The expression of substance P in human temporomandibular joint samples: an immunohistochemical study

The expression of neuropeptide substance P was examined in 18 human temporomandibular joint (TMJ) samples with internal derangement of the TMJ, and in 10 control specimens. The examination was carried out using an immunohistological technique, using paraffin-embedded tissue and specific anti-human substance P polyclonal antibody. We noted five characteristic distribution patterns of substance P expression: at the nerves' fibre bundles in the connective tissues of the anterior and/or posterior attachment; around the blood vessels in the attachments; at the margin of the TMJ disc and synovial membrane layer; on the surface of hypertrophic synovial membranes with inflammation and proliferation; and around the newly formed capillaries in the TMJ discs. In TMJs with internal derangement associated with severe pain, we found distinct substance P expression in most of the specimens. The expression was particularly intense at the margin of the TMJ disc and synovial membrane layer, on the surface of hypertrophic synovial membranes and around the newly formed capillaries in the TMJ discs. The clinical symptoms of internal derangement of the TMJ are thought to be associated with the degree of synovitis. We conclude that the expression of substance P seems to be closely related to histopathological changes of the human TMJ with internal derangement.     

The immunohistochemical distribution of vimentin in human temporomandibular joint samples

The aim of this investigation was to evaluate the immunohistochemical distribution of vimentin in the temporomandibular joint (TMJ) and to compare it with the control specimens. Immunohistochemical distribution in the disc and synovial membrane in 30 human TMJ (internal derangement of TMJ, n = 20; and control, n = 10) was studied immunohistologically using paraffin-embedded tissue and specific anti-human vimentin monoclonal antibody. Vimentin expression was distributed in chondrocyte-like cells, synovial cells and endothelial cells. There was an obvious distinction of vimentin immunoreactivity between the control specimens and internal derangement cases, in the posterior and/or anterior loose connective tissues. In particular, intensive vimentin expression was detected in the hypertrophic synovial membrane of internal derangement cases. The findings of the present study suggest that vimentin might be an important marker of pathological hypertrophy of the synovial membrane and/or connective tissue with internal derangement of TMJ.     

The expression of cyclooxygenase-2 in human temporomandibular joint samples: an immunohistochemical study

The aim of this investigation was to evaluate the immunohistochemical expression of cyclooxygenase-2 (COX-2) in the temporomandibular joint (TMJ) and to compare it with that control specimens. Expression of COX-2 in the TMJ disc and the synovial membrane in 26 human TMJ samples (internal derangement of TMJ; n=16, and control; n=10) was measured by an immunohistological technique using paraffin-embedded tissue and specific antihuman COX-2 polyclonal antibody. There were obvious distinction of COX-2 immunoreactivity between the control specimens and internal derangement cases, in the region of posterior and/or anterior loose connective tissues. In particular, intensive COX-2 expression was detected in the synovial membrane of internal derangement cases. The findings of the present study suggest that COX-2 might be an important mechanism regulating inflammation in the synovial membrane with internal derangement of TMJ.     

Localization of lymph capillaries and blood capillaries in human temporomandibular joint discs

The localization of lymph capillaries and blood capillaries in the human temporomandibular joint (TMJ) discs was examined immunohistologically with anti-human collagen IV antibody and anti-human von Willebrand factor in 26 human TMJ samples. The 16 internal derangement cases were then compared with the 10 normal control cases. The findings suggested that blood capillaries scarcely existed in all the fields of normal control TMJ discs (5/270, 1.9%) nor did lymph capillaries exist in the normal TMJ discs (0/270, 0%). New growth of blood capillaries had localized in all fields of the internal derangement discs specimens (113/378, 29.9%) and was concentrated in the lower area of the posterior part of the discs. The authors also observed a small distribution of lymph capillaries in all fields of this material (17/378, 4.5%). The new growth of lymph capillaries were always related to the blood capillary distribution and therefore their presence might be directly related to the capillary proliferation.     

The distribution of cyclooxygenase-1 in human temporomandibular joint samples: an immunohistochemical study

Cyclooxygenase-1,2 (COX-1,2) or prostaglandin (PG) H synthase, is the first enzyme of the pathway in which arachidonic acid is oxidized to PGs. Thus, we examined the expression of COX-1 in 16 human temporomandibular joint (TMJ) samples with internal derangement and in 10 control specimens by an immunohistological technique using paraffin-embedded tissue and specific antihuman COX-1 polyclonal antibody. There was obvious distinction of COX-1 immunoreactivity between the control specimens and internal derangement cases, at the endothelial cells and fibroblasts, in the region of posterior and/or anterior loose connective tissues and synovial membrane. The findings of the present study suggest that COX-1 might be an important mechanism for maintaining normal homeostasis at the endothelial cells and fibroblasts with internal derangement of TMJ.     

Expression of vascular endothelial growth factor in human dysfunctional temporomandibular joint discs

A high density of blood vessels is found in specimens of temporomandibular joint (TMJ) disc at any stage of internal derangement of the joint, but the factors responsible for angiogenesis in the disc have not been described. The purpose here was to investigate, in human TMJ discs, the expression of vascular endothelial growth factor (VEGF), a multifunctional cytokine that contributes to angiogenesis. Specimens, free of significant morphological alterations and with varying degrees of disc tissue degeneration/regeneration, were studied by immunohistochemistry for VEGF in order to correlate immunohistochemical with histopathological findings. In normal discs and discs with minor pathological changes, fibroblast-like cells, fibrochondrocytes and chondrocyte-like cells were either not or only weakly immunostained by VEGF antibody. In disc specimens from internal derangement of the TMJ with significant tissue degeneration/regeneration, VEGF was consistently expressed. In these specimens, immunoreaction products for VEGF were observed both in the disc and in the endothelial cells of newly formed vessels. This VEGF immunolocalization is consistent with the stimulation of angiogenesis and the morphogenesis and differentiation of chondrocytes. Therefore VEGF expression by disc chondrocyte-like cells might reflect the action of the cytokine as an inducer of angiogenesis and as an autocrine signal for cells of the chondrogenic lineage.     

Immunohistochemical distribution of lymph capillaries and blood capillaries in the synovial membrane in cases of internal derangement of the temporomandibular joint

The distribution of lymph capillaries and blood capillaries in the synovial membrane was examined immunohistologically with anti–human collagen IV antibody and anti–human von Willebrand factor in 26 human temporomandibular joint (TMJ) samples comprising discs with adjoining synovial membrane from 10 control TMJs and from 16 TMJs with internal derangement. Three different distribution types were observed in the synovial membrane. In the control samples, the occurence of blood capillaries and lymph capillaries was rare. In mildly hyperplastic synovitis. lymph capillaries were observed just beneath the surface of the synovial membrane, whereas blood capillaries occurred in a little deeper layer of the synovia! membrane. In a severely hyperplastic synovitis. both lymph and Wood capillaries were observed frequently. The present results suggest that the different distribution patterns of lymph capillaries and blood capillaries reflect the degree of synovitis but can not be attributed to specific clinical symptoms.     

Analysis of 70Kd heat shock protein expression in patients with internal derangement of the temporomandibular joint

Recent studies have demonstrated that the expression of heat shock protein (HSP) was enhanced under stress in joint diseases, such as rheumatoid arthritis and osteoarthritis. The purpose of this study was to analyze the expression of 70Kd HSP in patients with internal derangement of the temporomandibular joint (TMJ) by immunohistochemical and enzyme-linked immunosorbent assay (ELISA) methods. For immunohistochemistry, 5 extirpated discs and 16 synovial biopsy specimens from patients with TMJ internal derangement and 2 extirpated discs from normal subjects were examined. For ELISA, synovial fluid from 11 patients with TMJ internal derangement and from 6 normal volunteers were investigated. The results showed that the 70Kd HSP staining intensity in chondrocytes around the damaged area of the articular discs from patients with TMJ internal derangement was higher than that in chondrocytes in control specimens. In addition, 70Kd HSP expression in synovial fluid from patients with TMJ internal derangement was slightly higher than that in normal subjects. These findings suggest that elevated 70Kd HSP expression is related to the progression of TMJ internal derangement.     

Relationship of calcitonin gene-related peptide in synovial tissues and temporomandibular joint pain in humans

OBJECTIVE: To elucidate the expression of calcitonin gene-related peptide (CGRP) in synovial tissue taken from the human temporomandibular joint (TMJ) with internal derangement, and discuss the relationship between CGRP and joint pain. STUDY DESIGN: Using an immunohistochemical technique, 48 joints in 48 patients were examined. As controls, synovial tissue specimens from 7 joints with habitual dislocation without pain were also examined. RESULTS: In all of the internal derangement and control subjects, CGRP-positive cells were observed in the connective tissues around the blood vessels beneath the lining cells. The extent score of CGRP was significantly higher in the internal derangement group than in the control group (P=.033). There was a significant positive correlation between the extent score of CGRP and joint pain (P=.036, r=0.30). CONCLUSIONS: These results suggest that the expression of CGRP is increased in the synovial tissues from patients with internal derangement, and that CGRP seems to play an important role in the mechanism of pain production in patients with symptomatic internal derangement.     

Characterization of tissue components in the temporomandibular joint disc and posterior disc attachment region: internal derangement and control autopsy specimens compared by morphometry.

PURPOSE: Our aim was to morphologically investigate the occurrence of fibroblasts, chondrocytes, and blood vessels in the tissue of the temporomandibular joint (TMJ) disc, the intermediate zone, and the posterior disc attachment region in control autopsy specimens and to compare the results with those observed in corresponding tissues from patients with TMJ internal derangement. PATIENTS AND METHODS: First, 20 bilateral TMJ disc specimens from selected autopsy cases were analyzed by conventional morphometry. Thus, the volume density of fibroblasts, chondrocytes, and blood vessels was determined. Second, the obtained results from the right joint of the autopsy disc specimens were compared with 12 TMJ disc specimens obtained at surgery from patients with internal derangement. RESULTS: The tissue compartments of interest (disc, intermediate zone, and posterior disc attachment region) were identified unequivocally in all specimens. None of the autopsy cases showed any significant difference between the right and left joints or related to gender. The only variable that differed between autopsy and patient specimens was volume density of blood vessels, which was higher in patient specimens. CONCLUSIONS: We found that the volume density of blood vessels was significantly higher in the posterior disc attachment region in patient specimens than in autopsy controls. Whether this reflects a role for vessels in the pathogenesis of TMJ internal derangement or merely is a reaction to another type of injury remains to be settled. In both the autopsy control and patient specimens, chondrocytes and fibroblasts were characteristic for disc respective posterior disc attachment region. Thus it appears that the occurrence of these cells can be used to distinguish TMJ disc from posterior disc attachment in small biopsy specimens.     

Osteoarthritis and internal derangement of the temporomandibular joint: a light microscopic study

To describe osteoarthritic changes of the temporomandibular joint (TMJ) and their relation to internal derangements, 22 randomly selected TMJ autopsy specimens were dissected and studied by light microscopy. Normal disc position was seen in eight joints, partial anterior displacement of the discs in eight joints, and complete anterior displacement of the discs in five joints; one joint had a perforated disc. Degenerative changes, such as horizontal splitting, clustering of chondrocytes, bone marrow fibrosis, sclerosis, erosion, cyst formation, and reduction in TMJ size, were found in 11 of the 14 joints with displacement or perforation of the disc and in four of the eight joints with normal disc position. Internal derangement appeared to be associated with osteoarthritis. The relations between remodeling, aging, internal derangement, and osteoarthritis are discussed.     

Dysplasia-dependent abnormalities of the temporomandibular joint

The purpose of this study was to reveal the relationship between temporomandibular joint (TMJ) dysfunction and dysplasia of connective tissue (DCT). This investigation included 53 (34 female and 19 male) patients with TMJ internal derangement (ID) and 53 controls; 24 patients with marked and 53 patients with mild dysfunction of this joint. The symptoms of DCT (such as scoliosis, general joint hypermorbility) and TMJ ID were revealed. Results of this study prove that DCT is one of etiological factors of TMJ ID. The relationship between type of ID and severity of DCT was revealed.     

Correlations of the expression of fibroblast growth factor-2, vascular endothelial growth factor,and their receptors with angiogenesis in synovial tissues from patients with internal derangement of the temporomandibular joint

Synovitis in internal derangement of the temporomandibular joint (TMJ) is accompanied by the growth of new blood vessels. Fibroblast growth factor-2 (FGF-2) and vascular endothelial growth factor (VEGF) are well-characterized angiogenic factors. The objective of this study was to elucidate the correlation between the expression of FGF-2, VEGF, and their receptors-FGF receptor-1 (FGFR-1) and VEGF receptor-1 (Flt-1)-with microvessel density in synovial tissues of the TMJ. Using an immunohistochemical technique, we examined 47 joints (45 patients) with internal derangement. Individual microvessel density was evaluated by means of the CD34 antibody, a specific endothelial marker. The correlation between the percentage of immuno-positive cells and microvessel density was evaluated. In multiple logistic regression analysis, the correlation between the percentage of Flt-1-positive cells and microvessel density was significant [p = 0.005, odds ratio = 1.071, 95% confidence interval = 1.021-1.124]. These results suggest that the expression of the VEGF/Flt-1 system is involved in angiogenesis in inflamed synovial tissue in the TMJ.     

Apoptosis in displaced temporomandibular joint disc with and without reduction: an immunohistochemical study

J Oral Pathol Med (2011) 40 : 103–110 Internal derangement (ID) of the temporomandibular joint (TMJ) is due to an abnormal relationship of the articular disc to the mandibular condyle, glenoid fossa and articular eminence. The two most common types of internal derangement are anterior disc displacement with (ADDwR) and without reduction (ADDwoR). Disc displacement is associated with degenerative tissue changes. The histological features of discs from patients with TMJ ID reflect a general remodelling caused by abnormal loading. A correlation has been demonstrated between TMJ ID and apoptosis. Few investigations have addressed the role of apoptosis or caspase activity in TMJ ID. The apoptosis activation process was studied in different areas of discs from 18 patients with ID (both ADDwR and ADDwoR) and four cadavers (controls), with emphasis on the expression of caspase 3, whose activation makes the death process irreversible. The results showed a greater proportion of caspase 3‐positive cells in ADDwR and ADDwoR than in control discs. Immunopositivity also varied between disc areas; in particular, in ADDwoR sections labelled cells were significantly more numerous (P < 0.01) in the posterior disc attachment than in the anterior and intermediate bands. In addition, a significantly greater proportion of labelled cells was seen in the anterior (+) and intermediate (++) band of ADDwR compared with ADDwoR discs both bands (P < 0.05). These data suggest the importance of programmed cell death in the progression of TMJ ID.     

Expression of interleukin 6 in synovial tissues in patients with internal derangement of the temporomandibular joint

Using an immunohistochemical technique, we examined synovial tissue from 46 temporomandibular joints (TMJ) with internal derangement in 44 patients. As controls, we examined synovial tissue specimens from 7 joints with habitual dislocation without pain. In synovial tissues from 21 of the 46 joints with internal derangement, interleukin 6 (IL-6) was expressed in the synovial lining cells and in the mononuclear cells infiltrating the periphery of the blood vessels. The density of IL-6-stained cells in specimens with internal derangement correlated significantly with the grade of joint effusion shown by magnetic resonance imaging (P=0.01, r=0.32).     

Microbiological investigation of retrodiscal tissues from patients with advanced internal derangement of the temporomandibular joint

The aim of this study was to investigate the presence of bacteria in samples of retrodiscal tissues taken from patients suffering from advanced internal derangement of the temporomandibular joint (TMJ). 12 fresh retrodiscal tissue samples were taken from 12 consecutive patients who underwent unilateral TMJ discectomy for advanced TMJ internal derangement (Wilkes stage IV). The retrodiscal tissue samples were stained and cultured for the presence of micro-organisms in microbiology laboratories. No evidence of bacteria or other micro-organisms was found in any of the tissue specimens procured from the TMJ. This study failed to identify the presence of bacteria or other micro-organisms in fresh retrodiscal tissue specimens of the TMJ in patients with advanced TMJ internal derangement.     

Correlation between the arthroscopic diagnosis of synovitis and microvessel density in synovial tissues in patients with internal derangement of the temporomandibular joint.

OBJECTIVE: To elucidate the correlation between the arthroscopic diagnosis of synovitis and microvessel density in synovial tissues in patients with internal derangement of the temporomandibular joint (TMJ). STUDY DESIGN: Forty-three joints in 41 patients with internal derangement were examined and biopsies taken. Microvessel density was evaluated using the immunohistochemical method for CD 34 antibody. Arthroscopically diagnosed synovitis was evaluated according to Murakami's criteria. RESULTS: In patients with internal derangement, arthroscopically diagnosed synovitis scores averaged 5.2+/-2.0, according to Murakami et al. (1991). Small to large blood vessels were observed clearly with CD 34 stain. The mean microvessel density was 22.7+/-15.6 per two high power fields (magnification x200). Synovitis scores correlated significantly with microvessel density (p=0.002, r=0.43). CONCLUSION: Synovitis evaluated using Murakami's scores correlated well with the number of blood vessels in synovial tissues in patients with internal derangement of the TMJ. This demonstrates that synovitis is linked to inflammation-related blood vessel density of the synovial tissues.     

Specific expression of substance P in synovial tissues of patients with symptomatic, non-reducing internal derangement of the temporomandibular joint: comparison with clinical findings

Our aim was to find out the extent of expression of substance P in synovial tissue from the human temporomandibular joints (TMJ) with symptomatic, non-reducing internal derangement, and to investigate the relationship between substance P and clinical findings. Fifty-four joints in 54 patients were examined immunohistochemically. Specimens of synovial tissue from 10 joints in 8 subjects with habitual dislocation of the TMJ with no pain were examined as controls. Cells that stained for substance P were found mainly among the endothelial cells in the blood vessels beneath the lining cells in synovial tissues from 47 of the 54 joints (87%) with internal derangement and from 5 of the 10 control joints. The extent score of cells that stained for substance P in joints with internal derangement was significantly higher than that in controls (p=0.02). The extent score of these cells did not correlate with pain in the joint or the degree of synovitis. These results suggest that substance P may have some roles in both the physiological and pathological conditions in patients with symptomatic internal derangement of the TMJ.     

Viscoelastic properties of the human temporomandibular joint disc in patients with internal derangement.

PURPOSE: This study investigated the viscoelastic properties of human temporomandibular joint (TMJ) discs in patients with severe internal derangement (ID). PATIENTS AND METHODS: TMJ discs obtained from 5 patients with severe TMJ internal derangement were analyzed. Normal discs derived from 2 fresh cadavers and 4 patients without ID served as the controls. The viscoelastic responses of the discs to tensile forces were evaluated by means of stress-strain analyses. RESULTS: The discs in both groups exhibited a nonlinear stress-strain relationship that was represented by a power function of the strain. However, after stress relaxation, the ID discs were likely to exhibit a linear stress-strain relationship. The instantaneous elastic moduli were almost the same in both discs, but the relaxed elastic modulus of the ID discs was significantly greater than that of the controls in lower strain range of less than 2%. CONCLUSIONS: ID discs are more rigid than normal discs. These findings suggest that the changes in viscoelastic property of the discs in patients with ID are somewhat different from those that occur with aging.     

Bradykinin expression in synovial tissues and synovial fluids obtained from patients with internal derangement of the temporomandibular joint

Bradykinin has been implicated in the pathogenesis of inflammatory arthritis by virtue of the potent pro-inflammatory properties. The purpose of this study is to investigate the expression of bradykinin in patients with internal derangement of the temporomandibular joint (TMJ). We examined 33 TMJ synovial biopsy specimens from 31 patients with internal derangement of the TMJ by an immunohistochemical technique using specific antibodies. We also determined the concentration of bradykinin in 20 synovial fluids from 18 patients with TMJ internal derangement by enzyme-linked immunosorbent assay. These data were compared with those of the control subjects. Bradykinin was predominantly localized in the synovial lining cell layer of TMJ samples obtained from patients with TMJ internal derangement. Bradykinin was also detected in 19 patients' TMJ synovial fluids and the average of bradykinin concentration in the synovial fluids of patients was higher than that of the healthy controls. Although a statistically significant correlation was not observed, these findings support the hypothesis that bradykinin may also be involved in the pathogenesis of TMJ pain and synovitis.