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The pros and cons of, and treatment considerations for, simultaneous orthognathic and temporomandibular joint surgery are discussed. Several cases of patients treated with simultaneous orthognathic and temporomandibular joint surgery are presented.
Previous kinesiological studies of the temporomandibular joint (TMJ) were based on the motion of only one or two selected points on the mandible (such as the lower central incisor, the mandibular condyle). In the present study, a technique was developed to measure, analyze, and describe the full three-dimensional kinematic characteristics of the TMJ during any mandibular activity. The technique was based on determination of the relative position between the mandible and the temporal bone from measurement of the location of points on light-weight frames rigidly attached through splints to the maxillary and mandibular teeth. An optoelectric kinematic data acquisition system has been used to record the location of these points. The results of the study indicate the following major advantages of this technique over previously reported kinesiological methods: (1) the technique provides a full description of the motion of the mandible with respect to the temporal bone, including all the six degrees of freedom associated with this motion; (2) the description of motion in terms of joint parameters enhances interpretation of the data by clinicians; (3) the motion of any point of interest on the mandible can be easily derived from the data and; (4) the system provides only negligible interference with the natural jaw motion of the subject. It does not require head fixation, does not alter or interfere with the natural occlusion, and its light weight causes only minimal (and negligible) loading of the mandible.
A kinematic analysis of the temporomandibular joint (TMJ) is developed to determine the range of motion of the mandible during normal opening and during special motions required for arthroscopic surgery. The translation of the mandible is restricted by the constraint of the ligaments. By accounting for the maximum allowable stretch of a ligament, limits of translation are determined for any normal opening angle of the mandible. The present analysis provides information useful in securing the maximum available space for the protrusion of arthroscopic instruments during TMJ surgery.
26 cases with Temporomandibular Joint Dysfunction Syndrome (TMJDS) were included in the present study. Fully corrected lateral tomogrames of TMJ in the intercuspid position were taken for all the cases; and fully corrected lateral arthrotomogrames were taken for 19 cases (21 joints) of them. The area and linear measurements of the joint space were made with the aid of computer. The results showed that the position of the condyle in the patients with TMJDS was located in the posterior position of the fossa. Statistics results showed that there was significant difference between the patient group and control group. Although the posterior displacement of the condyle was often associated with the anterior displacement of the disc, it was not always agreement with the anterior disc displacement. So, the exact diagnosis of disc displacement should be still on the basis of arthrography or other examinations, such as CT or MRI.
BACKGROUND: The synovial tissues with temporomandibular disorders (TMDs) often show chronic inflammatory changes and the synovial cells participate in the pathogenic processes of TMDs. The synovial membrane is composed of a synovial lining layer and a connective sublining layer. The synovial lining layer is made up of two kinds of cells: macrophage-like type A and fibroblastic type B cells. The aim of this study was to isolate and characterize synovial cells from the human temporomandibular joint (TMJ). METHODS: Synovial cells were isolated using an explant culture method. Then, we characterized the cultured synovial cells (SGA2 cells) using immunocytochemistry. RESULTS: SGA2 cells expressed the fibroblastic markers vimentin and prolyl 4-hydroxylase; they also expressed laminin and heat shock protein 27, all of which are markers of type B cells. However, some cells expressed the macrophage marker CD68. These CD68-positive cells simultaneously expressed laminin. CONCLUSIONS: We isolated and cultured synovial type B cells from the human TMJ, and identified the presence of intermediate type synovial lining cells, having the phenotypic properties of both type A and type B cells, among the synovial lining cells.
Ankylosis of the temporomandibular joint leads in children to serious disorders such as loss of dentition, growth retardation of the lower jaw, facial asymmetry etc. During the period from 1993 till 1997 we treated 12 children incl. eight who had unilateral and four bilateral ankylosis. In six patients, after elimination of the ankylosis, reconstruction of the head was made with a total of nine costochondral grafts. In entire all patients the temporal muscle or a silicone plate was interposed between the skull base and mandible. Postoperative complications were minimal. Surgical treatment, which is only half of the issue of treatment, must be followed by long-term careful rehabilitation. The results which were achieved contributed in a significant way to a more favourable further development of the children.
The temporomandibular joint disk exhibits morphological and biochemical age-related changes. However, the possible age-related changes of the dynamic viscoelasticity in the disk are unclear. We tested the hypothesis that the dynamic viscoelastic properties of the disk change with age. Thirty-six disks from young-adult, adult, and mature-adult cattle were used for dynamic tensile tests. In all disks, the magnitudes of the complex modulus, the storage modulus, and the loss modulus increased as the frequency increased. The mature-adult disks had higher values of these moduli than did the younger disks. The loss tangent ranged from 0.1 to 0.3, which means that the disk has relatively large elasticity and relatively small viscosity. It was concluded that both the elasticity and viscosity of the disk increase with age. This may reflect age-related changes in biochemical composition.
Temporomandibular joint (TMJ) ankylosis is a distressing affliction that denies the victim the benefit of normal diet, careers that require normal speech and causes severe facial disfigurement that aggravates psychological stress. Opinions in current literature portray controversy in its management. Hurried clinicians take shortcuts and partially treat symptoms and often make the condition worse. Others ignore shortcomings and erroneously prescribe their preferred techniques as absolute indication to the peril of the affected children. Gap arthroplasty if applied in a growing maxillofacial skeleton as in children, causes iatrogenic arrest of facial growth. The intended correction of facial disfigurement is therefore not achieved. Early detection and immediate psychological support by excision and reconstruction of ankylosed TMJ with a costochondral graft, improves patient comfort and rehabilitation when used as a planned part of a comprehensive therapy. This paper questions prior varied opinions and discusses scientific baseline considerations in management of long standing TMJ ankylosis in children in relatively affordable circumstances.
Stress analysis of the human temporomandibular joint (TMJ) consisting of mandibular disc, condyle and fossa-eminence complex during normal sagittal jaw closure was performed using non-linear finite element analysis (FEA). The geometry of the TMJ was obtained from magnetic resonance imaging (MRI). The tissue proportion was measured from a cadaver TMJ. Contact surfaces were defined to represent the interaction between the mandibular disc and the condyle, and between the mandibular disc and the fossa-eminence complex so that finite sliding was allowed between contact bodies. Stresses in the TMJ components (disc, condyle and fossa-eminence complex), and forces in capsular ligaments were obtained. The results demonstrated that, with the given condylar displacement, the stress in the condyle was dominantly compressive and in the fossa-eminence complex was dominantly tensile. The cancellous bone was shielded by the shell shaped cortical bone from the external loading. The results illustrate the stress distributions in the TMJ during a normal jaw closure.
Using subjects conscious of temporomandibular joint sound and normal subjects, the ratio of the masticatory area to the mandibular border movement area was measured. Also, splints were fitted to subjects conscious of TMJ sound and changes of sound and masticatory areas were measured. 1. In normal subjects, the ratio tended to vary little with any of the test foods. 2. In subjects conscious of the TMJ sound, the ratio decreased in the case of all test foods when compared with the normal subjects. 3. In subjects conscious of TMJ sound, it was observed that the TMJ sound occurred in some subjects but not in others during mastication. 4. The decrease in the ratio of the subjects with no TMJ sound during mastication was more outstanding than that of subjects in which TMJ sound occurred during mastication. 5. After fitting splints, the change in the TMJ sound was accompanied by a change in the masticatory area. 6. These findings suggest that the decrease in the mastication area experienced by subjects conscious of TMJ sound, when compared with normal subjects, may be caused by the TMJ sound.
A review of 27 cases of temporomandibular joint arthritis in patients with psoriasis reveals the main pathologic features to be condylar erosions, condylar osteoporosis, calcification of the articular disc, and subchondral cyst formation. We present another pathological process, temporomandibular joint bony ankylosis in a patient with psoriasis. Surgical management consisted of a high condylectomy, with a silastic implant to maintain the vertical dimension of the ramus. A very good functional result was obtained and 21/2 years later her incisive distance is 44 mm.
OBJECTIVE: Neoplasms of the temporomandibular joint (TMJ) usually mimic common causes of TMJ syndrome, leading to delay in diagnosis. To increase awareness of TMJ neoplasms and establish guidelines for early intervention, we performed a retrospective analysis of a series of patients with neoplasms of the TMJ. STUDY DESIGN AND SETTING: A retrospective review of the records of patients with neoplasms of the TMJ from 1990 to 1997 was done. RESULTS: Six patients were identified. The neoplasms included benign and malignant neoplasms. The time from initial presentation to final diagnosis was in most cases prolonged, ranging from 3 months to 8 years. Patients typically showed advanced lesions radiographically. All patients required surgical extirpation. Postoperative radiation therapy was used for malignant lesions. Patient outcomes were delineated. CONCLUSIONS AND SIGNIFICANCE: Neoplasms, both benign and malignant, of the TMJ are rare but represent a challenging diagnostic problem. In patients with 1 month or more of recalcitrant TMJ swelling or pain, radiographic imaging may be considered to rule out these rare neoplasms. This may lead to earlier intervention and improved outcome.
The developmental history of the temporomandibular joint (TMJ) was investigated in 10 fetuses of 4 to 10 months of gestational age. The S-type structure of the disc is formed by the following bases: 1) the flat upper and concave lower surfaces of the disc; 2) thinner intermediate zone and thicker anterior and posterior bands; 3) the projection of the articular tuberculum and superoposterior growth of the condyle. The posterolateral part of the disc was the thickest and the corresponding part of the fossa was the deepest. The condyle was originally positioned beneath the part of disc that was considered the main force-bearing area. The distribution and arrangement of elastic and collagen fibers in the disc was proportional to disc function. Gross elastic fibers in the posterolateral part of the posterior band were connected with the upper head of the pterygoideus lateralis muscle fibers running medioanteriorly. They were indicated to be antagonistic with each other. At 4 months of gestational age, a few elastic fibers appeared in the bilaminar region and began to form bundles as the fetus grew. At full-term dense elastic fibers were found in the upper stratum of the bilaminar region.
The bovine temporomandibular joint disc is a fibrocartilaginous structure composed largely of collagen and proteoglycans. Little is known about changes in its composition accompanying growth and maturation. Discs were collected from immature foetuses (3-5 months), mature foetuses (6-8 months, adolescents (18 months), young adults (2-3 yr) and mature adults (over 4 yr), dissected free of fibrous attachments, and separated into outer and inner tissues. For the outer tissues the major findings were that: (1) water content in postnatal specimens was less than in prenatal specimens: (2) collagen content (relative to tissue dry weight) increased up to adolescence with little change thereafter; (3) total glycosaminoglycan, chondroitin sulphate and hyaluronic acid contents decreased during foetal development and then remained relatively constant, and (4) dermatan sulphate (the major glycosaminoglycan at all ages) decreased at maturity while keratan sulphate increased slightly. Results for the inner tissues were similar except that: (1) total glycosaminoglycan content was much higher in postnatal animals; (2) chondroitin sulphate was the major glycosaminoglycan after birth; and (3) keratan sulphate, which was barely detectable in the foetal specimens, increased rapidly after birth. Evidence was also obtained for changes in the copolymeric nature of galactosaminoglycans in the inner tissue. These findings, especially the different pattern of age-related changes in outer (presumably non-compressed) and inner (presumably compressed) tissue, suggest that the disc has the capacity to continually modify its composition in response to the mechanical stresses placed on it.
The temporomandibular joint (TMJ) is a exceptional joint involved in growth as well as mastication. In adult mice, it provides a model for age related natural osteoarthritis (OA). The insulin-like growth factor (IGF-) system plays was tested because it plays important roles in cartilage biology and OA pathogenesis. Decalcified and paraffin embedded TMJs of 48 NMRI mice sacrificed in groups of three male and females each at the ages of 3, 4, 5, 7, 9, 10, 12, and 18 months were prepared for histopathology and immunohistochemistry for IGF-I and -II, IGF1 receptor and IGF binding proteins -1, -2, -3, -4, -5, and -6. Histopathological signs of OA were obvious in the TMJ of all animals older than 5 months, but did not show a clear age-related staging. Immunoreactivity for all IGF components was found in unchanged anterior and posterior regions of the condyle and in regions of advanced OA lesions. Receptor immunostaining was obvious in all ages. Most IGFBPs showed immunostaining patterns similar to IGFs. While the anterior and posterior zones of the condylar cartilage appear to be specialized judging by structure and IGF immunostaining pattern, probably due to metabolic or biomechanical peculiarities, the central portion undergoes early degeneration. In advanced OA stages, the IGF system seems to be upregulated to induce repair processes. According to their mainly inhibiting functions, IGFBPs may suppress anabolic IGF activities.
A review is presented of the effects of loss of teeth, with impaired occlusal stabilization, on the temporomandibular joint in experimental animals. Loss of teeth, with subsequent abnormal loading of the temporomandibular joint, leads to histomorphological, pathological and pathophysiological changes in the articular cartilages, the articular disc, the synovium, and the bony articular components. The severity of the changes increases with increasing age, and an existing arthritis of the joint is aggravated by impaired occlusal stabilization. The experimentally induced changes resemble those in human subjects with extensive loss or extensive attrition of teeth.
The adult mammalian temporomandibular joint (TM) disc is a fibrocartilaginous tissue that undergoes normal developmental remodeling, requiring removal of the existing extracellular matrix and its replacement by new matrix macromolecules. This remodeling is probably mediated by matrix-degrading enzymes, but to date none has been demonstrated in association with the TMJ disc. We characterized, identified, and determined the regulation of proteinases and proteinase inhibitor (PIs) synthesized by TMJ disc cells in organ and cell cultures. TMJ discs were retrieved from 14-week-old male NZW rabbits and both tissue- and disc-derived cells were cultured in serum-free medium. The conditioned media were retrieved at 12-hour intervals and assayed for proteinases and PIs in gelatin- and casein-impregnated polyacrylamide gels. Three proteinases with gelatinolytic activities at 92 kDa, 72 kDa, and 42/57 kDa and one caseinolytic activity at 51/54 kDa were detected. All were inhibited by 1,10-1 phenanthroline, thus characterizing these enzymes as matrix metalloproteinases (MMPs), most likely 92-kDa gelatinase (proMMP-9), 72-kDa gelatinase (proMMP-2), procollagenase (proMMP-1), and prostromelysin (proMMP-3). The identity of the latter two MMPs was confirmed by Western blots. Two PIs and 30 kDa and 20 kDa, probably tissue inhibitors of metalloproteinase (TIMP) and TIMP-2, were observed on reverse zymograms. TPA, a protein kinase-C agonist, increased the expression of 92-kDa gelatinase and 30-kDa PI by both explanted discs and isolated disc cells. The profile of MMPs constitutively expressed by disc cells is similar to that of synovial fibroblasts but different from that of chondrocytes.(ABSTRACT TRUNCATED AT 250 WORDS)
Surgery of the temporomandibular joint (TMJ) plays a small, but important, role in the management of patients who have temporomandibular disorders (TMDs). There is a spectrum of surgical procedures for the treatment of TMD that ranges from simple arthrocentesis and lavage to more complex open joint surgical procedures. It is important to recognize that surgical treatment rarely is performed alone; generally, it is supported by nonsurgical treatment before and after surgery. Each surgical procedure should have strict criteria for which cases are most appropriate. Recognizing that scientifically proven criteria are lacking, this article discusses the suggested criteria for each procedure, ranging from arthrocentesis to complex open joint surgery. The discussion includes indications, brief descriptions of techniques, outcomes, and complications for each procedure.