节功能的影响。方法获取病人术前和术后头部CT图像数据,通过Simpleware有限元建模软件生成计算模型,利用Abaqus软件观察手术前后模型上的应力分布及数值大小。结果获得了具有良好形态的下颌骨三维有限元模型,根据在不同部位施加不同负荷模拟模型各部分的力学改变,发现手术前后下颌骨部及关节附近的应力分布有差异。结论基于东方经典美丽分析面罩的下颌角整形术,手术前后对病人的下颌骨及颞颌关节附近的应力减小。     

ADAMTSL1 and mandibular prognathism

Mandibular prognathism is characterized by a prognathic or prominent mandible. The objective of this study was to find the gene responsible for mandibular prognathism. Whole exome sequencing analysis of a Thai family (family 1) identified the ADAMTSL1 c.176C>A variant as the potential defect. We cross-checked our exome data of 215 people for rare variants in ADAMTSL1 and found that the c.670C>G variant was associated with mandibular prognathism in families 2 and 4. Mutation analysis of ADAMTSL1 in 79 unrelated patients revealed the c.670C>G variant was also found in family 3. We hypothesize that mutations in ADAMTSL1 cause failure to cleave aggrecan in the condylar cartilage, and that leads to overgrowth of the mandible. Adamtsl1 is strongly expressed in the condensed mesenchymal cells of the mouse condyle, but not at the cartilage of the long bones. This explains why the patients with ADAMTSL1 mutations had abnormal mandibles but normal long bones. This is the first report that mutations in ADAMTSL1 are responsible for the pathogenesis of mandibular prognathism.     

Angiosarcoma of the mandibular gingiva

Angiosarcoma of the oral cavity is extremely rare. A 77-year-old woman consulted to our hospital because of polypoid mass of the mandibular gingival. Physical examination showed polypoid reddish mass measuring 1.5 × 1.5 × 1 cm in the mandibular gingival posterior to the front tooth. Enucleation of the tumor was performed. Grossly, the tumor was not encapsulated. Histologically, the tumor consisted of atypical spindle with hyperchromatic nuclei with nucleoli. Mitotic figures were scattered. Vasoformative channels were present in some areas. The surgical margins were positive. Immunohistochemically, the tumor cells were positive for factor VIII-related antigen, CD31, CD34, vimentin, p53 protein, but negative for pancytokeratin (AE1/3 and CAM5.2), S100 protein, α-smooth muscle antigen, and desmin. The Ki-67 labeling was 60%. A pathological diagnosis of angiosarcoma was made. Radical operation is planned now.