The advanced platelet-rich fibrin(A-PRF)and concentrated growth factor(CGF)are platelet concentrates(PCs)obtained through the collection of venous blood from the patient and using different centrifugation procedures.Both are rich in growth factors,and the internal fibrin structure within them serves as a natural three-dimensional scaffold for the release of growth factors.They possess characteristics such as low cost,high safety and superior regenerative potential.Currently,they have gained wide-spread attention in the field of regeneration and repair of soft and hard tissues in oral implantation.This review provides the progress of A-PRF and CGF research,focusing on their preparation methods,application methods,potential regeneration mechanisms and a comparison of components and scaffold structures promoting alveolar bone defect repair between A-PRF and CGF.

This paper reports a case of edentulous patient with severe resorption of mandibular alveolar ridge who was treated with tissue conditioner to obtain the shape and marginal position of mandibular personalized denture base,and the final denture was dupli-cated by digital subtraction milling technique.After one year of follow-up,the retention of denture was significantly improved,and there was no soft and hard tissue tenderness or discomfort during mastication.These results suggest that the treatment plan for severe alveolar ridge absorption has clinical application value and promotion potential.

Objective:The transcriptome data was utilized to screen cuproptosis-related genes(CRGs)in oral squamous cell car-cinoma(OSCC),and the characteristic genes were identified for constructing a prognostic model for predicting patients'survival time.Methods:OSCC transcriptome gene expression and clinical data were obtained from TCGA and GEO.Through Lasso regres-sion analysis and Cox regression analysis,relevant prognostic genes were screened and prognostic models were constructed.Ac-cording to the median value of risk scores,patients were divided into high and low risk groups,and their survival rates were com-pared.Finally,the predictive performance of the model was verified.Results:In this study,9 characteristic genes with prognostic value(ENO2,P4HA1,SLC2A3,AQP1,PLS1,NXPH4,CTSG,TRAC,THBS1)were screened out and a 9-gene prognostic model was constructed.The survival rate of high-risk group based on prognostic model was significantly lower than that of low-risk group.The area under curve(AUC)of receiver operating characteristic curve(ROC)was 0.701,0.729 and 0.702 at 1 year,3 years and 5 years,respectively,which verifies that the risk model has good predictive performance.The nomogram predicted that the 1-year,3-year,and 5-year survival probabilities of OSCC patients are 89.6％,72.4％,and 63.9％respectively,and the cal-ibration curve confirmed the accuracy of the nomogram prediction.Conclusion:The 9-gene prognostic model based on CRGs screening could predict the prognosis of OSCC patients,which is helpful for clinical personalized treatment of OSCC patients and prediction of their survival rate.

Objective:To study the influence of methyltransferases like 3(METTL3)on the radiosensitivity of oral squamous cell carcinoma cells(OSCCs).Methods:The apoptosis level of OSCCs CAL27,SCC9 and SCC15 treated with X-ray radiation doses of 2,4 and 8 Gy respectively was compared by flow cytometry,the expression of methylated gene RNA and protein in the cells were examined by qRT-PCR and Western blot.m6A in the cells was quantified by LC/LC-MS method.qRT-PCR and Western blot were used to investigate the expression of methylated gene RNA and protein in the cells.Flow cytometry was used to examine the cell apoptosis level of CAL27 and SCC15 cells treated with METTL3 overexpression and knockdown respectively.The clone forma-tion of CAL27 and SCC15 cells after knockdown and overexpression of target genes followed by radiation treatment was observed by clonogenic assays.Results:The apoptosis rate of all the cell lines increased with the increase dose of radiation at each dose,CAL27 cells showed the highest and SCC15 showed the lowerst apoptosis rate.The RNA and protein expression levels of METTL3 in CAL27 were significantly lower than those of SCC15.m6A quantification showed that the methylation modification in CAL27 cells was lower than that in SCC15.The expression of METTL3 was increased in CAL27 and SCC15 cells after radiation treatment.Knockdown of METTL3 increaced the apoptosis rate and decreased the clonogenesity,overession of METTL3 the decreaced the ap optosis rate and increased the clonogenecity of the cells.Conclusion:Regulation of METTL3 can affect the radiotherapy sensitivity of OSCCs,METTL3 may become a new target for radiosensitization of OSCCs.

Objective:To establish a three-dimensional culture and stress-loaded model of human periodontal ligament cells(hP-DLCs)in vitro and to determine the effect of static pressure on autophagy.Methods:Periodontal tissue was scraped from fresh ex-tracted tooth surfaces for culture and hPDLCs were obtained.Type Ⅰ rat tail collagen was extracted to prepare collagen-sodium algi-nate composite hydrogel,in which third-generation hPDLCs were embedded.After 72 h of culture,gene expression of autophagy-related proteins LC3,Atg-5 and Beclin-1 was detected by quantitative real-time polymerase chain reaction(qRT-PCR),and the expression of Atg-5,Beclin-1 and LC3 was detected by Western blotting.Results:Cells grew well in collagen-alginate hydrogels.After 15 min of compressive stress loading,the level of autophagy of hPDLCs increased significantly and then gradually decreased to the baseline level.Conclusion:Collagen-alginate hydrogel has good biocompatibility and safety,and can be used as an excellent scaffold for three-dimensional cell culture in vitro.Static compressive stress can accelevate autophagy,and this acceleration is rapid and short-lived.

Mandibular retrusion is a common dentofacial deformity of maxillofacial region in clinical practice,which seriously af-fects facial appearance and oral function.Severe mandibular retrusion can lead to systemic diseases,and even lead to sleep apnea,which is life-threatening.The etiology of mandibular retrusion is not clear,but heredity,bad habits and endocrine dysfunction are related to its occurrence and development.At present,functional appliance treatment,camouflage treatment,combined orthodontic and orthognathic treatment are the main ways to treat mandibular retrusion.This article discusses the pathogenesis,clinical manifes-tations,and treatment strategies of class Ⅱ malocclusion with mandibular retrusion.

Objective:To study the effects of 3D printing digital positioning guide plate for orthodontic treatment of impacted teeth.Methods:88 patients with single impacted teeth(excluding third molars)with a total of 88 impacted teeth were included and were randomly divided into guide group and conventional group(n=44).Helical nickel-titanium push springs were placed be-tween adjacent teeth on both sides of the impacted teeth to open the gap.CBCT scanning and 3D reconstruction,and digital positio-ning guides were used to assist the positioning.Results:The operation time of the guide group and conventinal group was(26.42±4.94)min and(35.78±9.27)min(P＜0.001),the average bone removal area of the window was(66.03±4.67)mm2 and(69.75±7.22)mm2(P＜0.05),respectively.43 and 41 embedded teeth were successfully erupted in the guide group and the conventinal group,respectively(P＞0.05).The average eruption time of the impacted teeth in the guide group and conentinal group was(176.68±9.89)d and(178.18±10.17)d respectively(P＞0.05).Before treatment,there was no significant difference in the levels of IL-6,IL-1β and TNF-α in saliva between the 2 groups(P＞0.05).After one week of treatment,the levels of saliva IL-6,IL-1β and TNF-α in the guide group were lower than those in the conventinal group(P＜0.05).Conclusion:The use of 3D print-ing digital positioning guide plate for orthodontic treatment of impacted teeth can provide accurate positioning,avoid damage to ad-jacent teeth and surrounding vascular and nerve bundles,reduce the difficulty of operation,shorten operation time,and reduce fen-estration and boneless area,can reduce postoperative inflammatory factor secretion and inhibit periodontal inflammatory response.

Objective:The aim of this study is to explain the key role of chondrocyte ferroptosis in TMJ OA and demonstrate that abnormal occlusion stimulation is an important causative factor of ferroptosis.Methods:We observed the morphological changes of mouse condylar cartilage in unilateral anterior crossbite(UAC,an abnormal occlusion stimulation)and bilateral anterior elevation(BAE,a proliferation occlusion stimulation)mice by HE and SO staining,and analyzed the expression of intracellular GPX4 by im-munofluorescence staining,and analyzed the changes in the content of mitochondria and reactive oxygen species by JC-1 and ROS staining.Results:The UAC caused degeneration of condylar cartilage and ferroptosis of chondrocytes in mice.The accumulation of iron ions and the dysfunction of mitochondria in chondrocytes significantly upregulated.The expression of GPX4,which is a key reg-ulator in the regulation of ferroptosis was lowered in UAC mice condyle cartilage.Moreover,in BAE model the condylar cartilage hy-perplasia was observed,but not the ferroptosis of chondrocytes.Conclusion:This study revealed that the abnormal biological force caused by abnormal occlusion could induce ferroptosis of chondrocytes,and ferroptosis is one of the main factors leading to the de-generation and thinning of condylar cartilage.GPX4 could regulate the ferroptosis of chondrocytes.

Objective:The objective of this study was to search for targeted small molecule inhibitors of Sortase A(SrtA)of Streptococcus mutans(S.mutans),and to provide an experimental basis for the exploration of novel and effective anti-caries drugs.Methods:Using the crystal structure of SrtA enzyme of S.mutans UA159(PDB code:4TQX)as the receptor and amino acid Cys205 as the covalent binding site,we screened potential small molecule compounds from the natural small molecule drug-like molecule libraries of the compounds using molecular covalent docking technology and ADMET drug-forming filtration.The study screened small molecule compounds that inhibit adhesion without antibacterial effect,as determined by the minimum inhibitory concentration(MIC)and bacterial adhesion experiments.The binding modes and stabilities of the small molecule compounds were verified through molecular dynamics simulation.Results:A total of 20 small molecule compounds were selected by molecular co-valent docking technology and ADMET druggability filtration,among which AK-968/40369373 and AK-968/40385877 inhibited the adhesion of S.mutans better than trans-chalcone,and the difference was statistically significant(P＜0.05).Molecular dynam-ics simulations confirmed that AK-968/40369373 and AK-968/40385877 could form stable covalent binding to SrtA.Conclusion:Virtual screening and validation are effective methods for selecting potential targeting inhibitors of SrtA.The small-molecule com-pounds AK-968/40369373 and AK-968/40385877 obtained in this study are expected to be used as small-molecule inhibitors tar-geting S.mutans SrtA.

Recent studies have shown that the physiological homeostasis of oral mucosal cells is regulated by the circadian clock.Dis-ruption or dysfunction of the circadian clock is closely associated with the development of oral squamous cell carcinoma(OSCC).Research based on the circadian clock offers a novel perspective on the pathogenesis and therapeutic strategies for OSCC.However,there is current-ly limited research on this topic,and people generally have insufficient understanding and recognition of the circadian clock.Given the complexity and challenges of circadian clock which is the fourth dimension of medical research,we organize relevant experts based on summarizing the current research results of circadian clock in the pathogenesis and precision diagnosis and treatment of OSCC,combining the scientific principles of the circadian clock's role and their long-term research experience,then summarizes and recommends the con-sensus opinions for the research of circadian clock in the pathogenesis mechanism and precision diagnosis and treatment of human OSCC,with the hope of providing guidance for the basic research and clinical application of circadian clock or circadian rhythm in the pathogene-sis mechanism and precision diagnosis and treatment of oral and maxillofacial squamous cell carcinoma.