Effect of glucosamine sulphate on the temporomandibular joint of ovariectomised rats

Glycosamine is an amino-monosaccharide present in connective and cartilage tissues that contribute to the maintenance, resistance, flexibility, and elasticity of these tissues. This study aimed to determine the in vivo effects of glucosamine sulphate (GS) on the temporomandibular joint (TMJ) of ovariectomised rats (OVX).Thirty-two rats were distributed into four groups as follows: G1, sham-OVX + saline solution; G2, sham-OVX + glucosamine sulphate (80 mg/kg) – oral administration; G3, OVX + saline solution; G4, OVX + glucosamine sulphate (80 mg/kg) – oral administration. Animals were treated for seven days. The TMJ was removed and stained with toluidine blue. The thickness of the cartilage layers and cytokines IL-1β, IL-6, and TNF-α levels were determined by histomorphometry and immunoassay, respectively. The administration of GS to OVX females did not change the thickness of condylar cartilage when compared with the other groups (p > 0.05). There was an increase in the total cartilage thickness in sham-OVX females. IL-1β and TNF-α levels were significantly lower in sham-OVX females than in OVX females, indicating that ovariectomy acts as potent cytokine inducer. IL-6 levels were significantly higher in sham-OVX females. GS did not affect cytokine production in OVX females (p > 0.05). In conclusion, the administration of GS did not affect cytokine levels, but did induce an increase in the total thickness of the TMJ condylar cartilage in sham-OVX rats.     

The effect of omega-3 in temporomandibular joint synovial tissues of rats with induced arthritis: pilot study

This study evaluated the effect of systemic administration of omega-3 on the expression of interleukins IL-1β and IL-10 and tumour necrosis factor alpha (TNF-α) and on the thickness of cartilage in the temporomandibular joint (TMJ) inflammatory model induced by complete Freund’s adjuvant (CFA). Thirty-two adult rats were divided equally into four groups: control, CFA (induced arthritis), and induced arthritis animals treated with dexamethasone or omega-3. The TMJs were then removed and assigned to histomorphometric analysis or immunoassay. The Kruskal–Wallis test with Dunn post hoc test was applied to the data; the significance level was set at 5%. IL-1β levels (median; interquartile range) were higher (P < 0.0001) in the CFA group (46.4 ng/ml; 39.4–53.3) than in the control group (1.81 ng/ml; 1.5–5.4), but there were no differences between the control, omega-3, and dexamethasone groups. TNF-α levels were also higher (P < 0.0001) in the CFA group (122.7 ng/ml; 92.9–284.7) than in the control group (29.1 ng/ml; 23.7–31.3). IL-10 levels were lowest (P < 0.0001) in the CFA group (73.5 ng/ml; 52.8–90.5), and no differences were found amongst the other groups. In conclusion, omega-3 successfully reduced the damage in the TMJ of induced arthritis rats. Further investigations are warranted to confirm whether the administration of omega-3 has a comparable effect to glucocorticoids in rheumatoid arthritis patients.     

TMD before and after correction of dentofacial deformities by orthodontic and orthognathic treatment

The aims of the study were to investigate the alteration of temporomandibular disorders (TMD) after correction of dentofacial deformities by orthodontic treatment in conjunction with orthognathic surgery; and to compare the frequency of TMD in patients with dentofacial deformities with an age and gender matched control group. TMD were evaluated in 121 consecutive patients (treatment group), referred for orthognathic surgery, by a questionnaire and a clinical examination. 18 months after treatment, 81% of the patients completed a follow-up examination. The control group comprised 56 age and gender matched subjects, of whom 68% presented for follow-up examination. TMD were diagnosed according to research diagnostic criteria for TMD. At baseline examination, the treatment group had a higher frequency of myofascial pain (P = .035) and arthralgia (P = .040) than the control group. At follow-up, the frequencies of myofascial pain, arthralgia and disc displacement had decreased in the treatment group (P = .050, P = .004, P = .041, respectively). The frequency of TMD was comparable in the two groups at follow-up. Patients with dentofacial deformities, corrected by orthodontic treatment in conjunction with orthognathic surgery, seem to have a positive treatment outcome in respect of TMD pain.     

Neurosensory assessment in patients with total reconstruction of the temporomandibular joint

Somatosensory sensitivity and postoperative endogenous pain modulation have not been investigated in temporomandibular joint (TMJ) prosthesis patients. The objectives of this study were to assess somatosensory function at the TMJ and examine possible differences in conditioned pain modulation (CPM) between patients with total TMJ prostheses (n = 7) and a reference group of healthy controls (n = 20). Somatosensory abnormalities were assessed using quantitative sensory testing (QST), which encompasses thermal and mechanical testing procedures. CPM was tested by comparing pressure pain thresholds (PPT) before (baseline), during, and after the application of painful and non-painful cold stimuli. PPTs were measured at the TMJ and thenar eminence (control). The effect of CPM on PPT values was tested with analysis of variance. Three patients exhibited mixed somatosensory loss (i.e., decreased thermal and mechanical detection) with mixed hyperalgesia (i.e., increased sensitivity to thermal and mechanical pain) and two patients exhibited mixed loss with only mechanical hyperalgesia. There was a significant decrease in pressure pain sensitivity at both sites during painful cold application in healthy controls (P < 0.001) but not in patients (P = 0.476). In conclusion, QST measures demonstrated somatosensory abnormalities in patients with total TMJ prostheses. Noxious conditioning cold stimuli evoked CPM-like effects in healthy subjects but not in patients with TMJ reconstruction.     

Groningen temporomandibular total joint prosthesis: An 8-year longitudinal follow-up on function and pain

Total temporomandibular joint replacement is a surgical procedure for patients with severe temporomandibular joint afflictions affecting quality of life, which have not responded beneficially to previous conventional surgery. The aim of this study was to assess the long-term outcome of the Groningen temporomandibular joint (TMJ) prosthesis in patients with chronic pain and mutilated temporomandibular joints following multiple surgical procedures, with respect to prosthesis failure, the patient's postoperative level of satisfaction and longitudinal changes in maximum mouth opening, functional mandibular impairment and pain. Eight female patients were studied in whom Groningen TMJ prostheses were inserted, two unilaterally and six bilaterally.The Groningen TMJ prosthesis was mechanically successful during 8 years of follow-up in seven out of eight patients with a disc dislocation being seen in one patient (7%). Patients were satisfied, despite the limited improvement of the maximum mouth opening, and pain scores.Although the decline of MFIQ scores during 8 years of follow-up was significant compared to baseline (p = 0.027), the effects of the prosthesis on maximum mouth opening, function and pain were limited. This may be due to persistent chronic pain and the adverse effects of multiple previous surgical procedures.     

Relationship of age to foramen of Huschke and investigation of the development of spontaneous temporomandibular joint herniation

The aim of this study was to determine the prevalence, localization, and width of the foramen of Huschke (FH) and the relationship between age and FH. Another aim was to investigate the development of spontaneous temporomandibular joint (TMJ) herniation. This was a retrospective review of high-resolution computed tomography images of the temporal bone of 1025 patients. The prevalence of FH and the axial and sagittal diameters of the foramen were evaluated. Cases were found in which the TMJ had herniated through FH into the EAC. FH was detected in 137 (13.4%) of 1025 patients. The prevalence of FH was higher in females (18.4%) than in males (6.6%) (P < 0.001). The presence of FH increased with age (P = 0.005). Herniation of the TMJ through FH into the EAC was seen in four patients (0.4%), and 2.9% of patients with FH detected had TMJ herniation into the EAC. As well as being congenital, FH can also be senile; the prevalence may increase with age. Herniation of the TMJ through FH into the EAC is very rare; this was observed in 0.4% of all patients and 2.9% of patients with FH detected.     

Proinflammatory cytokines detectable in synovial fluids from patients with temporomandibular disorders

Objective. To measure the levels of the proinflammatory cytokines, interleukin (IL)-1β, IL-6, tumor necrosis factor- (TNF)α, IL-8, and interferon- (IFN) γ in synovial fluid samples taken from patients with temporomandibular disorders (TMD).Study design. We studied 6 asymptomatic volunteers and 51 patients with TMD. The IL-1β, IL-6, TNF-α, IL-8, and IFN-γ levels in temporomandibular joint synovial fluid were measured using enzyme-linked immunosorbent assay.Results. Measurable level of at least one cytokine in the synovial fluid was found in 40 (64.5%) of 62 joints in the patients: IL-1β and IFN-γ were each detected in 18 (29.0%) of 62 joints; IL-6 in 13 (21.0%) of 62 joints; IL-8 in 11 (19.3%) of 57 joints; and TNF-α in only 5 (8.1%) of 62 joints. None of these cytokines was detectable in the synovial fluid in the control group. Furthermore, there was a strong correlation between the detection of IL-1β and pain in the joint area.Conclusions. These data clearly demonstrate increased levels of several proinflammatory cytokines in certain patients with TMD and suggest that these cytokines may play a role in the pathogenesis of synovitis and degenerative changes of the cartilaginous tissue and bone of the temporomandibular joint.     

小型猪一侧失牙及义齿修复后TMJ关节液中IL-1β、TNF-α、TGF—β1含量的变化

目的：检测小型猪一侧失牙及义齿修复后颞下颌关节（temporomandibularjoint，TMJ）关节液中IL-1β、TNF-α、TGF-β1含量，探讨其在颞下颌关节紊乱病中的作用及相互关系。方法：11头小型猪随机分为空白组2头、拔牙组4头和修复组5头，拔牙组和修复组左侧后牙全部拔除，修复组于拔牙后3个月义齿修复；每月采集双侧TMJ关节液，ELISA法测定IL-1β、TNF-α、TGF-β1含量（共6个月）。结果：拔牙组和修复组关节液中IL-1p浓度于第1个月达到最大值，拔牙组于第3个月、修复组于第5个月IL-1β浓度达到最小值；拔牙组于第4个月、修复组于第3个月TNF-α达到最大值；拔牙组和修复组于第3个月TGF-β1浓度达到最大值。结论：IL-1β启动并与TNF—α协同破坏TMJ；TGF-β1在TMJ损伤的修复中发挥重要作用。     

Effect of orthodontic force on expression levels of ten cytokines in gingival crevicular fluid

Various types of inflammatory mediators are involved in the cascade of biological events behind tissue remodeling allowing orthodontic tooth movement. This split-mouth longitudinal study aimed to evaluate the gingival crevicular fluid (GCF) levels of ten cytokines, IL-6, IL-8, IL-10, IL-13, IL-17, IFN-γ, GM-CSF, MCP-1, MIP-1β and TNF-α, during initial orthodontic treatment. The sample comprised 15 healthy patients (9 males and 6 females, 13.9 ± 2.5 years). The lower (test) incisors were moved using fixed appliance carrying a 0.014-inch nickel titanium wire, whereas the upper (control) incisors were bonded without any force. The GCF was collected from the test and control teeth before fixed appliance mounting (baseline) and after 1, 7 and 21 days. In 6 sites per tooth, from canine to canine, periodontal conditions were defined as the percentage of sites with visible plaque and bleeding on probing. The total GCF cytokines levels were quantified using multianalysis Luminex technology. Throughout the experimental term, and for both test and control teeth, the mean percentage of sites with visible plaque and bleeding on probing were generally below 25% and 15%, respectively, although variability was also seen. In the test teeth, the GCF levels of all the cytokines remained constant throughout the experimental term. On the contrary, significant reductions were seen in the control teeth for each cytokine. Moreover, significantly greater levels of IL-6, GM-CSF, MCP-1 and TNFα were seen in the test teeth as compared to the control teeth at 7 days. The reasons for the differential behavior in the levels of all the investigated cytokines between the test and control teeth may be related to the presence of orthodontic forces and/or subclinical tissue inflammation. Further investigation is needed to elucidate potential roles for these biomarkers in the tissue remodeling incident to orthodontic tooth movement.     

Total reconstruction of the temporomandibular joint. Up to 8 years of follow-up of patients treated with Biomet® total joint prostheses

12 patients underwent temporomandibular joint (TMJ) reconstruction with Biomet total joint prostheses. Indications for TMJ reconstruction included ankylosis, rheumatoid arthritis, degenerative joint disease and condylar resorption. Five patients had unilateral procedures, seven had bilateral. The follow-up ranged between 2 and 8 years. Amongst the ankylotic patients the mean jaw-opening capacity increased from 3.8 mm preoperatively to 30.2 mm 1 year after surgery, and in most of those patients the opening capacity remained stable over the years. The other patients maintained a mean opening capacity of more than 35 mm. Joint related pain and interference with eating were eliminated after TMJ reconstruction. There were no permanent facial nerve disturbance, no postoperative infections and no device related complications. The outcome supports prosthetic TMJ reconstruction as a useful treatment modality in patients with advanced TMJ disease.     

The action of anti-inflammatory agents in healthy temporomandibular joint synovial tissues is sex-dependent

This study evaluated the effects of dexamethasone, parecoxib, and glucosamine on cartilage thickness and cytokine levels in the temporomandibular joint (TMJ). Forty-eight rats (24 female, 24 male) were assigned to four treatments administered once daily for 7 days: control (saline intramuscularly), parecoxib (0.3 mg/kg intramuscularly), dexamethasone (0.1 mg/kg intramuscularly), and glucosamine (80 mg/kg orally). The thickness of TMJ cartilage and levels of four cytokines were measured. Median cartilage thickness was higher in males than in females in the control (253.2 vs. 240.4 μm, P = 0.0036), parecoxib (227.3 vs. 192.1 μm, P < 0.0001), and dexamethasone (227.1 vs. 170.5 μm, P = 0.017) groups, but was lower in males in the glucosamine group (214.5 vs. 239.6 μm, P = 0.0001). IL-1β was not detected. Median IL-1α levels differed between males and females in the parecoxib group (0.08 vs. 0.04 ng/ml, P = 0.0055), but not in the control (0.07 vs. 0.06 ng/ml), dexamethasone (0.06 vs. 0.04 ng/ml), or glucosamine (0.08 ng/ml vs. 0.06 ng/ml) groups (all P > 0.05). Only dexamethasone induced lower IL-6 levels in males than in females (median 4.6 vs. 2.1 ng/ml, P = 0.0044). Median TNF-α levels did not differ between males and females in the control (0.07 vs. 0.05 ng/ml) or parecoxib (0.07 vs. 0.05 ng/ml) groups (both P > 0.05), but dexamethasone (0.09 vs. 0.05 ng/ml, P = 0.0002) and glucosamine (0.09 vs. 0.07 ng/ml, P = 0.0259) induced higher TNF-α levels in females. Thus, the effects of the three treatments on the levels of cytokines and thickness of condylar cartilage were sex-dependent.     

Effectiveness of occlusal splint therapy in the management of temporomandibular disorders: network meta-analysis of randomized controlled trials

A network meta-analysis (NMA) of randomized controlled trials (RCTs) was performed to assess the effectiveness of various types of occlusal splint in the management of temporomandibular disorders (TMDs) and to rank them according to their effectiveness. An electronic search was undertaken to identify RCTs published until August 2019. Predictor variables were control, non-occluding splint, hard stabilization splint (HSS), soft stabilization splint (SSS), prefabricated splint, mini-anterior splint, anterior repositioning splint (ARS), and counselling therapy (CT) with or without HSS. Outcome variables were pain improvement, post-treatment pain intensity, improvement in mouth opening, and disappearance of temporomandibular joint (TMJ) sounds. Forty-eight RCTs were included. There was a significant decrease in post-treatment pain intensity in arthrogenous TMDs after ARS (low quality evidence), CT + HSS (moderate quality evidence), mini-anterior splints (very low quality evidence), and HSS alone (low quality evidence), when compared to the control. There was a significant decrease in post-treatment pain intensity in myogenous TMDs with mini-anterior splints (very low quality evidence), SSS (very low quality evidence), CT alone (moderate quality evidence), CT + HSS (moderate quality evidence), and HSS alone (moderate quality evidence), when compared to control. ARS and CT were superior in decreasing TMJ clicking than control and HSS alone. The three highest-ranked treatments for post-treatment pain reduction in arthrogenous TMDs were ARS (92%, very low quality evidence), CT + HSS (67.3%, low quality evidence), and HSS alone (52.9%, moderate quality evidence). For myogenous TMDs, they were mini-anterior splints (86.8%, low quality evidence), CT + HSS (61.2%, very low quality evidence), and HSS alone (59.7%, moderate quality evidence). Based on this NMA of 48 RCTs, there is moderate to very low quality evidence confirming the effectiveness of occlusal splint therapy in the treatment of TMDs. Multimodal therapy consisting of CT + HSS may produce the maximum improvement for TMD patients.     

Comparison of clinical outcomes of treatment of dysfunction of the temporomandibular joint between conventional and ultrasound-guided arthrocentesis

Patients with disorders of the temporomandibular joint (TMJ) who do not respond to non-operative treatment may require invasive procedures such as arthrocentesis and arthroscopy. We divided 80 patients with dysfunction of the TMJ into two groups: a control group who were treated by conventional arthrocentesis, and an experimental group who were treated by ultrasound-guided arthrocentesis. Both groups were monitored three days, one week, and one month postoperatively and the clinical outcomes compared. The experimental group had a significant reduction in the degree of pain in the immediate postoperative period (p = 0.015). However, ultrasound-guided arthrocentesis showed no significant improvement in symptoms overall compared with conventional arthrocentesis. Both techniques seem to be effective in the management of dysfunction of the TMJ.     

Biomechanical effect of asymmetric mandibular prognathism treated with BSSRO and USSRO on temporomandibular joints: a three-dimensional finite element analysis

Asymmetric mandibular prognathism is a clinically common skeletal dentomaxillofacial deformity. Unilateral sagittal split ramus osteotomy (USSRO) is an effective alternative procedure to bilateral sagittal split ramus osteotomy (BSSRO) for some patients. However, the biomechanical effect of temporomandibular joint (TMJ) of USSRO has not been fully studied. This study aims to evaluate the stress distribution changes in the TMJ of asymmetric mandibular prognathism treated with BSSRO/USSRO, to validate the clinical feasibility of USSRO. Nineteen patients with mandibular prognathism patients who were treated with BSSRO (n = 12) and USSRO (n = 7) had preoperative and postoperative computed tomographic scanning. Preoperative and postoperative 3-dimensional finite element analysis (FEA) of functional TMJ movements were made on one BSSRO patient and one USSRO patient. In all patients, the ANB angle and mandibular deviation were significantly improved postoperatively. There was no significant difference in the postoperative ANB angle and mandibular deviation between the BSSRO group and the USSRO group. In two preoperative FEA models, the maximum stresses of non-deviation side TMJ structures were greater than the deviation side during functional movements. The unbalanced stress distribution was corrected postoperatively in both BSSRO/USSRO FE models. Both BSSRO/USSRO can improve the ANB angle and mandibular deviation. The bilateral TMJ structure in patients with asymmetric mandibular prognathism had unbalanced stress, which could be significantly improved with the USSRO as effectively as BSSRO.     

Comparison of the outcomes of three surgical treatments for end-stage temporomandibular joint disease

The aim of this study was to determine whether there are any differences between condylectomy, rib grafts, and prosthetic joints (Biomet TMJ stock prosthesis) with regard to outcomes for patients with end-stage temporomandibular joint (TMJ) disease. Fifty-six of a total 127 patients who presented with category 5 end-stage TMJ disease over 3 years (2010–2013) agreed to participate in this retrospective, comparative, cohort study. Patients were divided into four groups: preoperative (n = 16), condylectomy (n = 8), rib graft (n = 16), and prosthetic joint (n = 16). They were assessed for major postoperative complications (i.e., return to theatre) and maximum range of mandibular motion, and all completed a specific quality of life (QOL) questionnaire. Whilst the condylectomy group demonstrated the best mandibular range of motion (P < 0.01), rib graft patients were more likely to experience complications (43.8%) necessitating a return to theatre. The prosthesis group recorded the best mean aggregate QOL score, but the difference compared to the rib graft and condylectomy groups was not statistically significant. The results of this study suggest that for dentate patients, prosthetic joints are highly dependable with no returns to theatre and favourable QOL outcomes. For edentulous patients, condylectomies alone also appear to work well. Future TMJ prosthetic designs should focus on improving mandibular range of motion, as the current stock prosthesis allows only a restricted range, no better than that achieved with rib graft (P > 0.05) and far less than that achieved with condylectomy (P < 0.01).     

The use of pseudo-dynamic magnetic resonance imaging for evaluating the relationship between temporomandibular joint anterior disc displacement and joint pain

The relationship between temporomandibular joint (TMJ) pain and the magnetic resonance imaging (MRI) finding of articular disc displacement is debated. The purpose of this study is to investigate the correlation between TMJ pain and anterior disc displacement (ADD) using pseudo-dynamic MRI. A retrospective review of MRI studies was carried out on 130 TMJs in 65 patients presenting unilateral TMJ pain. The contralateral asymptomatic joints served as the control group. Bilateral oblique sagittal and coronal MRIs as well as pseudo-dynamic studies in the oblique sagittal plane were obtained. The disc–condyle relationship was divided into three subtypes (normal disc position, ADD with reduction, and ADD without reduction), based on the pseudo-dynamic MRI findings. Fisher's exact test was used to determine whether the TMJ pain was linked to ADD. The results showed that TMJ pain was significantly related to ADD (with and without reduction) compared to the group with a normal disc position (P = .0001). A significant correlation was found between TMJ pain and the ADD subtype without reduction, as compared to the ADD subtype with reduction (P = .0156). These data suggest that a displaced disc, particularly in the subtype without reduction, is an important source of pain.     

Characteristics related to TMJ arthralgia,visualized by magnetic resonance imaging (3.0 Tesla)

PatientsSix women, with ages ranging from 52 to 64 years old, clinically evaluated (Research Diagnostic Criteria for Temporomandibular Disorders) by a single examiner were submitted to MRI (3.0 T). They had only arthralgia diagnosis. The images were evaluated by two radiologists who were not informed about the patients’ clinical conditions, in which discs displacements, osteophytes and morphological irregularities, as well as completely normal images, i.e., without any characteristics were identified.DiscussionTMJ arthralgia can be caused by various conditions, few of which are objectively observed when investigating its causes or diagnose temporomandibular disorders (TMD). In some cases, imaging exams can detect some conditions and magnetic resonance imaging (MRI) is commonly used for this purpose. Here, the MRI (3.0 T) enabled a detailed visualization of the structures of the TMJ, allowing the characterization of the symptomology in some cases. Despite, some images were completely normal.ConclusionThis case report detected some features seen on the MRI that justified a clinical diagnosis arthralgia, not associated with other clinical diagnosis. However, the detailed clinical examination should be sovereign even in the face of equipment with advanced technology.     

Axis II psychosocial findings predict effectiveness of TMJ hyaluronic acid injections

The objective was to investigate the correlation between levels of depression, somatization, and pain-related impairment, as assessed by the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMDs) axis II, and the treatment outcome of a cycle of five weekly injections of hyaluronic acid immediately following arthrocentesis. 57 consecutive patients with a diagnosis of temporomandibular joint (TMJ) osteoarthritis according to the RDC/TMD underwent the treatment protocol and a follow-up assessment at 6 months. Axis II findings were assessed as potential predictors of improvement in visual analogue scale (VAS) values at the end of the observation period with respect to baseline. The percentage of VAS improvement at the end of treatment was inversely related to all the psychosocial variables. The best fitting model identified pain-related impairment (p < 0.001) and disability points (p < 0.001) as the most significant predictors of VAS changes. The percentage of variance in the outcome variable explained by the significant predictors was high (R² 70.5%). All the RDC/TMD axis II psychosocial scores (depression, somatization, and pain-related impairment levels) were inversely correlated with therapeutic outcome. The clinical relevance of these findings is important, since psychosocial diagnosis may be even more important than physical evaluation in terms of prognostic impact.