Comparison of imaging follow-up between joints with arthroscopic surgery (lysis and lavage) and those with nonsurgical treatment.

PURPOSE: To assess the influence of arthroscopic surgery on radiographically evident degenerative change of the temporomandibular joint (TMJ). The post-treatment course was compared between the joints that underwent arthroscopic lysis and lavage and those that underwent nonsurgical treatment. PATIENTS AND METHODS: Twenty-eight patients agreed to imaging follow-up examination of 35 joints. Twenty-four joints of 19 patients underwent only nonsurgical treatment (nonsurgical joints). Eleven joints of 9 patients failed the nonsurgical treatment and consequently underwent arthroscopic lysis and lavage (arthroscopic joints). The joints were assessed at first visit and at least 20 months later (mean, 79 months) for disc displacement, disc position, disc morphology, disc mobility, condylar morphology, morphology of the articular eminence, and horizontal condylar angle and size. Thereafter, interval change was assessed and compared between the groups. RESULTS: There was no significant difference in the prevalence of the progressive degenerative changes between the groups. In addition, there was no significant difference in the change of size and morphology of the condyle. However, a higher prevalence of improvement of disc mobility in the arthroscopic joints rather than the nonsurgical joints was significant (Goodness of fit test for chi(2), P < .05). CONCLUSIONS: The results of this study suggest that the post-treatment course of radiographically evident degenerative change was not significantly different between arthroscopy and nonsurgical treatment; however, arthroscopic surgery showed a greater ability to improve disc mobility. In imaging follow-up, arthroscopic lysis and lavage is a minimally invasive treatment modality that is equivalent to nonsurgical treatment.     

Correlation between eminence steepness and condyle disc movements in temporomandibular joints with internal derangements on magnetic resonance imaging.

A steep articular eminence is reported to be a predisposing factor for the development of disc displacement. The purpose of this study was to evaluate the biomechanics of the temporomandibular joint (TMJ) in internal derangements and, additionally, to investigate whether a relationship exists between the steepness of the articular eminence and disc displacement, with (DDR) and without reduction (DDWR). The material consisted of the sagittal TMJ magnetic resonance images (MRIs) of 39 joints (26 DDR and 13 DDWR). Sagittal and coronal TMJ MRIs were obtained at maximum inter-cuspation and in the maximum mouth-opening position. The steepness of the articular eminence, disc, and condyle rotation, and condyle translation were investigated. A Student's t-test was performed and correlation coefficients calculated. The results revealed an increase in disc rotation in the DDR group and in condyle translation in the DDWR group (P < 0.01). Condyle rotation and the steepness of the articular eminence were similar in both groups. Disc rotation was positively correlated with condyle rotation and negatively correlated with condyle translation in the DDR group (P < 0.05, r = 0.44). Condyle translation was positively correlated with steepness of the articular eminence in the DDWR group (P < 0.01, r = 0.74). There was no correlation between movements of the disc-condyle assembly and the steepness of the articular eminence in the DDR group. Nevertheless, a relationship between condyle translation and the steepness of the articular eminence was found in the DDWR subjects.     

髁突运动中心大张口轨迹与关节窝形态的关系及临床应用探讨

目的　探讨髁突运动中心大张口轨迹与关节窝形态的关系 ,对TMD患者髁突运动中心轨迹特征进行初步研究。方法　利用自行开发的髁突运动中心轨迹显示分析系统 ,分别以运动中心、终末绞链轴点作为参考点 ,观察 10名健康人和 7例临床检查怀疑盘前移位的TMD患者大张口轨迹 ,与磁共振成像得到的相应关节窝形态及关节盘位置诊断结果进行比较。结果　健康人左右侧运动中心轨迹与关节窝形态曲线重合率分别为 80 % (8/ 10 )和 90 % (9/ 10 ) ;终末绞链轴点轨迹与关节窝形态重合率均为 0 (0 / 10 )。TMD患者中 ,11侧盘前移位关节 ,除 1侧可复性盘前移位关节外 ,髁突运动中心轨迹均与正常的轨迹明显不同 ,出现各种改变 ;3侧正常盘位关节 ,髁突运动中心轨迹均与健康人的轨迹相似。结论　运动中心轨迹较终末绞链轴点个体稳定 ,可认为是较理想的研究髁突运动轨迹的参考点     

Analysis of kinesiograph recordings and masticatory efficiency after treatment of non-reducing disk displacement of the temporomandibular joint

The purpose of this study was to clarify the kinesiographs of chewing movement and masticatory efficiency before and after treatment in patients with non-reducing disk displacement of the temporomandibular joint (TMJ). Twenty patients who were diagnosed with unilateral non-reducing disk displacement of the TMJ were treated with pumping of the joint with injection of sodium hyaluronate. Chewing movement patterns in these patients were evaluated, using mandibular kinesiography (MKG) at their initial visit and at mean 19-month follow-up and the results were compared. Masticatory efficiency was also measured. As controls, 23 volunteers without TMJ dysfunction were employed. Far from the results of normal volunteers, chewing movement patterns of the patients on MKG did not show deviation to the chewing side in the TMJ-unaffected-side chewing in the horizontal plane. However, such patterns of the patients became similar to those of normal volunteers after treatment. Masticatory efficiency of the patients improved after treatment, though it was impaired at initial visit. The MKG and masticatory efficiency test appeared to be a useful method of comparing masticatory function before and after treatment in patients with non-reducing disk displacement of the TMJ.     

Inclination of the temporomandibular joint eminence and anterior disc displacement

The articular eminence angle of 179 temporomandibular joints (TMJ) with anterior disc displacement (ADD) in 179 patients was measured and compared with 200 left and 200 right joints of 400 young adults without TMJ dysfunction. A steeper inclination of the posterior slope of the articular eminence, with a mean difference compared to the control group of 14.5 degrees, was seen in joints with ADD. In the group of 179 joints with ADD of the TMJ, no difference was seen in the mean articular eminence angle between joints with an ADD with reduction, and an ADD without reduction, between conservatively or surgically treated joints, or between joints with different presumed causes of ADD.     

Effect of pumping with injection of sodium hyaluronate and the other factors related to outcome in patients with non-reducing disk displacement of the temporomandibular joint.

We retrospectively examined the effect of pumping with injection of sodium hyaluronate into the temporomandibular joint (TMJ) and the other factors influencing outcome in patients with non-reducing disk displacement of the TMJ. Fifty-nine patients underwent pumping with injection of sodium hyaluronate into the TMJ. As control, 62 patients were observed without any treatment. Both groups were observed for 12 months. The relation between outcome and the following clinical characteristics was also studied: sex, age, range of motion for maximal mouth opening, TMJ pain, TMJ noise, tenderness of masticatory muscles, locking duration, intercuspal occlusions, angle of posterior slope of articular eminence and degenerative bony changes of the condyle. Logistic regression analysis revealed that pumping with injection of sodium hyaluronate was related to a good outcome. Clinical characteristics of presentation significantly related to a good outcome were a large maximal mouth opening, a short locking duration, and a steep posterior slope of articular eminence. We conclude that pumping with injection of sodium hyaluronate into the TMJ is an effective treatment method for non-reducing disk displacement of the TMJ and that some clinical characteristics also influence outcome.     

Natural course of non-reducing disc displacement of the temporomandibular joint: changes in electromyographic activity during chewing movement

The purpose of this study is to examine whether electromyographic activity (EMG) during chewing movement changes towards the control level spontaneously in the subsequent course after diagnosis in patients with non-reducing disc displacement of the temporomandibular joint (TMJ) who do not receive any treatment. In 15 such patients, EMG data were examined at initial visit and at a mean follow-up of 21.7 months. As a control, 23 persons who had no TMJ dysfunction were studied. The results of EMG were compared among patients at initial visit, those at follow-up, and controls. The patients' clinical signs and symptoms were alleviated during the follow-up period. Duration of muscle contraction, cycle time and integrated EMG value (IEMG) at initial visit in patients were significantly different from those in the controls. In patients, IEMG for chewing-side masseter during chewing in the TMJ-affected side was greater at follow-up (14.2 +/- 8.01 microV s) than that at initial visit (10.5 +/- 3.69 microV s) (P < 0.05). In patients, duration of muscle contraction or cycle time at follow-up was not different from that at initial visit. Patients with non-reducing disc displacement of the TMJ showed spontaneous increasing of IEMG without any treatment in the subsequent course after diagnosis, coupled with improvement of clinical signs and symptoms. Duration of muscle contraction or cycle time did not change towards the control level. The results presented are useful as control data to understand the true effect of a particular treatment for patients with non-reducing disc displacement of the TMJ.     

Histopathological changes in rabbit craniomandibular joint associated with experimentally induced anterior disk displacement (ADD)

Several studies have shown that anterior disk displacement (ADD) of human temporomandibular joint (TMJ) can lead to cellular and extracellular alterations in the disk proper, bilaminar zone (BZ), condyle, articular eminence and synovial membrane. Due to lack of an animal model for this disease, it is not known whether the mechanical displacement of the disk could lead to the observed histopathological changes. The purpose of this experiment was to investigate the histopathological changes that occur in the rabbit craniomandibular joint (CMJ) following surgical induction of ADD. The right CMJ was exposed surgically and the discal attachments were severed except for the BZ attachments. Then the disk was displaced anteriorly and sutured to the zygomatic arch. The left joint served as surgical control. The CMJs were removed after 24 h, 1 week, 2 weeks or 6 weeks and stained with H&E or modified Masson stain. The results showed neovascularization, cell clustering and fibrillation of the displaced disk. The BZ showed marked fibrosis. The condyle showed subchondral hemorrhage and fibrosis followed by osteoarthritic changes in the articular cartilage. The articular eminence showed chondrocytic clustering and an increase in the amount of chon-droid bone. Synovial membrane exhibited marked hyperplasia. We concluded that surgical induction of ADD in the rabbit CMJ leads to cellular and extracellular alterations in the disk proper, BZ, condyle, articular eminence and synovial membrane similar to those described previously in human ADD. It appears that the mechanical trauma resulting from ADD could lead to a cascade of reparative and degenerative changes of the affected joints similar to those described for osteoarthritis.     

Multifactorial analysis of differences in temporomandibular joint hard tissue anatomic relationships between disk displacement with and without reduction in women.

STATEMENT OF PROBLEM: Without multifactorial models, it is difficult to resolve whether hard tissue tomographic relationships can distinguish differences between temporomandibular joint (TMJ) internal derangement diagnoses. PURPOSE: The purpose of this study was to use multifactorial models to examine whether there are hard tissue anatomic and orthopedic characteristics that distinguish temporomandibular joints with disk displacement with reduction from disk displacement without reduction. MATERIAL AND METHOD:. TMJ tomograms from female patients who had unilateral disk displacement diagnosed with (n = 84) or without (n = 78) reduction were compared with the use of 14 linear and angular measurements and 8 ratios. A representative classification tree model was tested for fit with sensitivity, specificity, accuracy, and likelihood accountability, and the results were compared with a multiple stepwise logistic regression model and univariate analysis. RESULTS: Disk displacement without reduction joints had longer mean postglenoid fossa heights (P<.0005), greater mean fossa depth (P<.017), and narrower mean absolute superior joint spaces (P<.041) than disk displacement with reduction joints (univariate t test). The classification tree had 4 terminal nodes; to differentiate the joints, it used the eminence radius and the absolute superior joint space to anterior joint space ratio subordinate to the postglenoid process height. The tree model accounted for 31.4% of the likelihood (Rescaled Cox and Snell R(2)) with 73.5% accuracy (sensitivity 82.6% and specificity 65.4%). Disk displacement without reduction joints had either deeper posterior fossa walls or posterior walls of average length combined with a superior-to-anterior joint space ratio of less than 0.83; this suggests a more open-wedge-shaped anterior joint space combined with a less-rounded articular eminence. In contrast, most disk displacement with reduction joints had shorter posterior fossa wall height combined with more equal or larger superior-to-anterior joint spaces. The logistic regression model was less accurate than the classification tree model (sensitivity 60.9%, specificity 66.7%) and accounted for only 9.9% of the likelihood (Rescaled Cox and Snell R(2)) and 63.6% accuracy. The postglenoid process height was the strongest differentiating factor in all models. CONCLUSION: Hard tissue relationships revealed by central tomogram sections were able to model notable differences between disk displacement with and without reduction joints when examined as contingency-based multifactorial systems.     

Natural course of nonreducing disc displacement of the temporomandibular joint: changes in chewing movement and masticatory efficiency.

PURPOSE: The purpose of this study was to examine changes of chewing movement and masticatory efficiency during the natural course of nonreducing disc displacement of the temporomandibular joint (TMJ). PATIENTS AND METHODS: The subjects were 15 patients who had been diagnosed with nonreducing disc displacement of the TMJ but had received no treatment. Chewing movement and masticatory efficiency were examined at the initial visit and at a mean follow-up of 21.7 months, using mandibular kinesiography and adenosine triphosphate ebteric-coated granules. As a control, 23 persons who had no current or previous TMJ symptoms were studied. RESULTS: The patients' clinical signs and symptoms tended to be alleviated during the follow-up period. In normal controls, chewing movement showed lateral excursion to the chewing side on both the right and left sides. In patients, chewing movement at the initial visit showed lateral excursion to the chewing side during chewing on the TMJ affected side, but no such deviation was noted during chewing on the TMJ unaffected side in the horizontal plane. However, chewing movement at follow-up became similar to that of controls. In patients, masticatory efficiency became better during the natural course, although that at follow-up did not always reach the control's level. CONCLUSION: In untreated patients with nonreducing disc displacement of the TMJ, chewing movement and masticatory efficiency tend to improve spontaneously.     

Eminectomy and meniscorhaphy for internal derangements of the temporomandibular joint. Rationale and operative technique

To date, most reports of surgical procedures to correct anterior meniscal displacement have focused on excision and repair of redundant posterior attachment tissue in conjunction with some form of arthroplasty. A procedure involving direct plication of the fibrous disk to the articular capsule (meniscorhaphy) and excision of the articular eminence (eminectomy) has yielded good results in most of the thirty-three patients with internal TMJ derangements on whom this operation has been performed within the past 44 months. The procedure is uncomplicated and physiologically sound, and it satisfies the concept of intracapsular decompression which is developed and described in this article. When surgical intervention is indicated for patients with internal TMJ derangements, eminectomy and meniscorhaphy should be given strong consideration.     

Association between disk position and degenerative bone changes of the temporomandibular joints: an imaging study in subjects with TMD

The aim of this study was to determine the frequency and relationship between disk position and degenerative bone changes in the temporomandibular joints (TMJ), in subjects with internal derangement (ID). MRI and CT scans of 180 subjects with temporomandibular disorders (TMD) were studied. Different image parameters or characteristics were observed, such as disk position, joint effusion, condyle movement, degenerative bone changes (flattened, cortical erosions and irregularities), osteophytes, subchondral cysts and idiopathic condyle resorption. The present study concluded that there is a significant association between disk displacement without reduction and degenerative bone changes in patients with TMD. The study also found a high probability of degenerative bone changes when disk displacement without reduction is present. No association was found between TMD and condyle range of motion, joint effusion and/or degenerative bone changes. The following were the most frequent morphological changes observed: flattening of the anterior surface of the condyle; followed by erosions and irregularities of the joint surfaces; flattening of the articular surface of the temporal eminence, subchondral cysts, osteophytes; and idiopathic condyle resorption, in decreasing order.     

Analysis of post-treatment electromyographs in patients with non-reducing disc displacement of the temporomandibular joint

The purpose of this study was to clarify the electromyographic property of chewing movement before and after treatment in patients with non-reducing disc displacement of the temporomandibular joint (TMJ). Twenty patients who were diagnosed with unilateral non-reducing disc displacement of the TMJ were treated by pumping and injection of sodium hyaluronate into the joint. Chewing movement in these patients was evaluated by electromyography (EMG) at the initial visit and at mean 19-month follow-up and the results were compared. Chewing movement in 23 normal controls were also examined. Duration of contraction, cycle time and integrated value at the initial visit which were different from those in the controls without TMJ dysfunction tended to be at the control level mean 19 months after treatment of pumping and injection of sodium hyaluronate into the joint in patients with non-reducing disc displacement of the TMJ. Electromyography appeared to be a method of documenting the chewing movement which was impaired at initial visit improved after treatment in patients with non-reducing disc displacement of the TMJ.     

颞下颌关节损伤的早期MRI表现

目的:探讨MRI在颞下颌关节损伤中的应用价值.方法:对22例颞下颌关节损伤患者于3～14 d内行颞下颌关节MRI检查.结果:22例44侧颞下颌关节,共发现关节盘移位29侧,关节盘变形23侧,关节液改变19侧,关节骨异常9侧.结论:MRI能很好的显示颞下颌关节损伤情况,是颞下颌关节损伤的重要检查与评价手段,具有很高的临床应用价值.     

Temporomandibular joint: surgically created disk displacement causes arthrosis in the rabbit.

To document a causal relationship between temporomandibular joint disk displacement and arthrosis, the disk was surgically displaced in one temporomandibular joint in each of three rabbits. The rabbits were sacrificed after 4 weeks and the mandibular condyles were studied radiographically and histologically. All three joints that underwent disk displacement had radiographic and histologic evidence of arthrosis, which included erosion of the bone, irregularity and fissure formation of the articular soft tissue cover, disruption of the subchondral layer of cartilage cells, and chondrocyte proliferation. No radiographic or histologic changes occurred in the joints that were untouched. The results suggest that surgically created disk displacement can cause arthrosis in the temporomandibular joint of the rabbit.     

Morphology of the articular eminence in temporomandibular joints and condylar bone change

The purpose of the present study was to investigate the relationship between the inclination of the articular eminence and temporomandibular joint (TMJ) pathology in orthognathic surgery patients with signs and symptoms of TMJ disorders. Twenty-one female orthognathic surgery patients with signs and symptoms of TMJ disorders were examined using pre-treatment helical computed tomography scans. The slope of the eminence in the medial, central and lateral sections of the subjects with osteophyte formation was significantly less than in the subjects with no bone change, and the medial section of the subjects with osteophyte formation was also significantly less steep than in the subjects with erosion. The central and lateral sections in the subjects with anterior disc displacement with reduction were significantly steeper than in subjects with anterior disc displacement without reduction. These results suggest that eminence flattening might occur during changes from erosion to osteophyte formation and from anterior disc displacement with reduction to anterior disc displacement without reduction. This appears to represent adaptation of the condyle, articular disc and articular eminence to changes in loading.     

The prevalence of osteoarthrosis in cases of advanced internal derangement of the temporomandibular joint: a clinical, surgical and histological study

INTRODUCTION: The articular disk has a central role in the pathology of internal derangement of the Temporomandibular Joint (TMJ). What is less clear is the role of osteoarthrosis in the development of internal derangement. The aim of this study is to determine the prevalence of osteoarthrosis in cases of advanced and recalcitrant TMJ internal derangement that were treated by diskectomy. MATERIALS AND METHODS: This study involved 22 joints in 18 patients who underwent surgery for the treatment of advanced and recalcitrant internal derangement of the TMJ. All patients included in the study failed to respond to at least 6 months of pre-operative conservative treatment and the clinical diagnoses of advanced TMJ internal derangement were confirmed on pre-operative MRI's. Tissue specimens were obtained from all 22 joints for histopathology. The specimens included articular disks that were excised from all 22 joints which were found to have severely displaced and deformed disks that were judged to be irreparable at the time of surgery. Also included were eight tissue samples from the mandibular condyles that were judged to be diseased on pre-operative tomograms and at the time of surgery. All samples were prepared in serial sections in the standard way and examined under light microscopy by two experienced Oral Pathologists. RESULTS: There were 22 specimens of articular disk examined together with 8 specimens from the mandibular condyle. All 22 joints (100%) showed histological evidence of disk pathology and eight of the 22 joints (34.4%) were found to have condylar pathology. The most common disk pathology was hyalinization indicative of disk degeneration (12/22). The most common condylar pathology found was articular surface degeneration indicative of osteoarthrosis (8/22). CONCLUSION: The clinical and radiological diagnoses of advanced TMJ internal derangement correlated with histological findings of degeneration and inflammation of the articular disk in all 22 specimens. The 8 specimens obtained from the condylar head showed histological features consistent with osteoarthrosis. This study showed that osteoarthrosis and internal derangement were found to co-exist in the same joint in about one-third of cases. The fact that osteoarthrosis was not found in all cases suggests that perhaps the widely held view that subclinical osteoarthrosis may lead to pathologic tissue responses in the form of internal derangement will need to be re-examined.     

The effect of gap arthroplasty on temporomandibular joint ankylosis: an experimental study.

The aim of this study was to demonstrate the functional and anatomical changes after gap arthroplasty release of unilateral temporomandibular joint (TMJ) ankylosis. Five adult sheep weighing an average of 57 kg were used. All right joints were operated. Ankylosis was induced in the right TMJ by articular damage, disk removal and placement of a bone graft plus immobilization wire. At 3 months the gap arthroplasty were performed. All TMJs were examined functionally, radiologically, macroscopically and histologically. Functionally, the range of jaw movements decreased following induction of ankylosis (P<0.0001), increased immediately on release but was reduced again at 3 months after release (the vertical movement, no statistically significant difference; the right movement, P<0.001; the left movement, P<0.0001). Histologically, all operated joints showed fibrous adhesions across the gap, and further, the articular surface was irregular with osteophytes and with bony islands in the gap. This appearance is more consistent with a fibrous reankylosis than a functioning pseudo joint. This study shows that the gap arthroplasty for TMJ ankylosis did not restore the TMJ functionally and histologically to the preexisting state.     

Changes of the elastic fibre network of the rabbit temporomandibular joint following discectomy

Elastic fibres are thought to be very important for the function of various organs including the temporomandibular joint (TMJ). The current study was designed to examine changes in the elastic fibres of the TMJ following discectomy. The TMJs of six rabbits were surgically exposed, and the disc removed with a scalpel. Three untreated and three sham-operated rabbits were used as controls. Complete TMJs were removed in three rabbits 1 month and in three rabbits 3 months after discectomy and processed for histochemical demonstration of elastic fibres. In the TMJ 1 month after discectomy, osteoarthritic changes and a significant increase in the numbers of elastic fibres were observed in the condyle and articular eminence. In the TMJs 3 months after discectomy, they tended to revert to the levels in the condyle and articular eminence of the control TMJs. Our results show that after experimental discectomy, elastic fibres very often appear initially in the condyle and articular eminence, but they are destined to disappear later. This information may improve our understanding of the consequences of removal of the disc in clinical practice.     

A prospective study of Twin-block appliance therapy assessed by magnetic resonance imaging.

Forty children displaying Class II Division 1 malocclusion were involved in a prospective magnetic resonance image investigation to evaluate the effects of Twin-block functional appliances on the temporomandibular joints. None of these children had clinical signs or symptoms of temporomandibular disorders. Nineteen children were treated with a Clark Twin-block appliance for 6 months; the other 21 children received no treatment and served as controls. Comparison between control and Clark Twin-block groups suggested that reduction of the condylar axial angle represents a feature of untreated Class II growth patterns, whereas axial angle stability with Clark Twin-block therapy may suggest alteration of condylar growth direction. Condyles that were positioned at the crest of the articular eminence by the Clark Twin-block at the beginning of treatment had reseated back into the glenoid fossa after 6 months. However, 75% of the condyles were more anteriorly positioned in successfully treated Clark Twin-block cases.There was no clear evidence of remodeling of the glenoid fossa at the eminence as a result of Clark Twin-block treatment. The initial prevalence of disk displacements for the combined groups was 7.5% anterior, 5% medial, and 12.5% for lateral disk displacement. Clark Twin-block therapy had neither positive nor negative effects on disk position, and there was no convincing evidence that the disk was recaptured.