Application of temporomandibular joint prosthesis in oral and maxillofacial surgery: strategic thinking and prospects.

The temporomandibular joint (TMJ) is the critical functional unit in the human stomatognathic system. Damage of the TMJ causes orofacial dysfunction and secondary jaw deformities, leading to seriously decreased quality of life in patients. The TMJ prosthetic replacement is an important treatment method for severe joint destruction because of its remarkable advantages compared with other methods.

Accessing Furan-Linked Methylene Oxindoles/Benzofurans via Stereoselective Palladium-Catalyzed Domino Cyclization/Cycloisomerization.

A palladium-catalyzed domino cyclization/cycloisomerization reaction of alkyne-tethered carbamoyl chlorides with ()-β-chloroenones is reported. This reaction proceeds via a -carbopalladation of the alkyne, followed by a vinyl-Pd-catalyzed cycloisomerization of the ()-β-chloroenone cascade, which provides an efficient method to synthesize furan-linked methylene oxindoles. The reaction features stereodefined vinyl-Pd species, high to excellent 5-exo/6-endo selectivity, excellent / selectivity, and the sequential formation of three bonds and bis-heterocycles.

Comparing microstructural and micromechanical deformation of the TMJ disc in two anterior disc displacement models.

Objective: Anterior disc displacement (ADD) has been used to establish temporomandibular joint disorder (TMD) models. Based on whether preserve of the retrodiscal attachment, the modelling methodologies include ADD with dissecting the retrodiscal attachment (ADDwd) and ADD without dissecting the retrodiscal attachment (ADDwod). This article aims to determine which model better matches the micromechanical and microstructural progression of TMD.

Comparison of the biomechanical behavior between commercial and 3D-printed patient-specific Ti6Al4V L-Shaped titanium plates following le fort i osteotomy using finite element analysis: A technical Note.

Objective: To evaluate and compare the biomechanical behavior of three-dimensionally (3D) printed patient-specific Ti6Al4V with commercially made titanium mini plates following Lefort-I osteotomy using finite element analysis.

Methods: Le Fort I osteotomy was virtually simulated with a 5 mm maxillary advancement and mediolateral rotation in the coronal plane, resulting in a 3 mm gap on the left side's posterior. Two fixation methods were modeled using software to compare 3D-printed Ti6Al4V and commercial titanium mini plates, both featuring a 4-hole l-shape with thicknesses of 0.

The effect of different hybrid rigid internal fixation techniques on the postoperative stability following a mandibular advancement using a bilateral sagittal split ramus osteotomy: A retrospective three-dimensional comparative study.

Objective: To three-dimensionally evaluate post-operative mandibular stability following bilateral sagittal split ramus osteotomies between hybrid and non-hybrid rigid internal fixation techniques.

Materials And Method: Seventy adults with skeletal class II deformity who underwent bilateral split sagittal osteotomy with mandibular advancement were included. Patients were divided into four groups based on their fixation techniques: hybrid technique (HT) groups I, II, and IV received a 4-hole 2 mm miniplate with either a bicortical screw (BS), additional 2 mm 4-hole miniplate, or two-hole miniplate, while non-HT group III received a 4-hole 2 mm miniplate with four mini-screws (MS).

Isolation, characterization, identification and quantification of 6-F oxyphenisatin dipropionate, a novel illegal additive, from a fruit-flavored jelly.

Objective: This study is aimed to screen, identify and detect illegal additives from healthcare products which claim or imply to have weight-loss effects.

Method: Ultra-high performance liquid chromatography-quadruple-time-of-flight mass spectroscopy (UPLC-Q-TOF/MS) was employed to perform non-targeted screening of illegal additives from a total of 26 batches of healthcare products with weight-loss effects. A novel oxyphenisatin dipropionate analog was discovered in a fruit-flavored jelly that was not clearly labeled as containing added drugs.

Bone Volume Analysis and Associated Influencing Factors in Mandibular Distraction Osteogenesis: A Retrospective Analysis.

Background: Distraction osteogenesis is a progressively popular technique for maxillofacial bone reconstruction, but there is a notable gap in the analysis of bone volume within the distraction segment and the exploration of associated influencing factors.

Purpose: The purpose of this study was to quantitatively analyze the new bone volume and the distraction gap volume in the three-dimensional (3D) model and explore the influencing factors associated with the percentage of the new bone volume to the distraction gap volume.

Study Design, Setting, Sample: This retrospective study included patients who underwent maxillofacial distraction osteogenesis treatment at the West China Hospital of Stomatology between 2014 and 2022, utilizing the mandibular distractor (Cebei, Ningbo, China).

Arthroscopic reduction and rigid fixation of the anteriorly displaced temporomandibular joint disc without reduction using titanium screw: a case series.

Objectives: To evaluate the effectiveness of arthroscopic reduction and rigid fixation (ARRF) using a suture-free titanium screw as a treatment approach to temporomandibular joint's (TMJ) anterior disc displacement without reduction (ADDwoR) and assess its impact on clinical outcomes, including improvements in symptoms related to TMJ disorders.

Materials And Methods: A series of twenty patients presented to the Department of Orthognathic and Temporomandibular Surgery at West China Hospital of Stomatology between September 2022 and January 2023, complaining of symptoms such as pain, clicking, and limited mouth opening. Standard magnetic resonance image (MRI) imaging T1 and T2 sequences in both sagittal and coronal views study with closed and maximal open mouth positions were taken preoperatively to assess the disc's position, integrity, and shape.

Understanding the Mechanics of the Temporomandibular Joint Osteochondral Interface from Micro- and Nanoscopic Perspectives.

The condylar cartilage of the temporomandibular joint (TMJ) is connected to the subchondral bone by an osteochondral interface that transmits loads without causing fatigue damage. However, the microstructure, composition, and mechanical properties of this interface remain elusive. In this study, we found that structurally, a spatial gradient assembly of hydroxyapatite (HAP) particles exists in the osteochondral interface, with increasing volume of apatite crystals with depth and a tendency to form denser and stacked structures.

The Dual Role of Small Extracellular Vesicles in Joint Osteoarthritis: Their Global and Non-Coding Regulatory RNA Molecule-Based Pathogenic and Therapeutic Effects.

OA is the most common joint disease that affects approximately 7% of the global population. Current treatment methods mainly relieve its symptoms with limited repairing effect on joint destructions, which ultimately contributes to the high morbidity rate of OA. Stem cell treatment is a potential regenerative medical therapy for joint repair in OA, but the uncertainty in differentiation direction and immunogenicity limits its clinical usage.

Studying positional changes of the disc-condyle-fossa complex in ADDWoR patients after TMJ disc repositioning surgery.

Objetives: To investigate the positional changes in the temporomandibular joint (TMJ) disc-condyle-fossa complex of patients with anterior disc displacement without reduction (ADDWoR) and to evaluate the effect of disc repositioning (DR) surgery.

Material And Methods: Fifteen patients with unilateral ADDWoR (30 joints) were included. MRI of the TMJ was performed at T0 (1 week before surgery), T1 (1 month after surgery), and T2 (9-12 months after surgery).

A novel vardenafil analog in a healthcare product: Preparation, characterization, and quantification.

Objective: This study is aimed to develop a qualitative and quantitative method to detect a novel vardenafil analogue from a healthcare product, which is claimed to enhance sexual function. The unknown compound was detected by non-targeted screening using ultra-high performance liquid chromatography-quadrupole-time-of-flight mass spectrometry (UPLC-Q-TOF-MS). MS spectra showed that the characteristic fragment ions of this unknown compound were highly similar to those of vardenafil.

Heterogeneous Characteristics of the CD90 Progenitors in the Fibrocartilage of Different Joints.

Objective: This study aimed to isolate and compare the mesenchymal stem cell characteristics of CD90 cells from different fibrocartilage tissues in the temporomandibular joint (TMJ), the knee joint, and the intervertebral joint to further understand the similarities and differences of these 4 fibrocartilage tissues.

Methods: CD90 cells were isolated from TMJ disc, condylar cartilage, meniscus, and intervertebral disc by using magnetic-activated cell sorting. Cellular assays including 4.

Comparison of Class II open bite correction by temporomandibular joint prostheses or bimaxillary orthognathic surgery.

Introduction: The aim of this study was to evaluate the outcome of skeletal Class II and anterior open bite patients who received simultaneous Le fort I osteotomies with temporomandibular joint (TMJ) prostheses or bimaxillary orthognathic surgery.

Materials And Methods: Patients with condylar resorption (CR) were treated by TMJ prostheses and orthognathic surgery and divided into two groups. Cephalometric radiographs were obtained before and after operation to find out the surgical alteration by comparing measures at different time points.

Divergent chondro/osteogenic transduction laws of fibrocartilage stem cell drive temporomandibular joint osteoarthritis in growing mice.

The anterior disc displacement (ADD) leads to temporomandibular joint osteoarthritis (TMJOA) and mandibular growth retardation in adolescents. To investigate the potential functional role of fibrocartilage stem cells (FCSCs) during the process, a surgical ADD-TMJOA mouse model was established. From 1 week after model generation, ADD mice exhibited aggravated mandibular growth retardation with osteoarthritis (OA)-like joint cartilage degeneration, manifesting with impaired chondrogenic differentiation and loss of subchondral bone homeostasis.

Condylar positional changes and remodeling following bimaxillary anterior segment osteotomy with and without Le Fort I osteotomy: a three-dimensional comparative analysis.

Objective: To evaluate 3D condylar displacement and long-term remodeling following the correction of bimaxillary protrusion by anterior segment osteotomy (ASO) with and without Le Fort I surgery.

Materials And Method: This retrospective study included 32 adults with bimaxillary protrusion who underwent ASO alone (group 1) or with concomitant Le Fort I osteotomy (group 2). Subject's computed tomography scans at basic (T0), immediate postoperatively (T1), and at 1 year or more follow-up (T2) were collected.

TMJ anterior disc displacement anchorage surgery: a retrospective study based on a suture-free titanium screw strategy.

Objective: To evaluate the feasibility and effectiveness of using a suture-free titanium screw in repositioning anterior disc displacement without reduction (ADDwoR) of the temporomandibular joint (TMJ).

Methods: A consecutive sample of twelve patients (fifteen joints) was included in this study. All patients were diagnosed with ADDwoR and showed limited mouth opening or temporomandibular joint pain symptoms.

Interspecies comparison of temporomandibular joint condylar cartilage extracellular matrix from macro to microscopy.

Interspecies comparisons of the extracellular matrix of temporomandibular joint (TMJ) condylar cartilage are necessary to elucidate the mechanisms underlying its superior mechanical properties, to guide the construction of animal models of TMJ-related diseases, and to establish standards for the engineering of TMJ condylar cartilage. Here we characterize and compare TMJ condylar cartilage from six different species from a materials science perspective, including structure, composition and mechanical properties from the macroscopic to the microscopic level. The gross morphology showed obvious interspecies differences in size and shape, which may be related to the different joint motion patterns.

Effect of the magnitude of condylar head displacement on the TMJ function in skeletal class II patients undergoing different degrees of mandibular advancement: A retrospective comparative study.

Purpose: This study aimed to compare the condylar head displacement (CHD) after bilateral sagittal split ramus osteotomy (BSSO) between different degrees of mandibular advancement in skeletal class II patients and to evaluate whether the temporomandibular joint (TMJ) function would be affected.

Patients And Methods: Fifty-nine patients (118 condyles) were included in this retrospective study and were divided into three groups based on the distance of mandibular advancement. The CHD in three directions, x (sagittal direction), y (coronal direction), and z (axial direction), was measured before operation (T0), immediately after operation (T1), and at least 6 months after operation (T2), and the TMJ function of patients was followed up and scored using the Helkimo index system.

Near-Infrared Light-Activated Mesoporous Polydopamine for Temporomandibular Joint Osteoarthritis Combined Photothermal-Chemo Therapy.

The treatments generally employed for temporomandibular joint osteoarthritis (TMJOA) involve physical therapy and chemotherapy, etc., whose therapeutic efficacies are impaired by the side effects and suboptimal stimulus responsiveness. Although the intra-articular drug delivery system (DDS) has shown effectiveness in addressing osteoarthritis, there is currently little reported research regarding the use of stimuli-responsive DDS in managing TMJOA.

Spatial Heterogeneity Directs Energy Dissipation in Condylar Fibrocartilage.

Condylar fibrocartilage with structural and compositional heterogeneity can efficiently orchestrate load-bearing and energy dissipation, making the temporomandibular joint (TMJ) survive high occlusion loads for a prolonged lifetime. How the thin condylar fibrocartilage can achieve efficient energy dissipation to cushion enormous stresses remains an open question in biology and tissue engineering. Here, three distinct zones in the condylar fibrocartilage are identified by analyzing the components and structure from the macro-and microscale to the nanoscale.

Importance of the average radius of coal particles on determining the methane diffusion coefficient.

The average radius of coal particles is an estimate of the diffusion path in the particle method for determining the diffusion coefficient. It is currently calculated using the arithmetic mean of coal particle sieved intervals. This calculation, however, ignores the coal particle size distribution, resulting in significant deviations when calculating the gas diffusion coefficient.

Insight on Serum Albumin: From Structure and Biological Properties to Functional Biomaterials for Bone Repair.

Serum albumin (SA), one of the most abundant proteins in blood plasma, plays essential roles in all living processes and has been used in various biomedical applications. Biomaterials fabricated from SAs (human SA, bovine SA, and ovalbumin) exhibit proper microstructure and hydrophilicity as well as remarkable biocompatibility; this makes them ideal for use in bone regeneration. This review provides a comprehensive overview of the structure, physicochemical properties, and biological features of SAs.

Micron/Submicron Scaled Hierarchical Ti Phosphate/Ti Oxide Hybrid Coating on 3D Printed Scaffolds for Improved Osteointegration.

Three-dimensional (3D) printed implants have attracted substantial attention in the field of personalized medicine, but negative impacts on mechanical properties or initial osteointegration have limited their application. To address these problems, we prepared hierarchical Ti phosphate/Ti oxide (TiP-Ti) hybrid coatings on 3D printed Ti scaffolds. The surface morphology, chemical composition, and bonding strength of the scaffolds were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), contact angle measurement, X-ray diffraction (XRD), and scratch test.