An interspecies comparison of the temporomandibular joint disc

The temporomandibular joint (TMJ) disc plays a critical role in normal function of the joint, and many disorders of the TMJ are a result of disc dysfunction. Previous quantitative TMJ characterization studies examined either the human or a specific animal model, but no single study has compared different species, in the belief that differences in joint morphology, function, and diet would be reflected in the material properties of the disc. In this study, we examined topographical biochemical (collagen, glycosaminoglycan, and DNA content) and biomechanical (tensile and compressive) properties of the human TMJ disc, and also discs from the cow, goat, pig, and rabbit. Regional and interspecies variations were identified in all parameters measured, and certain disc characteristics were observed across all species, such as a weak intermediate zone under mediolateral tension. While human discs possessed properties distinct from those of the other species, pig discs were most similar to the human, suggesting that the pig may be a suitable animal model for TMJ bioengineering efforts.     

兔颞下颌关节盘前移位后关节软骨细胞的凋亡及其意义

目的　观察颞下颌关节盘前移位动物模型的关节软骨细胞凋亡动态改变 ,探讨软骨细胞凋亡的意义。方法　日本大白兔 2 6只 ,实验组 2 0只行手术 ,在不打开颞下颌关节囊的情况下制成关节盘前移位动物模型 ,采用原位末端标记法 (TUNEL)观察术后不同病变时期关节区组织学的改变和软骨细胞凋亡的情况。结果　术后 1～ 2周为髁突软骨细胞凋亡的高峰期 ,集中于功能区的肥大层和增殖层。 4～ 6周进入关节改建期。结论　关节盘前移位后可激活软骨细胞的凋亡机制 ,启动关节软骨的适应性改建     

Use of cross-linked bovine pericardium as a disc replacement in the rabbit temporomandibular joint

Chemically purified bovine pericardial membrane, highly cross-linked with monomeric glutaraldehyde, was implanted in the TMJ area in ten adult rabbits in place of partially excised discs. Sham controls had the temporal aspect of the TMJ scraped with a scalpel. After 3 months, the whole TMJ area was processed for morphologic and scanning electron micrographic (SEM) evaluation. Evidence was found of the disintegration of the implanted pericardium, which was extensively infiltrated by inflammatory cells. The collagen matrix of the membrane was distended and dissociated, showing signs of degradation by its stainability with trichrome stain. It was concluded that cross-linking of a collagenous structure such as pericardium does not prevent it from being resorbed. It is suggested that the cytotoxic residues of polymeric glutaraldehyde within the implant may render the implant more resistant to cellular degradation.     

Autogenous dermal grafts for repair of temporomandibular joint disc perforations

Perforations of the temporomandibular joints (TMJs) disc were made in the rabbits and repaired with autogenous dermal grafts. The healing process was investigated histologically. Twenty-one rabbits (forty-two TMJs) were divided into 3 experimental groups. Group 1. Six TMJs in which the superior aspects of the discs were exposed by the incision of the articular eminence. Group 2. Fifteen TMJs in which the discs were perforated. Group 3. Twenty-one TMJs in which the dermal grafts were sutured on the disc perforations. The results obtained were as follows: In group 2, all perforations were not repaired, except in one case. In group 3, 14/19 grafted disc perforations were repaired. One week after surgery, young, loose, collagenous tissue from the synovial membrane lined the margins of the perforations. Two weeks after surgery, vascularity from the synovial membrane and young collagen fibers were seen in the area of the repaired perforations. Four weeks after surgery, long and thick collagen fibers bridged the perforations.     

Autogenous dermal grafts for repair of temporomandibular joint disc perforations

In five Macaca fascicularis monkeys bilateral 5-mm perforations of the intra-articular disc were followed by unilateral repair with autogenous dermal grafts. The monkeys were killed at three, six, 12, 24, and 36 weeks after surgery. The temporomandibular joints (TMJs) were removed en bloc, decalcified, and sectioned in the sagittal plane for histologic examination. All of the control untreated disc perforations, with the exception of one, failed to heal. With all of the grafted disc perforations, viable dermis and fibrous connective tissue proliferation were seen in the area of the repaired perforation. Therefore, autogenous dermal grafting appears to be an acceptable technique for repair of the damaged disc in degenerative joint disease of the TMJ.     

Arthroscopic surgery of the temporomandibular joint: comparison of two successful techniques

We have compared two techniques of arthroscopic surgery for advanced internal derangement of the temporomandibular joint (TMJ). Patients with stage III or above TMJ internal derangement, who had not responded to three months of non-surgical treatment, were prospectively and randomly assigned to one of two types of treatment. One group had arthroscopic lysis and lavage (ALL) and the other had ALL plus arthroscopic anterolateral capsular release (AALCR). All patients were assessed preoperatively, and at 1, 3, 6, and 12 months postoperatively. Thirty-five patients (41 joints) had ALL and 66 patients (73 joints) had AALCR. The only significant difference was at 1 month, when the ALL group could not open their mouths as far as the AALCR group (P < 0.01). Both groups had significantly less pain in the joint and better jaw opening one year postoperatively. The stage of disease did not affect the outcome. Both ALL and AALCR gave good results in the management of advanced internal derangement of the TMJ. Unless early wide mouth-opening is required, the less invasive procedure of lysis and lavage should be chosen.     

Effects of experimental defects of the articular disc of the temporomandibular joint in rats

Triangular defects were made in different locations of the disc in rat temporomandibular joints. After 3 months the following effects were observed. Central defects had become rounded without gross changes in the mandibular head. Peripheral defects were enlarged towards the centre, occasionally accompanied by condylar hyperplasia. Microscopically the cartilagenous covering of the mandibular head in all operated cases was characterized by thickening, dispersion of cells normally closely packed in the intermediate zone, and the constant appearance of a tear parallel to the surface.     

改良切口关节盘锚固术治疗颞下颌关节盘不可复性前移位的临床评价

目的: 评价应用改良切口关节盘锚固术治疗颞下颌关节盘不可复性前移位的临床疗效。方法: 选取2014年9月—2016年9月我院颞下颌关节专科就诊的24例（30侧）颞下颌关节紊乱病患者,采用改良切口颞下颌关节盘锚固术进行治疗, 分析术前、术后6个月不同时期患者的疼痛值、开口度的变化及MRI影像学表现,采用SPSS17.0软件包中的t检验评价手术效果。结果: 治疗前平均开口度为（23.63±3.31）mm(17~29 mm),治疗后平均开口度为（38.00±2.30）mm(32~42 mm),治疗后开口度≥35 mm 的患者占 87.5%（21/24）;疼痛直观模拟标尺（visual analogue scale,VAS）值术前为29.76±23.35（0~80）,术后6个月为3.71±7.91（0~50）,术后6个月的开口度及VAS值均与治疗前有显著差异（P<0.05）。MRI影像学评价有效率达96.67%（29/30侧）,所有病例均无并发症发生。结论: 颞下颌关节盘锚固术能有效治疗颞下颌关节盘不可复性前移位,在复位关节盘的前提下,显著改善开口度和缓解疼痛。     

兔颞下颌关节盘移位与骨关节病关系的评价

目的评价颞下颌关节盘移位与骨关节病的关系。方法通过手术方法将２５只大耳白兔的颞下颌关节盘前移，术后１、２、４、８、１２周进行组织病理学检查。结果１１侧手术关节为部分关节盘前移位，８侧为完全性关节盘前移位，６侧为关节盘穿孔。部分关节盘前移位出现早期退行性改变和后期生理性改建，完全性关节盘前移位和关节盘穿孔出现退行性改变和严重的骨关节病。结论颞下颌关节盘前移位的程度与骨关节病有关，关节盘前移位越明显，越易出现骨关节病     

Surgical treatment of internal derangements of the temporomandibular joint: evaluation of two techniques

One hundred ten cases of internal derangement of the temporomandibular joint were treated by high condylectomy (47) and eminectomy (63) in combination with discorrhaphy and disc repair. Preoperative and postoperative findings (greater than 24 months follow-up) relating to mandibular mobility, pain, and stability of occlusion were compared. Both procedures resulted in a reduction in symptoms, but differences in postoperative findings were observed. Each procedure resulted in increased translation, with eminectomy patients exhibiting greater opening distances at endstage evaluation. In addition, a greater incidence of residual deviation to the affected side occurred in the majority of high condylectomy patients. Although pain was reduced in both groups, less residual pain was observed in the eminectomy group. Alteration in maxillomandibular centric relation was a rare finding, seen only in two high condylectomy patients. Possible factors contributing to these differences are discussed.     

Healing of surgical incisions in the disc and retrodiscal tissue of the rabbit temporomandibular joint

The purpose of this study was to evaluate histologically the healing potential of surgical incisions placed in various areas of the TMJ disc and retrodiscal tissue. Eight weeks after surgery, it was found that incisions completely within retrodiscal tissue had healed and had a normal appearance. Incisions at the junction of the disc and retrodiscal tissue also had healed, but at a slower rate and with more random orientation of the collagen fibers. Defects within the disc had not healed, however, and degenerative changes had developed in the hard and soft tissues. The implications of these observations are discussed.     

Facial nerve injury during surgery of the temporomandibular joint: a comparison of two dissection techniques

Changing the dissection technique for gaining access to the temporomandibular joint decreased the incidence of facial nerve injury from 25% to 1.7%. This decrease can be attributed to the elimination of both development of a skin flap and dissection of tissue overlying the lateral capsule. Normal anatomic variation in the distribution of facial nerve branches may relate to the incidence of clinically apparent injury.     

Intraoperative comparison of single- and double-puncture techniques in temporomandibular joint arthrocentesis

The objective of this study was to compare techniques for temporomandibular joint (TMJ) arthrocentesis intraoperatively and to determine the ease of performance of these techniques for the physician. A total of 33 TMJ treatments were done using single-puncture arthrocentesis (SPA) type 1, SPA type 2, and double-puncture arthrocentesis (DPA) (n = 11 in each treatment group) between December 2013 and December 2017. A retrospective analysis of the duration of the procedure (minutes), occurrence of complications, number of cannula relocations, and ease of the procedure was performed. Ease of the procedure was measured using a Likert-type visual analogue scale (VAS; 0–10). All measurement variables were recorded intraoperatively, and related data were analyzed statistically. Significant differences were found between SPA type 2 and the other techniques in terms of procedure duration and ease of the procedure (P < 0.05). No significant differences were found in the occurrence of complications or number of cannula relocations between the techniques (P > 0.05). Compared to the other TMJ arthrocentesis techniques, SPA type 2 is easier, and physicians can perform it in a shorter time.     

Mechanisms of disc displacement in the temporomandibular joint

The sign of 'clicking' in the temporomandibular joint is not a normal phenomenon. It is, in fact, often the first indication of potential myofascial pain or temporomandibular joint pain dysfunction syndrome and as such should be detected early and diagnosed correctly. Clicking is a cardinal sign of altered function within the joint, the aetiology for which can only be diagnosed from a sound knowledge of anatomy and physiology. With this background it is possible to ascertain whether the cause is essentially biochemical, neuromuscular, or occlusal in nature or multifactorial components of all three categories. An attempt has been made to provide background knowledge in order that a correct diagnosis can be made.     

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.     

Changes in chewing pattern after surgically induced disc displacement in the rabbit temporomandibular joint.

PURPOSE: This study investigated whether surgically induced disc displacement (DD) in the rabbit temporomandibular joint leads to joint dysfunction. MATERIALS AND METHODS: Fourteen adult Japanese white rabbits were divided into two groups. Eight animals had surgically induced DD, and 6 were used as a sham operation group. Jaw movement trajectories during chewing were recorded preoperatively and 2 weeks after induction of DD. Postoperative recordings after administration of a nonsteroidal anti-inflammatory drug (NSAID) were also performed to eliminate any influence of joint pain on chewing. Vertical and horizontal ranges of chewing movement, duration of the opening and closing phase, and total cycle of chewing were analyzed. Thereafter, the presence of induced DD was confirmed histologically. RESULTS: In the sham group, the rhythm and pattern of chewing were almost the same as preoperatively. In the experimental group, increase in the cycle duration and decrease in the vertical and horizontal ranges of movement were observed. When the sham and experimental groups were compared, there was a decreased ratio of vertical movement in the experimental animals. There was no effect of preadministration of the NSAID in either the DD or sham group. All of the experimental animals had total anterior DD histologically. CONCLUSION: Changes in the chewing pattern of the experimental animals occurred from mechanical interference of the displaced disc. This animal model can be used as a model for human internal derangement.     

颞下颌关节盘穿孔的外科治疗

颞下颌关节盘穿孔是颞下颌关节紊乱病骨关节病中的一种病症，多因外伤、关节盘前移位和骨关节病导致关节盘后带与双板区交界处和双板区穿孔，以及关节盘本体穿孔或破裂。临床上常伴有关节组织的退行性改变。颞下颌关节盘穿孔的治疗有保守治疗和手术治疗，以下重点介绍颞下颌关节盘穿孔的外科治疗。