开诱导大鼠颞下颌关节骨关节炎样退变的实验性研究

目的研究过度张口对大鼠颞下颌关节软骨和软骨下骨的影响,建立异常负荷导致的关节炎动物模型。方法 10只6周龄SD雌性大鼠,随机分成两组,实验组被动张口3 h/d,持续5 d,开口度达25 mm。使用Micro-CT对髁突软骨下骨骨密度进行分析,使用甲苯胺蓝染色和免疫组化的方法观察髁突软骨细胞和细胞基质变化。结果实验组软骨下骨表面界限模糊,骨密度下降,关节后区有组织缺损。实验组关节软骨基质Ⅱ型胶原和蛋白多糖表达较对照组下降,软骨层厚度变薄,尤其表现于增殖层的变薄。结论实验性开可以导致大鼠颞下颌关节出现早期的关节炎样变化,这一模型将有助于阐明异常负荷所致的颞下颌关节炎软骨破坏内在机制的研究。     

Clinical course of an antigen induced arthritis model in the rabbit temporomandibular joint

The aim of this study was to investigate clinical features of an antigen-induced arthritis model in the rabbit temporomandibular joint (TMJ) and compare them to those in knee joint (KJ) arthritis. Eighteen adult male New Zealand White rabbits were divided into a TMJ arthritis group and a KJ arthritis group. Monoarthritis was induced unilaterally with ovalbumin and clinical observations, including joint swelling, skin surface temperature (SST) over the joints, and the withdrawal reflex threshold (WRT) to noxious pressure, were performed over a 3 week period. The joints were then evaluated histologically. The WRT was decreased during the 3 weeks after induction of TMJ arthritis, together with mild but significant joint swelling. The arthritic KJ also showed significant swelling and reduced WRT during the 3 week period. A significant increase of SST over the arthritic TMJ was present during the first week, while changes in SST over the KJ were inconsistent. The histological evaluation showed chronic arthritic features in all arthritic joints of both groups and no difference in the severity of arthritis was found between the TMJ and the KJ.     

Quantification of translational and gliding components in human temporomandibular joint during mouth opening

OBJECTIVE: In humans, the opening movement of the mouth requires a complex combination of rotation in the lower temporomandibular joint compartment and of translation in the upper compartment. The aim of the current study was to quantitatively assess the percentage contribution of rotation and translation movements of the mandible at maximum mouth opening in normal, healthy individuals. DESIGN: Free, habitual movements of mouth opening were recorded in 12 men and 15 women aged 19-30 years using an optoelectronic three-dimensional motion analyser. All subjects had a sound, complete, permanent dentitions with Angle Class I jaw relationships, without cast restorations or cuspal coverage, TMJ or craniocervical disorders. For each subject, the mandibular movements at the interincisor point (occlusal plane) were reconstructed, and, using suitable mathematical algorithms, divided into their rotation and gliding components. The relative contribution of the two components to the total movement was calculated for each frame of motion. In particular, the situation at maximum opening was assessed. RESULTS: At maximum mouth opening, on average, men had significantly larger displacement of the mandibular interincisor point (56 mm versus 46 mm) and angle of rotation (34 degrees versus 32 degrees), than women. The percentage of mandibular movement explained by rotation at maximum mouth opening (77%) was not influenced by sex. The degree of rotation was significantly related to the displacement of the interincisor point: in women r2 = 87%, in men, r2 = 45%. CONCLUSIONS: Overall, in normal subjects with a healthy stomatognathic apparatus, mouth opening was more determined by mandibular rotation than by translation.     

小儿颞下颌关节强直手术的麻醉处理

目的: 探讨小儿颞下颌关节强直手术的麻醉和困难气道管理。方法: 回顾性分析43例小儿颞下颌关节强直开口受限,困难气道病例资料,在保留自主呼吸的情况下,分为氯胺酮组（K1组）和氯胺酮复合右美托咪定组（K2组）。K1组和K2组均静脉给予氯胺酮1~2 mg/kg,K2组则追加静注右美托咪定1 μg/kg。患者意识消失后,辅以气管内和咽喉区表面麻醉。采用纤维支气管镜经鼻腔气管插管。插管过程中,根据患者反应小剂量滴定氯胺酮,维持麻醉深度。采用GraphPad Prism 6.0软件对数据进行统计学分析。结果: 所有患儿均在纤维支气管镜下经鼻腔成功气管插管。插管过程中,氧饱和度<95%发生率K2组略低于K1组,差异无统计学意义（P>0.05）。插管过程中追加氯胺酮次数和氯胺酮总剂量K2组显著低于K1组（P<0.05）,插管时心率变化和插管用时K2组显著低于K1组（P<0.05）。结论: 氯胺酮麻醉辅以良好的气管内和咽喉区表面麻醉,可完成小儿颞下颌关节强直开口受限的困难气道纤维支气管镜插管,氯胺酮复合右美托咪定可使小儿困难气道的插管过程更短、更平稳。     

张口训练对伴张口受限的颞下颌关节紊乱病患者最大开口度恢复的短期影响

目的研究主动与被动结合的张口训练对伴张口受限的患者透明质酸钠关节腔注射治疗后短期最大开口度（MMO）恢复的影响。 方法收集2017—2018年就诊于广州医科大学附属口腔医院颞下颌关节科伴张口受限的颞下颌关节紊乱病（TMD）患者49例，所有患者均接受透明质酸钠关节腔注射治疗。其中25例患者术后接受常规健康宣教方案（对照组），另外24例患者术后在常规健康宣教方案基础上结合主动、被动张口训练治疗（张口训练组），并使用t检验、卡方检验、线性回归模型对两组患者MMO恢复情况进行比较。 结果对照组患者在术后2周MMO较张口训练组小3 mm，差异有统计学意义（t = 2.049，P = 0.046），对照组患者在术后4周MMO较张口训练组小4 mm，差异有统计学意义（t = 3.128，P = 0.003）。 结论张口训练对TMD患者术后张口度恢复有积极作用，并可在4周内体现出辅助MMO恢复的优势。     

Mechanical loading leads to osteoarthritis-like changes in the hypofunctional temporomandibular joint in rats

ObjectivesTemporomandibular joint (TMJ) hypofunction secondary to feeding a liquid diet in the growing period leads to morphological hypoplasia. However, few studies have evaluated the results of mechanical loading on the hypoplastic TMJ. This study investigated whether TMJ hypofunction in rats causes osteoarthritis (OA)-like changes when exposed to mechanical loading.DesignMale 21-day-old Wistar rats were divided into four groups. The first group (C) served as the control. In the second group (W), mechanical loading was applied to the TMJ by continuous steady mouth opening (3 h/day for 5 days) from 63 days of age. A jaw-opening device was used to hold the mandible open in the maximal mouth-opening position with a cobalt–chromium (Co–Cr) wire (φ: 0.9 mm). Groups C and W both received a normal hard diet. The third group (L) and fourth group (LW) were fed a liquid diet and group LW were subjected to the same loading as group W. We evaluated the TMJ using micro-CT, toluidine blue staining and immunohistochemistry of matrix metalloproteinase (MMP)-13.ResultsIn group LW in the superior and posterior regions of the condyle, bone volume fraction, trabecular thickness and trabecular number were significantly decreased and trabecular spacing was significantly increased. The ratio of MMP-13 immunopositive cells was significantly higher than in the other groups. OA-like changes were also observed, including reduced thickness of the cartilage, irregularities in the chondrocytic layer, and cell-free areas.ConclusionsTMJ hypofunction in rats is likely to lead to OA-like changes when exposed to mechanical loading.     

How do I manage restricted mouth opening secondary to problems with the temporomandibular joint?

Restricted mouth opening is a common problem that presents to secondary care, and management depends on the primary cause. The most common differential diagnoses related to the temporomandibular joint (TMJ) include muscle spasm secondary to pain, anchored disc phenomenon, irreducible anterior disc displacement, rheumatoid diseases, and ankylosis. In this paper each is considered in turn.     

A mouth opening index for patients with temporomandibular disorders.

Limitation of mouth opening is an important sign of temporomandibular disorders. It is usually measured linearly from the incisal edge of the maxillary incisors to the incisal edge of the mandibular incisors. This measurement has been queried. A new measure of mouth opening, the opening index is suggested. It was shown that the mean opening index differs for groups of patients with a myogenous or arthrogenous temporomandibular joint problem.     

Smallest detectable difference of maximal mouth opening in patients with painfully restricted temporomandibular joint function

Changes in maximal mouth opening reflect the impact of temporomandibular disorders and the effect of a therapeutic intervention. No information about the amount of change in maximal mouth opening with regard to reasoned decision‐making is available. The smallest detectable difference, as a measure of reliability assessment, provides this information and is expressed in the unit of the measurement instrument. Twenty‐five consecutive patients (5 males, 20 females) with a painfully restricted temporomandibular joint participated in this study. Measurements of maximal mouth opening were performed by two well‐trained observers on two separate measurement days, one week apart. The maximal mouth opening measurements were repeated three times. Inter‐observer, intra‐observer, and test‐retest reliability varied between 0.90 and 0.96. Inconsistency in measurement results analyzed in terms of absolute error variance, i.e. the measurement facets plus all the interactions, represented 11% of total variance. The smallest detectable difference of maximal mouth opening varied from 9 to 6 mm. For being successful in painfully restricted temporomandibular joint patients, statistically as well as clinically, the clinician has to measure at least 9 mm of improvement in maximal mouth opening. To reduce the smallest detectable difference from 9 to 6 mm, repeated measurement is necessary.     

牵伸支具对颞下颌关节盘锚固术后患者开口受限的作用评价

目的 :探讨颞下颌关节盘不可复性前移位患者行关节盘复位锚固术后,使用颞下颌关节牵伸支具治疗开口受限的疗效。方法:选择67例颞下颌关节盘锚固术后开口受限患者,其中支具牵伸组32例,对照组35例。对照组进行常规居家康复训练,支具组接受常规居家康复训练加颞下颌关节牵伸支具牵伸。评估患者治疗前与治疗6周后的最大主动开口度、疼痛评分以及下颌功能受限评分(JFLS-8)。采用SPSS 17.0软件包进行统计学分析。结果:随访结果显示,2组患者最大开口度与下颌功能受限评分均显著改善。支具组最大主动开口度(36.7 mm)显著大于对照组(29.1 mm,P<0.05),支具组JFLS-8评分(7.3)显著低于对照组(11.2,P<0.05)。结论 :牵伸支具的使用对颞下颌关节盘锚固术后患者开口度增加及功能改善有很好疗效,值得临床推广应用。     

Angle of mouth opening measurement: realibility of a technique for temporomandibular joint mobility assessment

SUMMARY The maximal interincisal distance added to the vertical overlap is generally used as a measure for temporomandibular joint mobility. However, the length of the mandible also has an influence on this measure. The angle of mouth opening as a measure of temporomandibular joint mobility is independent of the length of the mandible. The aim of the study was to develop a mandibular goniometer to measure the angle of mouth opening and to test its realiability. Ten subjects, two males and eight females (mean age 28.1 years) participated in the study. The measurements were performed during four independent sessions of three measurements each. The results were analysed with ANOVA. Intraobserver variability was found to be 2–0° when the result of all the measurements were analysed, and were found to be 1–2° when the mean value of the sessions were used for analysis. Based on the results of this study it can be concluded that the angle of mouth opening canbe measured reliably.     

Association between maximum mouth opening and area of bony fusion in simulated temporomandibular joint bony ankylosis

The aim of this study was to investigate the quantitative association between active/passive maximum mouth opening (AMMO/PMMO) and the severity of simulated temporomandibular joint (TMJ) bony ankylosis. Twenty-eight male sheep were divided randomly and equally into surgical and control groups. Surgical group animals underwent bilateral TMJ osteotomy during which left lateral pterygoid muscle function was blocked. Control animals did not undergo surgery. Body weight, AMMO/PMMO, and TMJ morphological features were evaluated preoperatively and at 12 and 24 weeks post-surgery. In the surgical group, only the right TMJ complexes with maintained lateral pterygoid muscle function developed TMJ bony ankylosis. The AMMO/PMMO and end-feel distance in the surgical group were significantly lower than those in the control group (P < 0.001, both) at 12 and 24 weeks post-surgery. Moreover, AMMO (r = −0.940 and −0.952, P < 0.001, both) and PMMO (r = −0.944 and −0.953, P < 0.001, both) were negatively correlated with the area (mm²) of bony fusion post-surgery. These findings may be useful for the clinical treatment of early mandibular condyle fracture, with the use of occlusal pads/open-mouth plates to relax the lateral pterygoid muscle and block its function. When bony ankylosis developed in the TMJ, the greater the area of bony fusion, the more limited were AMMO/PMMO.     

Serotonin in an antigen-induced arthritis of the rabbit temporomandibular joint.

The aim was to investigate the joint perfusate concentration of serotonin (5-HT) in antigen-induced monoarthritis of the rabbit temporomandibular joint (TMJ) and knee joint. Thirty adult male New Zealand White rabbits, of whom eight were first used as healthy controls, were divided into TMJ and knee arthritis groups. Unilateral arthritis was induced with ovalbumin intra-articularly and the contralateral joint was sham-induced. The joints were perfused with saline (flow rate, 0.05 ml/min; 10-min intervals during 50 min) 3 weeks later and the 5-HT concentration analysed. After the perfusion, the joints were evaluated histologically. The 5-HT concentration in the initial perfusate from the arthritic TMJ was higher than in both sham-induced and healthy control joints, and from the knee joint arthritis higher than in sham-induced joints. No histological difference in the arthritis was observed between the two groups. This study shows that the 5-HT concentration found immediately after puncture is increased in antigen-induced arthritis of the rabbit TMJ and knee joint.     

Arthroscopy of the rabbit temporomandibular joint

Arthroscopy of the rabbit temporomandibular joint was evaluated experimentally on 22 rabbits. A small arthroscope with so-called "Selfoc"-system was employed. The reaction to arthroscopy was analyzed clinically. Macroscopic dissection and histology were then employed to detect possible pathological changes in the joints at periodic intervals. The established criteria for evaluation of postoperative reactions were erythema, suppuration, weight changes and chewing capacity. The results of this study indicate that the rabbit temporomandibular joint may be arthroscoped with subsequent minor reversible changes. It also seems feasible to assume that temporomandibular joint arthroscopy in humans runs a low risk for postoperative complications.     

Occupational differentiation in dentistry 3. Hypermobility of the temporomandibular joint and condylar position at maximal mouth opening

Hypermobility of the temporomandibular joint is only noted when it interferes with smooth mandibular movements. These interferences may result from a condylar dislocation beyond the temporal eminence at maximum mouth opening. Aim of this study was to test whether the condyle of a symptomatically hypermobile temporomandibular joint is positioned more anterosuperiorly to the temporal eminence at maximum mouth opening than a condyle without hypermobility. Nine persons with a hypermobile temporomandibular joint and 9 control persons participated. Diagnostics were based upon opto-electronic mandibular movement recordings. Condylar positions at maximum mouth opening were assessed by magnetic resonance imaging. A small significant difference in condylar position was found between groups. Condyles of persons with a hypermobile temporomandibular joint moved beyond the temporal eminence. However, this was also true for nearly half of the control persons. This suggests that condylar position alone is not a sufficient condition for symptomatic hypermobility of the temporomandibular joint. Maybe, symptoms of hypermobility only become apparent in combination with a particular line of action of the masticatory muscles.     

Changes in pain and mouth opening at 1 year following temporomandibular joint replacement—a prospective study

We describe the outcome of 46 patients 12 months after partial or total replacement of the temporomandibular joint (TMJ) using the Christensen implant system (TMJ Implants Inc, Golden, CO, USA). The study group comprised 35 women and 11 men; the women were slightly older than the men at the time of operation. We studied three diagnostic groups in detail: patients who had ankylosis, internal derangement, and osteoarthritis. Those with ankylosis were slightly older than the others. Pain decreased over time in all three groups. There was a significant reduction between preoperative pain and that recorded 1 month postoperatively. After this point the pain decreased slowly, and by year 1 it had decreased significantly with respect to preoperative scores. Women reported worse preoperative pain than men, but not significantly so.     

Correlation between direction and severity of temporomandibular joint disc displacement and reduction ability during mouth opening

The most common temporomandibular joint (TMJ) internal derangement is an abnormal relationship of the disc with respect to the mandibular condyle, articular eminence and glenoid fossa‐disc displacement. The aim of our study was to analyse the correlation between partial/complete disc displacement in the intercuspal position (IP) and its reduction in the open‐mouth position (OMP) in both oblique sagittal and coronal planes on magnetic resonance imaging (MRI) in patients with temporomandibular disorders. Multisection MRI analysis of 382 TMJs was conducted in 191 patients with disc displacement according to the RDC/TMD criteria (148 women, 43 men; aged 14‐60 years). The disc position was evaluated on all oblique sagittal and coronal images in the IP and the OMP. Univariate logistic regression analysis showed that the severity of disc displacement in the sagittal plane is a statistically significant predictor of reduction ability during mouth opening (B = 3.118; P < .001). Moreover, the severity of disc displacement in both planes is also a significant predictor of disc reduction in OMP (B = 2.200; P < .05). In conclusion, reduction ability during mouth opening is associated with the severity of disc displacement in IP, in both sagittal and coronal planes. Multisection analysis of all MR images allows distinguishing the correct disc position from disc displacement and can improve the ability to distinguish between various stages of TMJ internal derangement.     

兔TMJ囊内黏连动物模型的建立

目的：介绍一种建立兔颞下颌关节囊内黏连动物模型的方法。方法：手术暴露16只兔右侧的颧突根部、眶下壁和眶后壁处组织,在颧突根部的前下方,用带有弹力橡皮筋的针自下向上垂直穿过关节盘的前伸部,将双股弹力橡皮筋从9.5mm向前牵引至40mm,达1.20N的牵引力,并将其固定于眶骨上制备的小孔中。术后分期进行MRI和内镜检查,确定有、无关节盘移位和黏连形成,随后处死动物取关节标本,以备光镜、电镜研究。结果：所有兔的下颌骨均不同程度地偏向对照侧,且伴有前牙的斜向磨耗。MRI证实,所有关节盘均出现了前移位,部分动物模型的实验侧关节上腔内有黏连带形成。结论：本实验提供了一种较好的建立颞下颌关节囊内黏连动物模型的方法。