Clinical Evaluation of Platelet Rich Growth Factors (PRGFS) in Treatment of Temporomandibular Joint Disc Displacement—Study Report

Objective: The aim of the study was to evaluate the effect of platelet rich growth factors (PRGFs) in treatment of temporomandibular joint disc displacement. Materials and Methods: The study subjects included 8 females having bilateral anterior disc displacement with reduction and 1 female having bilateral anterior disc displacement without reduction with the age range between 20 - 35 years. The process of obtaining PRGFs was carried out following the Anitua Technique. Results: Clinical parameters of Interincisal distance, Lateral excursion of mandible using digital caliper in millimeters and Visual Analogue Scale (VAS 0/10) for pain intensity score were used. All of these parameters were running through the intervals of two, four, and eight weeks till the end of the follow-up period at twenty-six weeks (six months). The participated patients showed the clinical improvement in the different clinical statuses such as interincisal distance;lateral excursion of mandible and Pain Score. Conclusion: the study reported early efficacy of PRGFs after the arthrocentesis of the joint in treatment of TMJ disc displacement, and according to our results, the injection of PRGFs could be a possible alternative treatment for patients who did not respond to standard treatment.

Distribution of pericellular matrix molecules in the temporomandibular joint and their chondroprotective effects against inflammation

The objectives of this study were to （1） determine the distribution and synthesis of pericellular matrix （PCM） molecules （collagen VI, collagen IV and laminin） in rat temporomandibular joint （TMJ） and （2） investigate the effects of PCM molecules on chondrocytes against inflammation in osteoarthritis. Four zones （fibrous, proliferating, mature and hypertrophic） of condylar cartilage and three bands （anterior, intermediate and posterior） of disc were analysed by immunohistochemistry for the presence of PCM molecules in rat TMJs. Isolated chondrocytes were pre-treated with PCM molecules before being subjected to interleukin （IL）-II~ treatment to stimulate inflammation. The responses of the chondrocytes were analysed using gene expression, nitric oxide release and matrix metalloproteinase （MMP）-13 production measures. Histomorphometric analyses revealed that the highest areal deposition of collagen VI （67.4%）, collagen IV （45.7%） and laminin （52.4%） was in the proliferating zone of TMJ condylar cartilage. No significant difference in the distribution of PCM molecules was noted among the three bands of the TMJ disc. All three PCM molecules were expressed intracellularly by chondrocytes cultured in the monolayer. Among the PCM molecules, pre-treatment with collagen VI enhanced cellular proliferation, ameliorated IL-lp-induced MMP-3, MMP-9, MMP-13 and inducible nitric oxide synthase gene expression, and attenuated the downregulation of cartilage matrix genes, including collagen I, aggrecan and cartilage oligomeric matrix protein （COMP）. Concurrently, collagen VI pretreatment inhibited nitric oxide and MMP-13 production. Our study demonstrates for the first time the distribution and role of PCM molecules, particularly collagen VI, in the protection of chondrocytes against inflammation.

Aberrant activation of latent transforming growth factor-β initiates the onset of temporomandibular joint osteoarthritis

There is currently no effective medical treatment for temporomandibular joint osteoarthritis(TMJ-OA) due to a limited understanding of its pathogenesis. This study was undertaken to investigate the key role of transforming growth factor-β(TGF-β)signalling in the cartilage and subchondral bone of the TMJ using a temporomandibular joint disorder(TMD) rat model, an ageing mouse model and a Camurati–Engelmann disease(CED) mouse model. In the three animal models, the subchondral bone phenotypes in the mandibular condyles were evaluated by μCT, and changes in TMJ condyles were examined by TRAP staining and immunohistochemical analysis of Osterix and p-Smad2/3. Condyle degradation was confirmed by Safranin O staining, the Mankin and OARSI scoring systems and type X collagen(Col X), p-Smad2/3 a and Osterix immunohistochemical analyses. We found apparent histological phenotypes of TMJ-OA in the TMD, ageing and CED animal models, with abnormal activation of TGF-βsignalling in the condylar cartilage and subchondral bone. Moreover, inhibition of TGF-β receptor I attenuated TMJ-OA progression in the TMD models. Therefore, aberrant activation of TGF-β signalling could be a key player in TMJ-OA development.

A study of the temporomandibular joint during bruxism

A finite element model of the temporomandibular joint （TMJ） and the human mandible was fabricated to study the effect of abnormal loading, such as awake and asleep bruxism, on the articular disc. A quasilinear viscoelastic model was used to simulate the behaviour of the disc. The viscoelastic nature of this tissue is shown to be an important factor when sustained （awake bruxism） or cyclic loading （sleep bruxism） is simulated. From the comparison of the two types of bruxism, it was seen that sustained clenching is the most detrimental activity for the TMJ disc, producing an overload that could lead to severe damage of this tissue.

Treatment of condylar osteophyte in temporomandibular joint osteoarthritis with muscle balance occlusal splint and long-term follow-up:A case report

BACKGROUND Condylar osteophytes,a remodeling form of temporomandibular joint osteoarthritis(TMJ OA),mainly manifest as marginal angular outgrowths of the condyle.Previous researchers have advocated surgical removal of condylar osteophytes.Reports on the effect of occlusal splint on TMJ OA patients’joints have mostly focused on treatment with this splint,which can reduce the absorption of the affected condyle and promote repair and regeneration.However,the effect of the splint on the dissolution of condylar osteophytes has not yet been reported.CASE SUMMARY A 68-year-old female patient suffered from occlusal discomfort with left facial pain for 2 years.Cone beam computed tomography showed a rare osteophyte on top of her left condyle.She was finally diagnosed with TMJ OA.The patient refused surgical treatment and received conservative treatment with a muscle balance occlusal splint.The pain experienced by the patient on the left side of her face was relieved,and her chewing ability recovered after treatment.The osteophyte dissolved,and the condylar cortex remained stable during long-term follow-up observations.CONCLUSION The muscle balance occlusal splint could be a noninvasive means of treating condylar osteophytes in TMJ OA patients.

Orthodontic retreatment of an adult woman with mandibular backward positioning and temporomandibular joint disorder:A case report

BACKGROUND The role of occlusal factors on the occurrence of temporomandibular joint disorders(TMDs)is still unclear and it is tricky for orthodontists to treat malocclusions in patients with TMDs.We report the case of the second orthodontic treatment of an adult female with Class II division 2 malocclusion associated with TMD.With the removal of anterior occlusal interference,TMD symptoms were alleviated and cone beam computed tomography(CBCT)images showed the bilateral condyles shifted forward.CASE SUMMARY This case report presented an orthodontic retreatment of an adult female with TMD and mandibular backward positioning based on CBCT examination and Joint Space Index(JSI)analysis.The left and right JSI values of-38.5 and-52.6 indicated that the position of bilateral condyles had posterior displacement.Ten years prior to this evaluation,she underwent orthodontic treatment resulting in the extraction of two upper premolars and one lower central incisor.The joint symptoms,including pain and sounds,were alleviated along with verified mandibular forward repositioning by extraction of another lower central incisor.CONCLUSION Mandibular backward positioning could be associated with TMD.JSI analysis based on CBCT is a convenient way to examine condylar positions quantitatively.

Effectiveness of Mesotherapy on Temporomandibular Joint Disorders

TMJDs （Temporomandibular joint disorders） are a common pathology but best treatment remains unclear. The goal of this study was to evaluate the effectiveness of mesotherapy on TMJD. We conducted a case review of all TMJD patients treated since 2006 with mesotherapy procedures only and using a cocktail of drugs composing of lidocaine, piroxicam and pentoxifylline. Patients were treated every 15 days until symptomatic relief was achieved and thereafter every two months. Main outcome was complete symptomatic relief, and associated factors were analysed. 27 patients were included. Complete pain relief was achieved in 26. The necessary number of procedures to get pain relief ranged from 1 to 6 （median of 1） and the total number of treatments from 1 to 40 （median of 11）. 19 patients had other painful complains mainly related with anxiety disorders. A weak correlation （r = 0.357; p = 0.05） between anxiety disorders and the required months of treatments was found. Mesotherapy is a valuable option on pain relief in a temporomandibular pain syndrome with none of the systemic effects of oral medication. Anxiety may have a role on the aetiology and therapeutic success highlights the holistic approach of these patients. Future comparative studies are necessary.

Pigmented Villonodular Tenosynovitis of the Temporomandibular Joint—A Case Report

Background: Pigmented villonodular synovitis is a rare condition typically affecting the major joints and the involvement of the temporomandibular joint is rare. Although, it is histologically benign, it can be locally aggressive, capable of extensive bone destruction. The disease has aggressive behavior and a high incidence of recurrence (40% - 60%). Case report: A 35 years old male presented with history of unilateral hearing loss and otalgia of six month duration. On examination, there was a soft bulge in the superior wall of external auditory canal. Contrast enhanced CT scan showed soft tissue density occupying the right external auditory canal and bulging into the middle ear cavity, displacing the intact ossicular chain medially with evidence of destruction of the posterior wall of the external auditory canal, glenoid fossa, mastoid bone and the scutum. The squamous part of the right temporal bone showed evidence of lateral bowing with discontinuity. Surgical resection was done through post aural approach. Histopathological examination revealed pigmented villonodular tenosynovitis which stained positive for CD 68. Post operatively patient was evaluated clinically and with radiological modalities which showed healthy mastoid cavity and no increase in post operative granulations on magnetic resonance imaging. Conclusion: Pigmented villonodular tenosynovitis of temporomandibular joint is a rare entity. Due to the aggressive behavior of the lesion, radical or aggressive surgical resection should be done. Long term follow up with radiological modality should be done due to the high recurrence rate.

Structural optimization of patient-specific temporomandibular joint replacement implants for additive manufacturing:novel metrics for safety evaluation and biomechanical performance

Total temporomandibular joint(TMJ)replacement is recommended only when there is irreversible damage to the joint and no conservative treatment can provide functional improvements.Several stock and custom-made TMJ implants have been made available;however,retrospective and comparative studies were unable to find significant differences between the two types of solutions.The introduction of additive manufacturing(AM)techniques in medical practice allows for a greater freedom of design and a higher degree of device customisation.The combination of AM with structural optimisation may streamline development and provide the key for fabricating biomechanic ally enhanced TMJ implants.In this study,structural optimis ation techniques were applied to develop and numerically validate a patient-specific TMJ implant.The biomechanical behaviour of each intermediate TMJ design was assessed under four different nominal and maximum biting tasks using finite element analyses.In addition,a new set of metrics were proposed to compare each design regarding biomechanical performance and implant safety.The results suggest that 55-82%of the natural/intact strain patterns can be recovered with the finally selected TMJ implant.This represents an increase of 15%in biomechanical performance for incisor biting,15%for right molar biting,17%for left molar biting and a decrease of 2%for left group biting compared with the initial design.The results also suggest that load transfer at the proximal ramus reduces the implant’s impact on the mandible’s strain patterns.Finally,structural optimisation allows for a volume reduction of up to 44%with a minimum loss of implant safety and biomechanical performance.

Management of disorder of temporomandibular joint syndrome using elastic resin occlusal pad: a clinical observation

Objective To investigate the possibility of occlusal pad in treating disorder of temporomandibular joint syndrome.Methods We treated 25 patients with disorder of temporomandibular joint syndrome using occlusal pad made of elastic resin,and evaluated the effects.Results Total effective rate was 96%.Clicking and pain dissappeared in all patients.Conclusion Occlusal pad made of elastic resin could be used for treating disorder of temporomandibular joint syndrome in clinic.

Calcium pyrophosphate deposition disease of the temporomandibular joint invading the middle cranial fossa:Two case reports

BACKGROUND Pseudogout is a benign joint lesion caused by the deposition of calcium pyrophosphate dihydrate crystals,but it is invasive.Pseudogout of the temporomandibular joint(TMJ)is uncommon,and it rarely invades the skull base or penetrates into the middle cranial fossa.The disease has no characteristic clinical manifestations and is easily misdiagnosed.CASE SUMMARY We present two cases of tophaceous pseudogout of the TMJ invading the middle cranial fossa.A 46-year-old woman with a history of diabetes for more than 10 years was admitted to the hospital due to swelling and pain in the right temporal region.Another patient,a 52-year-old man with a mass in the left TMJ for 6 years,was admitted to the hospital.Maxillofacial imaging showed a calcified mass and severe bone destruction of the skull base in the TMJ area.Both patients underwent excision of the lesion.The lesion was pathologically diagnosed as tophaceous pseudogout.The symptoms in these patients were relieved after surgery.CONCLUSION Tophaceous pseudogout should be considered when there is a calcified mass in the TMJ with or without bone destruction.A pathological examination is the gold standard for diagnosing this disease.Surgical treatment is currently the recommended treatment,and the prognosis is good after surgery.

Kindlin-2 loss in condylar chondrocytes causes spontaneous osteoarthritic lesions in the temporomandibular joint in mice

The progressive destruction of condylar cartilage is a hallmark of the temporomandibular joint(TMJ) osteoarthritis(OA);however, its mechanism is incompletely understood. Here, we show that Kindlin-2, a key focal adhesion protein, is strongly detected in cells of mandibular condylar cartilage in mice. We find that genetic ablation of Kindlin-2 in aggrecan-expressing condylar chondrocytes induces multiple spontaneous osteoarthritic lesions, including progressive cartilage loss and deformation, surface fissures, and ectopic cartilage and bone formation in TMJ. Kindlin-2 loss significantly downregulates the expression of aggrecan, Col2a1 and Proteoglycan 4(Prg4), all anabolic extracellular matrix proteins, and promotes catabolic metabolism in TMJ cartilage by inducing expression of Runx2and Mmp13 in condylar chondrocytes. Kindlin-2 loss decreases TMJ chondrocyte proliferation in condylar cartilages. Furthermore,Kindlin-2 loss promotes the release of cytochrome c as well as caspase 3 activation, and accelerates chondrocyte apoptosis in vitro and TMJ. Collectively, these findings reveal a crucial role of Kindlin-2 in condylar chondrocytes to maintain TMJ homeostasis.

Effect of Disc Position for Acute Closed Lock of the Temporomandibular Joint

In this manuscript, the authors have studied the Disc Displacement (DD) status of patients with acute Closed Lock (CL) to determine differences between DD with Reduction (DDwR) and DD without Reduction (DDwoR). Among the acute CL patients who visited our hospital within 2 weeks of the onset of CL, we studied 10 patients whose CL was released (DDwR) and 13 patients whose CL was not released (DDwoR). The DDwoR group was significantly older than the DDwR group. Although the mouth opening distance was significantly greater in the DDwoR group than in the DDwR group, the two groups were identical in the duration of CL. Sagittal MRI images showed no significant differences between the two groups in disc length and disc thickness (anterior band, intermediate zone, and posterior band). Multisection sagittal and coronal images identified lateral DD in 7 of the 10 patients in the DDwR group, although no specific direction of the DD was observed in the DDwoR group. Furthermore, deformation of the medial disc was common in the DDwoR group but uncommon in the DDwR group.

Synovial osteochondromatosis of the temporomandibular joint: A case report

BACKGROUND Synovial osteochondromatosis is a rare but benign condition that can result in significant impairment of joint functionality.This case report documents an uncommon presentation of this disorder occurring within the temporomandibular joint,causing the patient significant pain,trismus,and difficulty with daily activities such as eating and speaking.A review of the literature including disease mechanisms and previously documented cases is included to provide comprehensive background for clinical decision-making.CASE SUMMARY A 48-year-old male patient presented with a 3-mo history of trismus,crepitus with jaw movement and significant pain while chewing.Physical examination revealed a firm mass and tenderness to palpation at the right temporomandibular joint.Further workup revealed a bilobed mass extending into the joint space as well as significant bony erosion of the glenoid fossa.The patient underwent mass excision with joint reconstruction and pathology revealed synovial osteochondromatosis.The patient reported significant improvement in his symptoms postoperatively.CONCLUSION This report outlines the investigative approach and treatment course of synovial osteochondromatosis.The positive outcome following surgical intervention in this case emphasizes the importance of interdisciplinary collaboration and the potential for improvement in quality of life of this patient population.

Examination of the Diagnostic Value and Estimation of the Chaos Phenomenon in Temporomandibular Joint Sounds Using Fractal Dimension

The aim of this study is to estimate the chaos phenomenon in temporomandibular joints (TMJ) sound using fractal dimension (FD),and to examine the diagnostic value of the FD in comparing TMJ sounds produced by 6 asymptomatic and 25 symptomatic TMJ. Multiple mandibular opening and closing cycles recorded were used to calculate the waveform dimension and correlation dimension in the FD. Chaos in the TMJ sounds was estimated by the FD that was saturated with some constant value to an increase of embedding dimension. Results reveal that fractal analysis produces a high degree of reproducibility within,and similarity across subjects,and indicate that both FD values of the asymptomatic TMJ sounds are significantly higher than those of the symptomatic. These findings suggest that chaos is present in TMJ sounds and the difference in the FD is of diagnostic value in evaluation of pathological change in TMJ sound signals.

Imaging of the temporomandibular joint: An update

Imaging of the temporomandibular joint(TMJ) is continuously evolving with advancement of imaging technologies. Many different imaging modalities are currently used to evaluate the TMJ. Magnetic resonance imaging is commonly used for evaluation of the TMJ due to its superior contrast resolution and its ability to acquire dynamic imaging for demonstration of the functionality of the joint. Computed tomography and ultrasound imaging have specific indication in imaging of the TMJ. This article focuses on state of the art imaging of the temporomandibular joint. Relevant normal anatomy and biomechanics of movement of the TMJ are discussed for better understanding of many TMJ pathologies. Imaging of internal derangements is discussed in detail. Different arthropathies and commontumors are also discussed in this article.

THE EXPERIMENTAL STUDY ON SURGICAL TREATMENT OF TEMPOROMANDIBULAR JOINT ANKYLOSIS USING FREE ALLOLOGOUS COSTAL PERICHONDRIAL GRAFTS IN RABBITS

The growth of newborn cartilage ih 12o days following the allograft of free costal Pc tothe hone section or TMJ condyle was studied. Light microscope, electron microscope, biochemistryanalysis, and PCNA immune chemo-staining were used to make mobile observation and analysis ifthe changes in the new catilage's tissue structure, GA and collaged content. The results indicate asfollows: 07The transplanted homologous PC excaped observable immune repulsion so that it couldsurvive to form new joint cartilage with approxlmste normal tissue structure and biochemistry constitution j @The reproduction process was similar to the normal one, hut ovas prolonged a little. ':J)Withexcellent form structure and biology mechanical functions, the new cartilage was able to meet the requirement of TMJ, and successfully prevent the adhenslon of the bone section, as 'veil as biologicallyrebuild TMJ: @ In the later stage, the degeneration and calclfication in hasal layer increased. however, due to its limited scope, no apparent efrect on the cartilage growth and function was observed.

Topology Optimization and Fatigue Analysis of Temporomandibular Joint Prosthesis

Treatment of bone tumors in the mandible often involves extensive excavation of affected bone, followed by mandibular reconstruction. Prosthetic implants may be needed to restore jaw functionality. The challenges of making prosthetic bone implants include stress shielding and extending the mechanical life of the implant. We have developed a design algorithm to improve the efficiency of prosthesis design. A finite element model of the patient case is constructed from a computer tomography scan, and the computer implements topology optimization techniques to design the prosthesis with limited stress shielding affected by highly biomechanical compatibility. Topology optimization facilitates the design of low weight structures by automatically introducing holes into the structure. This is governed by engineering predetermined constraints to meet certain job specifications. Such a design will be tested for fatigue life before it is ready to be manufactured and used. Topology optimization can be performed as a design process to achieve a final design that takes stress shielding into consideration. The problem of stress shielding is solved by matching the stiffness of the orthopedic implant to the original bone that is being replaced. The material we used was titanium alloy (Ti-6Al-7Nb). Volume fraction of the orthodox implant was used (0.2872 for the studied case) as volume constraints. Compliance of the bulk bone was set as a further constraint to match the stiffness of the bone with the designed structure. Our results show a good life expectancy for the designed parts, with 12% higher life expectancy for stress-based topology optimization than for compliance-based topology optimization.

Septic Arthritis of the Temporomandibular Joint without an Apparent Source of Infection: A Case Report

Septic arthritis of the temporomandibular joint (TMJ) is a rare disease that is characterized by preauricular pain, edema, malocclusion, trismus and abscess formation in the TMJ region. An 85-year-old male visited our hospital with the complaint of left-sided TMJ swelling, pain and trismus. Septic arthritis of the left TMJ was diagnosed on the basis of considerable elevation of CRP (Creactive proteins) and CT imaging findings. The patient was treated with oral Faropenem at 450 mg daily, but CRP increased three days after the initial visit. He was hospitalized and treated with intravenous administration of cefazolin at 2 g and clindamycin at 1.2 g daily for six days. Propionibacterium species and Veillonella species grew in a culture of the joint aspirate, but there was no apparent source of infection. After acute infectious symptoms had passed, the patient was treated with oral amoxicillin at 750 mg daily for eight weeks and was instructed to do jaw opening exercise. The patient was discharged on the 11th hospital day. After three weeks of the hospital discharge, the patient healed completely. To avoid serious complications, clinicians should include septic arthritis of the TMJ in the differential diagnosis of preauricular pain, trismus and swelling.

Multidetector computed tomography of temporomandibular joint: A road less travelled

This article reviews the imaging anatomy of temporomandibular joint(TMJ), describes the technique of multi-detector computed tomography(MDCT) of the TMJ, and describes in detail various osseous pathologic afflictions affecting the joint. Traumatic injuries affecting the mandibular condyle are most common, followed by joint ankylosis as a sequel to arthritis. The congenital anomalies are less frequent, hemifacial microsomia being the most commonly encountered anomaly involving the TMJ. Neoplastic afflictions of TMJ are distinctly uncommon, osteochondroma being one of the most common lesions. MDCT enables comprehensive evaluation of osseous afflictions of TMJ, and is a valuable tool for surgical planning. Sagittal, coronal and 3D reformatted images well depict osseous TMJ lesions, and their relationship to adjacent structures.