Biomolecular aggregation within cellular environments via liquid–liquid phase separation (LLPS) spontaneously forms droplet-like structures, which play pivotal roles in diverse biological processes. These structures are closely associated with a range of diseases, including neurodegenerative disorders, cancer and infectious diseases, highlighting the significance of understanding LLPS mechanisms for elucidating disease pathogenesis, and exploring potential therapeutic interventions. In this review, we delineate recent advancements in LLPS research, emphasizing its pathological relevance, therapeutic considerations, and the pivotal role of bioinformatic tools and databases in facilitating LLPS investigations. Additionally, we undertook a comprehensive analysis of bioinformatic resources dedicated to LLPS research in order to elucidate their functionality and applicability. By providing comprehensive insights into current LLPS-related bioinformatics resources, this review highlights its implications for human health and disease.

The teaching of orthognathic surgery is difficult because it is complex and emphasizes the combination of theory and practice. The traditional teaching method focuses on theoretical teaching, but due to the limitation of conditions, it is difficult for students to master the operation. In this paper, we apply the digital three-dimensional surgical simulation system combined with 3D printing in specialist training of orthognathic surgery. Digital software and 3D printing are applied in the theoretical teaching, surgical operation, summary and reflection to combine practical teaching with theoretical teaching, so as to stimulate the subjective initiative of the students. The results showed that the teaching evaluation of the experimental group [(3.89±0.84) points] was better than that of the control group [(2.91±1.21) points]. The application of digital three-dimensional surgical simulation system combined with 3D printing has achieved satisfactory results.

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.In recent years,this technique has gradually attracted wide attention in China,but it has not been popularized on a large scale in our country because of several limitations.Thus,in this study,the clinical experience of patients with TMJ prosthetic replacement in clinical units was summarized,and the treatment principles,treatment processes,and technical advantages were systematically discussed,aiming to promote the popularization and application of TMJ prosthetic replace-ment in China.

Objective:To comprehensively investigate the biomechanical properties of the temporomandibular joint (TMJ) disc and to perfect the mechanical testing system of the TMJ disc by conducting tests of compression, tension, cyclic compression, cyclic tension, creep and friction.Methods:Fifteen fresh goat heads (weighing 2.5-3.0 kg) were purchased from the market. They were all ordinary goats (9-12 months old, body weighing 18-21 kg) regardless of gender. Bilateral articular discs (a total of 30) were dissected within 30 minutes after execution. According to the national standard for mechanical testing of viscoelastic materials, fresh TMJ disc specimens of goat were prepared and tests were carried out in physiological conditions. The universal mechanical testing machine was utilized to test biomechanical properties of TMJ discs.Results:The compressive modulus of TMJ discs was (8.41±2.12) MPa and the tensile modulus was (9.54± 3.26) MPa. The mechanical characteristics would be irreversibly altered once the load exceeded the physiological range. In addition, it underwent apparent creep relaxation under continuous strain (0.5 MPa or 3.0 MPa) and the surface friction coefficient of the TMJ discs (0.015+0.011) was much lower than that of general viscoelastic materials.Conclusions:The TMJ disc was a bio-viscoelastic structure with excellent tensile and compressive properties and its surface was extremely smooth in wet conditions.

Objective:To evaluate the 2-dimension and 3-dimension changes of upper airway of patients who were diagnosed with idiopathic condylar resorption (ICR) and anterior open bite as well as received bilateral temporomandibular joint (TMJ) prostheses replacement or bimaxillary orthognathic surgery.Methods:This study is a retrospective study. Seventeen patients diagnosed as ICR and anterior open bite in Department of Orthognathic and TMJ surgery, West China Hospital of Sichuan University were selected (January 2018 to December 2021) and divided into bilateral TMJ protheses replacement group (group R, n=8) and orthognathic group (group O, n=9), according to which surgery they have performed. In order to compare variation of upper airway before and after surgery in different dimensions and sections within the same group or between groups, Spiral computed tomography data were obtained before (1 month) and after operation (10 to 12 months) to measure the total volume of airway (VT), the maximum sagittal area (MSA), the maximum cross-sectional area (MACA), the minimum cross-sectional area (MICA), the area of the most posterior plane(PPA), the area of soft-palate plane (SPA), the area of the most posterior point of tongue base plane (PTA), the area of the root of epiglottis plane (EA), the oropharyngeal airway volume (VO), the glossopharyngeal airway volume (VG) and the laryngeal airway volume (VL). Wilcoxon signed-rank test were used to complete statistical analyses for VO (T2),SPA (T2),ΔMSA,ΔMACA in group R as well as PTA (T1),EA (T2) in group O. Statistical analyses of other items were performed with student′s t test. Results:VT, VO, VG, VL, MSA, MACA, MIC, PPA, PTA and EA of group R (T2) were significantly increased after TMJ prosthesis with Lefort Ⅰ osteotomy ( P<0.05). Meanwhile the VT, VO, VG, MSA, MACA, MICA, PPA and SPA of group O (T2) were significantly increased ( P<0.05). There were significant difference in ΔVT and ΔVL between group R [(6 854.80±3 197.82) mm 3, (2 252.85±1 527.96) mm 3] and group O [(3 367.91±3 124.62) mm 3, (413.21±1 244.44) mm 3]( t=2.27, P=0.038; t=2.74, P=0.015). Conclusions:Bilateral temporomandibular joint (TMJ) prostheses replacement and bimaxillary orthognathic surgery can both enlarge the areas and volumes of upper airway in patients who suffer from ICR and anterior open bite. Compared with bimaxillary orthognathic surgery, bilateral temporomandibular joint prostheses replacement plays a more pronounced role in enlargement and reconstruction of middle-inferior section of upper airway.

For patients with dento-maxillofacial deformities who receive orthodontic-orthognathic combined treatment, the conventional treatment approach is preoperative orthodontic-orthognathic surgery-postoperative orthodontics. However, with the development of techniques used in orthodontic and orthognathic treatment, the surgery-first approach (SFA), namely, orthodontic surgery-postoperative orthodontics, has been widely used currently and displays several advantages, such as improving the treatment efficiency and providing patients with more satisfaction. This review provides a brief discussion and review of SFA concerning its development, indications, advantages and disadvantages, outcomes and stability, and the application and research progress of SFA in orthodontic-orthognathic combined treatment for patients with maxillofacial deformity. The literature review results showed that compared with the conventional treatment approach, SFA has relatively strict indications, which usually include patients with skeletal class Ⅱ/Ⅲ malocclusion, skeletal open bite, and bimaxillary protrusion or patients with facial asymmetry but who require little preoperative orthodontic treatment or removal of the compensation of the dental arch, specifically as follows: ①well-aligned to mildly crowded anterior teeth, ②flat to mild curve of Spee, ③normal to mildly proclined/retroclined incisor inclination, ④acceptable arch coordination, ⑤extensive occlusal contact between the upper and lower dentition requiring at least 3 occlusal contacts. Any occlusion that may affect the outcome of surgery or final result of the overall treatment, as well as any disease that may jeopardize the healing process after surgery, is regarded as a contraindication. Furthermore, SFA has potential disadvantages, such as a possible higher incidence of complications, including unstable occlusion and malunion of bones, which still require further research to be confirmed. Most researchers believe that no significant difference occurs between the outcome and stability of the two approaches. However, currently, we still need a sufficient sample size of prospective studies to provide accurate evidence.

Objective:To conduct a retrospective study on the treatment outcomes of patients who underwent artificial temporomandibular joint (TMJ) replacement surgery and to evaluate the effectiveness of artificial TMJ treatment.Methods:This study selected 62 patients who received standard Biomet artificial TMJ treatment at Department of Orthognathic and TMJ Surgery, West China Hospital of Stomatology, Sichuan University from May 2010 to September 2023 as the study subjects. Among them, there were 15 male patients and 47 female patients. The average age was 33.5 years old(ranging from 18 to 67 years). This study statistically analyzed postoperative indicators, including maximum mouth opening, forward jaw movement, lateral movement, postoperative pain scores, and patient satisfaction.Results:This study included a total of 62 patients with 99 TMJ joints. No infections occurred postoperatively. The average follow-up period was 33.7 months (ranging from 7 to 170 months). At 6 months postoperatively, the mean mouth opening was (36.1±6.2) mm, lateral movement was (2.1±0.9) mm, and forward jaw movement was (1.0±0.9) mm. The pain visual analog scale score at 6 months postoperatively was (2.8±0.6), and patient satisfaction with the surgery was (8.8±1.1). Spiral CT scans conducted after surgery showed no joint dislocation or migration, and the artificial joint remained stable during the follow-up period.Conclusions:Artificial TMJ replacement is a valuable method for effectively restoring TMJ structure and essential functions related to mouth opening and chewing. It is worthy of promotion as a reconstructive approach for the temporomandibular joint

Objective: To generate a new classification for adult temporomandibular joint ankylosis (TMJA), which could effectively guide treatment strategies for adult TMJA patients with various clinical features. Methods: We developed a new "CD" classification system according to the preservation of the condyle (C) and the severity of dentofacial bone deformity (D). From January 2016 to April 2020, 56 TMJ patients (with 73 ankylosed joints) in our department were classified into 4 subgroups by ‘CD’ classification: condylar head preservation but no dentofacial deformities (C+D-), no condylar head preservation and no dentofacial deformities (C-D-), condylar head preservation and dentofacial deformities (C+ D+), and no condylar head preservation but dentofacial deformities (C-D+). Different strategies were used according to the clinical features of each subgroup. The clinical outcomes of these patients were analyzed. Different treatment strategies of temporomandibular joint reconstruction were adopted for different subclasses of patients and were followed. "C +": lateral arthroplasty (LAP) was used to remove the rigidity and preserve the medial residual condyle. "C-": if the ankylosing bone ball is small and the loss of ascending branch height is not obvious, arthroplasty should be performed to relieve ankylosis; however, if the ankylosing bone ball is large and the ascending branch height decreases significantly, joint reconstruction should be carried out after the ankylosis is relieved. "D +": surgical treatment of secondary dental and maxillofacial malformations at the same time or over stages. "D-": orthodontic treatment after operation to improve occlusal relationship and symptomatic treatment of oral diseases. Results: After treatment, all 73 ankylosed joints were completely released, and the average maximal interincisal opening increased from (3.6±3.2 )to (32.8 ± 5.4) mm (P<0.001), with no recurrence of ankylosis found during the 12-48 month follow-up period. Conclusion The generation and elaboration of a ‘CD’ classification system is intended to help as a TMJA reconstruction guide for adult TMJA treatment and be widely used in more hospitals.

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. Lineage tracing using Gli1-CreER⁺; Tm^fl/-mice and Sox9-CreER⁺;Tm^fl/-mice showed that ADD interfered with the chondrogenic capacity of Gli1⁺ FCSCs as well as osteogenic differentiation of Sox9⁺ lineage, mainly in the middle zone of TMJ cartilage. Then, a surgically induced disc reposition (DR) mouse model was generated. The inhibited FCSCs capacity was significantly alleviated by DR treatment in ADD mice. And both the ADD mice and adolescent ADD patients had significantly relieved OA phenotype and improved condylar growth after DR treatment. In conclusion, ADD-TMJOA leads to impaired chondrogenic progenitor capacity and osteogenesis differentiation of FCSCs lineage, resulting in cartilage degeneration and loss of subchondral bone homeostasis, finally causing TMJ growth retardation. DR at an early stage could significantly alleviate cartilage degeneration and restore TMJ cartilage growth potential.
Animals ; Mice ; Osteogenesis ; Zinc Finger Protein GLI1 ; Fibrocartilage ; Temporomandibular Joint ; Disease Models, Animal ; Osteoarthritis ; Stem Cells ; Growth Disorders