A Three-branch Jointed Feature and Topology Decoder guided by game-theoretic interactions for temporomandibular joint segmentation.

Segmentation of the temporomandibular joint (TMJ) disc and condyle from magnetic resonance imaging (MRI) is a crucial task in TMJ internal derangement research. The automatic segmentation of the disc structure presents challenges due to its intricate and variable shapes, low contrast, and unclear boundaries. Existing TMJ segmentation methods often overlook spatial and channel information in features and neglect overall topological considerations, with few studies exploring the interaction between segmentation and topology preservation. To address these challenges, we propose a Three-Branch Jointed Feature and Topology Decoder (TFTD) for the segmentation of TMJ disc and condyle in MRI. This structure effectively preserves the topological information of the disc structure and enhances features. We introduce a cross-dimensional spatial and channel attention mechanism (SCIA) to enhance features. This mechanism captures spatial, channel, and cross-dimensional information of the decoded features, leading to improved segmentation performance. Moreover, we explore the interaction between topology preservation and segmentation from the perspective of game theory. Based on this interaction, we design the Joint Loss Function (JLF) to fully leverage the features of segmentation, topology preservation, and joint interaction branches. Results on the TMJ MRI dataset demonstrate the superior performance of our TFTD compared to existing methods.

Effect of the application of digital technology-assisted optimization in the process of adjusting jaw position.

OBJECTIVES: The aim of this study was to demonstrate a novel jaw position adjustment technique derived from digital twins and evaluate the application effect of digital technology-assisted optimization in the process of adjusting jaw position on patients with temporomandibular disorders (TMD). METHODS: A total of 74 patients with TMD who attended the Department of Temporomandibular Joint, West China Hospital of Stomatology, Si-chuan University, between June 2022 and May 2023 were selected. The patient's initial computed tomography (CT) and bilateral temporomandibular joint data obtained by magnetic resonance imaging (MRI) were collected. The 148 joints were divided into the normal disc-condyle relationship (N) group, disc displacement with reduction (DDWR) group, and disc displacement without reduction (DDWoR) group. Assisted by digital technology, the patient's CT data were reconstructed, and a personalized reference plane was established to adjust the jaw position. A three-point bite guiding splint was designed by the adjusted occlusal space and then fabricated by 3D printing technology. It was worn by the patients and then reviewed by MRI. Before and after the adjustment of jaw position, the amount and direction of condyle and disc displacement and the angle between condyle and disc were measured as the evaluation indexes of the effect of the adjustment. The correlation with condylar displacement was evaluated. RESULTS: In the N group, the disc moved backward and downward along the X and Z axes by (-0.60±0.62) and (0.51±0.71) mm, respectively. In the DDWR group, the disc moved backward and upward along the X and Z axes by (-1.33±1.38) and (-0.09±1.31) mm, respectively. In the DDWoR group, the disc moved forward and downward along the X and Z axes by (0.49±1.76) and (1.35±1.76) mm, respectively. The angle between the condyle and the disc decreased after adjustment of the jaw position in all three groups. All patients showed improvement in symptoms after adjustment. CONCLUSIONS: Digital technology-assisted jaw position adjustment can simplify the process, reduce the sensitivity of the technique, and improve patients' disc-condyle structure and symptoms. Therefore, its application in the treatment of patients with TMD is of great clinical significance.

The relationship of ALPK1, hyaluronic acid and M1 macrophage polarization in the temporomandibular joint synovitis.

M1 macrophage polarization and synovitis play an important role in the pathogenesis of temporomandibular joint osteoarthritis (TMJOA). Reduced molecular weight of hyaluronic acid (HA) in synovial fluid of patients with TMJOA. In addition, high molecular weight hyaluronic acid (HMW-HA) is often used clinically to treat TMJ inflammation. As a pattern recognition receptor of the cytoplasm, ALPK1 was found to be pro-inflammatory in a variety of diseases. However, the relationship of ALPK1, HA and M1 macrophage polarization in TMJ synovitis remains unclear. We aimed to investigate the role of ALPK1 and HA in macrophage polarization and TMJ synovitis and the underlying mechanisms. The results demonstrated that ALPK1 was highly upregulated in the synovial macrophages in the inflamed TMJ synovium of patients. Low molecular weight hyaluronic acid (LMW-HA) promoted the expression of ALPK1 and M1 macrophage-associated genes. Besides, rhALPK1 promoted the expression of M1 macrophage-associated factors and the nuclear translocation of PKM2. Furthermore, ALPK1 knockout mice exhibited limited infiltration of macrophages and decreased expression levels of M1 macrophage-associated genes in CFA-induced TMJ synovitis. While HMW-HA inhibited the expression of ALPK1 and M1 macrophage polarization. Our results elucidated that ALPK1 promoted TMJ synovitis by promoting nuclear PKM2-mediated M1 macrophage polarization, whereas HMW-HA inhibited the expression of ALPK1 as well as M1 macrophage polarization.

[Recent research advances of angiogenesis in temporomandibular joint osteoarthritis].

Temporomandibular joint osteoarthritis (TMJOA) is a degenerative disease of temporomandibular joint, which has a high incidence and affects the quality of patients' life. While the pathogenesis of TMJOA remains unclear. It has been found that angiogenesis is involved in the development of TMJOA and it is closely related to the degradation of articular cartilage matrix, subchondral ossification, osteophyte formation and pain. This article reviews the recent advances in the study of angiogenesis in TMJOA, and provides a prospect for the treatment of TMJOA.

Analysis of clinical changes and magnetic resonance imaging features of 37 patients with temporomandibular joint disc condylar complex with anterior disc displacement without reduction.

OBJECTIVES: This study aims to investigate clinical outcomes, imaging changes, and age differences with regard to temporomandibular joint disc condylar complex with anterior disc displacement without reduction (ADDWoR). METHODS: A total of 37 patients (45 lateral joints) with ADDWoR who were admitted to The First Affiliated Hospital of Zheng Zhou University from January 2016 to June 2023 were selected. The patients were composed of 4 males and 33 females and had an average age of 23.5 years. The average course of the disease was 14.4 months. Clinical and magnetic resonance imaging (MRI) data were collected at the end of initial diagnosis and follow-up, and the length and thickness of the articular disc, the angle of the disc condyle, and the height of the condyle were measured. The statistical significance of the changes was assessed using SPSS 25.0 software package. RESULTS: At the end of follow-up, disc displacement in three patients (three lateral joints) was healed. Approximately 48.4% of the patients felt that limitation of mandibular movement was not alleviated; 58.3% of patients reported that pain during mouth opening was not reduced; 54.5% reported pain while chewing; 33.3% of the patients showed facial deviation, and only one showed remission. The mean disk-condyle angle increased from 61.63° to 67.81°. The average length of articular disc shortened from 8.20 mm to 7.27 mm, and the height of the condyle significantly decreased from 23.17 mm to 22.76 mm (P<0.05). The absorption ratio of the condyle increased, and no significant differences in the changes of joint soft and hard tissues between the adolescent and adult groups (P>0.05). CONCLUSIONS: In different age groups of patients with ADDWoR, clinical symptoms cannot be completely relieved. The disc is anteriorly displaced and shortens, condylar height decreases, and secondary facial asymmetry and mandibular retraction occur.

Metabolic profiling of synovial fluid in human temporomandibular joint osteoarthritis.

Introduction: Temporomandibular joint (TMJ) osteoarthritis (OA) is a common TMJ degenerative disease with an unclear mechanism. Synovial fluid (SF), an important component of TMJ, contains various proteins and metabolites that may directly contribute to OA. The present study aimed to investigate the influence of SF in TMJOA at the metabolite level. Methods: Untargeted and widely targeted metabolic profiling were employed to identify metabolic changes in SF of 90 patients with different TMJOA grades according to TMJ magnetic resonance imaging. Results: A total 1498 metabolites were detected. Most of the metabolites were amino acids and associated metabolites, benzene and substituted derivatives, and lipids. Among patients with mild, moderate and severe TMJOA, 164 gradually increasing and 176 gradually decreasing metabolites were identified, indicating that biosynthesis of cofactors, choline metabolism, mineral absorption and selenocompound metabolism are closely related to TMJOA grade. Combined metabolomics and clinical examination revealed 37 upregulated metabolites and 16 downregulated metabolites in patients with pain, of which 19 and 26 metabolites were positively and negatively correlated, respectively, with maximum interincisal opening. A model was constructed to diagnose TMJOA grade and nine biomarkers were identified. The identified metabolites are key to exploring the mechanism of TMJOA. Discussion: In the present study, a metabolic profile was constructed and assessed using a much larger number of human SF samples from patients with TMJOA, and a model was established to contribute to the diagnosis of TMJOA grade. The findings expand our knowledge of metabolites in human SF of TMJOA patients, and provide an important basis for further research on the pathogenesis and treatment of TMJOA.

Calcified Chondroid Mesenchymal Neoplasms.

Calcified chondroid mesenchymal neoplasms (CCMN) represent a morphologic spectrum of related tumors. Historically, chondroid matrix or chondroblastoma-like features have been described in soft tissue chondroma, tenosynovial giant cell tumors (especially of the temporomandibular joint (TMJ) region), and in a subset of tophaceous pseudogout. Recently, these tumors have been found to share FN1-receptor tyrosine kinase (RTK) fusions. This review discusses the clinical, morphologic, immunohistochemical, and molecular genetic features of CCMN. The distinction from morphologic mimics is also discussed.

[A three-dimensional imaging study of the effect of anterior disc displacement on the bony structural relationship of the temporomandibular joint].

Objective: To investigate the correlation between the osseous structure of temporomandibular joint (TMJ) and three different status of anterior disc location, so that it could guide the clinical diagnosis further. Methods: Fifty-two patients [46 females and 6 males, with an age of (27.8±8.3) years] who treated with MRI and cone beam CT, were recruited from the Temporomandibular Joint Specialist Clinic, The First Affiliated Hospital of Xinjiang Medical University, between March 2018 to December 2021. According to the radiographic findings of the level of anterior disc displacement (ADD) in TMJ, patients were divided into three groups: normal articular disc position (NADP, n=28 TMJs), anterior disc displacement with reduction (ADDWR, n=28 TMJs), and anterior disc displacement without reduction (ADDWoR, n=28 TMJs). In the light of the reconstructed three-dimensional model, ten representative morphological parameters including condylar volume (CV), condylar superficial area (CSA), fossa volume (FV), fossa superficial area (FSA), the proportion of the condylar volume in the articular fossa (CV%), the proportion of the condylar superficial area in the articular fossa (CSA%), superior joint space (SJS), anterior joint space (AJS), posterior joint space (PJS), and medial joint space (MJS), were measured respectively under one-way analysis of variance (ANOVA), Kruskal-Wallis Htest and receiver operator characteristic curve(ROC curve) analyses. Results: CV and CSA values varied significantly in the pathological progression from normal location to irreversible anterior displacement in TMJ. For CV value, NADP group [(1 834.90±667.67) mm3]>ADDWR group [(1 747.34±369.42) mm3]>ADDWoR group [(1 256.29±418.27) mm3] [t=4.31, P(NADP-ADDWoR)<0.001; t=3.66, P(ADDWR-ADDWoR)<0.001], for CSA value, NADP group [(859.27±216.01) mm2]>ADDWR group [(838.23±118.82) mm2]>ADDWoR group [(669.14±150.26) mm2] [t=4.27, P(NADP-ADDWoR)<0.001; t=3.80, P(ADDWR-ADDWoR)<0.001]. The difference of SJS value in NADP group [(2.22±0.88) mm], ADDWR group [(1.94±0.64) mm] and ADDWoR group [(1.45±0.57) mm], was statistically significant [t=4.11, P(NADP-ADDWoR)<0.001; t=2.63, P(ADDWR-ADDWoR)=0.010]. The results of MJS in NADP group [(5.03±1.41) mm], ADDWR group [(3.86±1.32) mm], and ADDWoR group [(4.91±1.65) mm] were significantly different [t=3.00, P(NADP-ADDWR)=0.004; t=2.63, P(ADDWR-ADDWoR)=0.009]. As calculated by the ROC curve analysis, CV, CSA and SJS showed that (AUCCV=0.77, AUCCSA=0.76; AUCSJS=0.76) for the NADP and ADDWoR groups, and (AUCCV=0.80; AUCCSA=0.80; AUCSJS=0.72) for the ADDWR and ADDWoR groups. While the diagnostic accuracy of MJS for the comparison in NADP versus ADDWR and ADDWR versus ADDWoR was respectively AUC(NADP-ADDWR)=0.73, and AUC(ADDWR-ADDWoR)=0.69. Conclusions: CV, CSA, SJS, and MJS were significantly associated with the different disc displacement status, and the condyle in TMJ ADD exhibited three-dimensionally altered dimensions. They could be considered as promising biometric markers to diagnose the ADD status.

Imaging features of temporomandibular joint synovial chondromatosis with associated osseous degenerative changes.

Synovial chondromatosis (SC) of the temporomandibular joint (TMJ) is a rare benign disease associated with the formation of multiple cartilaginous nodules in the synovial tissue of the TMJ. This can result in pain, swelling, clicking, limited mouth opening, and osseous degenerative joint changes. A retrospective cross-sectional study was performed to summarize the clinical features, radiographic findings, and surgical and histopathological findings of TMJ SC patients who underwent open surgery over a 24-year period. A radiographic scoring system was used to evaluate osseous changes and correlate condyle and joint fossa degeneration. The study included 38 patients and focused on 38 joints. All 38 of these joints showed degenerative changes in the condyle, while 37 showed osseous degenerative changes in the articular fossa. The degree of condylar degenerative changes was related to the duration of the chief complaints (r = 0.342, P = 0.036) and the histopathological stage of the TMJ SC (r = 0.440, P = 0.006), while the degree of joint fossa degenerative changes was associated with the radiographic extent of the SC (r = 0.504, P = 0.001), type of calcification (r = 0.365, P = 0.024), and the histopathological stage (r = 0.458, P = 0.004).

Glycyrrhizin regulates antioxidation through Nrf2 signaling pathway in rat temporomandibular joint osteoarthritis.

BACKGROUND: Regulation of redox homeostasis could reduce osteoarthritis severity and limit disease progression, while glycyrrhizin (GL) shows great antioxidant and anti-inflammatory capacity. OBJECTIVE: The aim of this study was to investigate the role of GL on oxidative stress and the potential regulatory mechanism in rat temporomandibular joint (TMJ) chondrocytes under oxidative stress, and investigate the effect of GL in the rat temporomandibular joint osteoarthritis (TMJOA) model. METHODS: Rat TMJ chondrocytes were cultured in oxidative stress with different doses of GL. The effect of glycyrrhizin on the nuclear factor-erythroid 2-related factor 2 (Nrf2) in oxidative stress was evaluated by western blot and immunofluorescence staining. A rat model of TMJOA was treated with GL. Micro-computed tomography, histological and immunohistochemical analysis were used to assess the pathological change of TMJOA. RESULTS: The expression of superoxide dismutase 1 (SOD1), heme oxygenase-1 (HO-1), and peroxiredoxin 6 (PRDX6) were decreased, and intracellular Nrf2 signaling pathway was activated in chondrocytes in oxidative stress. GL upregulates the expression of antioxidants, especially PRDX6, as well as increases Nrf2 expression and nuclear translocation in rat condylar chondrocytes. Administration of GL attenuates condylar bone destruction, cartilage degeneration, and synovitis in rats TMJOA. Meanwhile, GL alleviated oxidative stress and enhanced the antioxidant capacity of TMJOA cartilage. CONCLUSION: This study suggested that GL alleviates rat TMJOA by regulating oxidative stress in condylar cartilage.

Prevalence of temporomandibular disorders in juvenile idiopathic arthritis evaluated with diagnostic criteria for temporomandibular disorders: A systematic review with meta-analysis.

BACKGROUND: Juvenile idiopathic arthritis (JIA) is a very common systemic inflammatory rheumatic disorder affecting the musculoskeletal system in children below 16 years of age. Joint inflammation and tissue destruction is the prime characteristic of the disease. Along with the systemic involvement in the long joints, several studies are mentioning the increased association of temporomandibular disorders (TMDs) in JIA. This current systematic review intends to find the prevalence rate of TMD in JIA-affected individuals as compared to healthy controls. METHODS: We have searched in PubMed, Scopus and Ovid SP for articles published between the timeframe 1 January 1990 and 1 June 2023. All the searched articles were subjected to the Population, Exposure, Comparison, and Outcome model (PECO) based on which inclusion or exclusion is carried out. Participants (P) are children below 18 years of age, Exposure (E) is children or adolescents with a diagnosis of JIA, Comparator is age and gender-matched healthy controls who has no JIA or any systemic disorder, Outcome (O) is the prevalence of TMD. Only the studies that evaluated TMD using diagnostic criteria for evaluation of TMD (DC/TMD) were included in the analysis. We have set the exclusion to the following reasons- diagnostic sensitivity studies, case reports, and systematic reviews. The software Review Manager Version 5.4 (Cochrane Collaboration) was used to perform the pooled analysis. We measured the risk ratio (RR) between the two groups (JIA and no JIA) for the outcome TMD. RESULTS: The pooled total included subjects were 366 in this review with an established diagnosis of JIA as evaluated by DC/TMD. The overall effect of the pooled data suggests that there is a significant difference in the TMD prevalence in the JIA group when compared to the control, results suggest that TMD is more prevalent in the JIA group RR 3.86; 95% CI [2.59, 5.76]. CONCLUSION: Overall, based on the data we can suggest a positive relationship between JIA and TMD, hence presence of JIA can be a risk factor for the development of TMD. The sensitivity of DC/TMD is low when compared to magnetic resonance imaging.

Liproxstatin-1 alleviates cartilage degradation by inhibiting chondrocyte ferroptosis in the temporomandibular joint.

BGROUND INFORMATION: Ferroptosis contributes to temporomandibular joint osteoarthritis (TMJOA) lesion development and is still poorly understood. RESULTS: In this study, we used different TMJOA animal models to examine whether ferroptosis was related to disease onset in TMJOA induced by monosodium iodoacetate (MIA), IL-1ß, occlusion disorder (OD), and unilateral anterior crossbite (UAC). Immunohistochemical staining and Western blot analysis were used to detect ferroptosis- and cartilage degradation-related protein expression. Our results revealed reduced levels of the ferroptosis-related protein GPX4 in the cartilage layer, but the levels of ACSL4 and P53 were increased in the condyle. Injection of the ferroptosis inhibitor liproxstatin-1 (Lip-1) effectively decreased ACSL4, P53 and TRF expression. In vitro, IL-1ß reduced cartilage extracellular matrix expression in mandibular condylar chondrocytes (MCCs). Lip-1 maintained the morphology and function of mitochondria and ameliorated the exacerbation of lipid peroxidation and reactive oxygen species (ROS) production induced by IL-1ß. CONCLUSION: These results suggest that chondrocyte ferroptosis plays an important role in the development and progression of TMJOA. SIGNIFICANCE: Inhibiting condylar chondrocyte ferroptosis could be a promising therapeutic strategy for TMJOA.

Developing standards for MRI evaluation of joints in children with juvenile idiopathic arthritis utilizing the temporomandibular joint as a model.

The treatment of a patient with juvenile idiopathic arthritis (JIA) is best monitored with standardized and validated tools to measure joint changes over time. Treatment approaches are best indicated if the clinicians are aware of the structural status of the joint at a given time, especially in anatomically deep joints for which clinical assessment is limited. Magnetic resonance imaging (MRI) is of utmost importance for assessment of deep joints and extra-articular soft tissue of the entire body for which ultrasound may be suboptimal. Because the distinction between pathologic and physiologic joint changes on MRI is key for proper diagnosis and treatment of patients with arthropathies, a comprehensive standardized approach is needed to effectively measure outcomes of growing joints of children with JIA. Such an approach is essential for both clinical assessment and to conduct clinical trials in patients with JIA treated in different centers around the world. To meet this need, several international imaging collaborative research groups have been developing MRI scales over the past years, including the MRI in JIA (JAMRI) special interest group within the Outcome Measures in Rheumatology (OMERACT) research network. This manuscript reviews the efforts of the OMERACT JAMRI working group to generate and validate pediatric MRI scoring systems for different joints in children with JIA that can have ubiquitous utilization anywhere in the world. In particular, it describes the different steps of development and validation of an MRI scale using the TMJ as a model.

MRI of Temporomandibular Joint Disorders: A Comparative Study of 0.55 T and 1.5 T MRI.

OBJECTIVES: Temporomandibular disorders (TMDs) are common and may cause persistent functional limitations and pain. Magnetic resonance imaging (MRI) at 1.5 and 3 T is commonly applied for the evaluation of the temporomandibular joint (TMJ). No evidence is available regarding the feasibility of modern low-field MRI for the assessment of TMDs. The objective of this prospective study was to evaluate the image quality (IQ) of 0.55 T MRI in direct comparison with 1.5 T MRI. MATERIALS AND METHODS: Seventeen patients (34 TMJs) with suspected intraarticular TMDs were enrolled, and both 0.55 and 1.5 T MRI were performed on the same day. Two senior readers independently evaluated the IQ focusing on the conspicuity of disc morphology (DM), disc position (DP), and osseous joint morphology (OJM) for each joint. We analyzed the IQ and degree of artifacts using a 4-point Likert scale (LS) at both field strengths. A fully sufficient IQ was defined as an LS score of ≥3. Nonparametric Wilcoxon test for related samples was used for statistical comparison. RESULTS: The median IQ for the DM and OJM at 0.55 T was inferior to that at 1.5 T (DM: 3 [interquartile range {IQR}, 3-4] vs 4 [IQR, 4-4]; OJM: 3 [IQR, 3-4] vs 4 [IQR 4-4]; each P < 0.001). For DP, the IQ was comparable (4 [IQR 3-4] vs 4 [IQR 4-4]; P > 0.05). A sufficient diagnostic IQ was maintained for the DM, DP, and OJM in 92% of the cases at 0.55 T and 100% at 1.5 T. Minor image artifacts (LS score of ≥3) were more prevalent at 0.55 T (29%) than at 1.5 T (12%). CONCLUSIONS: Magnetic resonance imaging of the TMJ at 0.55 T yields a lower IQ than does MRI at 1.5 T but maintains sufficient diagnostic confidence in the majority of patients. Further improvements are needed for reliable clinical application.

Effect of occlusal stabilisation splint with or without arthroscopic disc repositioning on condylar bone remodelling in adolescent patients.

The aim of this study was to investigate the treatment effects of a stabilisation splint (SS) with and without arthroscopic disc repositioning (ADR) on condylar bone remodelling in adolescent patients with anterior disc displacement without reduction (ADDwoR). Cone beam computed tomography and magnetic resonance imaging were used to analyse condylar bone remodelling, condyle position, and disc position. Twenty-two temporomandibular joints of 14 patients who underwent ADR (age range 12-20 years; mean follow-up 12.5 ± 7.8 months) and 21 temporomandibular joints of 14 patients who did not undergo ADR (age range 13-20 years; mean follow-up 11.1 ± 5.1 months) were included. The change in bone volume (P < 0.001), rate of bone volume change (P < 0.001), and change in condyle height (P = 0.031) were significantly greater in patients with ADR than in those without ADR. The changes in posterior joint space (P = 0.013), superior joint space (P = 0.020), and ratio of condyle sagittal position (P = 0.013) were significantly greater in patients with ADR than in those without ADR. All discs in patients who underwent ADR and one disc in those who did not undergo ADR were backward repositioned. In conclusion, in adolescent patients with ADDwoR, ADR with SS therapy achieved better condyle and disc position than SS therapy alone, and also induced bone generation.

Mechanical stress can regulate temporomandibular joint cavitation via signalling pathways.

The temporomandibular joint (TMJ), composed of temporal fossa, mandibular condyle and a fibrocartilage disc with upper and lower cavities, is the biggest synovial joint and biomechanical hinge of the craniomaxillofacial musculoskeletal system. The initial events that give rise to TMJ cavities across diverse species are not fully understood. Most studies focus on the pivotal role of molecules such as Indian hedgehog (Ihh) and hyaluronic acid (HA) in TMJ cavitation. Although biologists have observed that mechanical stress plays an irreplaceable role in the development of biological tissues and organs, few studies have been concerned with how mechanical stress regulates TMJ cavitation. Based on the evidence from human or other animal embryos today, it is implicated that mechanical stress plays an essential role in TMJ cavitation. In this review, we discuss the relationship between mechanical stress and TMJ cavitation from evo-devo perspectives and review the clinical features and potential pathogenesis of TMJ dysplasia.

Dental and temporomandibular joint pathology of the red fox (Vulpes vulpes).

Skulls from 305 red foxes (Vulpes vulpes) were examined using predefined criteria to assess for the presence and severity of dental and temporomandibular joint (TMJ) pathology. Of the 305 specimens examined, 131 were male (42.9%), 103 were female (33.4%), 71 were of unknown sex (23.3%), 238 were adults (78.03%) and 67 were young adults (21.97%), with juveniles excluded from the study. Of a maximum of 12,810 possible teeth, 12,355 (96.5%) were present for examination, 72 (0.6%) were absent congenitally, 97 (0.8%) were acquired tooth loss and 280 (2.2%) were absent artefactually. Eight teeth (0.06%) in five specimens (1.6%) had abnormal tooth form and four (0.03%) supernumerary teeth were present across four (1.3%) specimens. Ten persistent deciduous teeth were present in seven (2.3%) specimens and six (0.05%) unerupted teeth were found in four (1.1%) specimens. Root number variation was present in 51 (0.4%) teeth, predominantly premolar teeth. Twenty-one (6.9%) specimens had lesions consistent with enamel hypoplasia and 42 (13.8%) showed root fenestrations in the maxillary alveolar bone. Periodontitis and attrition/abrasion were present in most specimens (56.7% and 96.1%, respectively). Three-hundred and eighty (3.1%) teeth were fractured, with the most common fracture type being root fractures. Eleven periapical lesions were found in nine (0.03%) specimens. Six-hundred and eight TMJs were evaluated and many specimens (11.5%) had evidence of low-grade TMJ osteoarthritis. Overall, these red foxes share similar dental pathology to other foxes, but had a higher prevalence of congenital tooth absence, persistent deciduous teeth, TMJ pathology and enamel hypoplasia.

Plumbagin alleviates temporomandibular joint osteoarthritis progression by inhibiting chondrocyte ferroptosis via the MAPK signaling pathways.

AIMS: The acceleration of osteoarthritis (OA) development by chondrocytes undergoing ferroptosis has been observed. Plumbagin (PLB), known for its potent antioxidant and anti-inflammatory properties, has demonstrated promising potential in the treatment of OA. However, it remains unclear whether PLB can impede the progression of temporomandibular joint osteoarthritis (TMJOA) through the regulation of ferroptosis. The study aims to investigate the impact of ferroptosis on TMJOA and assess the ability of PLB to modulate the inhibitory effects of ferroptosis on TMJOA. MATERIALS AND METHODS: The study utilized an in vivo rat model of unilateral anterior crossbite (UAC)-induced TMJOA and an in vitro study of chondrocytes exposed to H2O2 to create an OA microenvironment. Various experiments including cell viability assessment, quantitative RT-PCR, western blot analysis, histology, and immunofluorescence were conducted to examine the impact of ferroptosis on TMJOA and evaluate the potential of PLB to mitigate the inhibitory effects of ferroptosis on TMJOA. Additionally, RNA-seq and bioinformatics analysis were performed to investigate the underlying mechanism by which PLB regulates ferroptosis in TMJOA. RESULTS: Fer-1 demonstrated its potential in mitigating the advancement of TMJOA through its inhibitory effects on ferroptosis and matrix degradation in chondrocytes, thereby substantiating the role of ferroptosis in the pathogenesis of TMJOA. Furthermore, the observed protective impact of PLB on cartilage implied that PLB can modulate the inhibition of ferroptosis in TMJOA by regulating the MAPK signaling pathways. CONCLUSIONS: PLB alleviates TMJOA progression by suppressing chondrocyte ferroptosis via MAPK pathways, indicating PLB to be a potential therapeutic strategy for TMJOA.

Clinical retrospective analysis with a predictive model for diffused-tenosynovial giant cell tumors of the temporomandibular joint.

BACKGROUND: This study aimed to find out the characteristics in relation to tumor recurrence in diffused-tenosynovial giant cell tumor of temporomandibular joint and to develop and validate the prognostic model for personalized prediction. METHODS: From April 2009 to January 2021, patients with diffused-tenosynovial giant cell tumor of temporomandibular joint at a single center were included in this study. The clinical features and local recurrence-free survival were assessed through the expression of the Ki-67 index and colony-stimulating factor 1 receptor expression. Both univariate and multivariate analyses were performed on the prognostic factors for local recurrence-free survival. An independent predictor nomogram and pertinent tumor characteristics were included. RESULTS: The retrospective study enrolling seventy eligible patients at the Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine. During the follow-up time, eleven patients suffered tumor recurrence. Age was an independent risk factor for local recurrence-free survival (P = 0.032). The Ki-67 index varied significantly in different sites (P = 0.034) and tumor volume (P = 0.017). Multivariate logistic regression was used to develop the prediction model using both statistical significance and prognostic indicators. The C-index of the nomogram based on age, site, Ki-67, and colony-stimulating factor 1 receptor was 0.833. These variates provided good predicted accuracy for a nomogram on local recurrence-free survival. Diffused-tenosynovial giant cell tumor from the temporomandibular joint is extremely uncommon, and certain clinical traits are linked to the tumor proliferation index. CONCLUSIONS: We identified the risk indicators and developed a nomogram in this study to forecast the likelihood of local recurrence-free survival in patients with diffused-tenosynovial giant cell tumor from temporomandibular joint.

[A study on the arthroscopic temporomandibular joint disc reduction on the outcome of orthodontic patients with anterior disc displacement without reduction].

Objective: To investigate the arthroscopic temporomandibular joint disc reduction on the outcome of orthodontic patients with anterior disc displacement without reduction. Methods: From January 2012 to December 2021, forty treated orthodontic patients with anterior disc displacement without reduction (unilateral/bilateral) and no obvious articular cartilage absorption were selected from Department of Orthodontics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine. The patients were (17.5±3.8) years old (12-25 years old), including 8 males and 32 females. Twenty patients who had completed arthroscopic temporomandibular joint disc reduction were included in the control group, and twenty patients with untreated temporomandibular joint disc were included in the experimental group. Model measurement (including overjet, etc.), cephalometric analysis (including ANB angle, which was formed by subspinale, nasion and supramental, etc.) and temporomandibular joint magnetic resonance imaging (including measurement of the condyle height of the displacement sides) were used to compare the difference of two groups. Objective grading system was used to evaluate the efficacy of orthodontic treatment. Results: The overjet of the experimental group and the control group after orthodontic treatment was (2.19±0.76) and (1.92±0.94) mm, respectively. Both two groups achieved ideal overjet with no statistical difference (t=1.02, P=0.314). The ANB angle difference before and after treatment in the control group (-1.97°±2.87°) was greater than that in the experimental group (0.09°±1.82°), and the difference was statistically significant (t=2.72, P=0.010). The variation of condyle height before and after treatment was (0.30±1.11) mm in the experimental group and (0.82±1.25) mm in the control group, with no statistical significance (t=1.80, P=0.076). The post-treatment objective grading system scores of the experimental group and the control group were 21.00 (16.00, 24.00) and 21.00 (17.00, 25.00), respectively, which had no statistical difference (U=0.24, P=0.808). Conclusions: In orthodontic patients with anterior disc displacement without reduction and no obvious articular cartilage absorption, whether displaced discs are repositioned after arthroscopic surgery has no significant effect on the orthodontic treatment outcome.