[Preliminarily study of arthrocentesis combined with liquid phase concentrated growth factor injection in the treatment of unilateral temporomandibular joint osteoarthritis].

OBJECTIVE: To observe the clinical effect of arthrocentesis combined with liquid phase concentrated growth factor (CGF) injection in the treatment of unilateral temporomandibular joint osteoarthritis (TMJOA), in order to provide a new treatment option for TMJOA patients. METHODS: In this non-randomized controlled study, patients diagnosed with unilateral TMJOA who visited the center for temporomandibular joint disorder and orofacial pain of Peking University School and Hospital of Stomatology from June 2021 to January 2023 were selected as research objects. The patients were divided into experimental group and control group, which were selected by patients themselves. The experimental group received arthrocentesis combined with liquid phase CGF injection and the control group received arthrocentesis combined with HA injection. Both groups were treated 3 times, once every two weeks. The clinical effect was evaluated by the maximum mouth opening, pain value and the degree of mandibular function limitation 6 months after treatment. The change of condylar bone was evaluated by cone beam CT (CBCT) image fusion technology before and after treatment. RESULTS: A total of 20 patients were included in the experimental group, including 3 males and 17 females, with an average age of (34.40±8.41) years. A total of 15 patients were included in the control group, including 1 male and 14 females, with an average age of (32.20±12.00) years. There was no statistical difference in general information between the two groups (P > 0.05). There were no statistical differences in the mouth opening, pain value and the degree of jaw function limitation between the two groups before treatment (P > 0.05), and all of them improved 6 months after treatment compared with before treatment (P < 0.05). However, the mouth opening of experimental group was significantly higher than that of control group 6 months after treatment (P < 0.05), and the degree of jaw function limitation was significantly lower than that of control group (P < 0.05). CBCT 2D images showed that the condylar bone of both groups was smoother after treatment than before treatment, and image fusion results showed that 10 patients (50.0%) in the experimental group and 5 patients (33.3%) in the control group had reparative remodeling area of condylar bone, and there was no statistical difference between them (P > 0.05). Except for one CGF patient, the other patients in both groups had some absorption areas of condylar bone. CONCLUSION: The arthrocentesis combined with liquid phase CGF injection can improve the clinical symptoms and signs of unilateral TMJOA patients in short term, and is better than HA in increasing mouth opening and improving jaw function. CBCT fusion images of both patient groups show some cases of condylar bone reparative remodeling and its relevance to treatment plans still requires further study.

Retrospective study of synovial chondromatosis of the temporomandibular joint: clinical and histopathologic analysis and the early-stage imaging features.

OBJECTIVE: Herein, we aimed to study the clinical, radiographical, and histopathologic features of synovial chondromatosis in the temporomandibular joint (SC in TMJ) and provide references for early diagnosis and treatment prognosis. STUDY DESIGN: The medical records and imaging examinations of patients with SC in TMJ, diagnosed using postoperative histopathologic examination, were reviewed and analyzed. Among them, 18 cases who lacked calcified loose bodies on spiral computed tomography or cone beam computed tomography (SCT/CBCT) were selected for further study. Descriptive statistical methods were used to analyze the clinical characteristics of patients. RESULTS: The study included 100 patients with SC in TMJ, who were predominantly female (male to female: 1:3), and were aged from 21 to 77 years (median, 47). Radiopaque calcified lesions on SCT/CBCT were missing in 18 cases, but cartilaginous nodules were observed during surgery. The cases lacking calcification had a relatively shorter disease course, suggesting they were in the early stages of SC. CONCLUSION: In the early stage of SC, although calcified loose bodies cannot be detected on SCT/CBCT, attention should be paid to the widening of the posterior superior joint space and sclerosis or slight erosion of the joint fossa. Magnetic resonance imaging would be helpful to detect the early-stage SC in TMJ.

Diagnostic accuracy of fused CBCT images in the evaluation of temporomandibular joint condylar bone resorption.

OBJECTIVES: To evaluate the diagnostic accuracy of fused CBCT images for patients with condylar bone resorption of temporomandibular joint (TMJ) osteoarthrosis. MATERIALS AND METHODS: Forty-two TMJs from twenty-one patients were included. Bone resorption of condyles evaluated by three experts was used as the reference standard. Three oral and maxillofacial radiology residents evaluated the resorption of condyles with a five-point scale for the four sets of images (two consecutive CBCT images without fusion, fused 2D cross-sectional images, fused 3D images, and combining fused 2D cross-sectional images and fused 3D images) randomly and independently. Each set of images was evaluated at least 1 week apart, and a second evaluation was performed 4 weeks later. Intraclass correlation coefficients were calculated to assess the intra- and inter-observer agreement. The areas under the ROC curves (AUCs) were compared among the four image sets using the Z test. RESULTS: Twenty-four TMJs were determined as condylar bone resorption, and eighteen were determined as no obvious change. The average AUC values from the three observers for the three fused image sets (0.94, 0.93, 0.93) were significantly higher than the image set without fusion (p < 0.01). The intra- and inter-observer agreement on the three fused image sets (0.70-0.89, 0.91-0.92) was higher than the image set without fusion (0.37-0.63, 0.75). CONCLUSIONS: Fused CBCT images of TMJ osteoarthrosis patients can intuitively display the condylar bone resorption and significantly improve the diagnostic accuracy. CLINICAL RELEVANCE: Fused CBCT images can help clinicians intuitively observe bone changes of the condyle in TMJ osteoarthrosis patients.

Diagnostic efficacy of CBCT, MRI and CBCT-MRI fused images in determining anterior disc displacement and bone changes of temporomandibular joint.

OBJECTIVES: To evaluate the diagnostic efficacy of CBCT-MRI fused image for anterior disc displacement and bone changes of temporomandibular joint (TMJ), which are the main imaging manifestations of temporomandibular disorders (TMD). METHODS: Two hundred and thirty-one TMJs of 120 patients who were diagnosed with TMD were selected for the study. The anterior disc displacement, bone defect and bone hyperplasia evaluated by three experts were used as a reference standard. Three residents individually evaluated all the three sets of images, which were CBCT images, MRI images and CBCT-MRI fused images from individual CBCT and MRI images in a random order for the above-mentioned three imaging manifestations with a five-point scale. Each set of images was observed at least 1 week apart. A second evaluation was performed 4 weeks later. Intra- and interobserver agreements were assessed using the intraclass correlation coefficient (ICC). The areas under the ROC curves (AUCs) of the three image sets were compared with a Z test, and p < 0.05 was considered statistically significant. RESULTS: One hundred and forty-five cases were determined as anterior disc displacement, 84 cases as bone defect and 40 cases as bone hyperplasia. The intra- and interobserver agreements in the CBCT-MRI fused image set (0.76-0.91) were good to excellent, and the diagnostic accuracy for bone changes was significantly higher than that of MRI image set (p＜0.05). CONCLUSIONS: CBCT-MRI fused images can display the disc and surrounding bone structures simultaneously and significantly improve the observers' reliability and diagnostic accuracy, especially for inexperienced residents.

Effects of HDAC4 on IL-1ß-induced matrix metalloproteinase expression regulated partially through the WNT3A/ß-catenin pathway.

BACKGROUND: Histone deacetylase 4 (HDAC4) regulates chondrocyte hypertrophy and bone formation. The aim of the present study was to explore the effects of HDAC4 on Interleukin 1 beta (IL-1ß)-induced chondrocyte extracellular matrix degradation and whether it is regulated through the WNT family member 3A (WNT3A)/ß-catenin signaling pathway. METHODS: Primary chondrocytes (CC) and human chondrosarcoma cells (SW1353 cells) were treated with IL-1ß and the level of HDAC4 was assayed using Western blotting. Then, HDAC4 expression in the SW1353 cells was silenced using small interfering RNA to detect the effect of HDAC4 knockdown on the levels of matrix metalloproteinase 3 (MMP3) and MMP13 induced by IL-1ß. After transfection with HDAC4 plasmids, the overexpression efficiency was examined using Real-time quantitative polymerase chain reaction (qRT-PCR) and the levels of MMP3 and MMP13 were assayed using Western blotting. After incubation with IL-1ß, the translocation of ß-catenin into the nucleus was observed using immunofluorescence staining in SW1353 cells to investigate the activation of the WNT3A/ß-catenin signaling pathway. Finally, treatment with WNT3A and transfection with glycogen synthase kinase 3 beta (GSK3ß) plasmids were assessed for their effects on HDAC4 levels using Western blotting. RESULTS: IL-1ß downregulated HDAC4 levels in chondrocytes and SW1353 cells. Furthermore, HDAC4 knockdown increased the levels of MMP3 and MMP13, which contributed to the degradation of the extracellular matrix. Overexpression of HDAC4 inhibited IL-1ß-induced increases in MMP3 and MMP13. IL-1ß upregulated the levels of WNT3A, and WNT3A reduced HDAC4 levels in SW1353 cells. GSK-3ß rescued IL-1ß-induced downregulation of HDAC4 in SW1353 cells. CONCLUSION: HDAC4 exerted an inhibitory effect on IL-1ß-induced extracellular matrix degradation and was regulated partially by the WNT3A/ß-catenin signaling pathway.

Diagnostic efficacy of CBCT, MRI, and CBCT-MRI fused images in distinguishing articular disc calcification from loose body of temporomandibular joint.

OBJECTIVES: To evaluate the diagnostic efficacy of CBCT-MRI fused images for articular disc calcification of temporomandibular joint (TMJ). MATERIALS AND METHODS: Twenty patients (24 TMJs) whose image examinations showed dense bodies in the TMJ space were included in the study. The locations of dense bodies evaluated by the three experts were used as a reference standard. Three oral and maxillofacial radiology residents evaluated whether the dense bodies were disc calcification or not, with a five-point scale for four sets of images (CBCT alone, MRI alone, both CBCT and MRI observed at a time, and CBCT-MRI fused images) randomly and independently. Each set of images was observed at least 1 week apart. A second evaluation was performed after 4 weeks. Intraclass correlation coefficients were calculated to assess the intra- and inter-observer agreement. The areas under the ROC curves (AUCs) were compared between the four image sets using Z test. RESULTS: Ten cases were determined as articular disc calcifications, and fourteen cases were recognized as loose bodies in the TMJ spaces. The average AUC index for the CBCT-MRI fused images was 0.95 and significantly higher than the other sets (p < 0.01). The intra- and inter-observer agreement in the CBCT-MRI fused images (0.90-0.91, 0.93) was excellent and higher than those in the other images. CONCLUSIONS: CBCT-MRI fused images can significantly improve the observers' reliability and accuracy in determining articular disc calcification of the TMJ. CLINICAL RELEVANCE: The multimodality image fusion is feasible in detecting articular disc calcification of the TMJ which are hard to define by CBCT or MRI alone. It can be utilized especially for inexperienced residents to shorten the learning curve and improve diagnostic accuracy.

Postoperative outcomes of adult patients with sagittal fractures of mandibular condyle: Quantitative evaluation and retrospective factor analysis.

PURPOSE: We attempted to adopt quantitative methods to precisely evaluate the surgical effect of sagittal fractures of mandibular condyle (SFMCs) and aimed to determine differences in postoperative results between different groups of patients. MATERIALS AND METHODS: Postoperative data of patients with SFMC were collected and quantitative evaluations of subjective, clinical and imaging results were performed. SPSS software was used to analyze the data, and certain factors (gender, age, unilateral or bilateral SFMCs, injury time) were analyzed by univariate analysis. RESULTS: Forty-four postoperative patients were included with an average follow-up of 15.7 months. Averages of resting pain, moving pain, and chewing pain were all <10. Averages of maximum mouth opening, protrusion, and ipsilateral excursive movement were 42.20, 4.80, and 5.98 mm, respectively. Moreover, 85.71% of condylar healing and remodeling was good, and average condylar absorption was 1.52 mm. Early-operated patients (injury time ≤2 weeks) exhibited greater ipsilateral excursive movement, higher condylar index, and lesser condylar absorption than late-operated patients (injury time >2 weeks). Patients with unilateral SFMC showed greater protrusive movement and higher condylar index than those with bilateral SFMCs. CONCLUSION: Most patients with SFMCs could obtain good subjective, clinical and imaging results by appropriate surgical treatment. Early surgery could improve postoperative outcomes.

Diagnosis of Bilateral Calcifications of Temporomandibular Joint Disc by Image Fusion.

The calcification of the articular disc is an uncommon lesion, usually discovered in hips, elbows, and shoulders, but rarely in temporomandibular joints (TMJ). The TMJ disc calcification may be related to pain and limitation of the mandibular mobility, however, most of the patients were asymptomatic. A 61-year-old female was referred to our hospital after a maxillofacial fist injury, bilateral TMJ disc calcifications were found accidentally by radiological examination. Here the significance of image fusion of cone-beam computed tomography and magnetic resonance imaging (MRI) in the diagnosis of this lesion was emphasized.

Application of fused image in detecting abnormalities of temporomandibular joint.

OBJECTIVES:: To present a method for image fusion of cone beam CT (CBCT)/CT and MRI and to explore whether the image data sets fused in such a way could aid the detection of temporomandibular joint (TMJ) anatomical structures and lesions. METHODS:: There were five cases included in this study. One case was space occupying lesion giant cell tumour of tendon sheaths, one case was chronic inflammation in the condyle, one case was articular disc calcification of the bilateral TMJs, and the other two cases were TMJ disorders (anterior disc displacement without reduction). The digital imaging and communications in medicine format data of CT/CBCT and MRI of the cases were collected, and then imported to the Amira visual software where the registration process was conducted. Based on the different scan model, the registration process could be separated into automatic registration of CT/CBCT with quadrature slice MR images and the semi-automatic registration of CT/CBCT with oblique slice MR images by altering the registration parameters. Rigid transform model and the similarity metric of normalization mutual information was used for registration in the present study. RESULTS:: The relationship between the soft mass and hard tissue was shown clearly in the fused images when compared to sole observation of CBCT/CT or MR images. The fused images could define the tumour outline and the destructive bone clearly in the same image. The fused results helped the observers to ensure uncertain defects which could not be confirmed only by one image data set. CONCLUSIONS:: The CT/CBCT and MR images could be fused to aid detection of TMJ anatomical structures and related lesions.

A Giant Aneurysmal Bone Cyst in the Mandibular Condyle.

Aneurysmal bone cyst (ABC) is a rare, rapidly expanding, locally destructive, and easily misdiagnosed lesion. An ABC of the condyle is rare. This report presents a 25-year-old female with a giant ABC in the left mandibular condyle. This patient was treated with surgical resection of the affected bone and immediate mandibular reconstruction using autologous bone. Follow-up to date showed no signs of recurrence. The clinical feature, imaging finding, pathogenesis, and treatment methods of ABCs are discussed.

DNA methylation profiling in different phases of temporomandibular joint osteoarthritis in rats.

OBJECTIVE: Temporomandibular joint osteoarthritis (TMJOA) is a complex disease with strong genetic and epigenetic components in its pathogenesis. The aim of this study was to evaluate DNA methylation in mandibular head cartilage in different phases of experimentally-induced TMJOA in rats. DESIGN: DNA methylation was evaluated using microarrays in the mandibular head cartilage of early, intermediate and late stage experimentally-induced TMJOA, and of the normal age-matched control groups. Genes with differentially methylated CpG sites were analyzed to reveal the over-represented gene ontologies and pathways at different stages, and were compared with published expression profiles to assess their overlappings. The DNA methylation patterns of the target genes were validated by methylated DNA immunoprecipitation qPCR in additional independent cartilage samples and mRNA levels were analyzed by real-time PCR. RESULTS: We observed 9489 differentially methylated regions between the TMJOA and controls. A total of 440 consistently altered genes were revealed in all three stages; most (80%) were hypomethylated and many were associated with cell cycle regulation. We also detected different DNA methylation changes in early and late stage TMJOA (Rearly=0.68, Rlate=0.47), while the differences between age-matched healthy cartilage were subtle. Strong inverse changes between methylation status and mRNA levels were confirmed in Adamts5, Chad, Cldn11 and Tnf. CONCLUSIONS: Our data reveals dynamic DNA methylation patterns during the progression of TMJOA, with a different host of genes and pathways. The changes of cartilage DNA methylation patterns might contribute to understand the etiologic mechanisms of TMJOA epigenetically.

[Diagnosis and treatment of the ganglion cysts and synovial cysts arising from the temporomandibular joints].

OBJECTIVE: To give a reference for the early diagnosis and treatment of the cysts arising from the temporomandibular joint. METHODS: Nine patients finally diagnosed as temporomandibular joint cysts at the Peking University Hospital of Stomatology from May 1998 to August 2013 were selected and reviewed. Their clinical manifestations, imaging features, diagnoses and differential diagnoses, treatments and follow-ups were summarized and discussed. RESULTS: In the 9 patients, 3 were males and 6 females. Their ages ranged from 33 to 62 years with a median age of 39 years; the course of the disease ranged from 2 weeks to 3 years with a median of 4 months. The image examinations were performed with conventional X-ray examinations in 7 cases, CT scans in 8 cases, MRI in 6 cases and ultrasound in one case. Of the 9 cases, 7 were finally diagnosed as ganglion cyst and 2 as synovial cyst. Ganglion cysts mainly presented as the mass of preauricular area or joint area, with no obvious symptoms or only local discomfort, occasionally with pain. The synovial cysts manifested as the painful swelling of preauricular area and limited mouth-opening, accompanying with occlusal disorders. The treatments included surgical resection in 8 cases, repeated arthrocenteses and lavages in one case. The follow-ups were from 3 months to 9 years, one case with recurrence, and the remaining eight cases without recurrence. CONCLUSION: MRI examinations are very helpful in the early diagnosis and treatment planning of temporomandibular joint cysts. Surgical resection can have good results. Repeated arthrocenteses and lavages also have a good result, which may be an alternative choice for synovial cyst, but more accumulation of clinical experience is further needed.

Requirement of the NF-κB pathway for induction of Wnt-5A by interleukin-1ß in condylar chondrocytes of the temporomandibular joint: functional crosstalk between the Wnt-5A and NF-κB signaling pathways.

OBJECTIVE: We have previously reported that interleukin-1ß (IL-1ß) up-regulates the expression of Wnt-5A and the activation of Wnt-5A signaling induces matrix metalloproteinase (MMP) through the c-Jun N-terminal kinase pathway in condylar chondrocytes (CCs) of the temporomandibular joint (TMJ). These results suggest that Wnt-5A could play an essential role in IL-1ß-mediated cartilage destruction. The objective of this study was to investigate the molecular mechanism underlying IL-1ß-induced up-regulation of Wnt-5A in TMJ CCs. METHODS: Primary CCs, limb chondrocytes (LCs) and SW1353 human chondrosarcoma cells were treated with IL-1ß in the presence or absent of BAY 11-7082 (an inhibitor of IκBα-phosphorylation). Then, expression of Wnt-5A was estimated by real-time reverse transcriptase-polymerase chain reaction (RT-PCR), Western blotting and immunocytofluorescence. Transient transfection of p65 expression vector and chromatin immunoprecipitation (ChIP) assay was performed to define the effect of p65 on Wnt-5A expression. RESULTS: IL-1ß up-regulated Wnt-5A expression at both the RNA and protein levels in articular chondrocytes. The inhibitor of IκBα-phosphorylation, BAY 11-7082, blocked the induction of Wnt-5A by IL-1ß in a dose-dependent manner. Moreover, experiments with overexpression of p65 and ChIP established that induction of Wnt-5A by IL-1ß is mediated through the NF-κB pathway, especially the p65 subunit. CONCLUSION: These results clarify the molecular mechanism underlying up-regulation of Wnt-5A by IL-1ß in chondrocytes, suggesting an important functional crosstalk between Wnt-5A and NF-κB signaling pathways. This finding provides new insights into the involvement of Wnt signaling in the cartilage destruction caused by arthritis.

Clinical and radiologic findings of synovial chondromatosis affecting the temporomandibular joint.

OBJECTIVES: Our aim was to study the clinical and radiologic findings of synovial chondromatosis (SC) affecting the temporomandibular joint (TMJ) and provide references for diagnosis and treatment. STUDY DESIGN: Twenty patients confirmed as SC histopathologically were included in the investigation. Nineteen cases were treated with arthrotomy and 1 case with arthroscopy. The clinical manifestations, radiographic findings, histopathologic features, surgical treatment, and differential diagnosis were combined to study this disease. The SC features of TMJ on magnetic resonance (MR) images were summarized on proton density-weighted (PD) and T2-weighted images. RESULTS: Synovial chondromatosis of TMJ occurred more often in women and on the right. Symptoms included preauricular pain, swelling, limitation of mouth opening, crepitations, and deviation on opening. The detection rate of calcified loose bodies was 30% on conventional radiographs and 53.3% on computerized tomography. Multiple small ring-like or tubular signals could be seen on PD and T2-weighted MR images. SC mainly affected the superior joint space; it could involve the inferior space when a perforated or deformed disc was present. SC could extend into intracranial fossa, infratemporal fossa, and lateral pytergoid muscle. CONCLUSIONS: The characteristic ring-like signals could be found on MR images of the patients with SC of TMJ. This lesion should be differentially diagnosed with TMJ disorders and preauricular masses. Considering its recurrence and the different behavior of SC in different patients, various treatment strategies should be considered.

Role of Wnt-5A in interleukin-1beta-induced matrix metalloproteinase expression in rabbit temporomandibular joint condylar chondrocytes.

OBJECTIVE: To determine the possible involvement and regulatory mechanisms of Wnt-5A signaling in interleukin-1beta (IL-1beta)-induced increase in matrix metalloproteinase 1 (MMP-1), MMP-3, MMP-9, and MMP-13 expression in temporomandibular joint (TMJ) condylar chondrocytes. METHODS: Primary rabbit condylar chondrocytes were treated with IL-1beta, purified Wnt-5A protein, or both and transfected with Wnt-5A expression vector. Expression of Wnt-5A, MMP-1, MMP-3, MMP-9, MMP-13, and type II collagen, as well as cell morphologic changes, were examined. To explore the mechanisms of action of Wnt-5A, the accumulation and nuclear translocation of beta-catenin, the transcription activity of the beta-catenin-Tcf/Lef complex, phosphorylated JNK, phosphorylated ERK, and phosphorylated p38 were analyzed. SP600125, a JNK inhibitor, was used to investigate the role of the JNK pathway in Wnt-5A induction of MMP-1, MMP-3, MMP-9, and MMP-13. RESULTS: Treatment of rabbit condylar chondrocytes with IL-1beta up-regulated Wnt-5A expression. Purified Wnt-5A protein and transfection with Wnt-5A expression vector promoted the expression of MMP-1, MMP-3, MMP-9, and MMP-13. Wnt-5A did not cause accumulation and nuclear translocation of beta-catenin or activation of the beta-catenin-Tcf/Lef transcription complex. Instead, Wnt-5A activated JNK, and an inhibitor of JNK blocked the Wnt-5A-induced up-regulated expression of MMPs. CONCLUSION: These findings indicate that IL-1beta up-regulates Wnt-5A, and the activation of Wnt-5A signaling induces the expression of MMP-1, MMP-3, MMP-9, and MMP-13 via the JNK signaling pathway in rabbit TMJ condylar chondrocytes. Blockage of JNK signaling impairs the Wnt-5A-induced up-regulation of MMPs. Thus, Wnt-5A may be associated with cartilage destruction by promoting the expression of MMPs.

[A preliminary study of murine hemangioma model by delivery of recombinant adeno-associated virus mediated human vascular endothelial growth factor-121 gene].

OBJECTIVE: To investigate the feasibility of establishing a murine hemangioma model with injection of recombinant adeo-associated virus mediated human vascular endothelial growth factor-121 (rAAV-hVEGF(121)) gene. METHODS: rAAV-hVEGF(121) was constructed, identified and then implanted to the left back ear of each mouse (1.0 x 10(11)VG in 50 microl per mouse and 10 nude mice received the injection), the rights served as controls with an injection of the same volume of phosphate buffered solution (PBS). The skin color and swelling of left back ear were observed every other day. Histological examination was carried out after mice were sacrificed 2, 4, 6, 8, 12 weeks after injection. RESULTS: The rAAV-hVEGF(121) was correctly constructed and confirmed by restriction endonuclease analysis, polymerase chain reaction and DNA sequencing analysis. The skin of left back ear became red 2 weeks after injection and gradually exhibited a red lump which was at its utmost 12 weeks after injection. Such phenomena were not observed in right back ear. Histological examinations showed aggregates of endothelial cells by 2 weeks and at 8 weeks the swollen tissue contained many cysts filled with a mass of red cells. CD-34 staining suggested most of the newly-formed cells were endothelial cells. CONCLUSIONS: A hemangioma model was established in mice with injection of recombinant rAAV-hVEGF(121) gene.

[Investigation on disc position of the temporomandibular joint in asymptomatic volunteers by magnetic resonance imaging].

OBJECTIVE: To investigate the types of disc position of the temporomandibular joint (TMJ) and their relationship with age and gender in asymptomatic volunteers by magnetic resonance imaging (MRI). METHODS: A total of 100 asymptomatic volunteers were divided into 5 groups (11-, 21-, 31-, 41-, 51 - 60 years old), 10 male and 10 female were included in each group. A total of 200 TMJs were scanned with Siemens Trio Tim 3.0T MRI system oblique-sagittally at closed- and open-mouth positions. Visual evaluation of MR images were performed on 3 neighbour slices of each TMJ (lateral, central, medial). RESULTS: There was a normal disc-condyle relationship in 59 of the 100 asymptomatic subjects. The normal disc position, anterior disc displacement and insidious anterior disc displacement (IADD) were observed in 140 (70.0%), 14(7.0%) and 46(23.0%)joints respectively, which showed no significant differences among different age groups or between genders (P > 0.05). The maximum mouth opening of the 100 asymptomatic volunteers was (46.3 +/- 5.5) mm, with no significant difference among the various types of disc position (P > 0.05). CONCLUSIONS: Disc displacement does exist in the asymptomatic volunteers, however, its occurrence is not associated with age and gender. IADD is the main type of the disc displacement in asymptomatic volunteers. There is no close relationship between the imaging manifestation of the disc displacement and clinical symptoms.

[Diagnostic evaluation of the temporomandibular joint osteoarthritis using cone beam computed tomography compared with conventional radiographic technology].

OBJECTIVE: Osteoarthritic lesions of Temporomandibular joint(TMJ) were assessed by dental cone beam computed tomography(CBCT), and compared with conventional radiographic technology. METHODS: The study was conducted retrospectively on 511 joints of 350 patients, who had undergone dental CBCT, panoramic radiography, transcranial projection and transpharygeal projection of TMJ. The results were compared and the accuracy with CBCT was assessed. The types of osseous condylar abnormalities were observed. RESULTS: (1) The occurrence of osteoarthritis in male and female were 59.04% and 69.66%, respectively, with no significant difference. (2) Compared with CBCT, panoramic radiography, transpharygeal projection examination showed no significant difference, with the accuracy being 90.64% and 94.10%, respectively; However, transcranial projection indicated a significant difference in comparison with CBCT and the accuracy was 86.97%. (3) A higher occurrence of osteoarthritic lesions of the condyle was sclerosis (39.86%). Bony proliferation or osteophyte (28.18%) and ill-defined cortical bone (18.90%) were followed. CONCLUSION: Cone beam CT, which reproduces multiple images including axial, coronal and sagittal planes of the joint, provides a complete radiographic investigation of the bony components of the TMJ. It is one of the best choices of imaging diagnosis of TMJ osteoarthritis. Panoramic radiography and transpharygeal projection examination are also good choices for showing osseous condylar abnormalities in the clinic, but transcranial projection examination is inferior.

Aquaporin-1 and aquaporin-3 expressions in the temporo-mandibular joint condylar cartilage after an experimentally induced osteoarthritis.

BACKGROUND: Over 70% of the total tissue weight in the cartilage matrix consists of water, and the early-stage osteoarthritic cartilage is characterized by swelling. Water transport in the cartilage matrix and across the membranes of chondrocytes may be important in normal and pathological conditions of cartilage. The purpose of this study was to identify aquaporin-1 (AQP1) and aquaporin-3 (AQP3) expressions in the mandibular condylar cartilage after experimentally induced osteoarthritis (OA) in rats. METHODS: An experimental temporomandibular joint OA was induced by partial discectomy in rats. The pathological characteristics of the normal, early-stage, and late-stage osteoarthritic TMJ cartilages were verified by histological techniques. The AQP1 and AQP3 gene expressions in the normal and osteoarthritic cartilages were measured using quantitative real-time reverse-transcription PCR analysis. The cartilage sections were incubated in primary polyclonal antibodies to AQP3; immunofluorescent microscopy was used to examine the AQP3 expression shown by its protein level. RESULTS: The mRNA expression levels of AQP1 and AQP3, analyzed using quantitative PCR, revealed that AQP3 mRNA was highly up-regulated in the OA cartilage, which was considered significant. There was no notable difference in the expression of AQP1 mRNA between OA and normal controls. With the progressing of the OA, the localization of the AQP3 protein was quite different from that of the normal cartilage. Compared to the normal cartilage, the expressions of AQP3 protein were observed mainly in the proliferative zone and the upper mid-zone chondrocytes at the early-stage of OA, and were observed to appear frequently throughout the mid- and deep zone during the late-stage of OA. CONCLUSIONS: The high expression of AQP3 mRNA in the OA cartilage and the different localization of the AQP3 protein suggest that it may play a particular role in OA pathogenesis. Further study of AQP3 function may provide new insight into the understanding of the molecular mechanisms underlying OA.