PRAME is a useful marker for the differential diagnosis of melanocytic tumours and histological mimics.

AIMS: Although the morphological assessment of melanoma is generally straightforward, diagnosis can be especially difficult when the significant morphological and immunohistochemical results overlap with those of benign and malignant melanocytic tumours and histological mimics. This study assessed the potential diagnostic utility of measuring PReferentially expressed Antigen in MElanoma (PRAME) immunohistochemically in naevi, melanomas and clear cell sarcomas (CCSs) in Chinese patients. METHODS: We examined the immunohistochemical expression of PRAME in 317 melanocytic naevi, 178 primary melanomas, 72 metastatic melanomas and 19 CCSs and compared the sensitivity and specificity of PRAME immunohistochemistry (IHC) in the differential diagnosis of melanocytic tumours and histological mimics. RESULTS: Of the 317 melanocytic naevi, 98.1%were completely negative for PRAME; six cases showed focal PRAME immunoreactivity in a minor population of lesional melanocytes. Diffuse nuclear immunoreactivity for PRAME was found in 89.9% of primary melanomas and 93.1% of metastatic melanomas. Regarding melanoma subtypes, PRAME was expressed in 100% of superficial spreading melanomas, 100% of melanomas arise in congenital naevus, 91.4% of nodular melanomas, 87.8% of acral lentigo melanomas, 80.0% of lentigo malignant melanomas, 60.0% of Spitz melanomas, 96.2% of mucosal melanomas and 80.0% of uveal melanomas. None of the two desmoplastic melanomas expressed PRAME. Of the 19 CCS cases, 89.5% were negative for PRAME and 10.5% showed focal weak PRAME immunoreactivity in a minor population of tumour cells. CONCLUSIONS: Our findings indicate that PRAME may be a useful marker to support a suspected diagnosis of melanoma. In addition, lack of PRAME expression is a valuable hint to CCS in a suspected case, and then molecular confirmation of the presence of EWSR1 rearrangement is necessary.

Carbon Emissions Trading and Green Technology Innovation-A Quasi-natural Experiment Based on a Carbon Trading Market Pilot.

Carbon emissions trading policy has received widespread attention from scholars as a core policy tool to reduce carbon emissions. While most scholars have previously focused on the carbon emission reduction effect, this paper investigates the impact of carbon emissions trading policy on green technology innovation using a differences-in-differences method based on provincial panel data from 2005-2019, using a carbon emissions trading pilot as a quasi-natural experiment. The findings show that the policy can significantly promote green technology innovation, but with a lagged effect, and this finding still holds in the robustness test. Further heterogeneity analysis reveals that the stronger the human capital, the stronger the intellectual property protection and the stronger the marketization with better policy effects. In addition, carbon emissions trading policy can indirectly affect green technology innovation by influencing research investment.

[Influence of bilateral coronoidectomy on temporomandibular joint stress distribution after costochondral graft reconstruction: a finite element analysis].

PURPOSE: To explore the effect of bilateral coronoidectomy on stress distribution after reconstruction of temporomandibular joint (TMJ) by costochondral graft. METHODS: Ten groups of models were established to simulate costochondral graft reconstruction with simultaneously different distances (0, 2, 4, 6, 8 mm) of mandibular advancement, with or without coronoidectomy. Force and stress distribution in the rib-cartilage area were analyzed by finite element analysis. RESULTS: In the process of bilateral joint reconstruction with simultaneously mandible advancement ranging from 0 mm to 8 mm, when the coronoid processes were retained, the forward deformation of the cartilage occurred and the shear force decreased in turn, from 113.2 N to 26.7 N on the left side and from 133.7 N to 1.9 N on the right side. When the coronoid processes were removed, the cartilage deformed backward and the shear force increased successively, from 94.6 N to 188.5 N on the left and 70.1 N to 157.7 N on the right. The stress in the neck was obviously concentrated when mandible advanced 8 mm. CONCLUSIONS: Coronoidectomy has an important impact on stress distribution in the TMJ area, and keeping the coronoid process is beneficial to maintain the mechanical balance. Bilateral CCG reconstruction with coronoidectomy for lengthy mandible advancement (≥ 8 mm) may lead to prominent increase in shear force beyond CCG resistance, resulting in a costal-cartilage junction fracture.

Evaluation of internal fixation techniques for extracapsular fracture: A finite element analysis and comparison.

BACKGROUND AND OBJECTIVES: This study explored the optimal plates and screws fixation for extracapsular fracture by finite element analysis, and provided a biomechanical basis for clinical treatment. METHODS: Four extracapsular fixation models were built and evaluated: A. One single straight four-hole plate with two bi-cortical screws on both sides and two mono-cortical screws in the middle; B. One single straight four-hole plate with four bi-cortical screws; C. Two straight four-hole plates, each with two bi-cortical screws on both sides and two mono-cortical screws in the middle; D. One L-shape four-hole plate in the back and one straight four-hole plate in the front, each with two bi-cortical screws on both sides and two mono-cortical screws in the middle. Displacements of fractured bone blocks and stress of plates, screws, cortical and cancellous bone and the deformation of plates were analyzed by finite element analysis to investigate their stability in clinical using. RESULTS: Groups A and B showed larger displacements of the fractured bone block, greater deformation of plates and higher risk of the plate breakage during masticatory motion. Groups C and D exhibited the minimum displacements of the fractured bone block, the stress distribution within the safe range and less deformation of the plates. In addition, double plates fixation and bi-cortical screws exceeded single plate fixation and mono-cortical screws in stability, respectively, while an L-shape plate exhibited no significant differences in the stress dispersion and the displacement reduction. CONCLUSIONS: Double plates fixation of the extracapsular condylar fracture was a safe and stable way and bi-cortical screws should be selected as far as possible.

Characterization of Acetylation of Histone H3 at Lysine 9 in the Trigeminal Ganglion of a Rat Trigeminal Neuralgia Model.

Trigeminal neuralgia (TN) is a chronic neuropathic pain disorder characterized by spontaneous and elicited paroxysms of electric-shock-like or stabbing pain in a region of the face. The epigenetic regulation of TN is still obscure. In current study, a rat TN model subject to carbamazepine (CBZ) treatment was established, and transcriptome- and genome-scale profiling of H3K9ac and HDAC3 was performed by RNA-seq and ChIP-seq. We observed that H3K9ac levels in the trigeminal ganglion were lower in the TN rats compared with those in the control, and CBZ treatment led to recovery of H3K9ac levels. Further, we found that HDAC3 was overactivated, which interfered with H3K9 acetylation due to higher phosphorylation in TN compared with that in the control. Finally, the phosphokinase leucine-rich repeat kinase 2 (LRRK2) was demonstrated to contribute to HDAC3 activity via the MAPK signaling pathway. Taken together, we identified a regulatory mechanism in which the phosphate groups transferred from activated ERK and LRRK2 to HDAC3 caused genome-scale deacetylation at H3K9 and resulted in the silencing of a large number of genes in TN. The kinases or important enzymes within this regulatory axis may represent important targets for TN therapy and prevention.

Evaluation of internal fixation techniques for condylar head fractures: A finite element analysis and comparison.

OBJECTIVES: This study evaluated optimum stability of different screw techniques for condylar head fractures (CHF) (P close to an M fracture with the lateral pole preserved according to AO classification 2014) by finite element analysis (FEA) and provided a biomechanical basis for clinical treatment. STUDY DESIGN: Four CHF fixation models were evaluated: (A) single bicortical screw, (B) 2 bicortical screws, (C) 1 bicortical screw and 1 monocortical screw (used as a positional screw) inserted via a 2-hole titanium plate, and (D) 2 bicortical screws inserted via a titanium plate. Stresses were calculated (FEA) to measure mechanical properties. RESULTS: The displacement for A and C was larger than for B and D. The maximum stress on the screws for A and C exceeded their breaking limit but was safe for B and D. The stress on the titanium plate for C and D was safe. The stress on bone for A and C was larger than for B and D. CONCLUSIONS: The 2 bicortical screw fixation reduced the stress on implanted materials and surrounding bone tissue. Titanium plates further alleviated the lever action. Two bicortical screw fixation was more reliable for CHF, and early postoperative loading and functional training can be expected.

Biomechanical analysis of costochondral graft fracture in temporomandibular joint replacement.

This study is the first attempt to explore the reason of costochondral graft fracture after lengthy mandible advancement and bilateral coronoidectomy by combining finite element analysis and mechanical test. Eleven groups of models were established to simulate costochondral graft reconstruction in different degrees of mandible advancement, ranging from 0 to 20 mm, in 2 mm increment. Force and stress distribution in the rib-cartilage area were analyzed by finite element analysis. Mechanical test was used to evaluate the resistance of the rib-cartilage complex. Results showed a sharp increase in horizontal force between 8 and 10 mm mandible advancement, from 26.7 to 196.7 N in the left side, and continue increased after 10 mm, which was beyond bone-cartilage junction resistance according to mechanical test. Therefore, we concluded that bilateral reconstruction with coronoidectomy for lengthy mandible advancement (≥ 10 mm) may lead to prominent increase in shear force and result in a costal-cartilage junction fracture, in this situation, alloplastic prosthesis could be a better choice. We also suggested that coronoidectomy should be carefully considered unless necessary.

Progression of squamous cell carcinoma is regulated by miR-139-5p/CXCR4.

miR-139-5p has a tumor suppressor effect in some cancers and negatively regulates CXCR4. To this end, we examined the expression and mechanism of of action of miR-139-5p and CXCR4 in oral squamous cell carcinoma (OSCC). miRNA-139-5p was down-regulated whereas CXCR4 was increased in tissues and cells of OSCC. Moreover, low expression of miR-139-5p was associated with a low survival. Overexpression of miR-139-5p in OSCC inhibited in vitro and in vivo cell proliferation and in vitro mobility of OSCC and inhibited the expression of WNT responsive c-myc, cyclinD1, and Bcl-2, and such effects were all reversible by an inhibitor of miR-139-5p or over-expression of CXCR4. The inverse relation between expression of miR-139-5p and CXCR4 might be related to the fact that miR-139-5p negatively regulates CXCR4 expression by virtue of direct binding. These findings underscore the importance of miR-139-5p and CXCR4 in regulation of OSCC.

Changes of the condylar position after modified disk repositioning: A retrospective study based on magnetic resonance imaging.

OBJECTIVE: This study aimed to explain the malocclusion resulting from the changes in condylar position after unilateral open disk repositioning surgery. STUDY DESIGN: Patients treated with unilaterally modified temporomandibular joint disk repositioning were reviewed. All patients underwent magnetic resonance imaging (MRI) before and immediately after surgery. Occlusion was checked, and the changes in the joint space and condylar position were measured by using MRI. The paired t test was used for analysis. RESULTS: Thirty-two patients were included in the final analysis. The incidence rates of the posterior open bite in the affected side were 100%, 87.5%, 71.9%, 9.4%, 3.1%, and 3.1% at 0, 3, and 7 days and 3 and 6 months, and at the last follow-up after surgery, respectively. Mean distances of the condylar movements were 2.67 and 0.32 mm in the affected joints and normal joints, respectively. There were significant differences for the anterior (P = .03), superior (P < .001), and posterior (P < .001) joint spaces of the affected joints as demonstrated by MRI. CONCLUSIONS: The joint spaces significantly increased postoperatively, in addition to the changes in condylar position in anterior and inferior movements, leading to posterior open bite; however, the position returns to normal 3 months after surgery. We concluded that disk repositioning, when done unilaterally, results in stable occlusion over time.

Sugar-responsive Pickering emulsions mediated by switching hydrophobicity in microgels.

HYPOTHESIS: Pickering emulsions stabilized by soft and responsive microgels can demulsify on demand upon microgel collapse. The concept has been explored with simple model microgels such as poly(N-isopropylacrylamide) (pNIPAM) and their derivatives, but the role of functionalization is largely unexplored. EXPERIMENTS: Saccharide-responsive phenylboronic-modified microgels are used as Pickering emulsion stabilizers. Emulsion stability and microgel organization at drop surface are studied as a function of saccharide concentration. Better insight into their behavior at interfaces is gained through adsorption kinetics and Langmuir film studies at air-water interface. FINDINGS: The functionalization of water-swollen microgels by phenylboronic functions imparts some hydrophobicity to the structure, at the origin of additional internal cross-links analogous which rigidify the structure compared to non-functionalized microgels, as proved by their slow adsorption kinetics and poor interfacial compressibility. Upon boronate ester formation with diol groups of the saccharide, the hydrophobic character of the phenylboronic acid decreases, increasing the adsorption kinetics and their interfacial compressibility. Emulsions are stable in the presence of saccharide, given the high deformability of the yet-hydrophilic microgels, and mechanically unstable with less deformable particles in low saccharide concentration. The hydrophobic-hydrophilic switch acts as a trigger to tune the microgel stabilizing properties.

Diagnostic accuracy of synovial chondromatosis of the temporomandibular joint on magnetic resonance imaging.

The purpose of this study was to evaluate the diagnostic accuracy of magnetic resonance imaging (MRI) for synovial chondromatosis (SC) of the temporomandibular joint (TMJ). In this study, 1415 patients (2109 joints) with temporomandibular joint disorders were collected between January 2012 and January 2017. All patients had a preoperative MRI examination and were treated by either arthroscopy or open surgery. On reviewing all MRI images, the number of "positive", "suspicious", and "negative" cases was collected afterwards, then the number of reported SC cases in operative data was recorded. The SPSS software was used to process all collected data. The kappa coefficient and ROC curve (AUC-index) with sensitivity and specificity were calculated to evaluate the consistency between MRI and arthroscopy/open surgery. Compared to 156 joints with SC detected by arthroscopy and open surgery, the results of MRI examination showed "positive" in 117 joints, and "negative" in 1938 joints. The number of "true positive", and "true negative" cases was 95, and 1897 respectively. The AUC-index was 0.86 (0.82-0.90) with a kappa coefficient of 0.74 (P < 0.05). In conclusion, the incidence of synovial chondromatosis diagnosed on MRI was in accordance with the arthroscopic and open surgery. Therefore, being a relatively non-invasive tool, MRI could be recommended as an effective diagnostic modality for SC.

Biomechanical evaluation of Chinese customized three-dimensionally printed total temporomandibular joint prostheses: A finite element analysis.

PURPOSE: This work aims to evaluate the biomechanical behavior of Chinese customized three-dimensional (3D)-printing total temporomandibular joint (TMJ) prostheses by means of finite element analysis. METHODS: A 3D model was established by Mimics 18.0, then output in a stereolithography (STL) format. Two models were established to investigate the strain behaviors of an intact mandible and a one-side implanted mandible respectively. Hypermesh and LS-DYNA software were used to establish computer-aided engineering finite element models. The stress distribution on the custom-made total TMJ prosthesis and the strain distribution on the mandible were analyzed by loading maximal masticatory force. RESULTS: The maximum stress on the surface of the ultra-high-molecular weight polyethylene was 19.61 MPa. With respect to the mandibular component, the maximum stress in the mandibular component was located at the anterior and posterior surface of the condylar neck, reaching 170.01 MPa. The peak von Mises stress was observed on the topside screw of the mandible, which was found to be 236.08 MPa. For the intact model, it was observed that the strain distribution was basically symmetrical. For the model with the prosthesis, the curve of strain distribution was fundamentally consistent with that in the intact mandible, except for the last 24 mm along the control line. A prominent strain decrease between 41.4% and 58.3% was observed in this area. CONCLUSIONS: Chinese customized 3D-printed total TMJ prostheses exhibit uniform stress distribution without changing the behavior of the opposite side natural joint. Furthermore, the prostheses have a great potential to be improved in design and materials with a promising future.

Can a Novel Surgical Approach to the Temporomandibular Joint Improve Access and Reduce Complications?

PURPOSE: This clinical study investigated whether the vascular-guided multilayer preauricular approach (VMPA) to the temporomandibular joint (TMJ) could improve access and decrease complications. PATIENTS AND METHODS: This retrospective evaluation consisted of a consecutive series of patients who underwent TMJ surgeries through the VMPA from January through December 2013. Patients with a history of TMJ surgery were excluded. Clinical data, including operating times, subjective complaints of incision scars, functional conditions of the auriculotemporal nerve and facial nerve, and other complications, were recorded and analyzed. All patients in this study were followed for at least 6 months. RESULTS: All patients (606 joints) had successful TMJ surgeries through the VMPA. All incisions healed favorably with an uneventful recovery. No patient developed permanent weakness of the facial nerve or other severe complications. CONCLUSION: The VMPA can provide direct access and favorable visibility to the TMJ region and yield good esthetic and functional results. The VMPA can be considered the approach of choice for common TMJ surgeries.

Piezoelectric Versus Conventional Rotary Techniques for Impacted Third Molar Extraction: A Meta-analysis of Randomized Controlled Trials.

Impacted third molars are frequently encountered in clinical work. Surgical removal of impacted third molars is often required to prevent clinical symptoms. Traditional rotary cutting instruments are potentially injurious, and piezosurgery, as a new osteotomy technique, has been introduced in oral and maxillofacial surgery. No consistent conclusion has been reached regarding whether this new technique is associated with fewer or less severe postoperative sequelae after third molar extraction.The aim of this study was to compare piezosurgery with rotary osteotomy techniques, with regard to surgery time and the severity of postoperative sequelae, including pain, swelling, and trismus.We conducted a systematic literature search in the Cochrane Library, PubMed, Embase, and Google Scholar.The eligibility criteria of this study included the following: the patients were clearly diagnosed as having impacted mandibular third molars; the patients underwent piezosurgery osteotomy, and in the control group rotary osteotomy techniques, for removing impacted third molars; the outcomes of interest include surgery time, trismus, swelling or pain; the studies are randomized controlled trials.We used random-effects models to calculate the difference in the outcomes, and the corresponding 95% confidence interval. We calculated the weighted mean difference if the trials used the same measurement, and a standardized mean difference if otherwise.A total of seven studies met the eligibility criteria and were included in our analysis. Compared with rotary osteotomy, patients undergoing piezosurgery experienced longer surgery time (mean difference 4.13 minutes, 95% confidence interval 2.75-5.52, P < 0.0001). Patients receiving the piezoelectric technique had less swelling at postoperative days 1, 3, 5, and 7 (all Ps ≤0.023). Additionally, there was a trend of less postoperative pain and trismus in the piezosurgery groups.The number of included randomized controlled trials and the sample size of each trial were relatively small, double blinding was not possible, and cost analysis was unavailable due to a lack of data.Our meta-analysis indicates that although patients undergoing piezosurgery experienced longer surgery time, they had less postoperative swelling, indicating that piezosurgery is a promising alternative technique for extraction of impacted third molars.

Primary intra- and juxta-articular vascular malformations of the temporomandibular joint: a clinical analysis of 8 consecutive patients.

OBJECTIVE: To analyze primary intra- and juxta-articular vascular malformations of the temporomandibular joint. PATIENTS AND METHODS: This study retrospectively reviewed eight patients (seven venous malformations and one lymphatico-venous malformation) who were treated for intra- or juxta-articular vascular malformations of the temporomandibular joint from November 2005 to January 2011. All patients underwent magnetic resonance imaging (MRI) preoperatively. RESULTS: According to MRI findings, vascular malformations involving TMJ could be divided into 3 types; homogenous, lacunar and mixed types. All patients underwent surgical resection, and the final clinical diagnoses were confirmed by postoperative histopathology and immunohistochemical examinations. All treated patients had no clinical or radiographic signs of recurrence. CONCLUSION: Owing to the lower incidence and nonspecific clinical presentations, preoperative diagnosis of vascular malformations involving the TMJ region is very difficult. The classification based on MRI manifestations is proposed first, then it may greatly help in the initial diagnosis. Surgical resection is considered the first option for these TMJ lesions with excellent results.

Modified surgical techniques for total alloplastic temporomandibular joint replacement: One institution's experience.

OBJECTIVE: To present three modified techniques of total alloplastic temporomandibular joint replacement (TMJ TJR) and to evaluate the outcomes regarding prosthesis stability and heterotopic bone formation. MATERIAL AND METHODS: A total of 15 patients (19 joints), treated with the Biomet stock prosthesis from May 2006 to May 2013, were retrospectively analyzed. Surgical procedures were performed with the following three modifications: bone grafting of the glenoid fossa; salvage of TMJ discs; and harvesting of retro-mandibular subcutaneous fats. The glenoid fossa depth was measured preoperatively by Surgicase 5.0 software. All patients were evaluated by radiographic examination and surgical observation. RESULTS: The fossa was grafted with an autogenous bone in 15 joints (78.9%). In 4 joints (21.1%), only bone repair was performed. Radiographic evaluation revealed a good integration between the autogenous and host bones. All patients showed postoperative occlusal stability. In 5 joints (26.3%), the discs were salvaged. Both bleeding and operation time were reduced. Fat grafts were harvested in 17 joints (89.5%), in which there were no abnormalities in the periprosthetic bone structure. In 2 joints (10.5%), with no fat grafting, heterotopic bone formation was found. CONCLUSIONS: The modified techniques of TJR help to improve prostheses stability, reducing heterotopic bone formation and avoiding additional scars.

Pigmented villonodular synovitis of the temporomandibular joint with intracranial extension.

Pigmented villonodular synovitis is an uncommon benign tumor-like proliferative lesion with an undetermined origin. Involvement of the temporomandibular joint is uncommon. Although pigmented villonodular synovitis is a benign lesion, it can grow with an aggressive pattern, and it extends extra-articularly in most of the reported cases, about one-third of them exhibiting intracranial involvement. The authors reported an additional case of a 47-year-old woman with intracranial extension, who had a history of joint pain and trismus. The preoperative diagnosis was made with arthroscopy. The lesion was completely excised via preauricular approach and condylotomy. The bone defect was covered by the pedicled temporalis myofascial fat flap. The patient has been symptom-free for 40 months postoperatively.

Synovial chondromatosis of the tempromandibular joint: relationship between MRI information and potential aggressive behavior.

PURPOSE: To evaluate the types of synovial condromatosis (SC) of tempromandibular joint (TMJ) on MRI and their potential aggressive behavior. METHODS: 144 patients with pure SC of TMJ were included in. On MRI, 3 types of the lesion included loose body, homogeneous mass, and mixture of both loose body and homogeneous mass. Bony evaluations included 4 stages of erosion: without erosion, chondral breakdown, bony absorption and bony perforation. RESULTS: 47 (32.6%) cases were categorized in the type of loose body, 71 (49.3%) cases in the type of homogeneous mass, and 26 (18.1%) cases in the type of mixture. 80% of bony perforation belonged to the type of homogeneous mass and 20% belonged to the type of mixture. 2 patients were found recurrence. CONCLUSION: The types of homogeneous mass and mixture of both on MRI were more aggressive. Homogeneous mass with bony erosion on MRI had potential recurrence.

Post-infectious myositis ossificans in medial, lateral pterygoid muscles: A case report and review of the literature.

Myositis ossificans (MO) is a disease where heterotropic bone forms within a muscle or other type of soft tissue. MO is classified into two groups, MO progressiva and post-traumatic MO. It rarely occurs in the masticatory muscles and thus, only 20 cases involving the masticatory muscles have been reported since 2001. The majority of the reported cases occurred due to trauma, repeated injury or surgical manipulation. However, in a small number of cases, no specific traumatic event was identified as the cause of MO. To the best of our knowledge, this is the first case of post-infectious MO to be reported in the medial and lateral pterygoid muscles.

Tumors and pseudotumors at the temporomandibular joint region in pediatric patients.

OBJECTIVE: To describe the clinical manifestations and types of, and our surgical experience with, neoplasms in the region of the temporomandibular joint (TMJ) in pediatric patients. MATERIALS AND METHODS: From September 1997 to December 2013, a total of 18 patients with neoplasms in the region of the TMJ were treated at our department. They all underwent open surgeries. The clinical manifestations and radiological aspects of all the patients were reviewed. The average follow-up period was 61.8 months with a range of 12-221 months. We reviewed the history, physical examination, images, and related radiological examinations. RESULTS: Of the 18 patients, 14 had benign tumors or pseudotumors, and four had malignant tumors. The ratio of pseudotumor to benign tumor to malignant tumor was 2.5:1:1. Limitations of mouth opening were more likely to occur with malignant tumors, and facial deformity had a higher incidence in benign tumors. Local resection was the first choice for patients with benign tumors or pseudotumors. All patients with malignant tumors underwent whole-tumor resection along the boundary, including the joint capsule, disc, and part of the temporal bone and mandible. During the follow-up period, no tumor reformation or new deformity was detected. CONCLUSIONS: In the diagnosis of masses in the TMJ region, CT and MRI play an important role. Surgical removal of the mass with/without joint attachment was sufficient to treat benign and malignant tumors.