负荷改变对颞下颌关节软骨和软骨下骨的影响

负荷改变是颞下颌关节紊乱病的重要病因之一.通过负荷改变,软骨细胞可以分泌多种细胞因子和酶控制软骨基质的合成与分解.近年来,研究发现软骨下骨改变在骨关节病发病过程中起着重要作用.软骨下骨的硬化与骨关节病的发生、发展密切相关,而不只是骨关节病发生的结果,因此骨关节病的治疗有必要兼顾两者,既要关注软骨,又要对软骨下骨退变早作预防.本文就负荷改变对颞下颌关节软骨和软骨下骨影响的相关研究作一综述.     

颞下颌关节骨关节病的病理改变特征

人颞下颌关节是具有特殊的功能，结构的滑液关节，它易于罹患骨关节病，本文对患ＴＭＪＯＡ时ＴＭＪ关节软骨、软骨下骨组织、关节滑膜、关节盘及关节滑液的各种病理改变进行了系统的描述。ＴＭＪＯＡ与颞下颌关节紊乱综合征及颞下颌关节内紊乱症密切相关，但其因果尚不明确。对ＴＭＪＯＡ病理改变特更深层次的研究对于揭示ＴＭＪ关节病的发病机理，准确、有效地进行该疾病诊治均具重要意义。     

骨关节病时关节软骨细胞基质基因表达的改变

关节软骨的研究对于探讨骨关节病（OA）的发病机制和治疗方案具有重要意义。Ⅱ型胶原和蛋白多糖聚合体（aggrecan)是软骨细胞启动修复机制的主要产物。在骨关节病时,其合成和降解也将发生特异性变化。本文综述了有关文献,指出关节软骨Ⅱ型胶原和aggrecan比例失衡是OA的病因之一。在OA进程中,Ⅱ型胶原和aggrecan特殊的合成和降解方式也将加剧OA病变。结合TMJOA的特点,提出软骨化生是决定TMD转归的关键。     

颞下颔关节骨关节病临床病理研究

目的：研究颞下颌关节骨关节病的病理特点。方法：选取30例颞下颌关节骨关节病患者，均进行手术治疗。所有获取的新鲜标本用4％的福尔马林固定，然后用5％的甲酸脱钙，梯度酒精脱水，石蜡包埋，5μm厚连续切片，HE染色，光镜观察。结果：关节软骨表层纤维毛糙，排列紊乱，纤维水肿，互相分离，有的纤维断裂，出现水平裂隙及垂直裂隙；增殖带变薄甚至消失，有的软骨层明显增厚，增殖带内未分化间充质细胞较多；肥大带内可见到较多软骨细胞，细胞内有空泡形成；钙化层与非钙化层之间出现明显的潮标线；密质骨变薄，软骨直接与松质骨骨髓腔相通。结论：骨关节病的主要病理特征表现为关节软骨的破坏和增生，有时伴随软骨下骨质的破坏与改建。     

颞颌关节软骨及骨关节病的研究进展

骨关节病是一种严重危险人类健康的慢性，进行性骨关节损害。其病理及发病机制尚不完全清楚，临床上也缺乏有效的治疗方法。关节软骨的损害是骨关节病的首要表现。关节软骨的研究对揭示颞颌关节骨关节病的发病机制及临床上采取积极有效的治疗有着重要意义。本文综述了近年来关于软骨结构、并对影响软骨代谢，可能导致骨关节病发生的因素进行了讨论。     

颞下颌关节软骨下骨改建

颞下颌关节改建机制是正畸功能矫形和颞下颌关节紊乱病研究的主要内容。随着研究的深入,软骨下骨作为一个生物力学和生理学特性均有别于关节软骨和骨松质的基本功能单位,其在压力传递和关节改建中的重要性逐步凸现出来。本文就软骨下骨的解剖、功能、特性、病变类型以及与颞下颌关节改建的关系作一综述。     

颞下颌关节骨关节病临床病理研究

目的:研究颞下颌关节骨关节病的病理特点.方法:选取30例颞下颌关节骨关节病患者,均进行手术治疗.所有获取的新鲜标本用4%的福尔马林固定,然后用5%的甲酸脱钙,梯度酒精脱水,石蜡包埋,5 μm厚连续切片,HE染色,光镜观察.结果:关节软骨表层纤维毛糙,排列紊乱,纤维水肿,互相分离,有的纤维断裂,出现水平裂隙及垂直裂隙;增殖带变薄甚至消失,有的软骨层明显增厚,增殖带内未分化间充质细胞较多;肥大带内可见到较多软骨细胞,细胞内有空泡形成;钙化层与非钙化层之间出现明显的潮标线;密质骨变薄,软骨直接与松质骨骨髓腔相通.结论:骨关节病的主要病理特征表现为关节软骨的破坏和增生,有时伴随软骨下骨质的破坏与改建.     

颞下颌关节骨关节病动物模型的建立

为了研究胶原酶这一基质金属蛋白酶（ＭＭＰｓ）在骨关节病的发病机制中重要作用，本实验采用胶原酶关切腔内一次性注射方法，建立障碍 颞下颌关节骨关节病（ＴＭＪＯＡ）实验动物模型。该动物模型的建立为ＴＭＪＯＡ病理实质、发病机理及治疗方法的研究提供具了具有可比性的，便利的实验条件。     

一氧化氮合成酶抑制剂治疗骨关节病研究进展

一氧化氮合成酶抑制剂能够抑制一氧化氮合成酶的生物活性，防止颞下颌关节内产生过量的一氧化氮，阻止其对关节软骨的破坏，逐渐恢复软骨细胞合成蛋白多糖及胶原的能力，促进软骨修复，是治疗骨关节病的较理想的方法。     

颞下颌关节紊乱病相关疼痛与年龄、性别及骨关节病影像学改变的关系

目的探讨颞下颌关节紊乱病（TMD）患者相关疼痛和年龄、性别及骨关节病（OA）影像学改变的关系。方法1206例TMD患者根据年龄、性别、是否疼痛及影像学改变分组；计算颅下颌关节紊乱指数（CMI）并进行统计学分析。结果TMD相关疼痛女性多见，45岁以下各年龄组间CMI差异有统计学意义，女性OA影像学改变发生率高于男性（P〈0．001）。结论TMD相关疼痛和OA影像学改变易发生于女性，临床病例中16～30岁女性患者最多，并存在TMD相关疼痛和OA影像学改变。     

Jaw-muscle activity changes after the induction of osteoarthrosis in the temporomandibular joint by mechanical loading

AIMS: To examine the effect of mechanical loading on the induction of temporomandibular joint osteoarthrosis (TMJ OA). METHODS: Mechanical stress was applied to the rat TMJ by forced jaw opening of 3 hours a day for 5 days. The electromyographic (EMG) activity of the masseter and digastric muscles was continuously monitored by radio-telemetry. It was characterized by the total time each muscle was active (duty time), the number of bursts, and the average burst length. For histologic analysis, rats were sacrificed before, immediately after, and 3 weeks after the period of forced jaw opening. RESULTS: The condylar cartilage revealed OA-like lesions with a decrease in the number of chondrocytes immediately after forced jaw opening. Three weeks later, the OA-like lesions were repaired to some extent. After the forced jaw opening, the duty time of the masseter increased, whereas the duty time of the digastric decreased significantly (P < .01) at the 5% activity level. Three weeks later, the masseter duty time had decreased and the digastric duty time had slightly increased, returning to the levels observed before forced jaw opening. CONCLUSION: These results suggest that mechanical overloading of the TMJ induced OA-like lesions with a simultaneous influence on jaw muscle activity, especially at the low activity level. This might imply that muscle activity adapted to reduce the effects of (forced) joint overloading.     

Condylar atrophy and osteoarthrosis after bimaxillary surgery

Radiographic evidence of condylar atrophy was seen in 12 patients out of 206 patients who underwent surgical orthodontic treatment. All 12 patients had the same dentofacial deformity, high-angle mandibular retrognathia (Class II open bite), and all but one had bimaxillary surgery. The etiologic factors are discussed. The dentofacial deformity is considered to be the main reason for condylar resorption, but orthognathic surgery is supposed to stimulate the progress of the disease by increased loading, disk displacement, and immobilization.     

Severe bone resorption and osteoarthrosis after miniplate fixation of high condylar fractures. A clinical and radiologic study of thirteen patients

Thirteen cases of high condylar fracture treated by open reduction and fixation with miniplates were monitored for an average of 18 months postoperatively. Satisfactory functional results were achieved clinically in all but one patient. Radiologically, however, signs of condylar resorption and osteoarthrosis were diagnosed in all patients. In four patients with associated multiple fractures of the facial bones, rapid complete resorption of the condyle was observed. These changes were markedly more severe than those observed in our previous study, in which osteosynthesis was performed by transosseous wiring and subsequent intermaxillary fixation for 3 to 7 weeks. Indications for rigid and nonrigid fixation in the surgical treatment of condylar fractures are discussed.     

Are internal derangement and osteoarthrosis linked to changes in clinical outcome measures of arthrocentesis of the temporomandibular joint?

PURPOSE: Arthrocentesis and hydraulic distention of the temporomandibular joint (TMJ) have been described as an effective modality in the treatment of patients with clinical findings consistent with the diagnosis of disc displacement without reduction. The purpose of this study was to investigate whether the magnetic resonance (MR) imaging variables of internal derangement (ID) and osteoarthrosis (OA) and the presence of capsulitis/synovitis (C/S) may be linked to changes in TMJ signs and symptoms associated with the performance of arthrocentesis and hydraulic distention. PATIENTS AND METHODS: The study consisted of 27 TMJ pain patients, who were assigned a clinical unilateral TMJ diagnosis of ID type III (disc displacement without reduction). Bilateral sagittal and coronal MR images were obtained immediately preoperatively and at a 2-month follow-up to establish the presence or absence of ID and OA. TMJ pain level of function and mandibular range of motion were assessed preoperatively and compared with the respective 2-month follow-up findings. RESULTS: The pretreatment data revealed a significant relationship between the clinical finding of TMJ pain and the MR imaging findings of ID (P <.001), ID type (P <.001), and OA (P <.05). At 2-month follow-up, clinical evaluation showed a significant reduction in TMJ pain during function (P <.001), a significant reduction in the clinical diagnoses of ID type III (P <.05), and a significant increase in mandibular range of motion (P <.05). There was no change in the prevalence rates of associated MR imaging diagnoses of TMJ ID and/or OA. CONCLUSION: The study findings suggest that clinical pain is related to TMJ-related MR imaging findings of ID and OA. These diagnoses proved not to be linked to changes in therapeutic outcome measures of TMJ pain and mandibular range of motion.     

Osteoarthritis, osteoarthrosis, and idiopathic condylar resorption

The term "osteoarthritis" has classically been defined as a low-inflammatory arthritic condition. The term "osteoarthrosis," a synonym for osteoarthritis in the medical orthopedic literature, has recently come to be identified in the dental/temporomandibular joint (TMJ) disorders literature with any noninflammatory arthritic condition that results in similar degenerative changes as in osteoarthritis. The term "idiopathic condylar resorption," also known as "progressive condylar resorption," is described as a dysfunctional remodeling of the TMJ manifested by morphologic change, decreased ramal height, progressive mandibular retrusion in the adult, or decreased mandibular growth in the juvenile. This article discusses the diagnosis and management of osteoarthritic TMJ disorders and idiopathic condylar resorption.     

颞下颌关节骨关节炎与关节内紊乱关系的研究

目的 :探讨颞颌关节骨关节炎 (TMJOA)与颞颌关节内紊乱 (TMJID)的关系。方法 :利用MRI金标准 ,对 44例颞颌关节紊乱病患者 88侧关节完成开闭口T1加权成像 ,观察盘突关系和骨改变。结果 :88个关节中40 .9% ( 3 6/88)表现为TMJID ,13 .6% ( 12 /88)表现为TMJOA ,骨改变的分布情况 :正常盘突关系 (NDCR)关节中 2个 ,破坏和骨赘各 1个 ;可复性关节盘前移位 (ADDR)关节中 3个全部表现为骨破坏 ;不可复性关节盘前移位 (AD DWR)关节中 7个 ,表现为髁状突变平 3个 ;表现为破坏、骨赘、硬化和短小各 1个 ,统计学分析发现TMJOA与TMJID具有显著相关性。结论 :TMJOA的发生与关节结构紊乱显著相关。由于TMJOA可独立于TMJID之外而单独存在 ,目前将TMJOA看作是与TMJID密切相关的另一类疾病较为合适。