Objective:To investigate the impact of thread depth and pitch on the stress magnitude and distribution characteristics at the interface between the mini-implant and bone studied by three-dimensional finite element analysis(3D FEA).Methods:The approach of this study involved the use of CBCT scanning technology in the combination with medical image processing software Mimics,reverse engineering software Geomagic,3D design software SolidWorks and 3D FEA software Ansys Workbench.This methodology was employed to 3D FEA models of mini-implants with various thread morphologies and their supporting bone struc-tures,based on the geometric form of osstem mini-implants.Axial load was applied and the influence of thread depth and thread distance on the stress magnitude and stress distribution pattern of the micro implant bone interface was analyzed.Results:Both thread depth and thread distance affected the stress magnitude at the micro implant bone interface,but do not alter the stress distri-bution pattern.The cortical bone area in the neck of the micro implant and the trabecular bone area at the root apex were both stress concentration areas.The most reasonable conditions for this experiment were a 2.5 mm diameter pure titanium micro implant with a thread height of 0.3 mm and a thread distance of 0.6 mm.Conclusion:The design criteria for threads should avoid excessive or insufficient thread depth and thread distance.

Objective:To explore the effects of different titanium(Ti)surfaces on mitochondria metabolism and polarization of mac-rophages.Methods:The anodic oxidation method prepared nanotubes with distinct morphologies(NT5 and NT20 groups)on smooth titanium surfaces(P group)were characterized by scanning electron microscopy(SEM).After 24 hours of culturing RAW264.7 cells on the samples,SEM was employed to observe the morphology of the cells of all groups.Levels of mitochondria ATP and ROS,as well as the activity of hexokinase(HK),were measured by fluorescence probes and luciferase assays.The expression of iNOS,Arg-1,TNF-α and CD206 mRNA was evaluated by RT-qPCR.Changes in mitochondria metabolism and macrophage polarization were studied following inhibition of cellular glycolysis by using 2-deoxy-D-glucose(2-DG)in groups P*and NT20*.Results:Compared with the P group,the NT5 group showed no significant changes in mitochondria ATP,ROS levels and HK activity,but an upregula-tion in M2-associated gene expression was observed.In the NT20 group,mitochondria ATP and ROS levels were increased,HK ac-tivity was elevated,and M1-associated gene expression was upregulated.After glycolysis inhibition,there was no significant differ-ence in mitochondria ATP,ROS levels,HK activity and polarization-related gene expression levels between the P*and NT20*groups compared with the P group.Conclusion:Large-diameter nanotubes may promote macrophage M1 polarization by regulating the metabolic reprogramming that occurs in macrophage mitochondria.

Objective:To explore the prescription and medication patterns of traditional Chinese medicine for treating oral ulcers,and to explore the mechanism of the action of core drug combinations.Methods:The relevant literature in China Knowledge Network(CNKI),Wipro Chinese Journals(VIP),Wanfang Data(Wanfang)and Chinese Biomedical Literature(CBM)were searched and screened,EXCEL software was used to establish a database of traditional Chinese medicines compounded for the treatment of aph-thous stomatitis,the screened traditional Chinese medicines were analyzed in terms of frequency statistics,association rules,and studied by clustering analysis.The active ingredients,targets,and related pathways of core drug combinations for treating oral ulcers were studied by TCMSP,GeneCards,STRING,DAVID databases and Cytoscape software.Results:A total of 548 articles met the screening criteria,involving 368 traditional Chinese medicines.34 high-frequency drugs were found in more than 100 studies,with the majority of heat clearing and deficiency tonifying drugs.The drugs were mainly cold and bitter,the meridians of the liver and lung were more common.Further analysis revealed that the core drug combination with the highest support and confidence was"lico-rice-baicalin-huanglian".Network pharmacology analysis of"licorice-baicalin-huanglian"revealed that its main active ingredients were quercetin,kaempferol and wogonin,while AKT1,IL6,TNF,TP53,and IL1 β,JUN and others were the key core targets.KEGG pathway enrichment analysis revealed that it mainly involved cancer signaling pathway,NF-κB,PI3K-Akt,MAPK and JAK-STAT signaling pathway,etc.Conclusion:The prescription of traditional Chinese medicine for treating oral ulcers mainly focuses on tonifying qi and stomach,relieving pain and lowering bitterness.The combination of"licorice-huangqin-huanglian"medicine is im-portant in the treatment of oral ulcers.

Objective:To explore the effects of different combination of Er∶YAG laser irradiation parameters on the dentinal tu-bule sealing.Methods:160 dentin discs with 2 mm thickness were etched with 0.5 mmol/L EDTA to establish the dentine hyper-sensitivity models.The discs were randomly divided into 16 groups(n=10).The R02 and R14 handpieces were used to deliver Er∶YAG laser to the dentin discs according to the different output power(W),irradiation distance(cm)and irradiation time(s/cm2).Then,the samples of each group were divided into immediate irradiation subgroup and acid etching and wear subgroup(n=5).The dentinal tubules were observed with SEM,and the exposed area,the sealed rate and the occlusion depth of dentinal tubules were e-valuated with ImageE-Pro Plus 6.0 software.Results:The dentinal tubules in the control group opened uniformly with clear perime-ter,they were enlarged and opened after acid etching and tooth brushing.The dentinal tubules shrinked or sealed well with the melt layer after treatment by Er∶YAG laser irradiation with either parameter combination.Especially,uniform and seamless melt layer as well as similar dentin surface morphology before and post the acid etching and tooth brushing were obtained when the dentin discs were exposed to the following Er∶YAG laser irradiation parameter combinations,i.e.(R02,0.5 W,3 cm,20 s/cm2),(R14,0.5 W,3 cm,20 s/cm2)and(R14,0.6 W,3 cm,20 s/cm2).Significantly decreased exposed area and increased seal rate in the dentinal tubules treated in the above 3 laser irradiation parameter combina-tion groups were observed than those in the other groups(P＜0.05).Morphological analysis confirmed that whether the acid etching and tooth brushing were exerted.The occlusion depth of dentin tubule was more than 2.0 μm in the dentinal tubules treated in the above 3 groups.Conclusion:Er∶YAG laser irradiation parameter combinations of R02,0.5 W,3 cm,20 s/cm2,R14,0.5 W,3 cm,20 s/cm2 and R14,0.6 W,3 cm,20 s/cm2 are suitable for the best dentin tubule sealing.

Objective:To characterize the bacterial communities present in the root apical regions associated with persistent apical periodontitis(PAP).Methods:6 periapical lesion samples were collected from the teeth with PAP.DNA was extracted and ampli-fied by PCR based on the V3-V4 region of 16S rRNA gene.Illumina high throughput sequencing was applied to achieve the infor-mation of microbial community.Results:In total,447 OTUs were assigned,the average number of OTUs for the samples was 164.83±56.24.The phyla Firmicutes,Actinobacteria,Bacteroidetes,Proteobacteria and Fusobacteria were detected with high rela-tive abundances in all samples.At the genus level,the prevalent bacterial genera were Bifidobacterium,Streptococcus,Bacillus,En-terococcus and Porphyromonas,which were abundantly detected in all samples.The 6 samples were divided into 2 groups by hierar-chical cluster analysis.Prevotella and Treponema were abundant in group A,Bifidobacterium,Streptococcus and Enterococcus were abundant in group B.Conclusion:The bacterial profiles of root apical region of the teeth with PAP can be illustrated that diverse bacterial communities located in apical lesions.The bacterial composition of PAP can be divided into 2 microbial pattern and the re-lationship between different bacteria may guide new strategies to control infection.

Objective:To study the morphological characteristics and ethnic differences of the chin soft and hard tissue of Han and Uyghur adult females of class Ⅱ 1.Methods:90 Uyghur and Han female subjects of class Ⅱ 1 aged 18-35 years old were enrolled and respectively divided into 3 groups according to the vertical skeletal types:high,average and low angle groups(n=30).The various indexes of the chin soft and hard tissue of the subjects were measured by X-ray lateral cephalic radiographs.The data were statisti-caly analyzed.Results:(1)The Po-Pos of the Han subjects with high angle was higher than that of those with low and average an-gle;the minimum chin thickness,the ratio of the chin thickness to the chin height,the ratio of the minimum chin thickness to the chin thickness and the angle of chin in the high angle group were smaller than those in the average angle group and the low angle group(P＜0.05).The chin height,the chin depression and the cervical-mandibular angle of the Uyghur subjects with high angle were higher than those of the Uyghur subjects with low angle and average angle;the minimum chin thickness,the ratio of the chin thickness to the chin height and the ratio of the minimum chin thickness to the chin thickness in the high angle group were smaller than those in the average and the low angle groups(P＜0.05).(2)In the low angle group,there were significant differences in the angle of chin,cervical-mandibular angle,soft tissue chin angle and Me-Mes between the 2 ethnic groups(P＜0.05).In the average angle group,there were significant differences in the height of chin,LI-LL and Me-Mes between the 2 ethnic groups(P＜0.05).In the high angle group,there were significant differences in the ratio of anterior to posterior chin thickness,in the angle of chin,LL-Pos and Po-Pos between the 2 ethnic groups(P＜0.05).(3)The positive correlation between FH/MP and Po-Pos,cervical-mandib-ular angle,chin depression,chin lip angle,chin height,ratio of anterior and posterior chin thickness and LL-Pos were found in Han and Uyghur subjects(P＜0.05).Mentolabial sulcus,the chin thickness,the ratio of the chin thickness to the chin height,the angle of chin and the ratio of the minimum chin thickness to the chin thickness were negatively correlated with FH/MP in both ethnic groups(P＜0.05).Conclusion:Han and Uy-ghur adult females of class Ⅱ 1 have different chin soft and hard tissue morphology in different vertical skeletal types with certain differences between the ethnic groups in the same vertical skeletal types,and there is a correlation between the chin soft and hard tis-sue morphology of different vertical skeletal types and the vertical skeletal types in Han and Uyghur adult females of class Ⅱ 1.

A case report of adult skeletal class Ⅲ patient with high angle open bite is presented in this article.The patient underwent extraction of bilateral mandibular first molars and straightening the third molars,open bite was resolved,normal over bite,over jet and good occlusion were established.

Objective:To assess the feasibility and security the orientation of foreign bodies using a portable X-ray machine in computer-aided navigation surgery.Methods:A model with a metallic foreign body was constructed.Under the fluoroscopy of a portable X-ray machine,4 points on 2 straight lines passing through the tip of the foreign body were recorded by the navigation e-quipment,and subsequently,the midpoints of the common perpendicular segments of the 2 lines were calculated as the coordinates of the foreign body(Bilinear Method).2 operators measured the coordinates of the foreign body 10 times and compared the measured coordinates of the foreign body with the actual coordinates of the foreign body in order to analyze the accuracy of the Bilinear Method.Radiation doses to model area and operators at different locations were measured using ionizing radiation detectors.Results:The ac-curacy of the Bilinear Method for measuring foreign body coordinates was(1.98±0.77)mm,and that of the 2 operators was 1.55±0.68 and 2.40±0.36 respectively(P=0.02).The radiation dose was(221.45±50.15)μSv in the model and(4.44±1.35)μSv in the operator's chest.Conclusion:The accuracy of the coordinates of the foreign body intraoperation measured by Bilinear Method meets general clinical needs,and different operators may produce different accuracy.The radiation dose is small.

Objective:To develop rat models of oral mucosa ulcer using distinct experimental methodologies,fulfilling research requirements and adhering to the ethical standards for animal care.Methods:96 SD rats were randomly allocated into groups.The rats in control group(n=8)were regularly fed without other treatment.Those in chemical cauterization groups were treated by 20％,40％,60％of glacial acetic acid(GAA)on oral mucosa(n=8);in mechanical damage groups by 30 000 r/min high speed drill induced trauma of 10,20 and 30 mm2 respectively(n=8);in ionizing radiation groups were treated with 10,12,15,20 and 30 Gy on the mucosa respectively(n=8).After the ulcer was appeared,the morphology of the mucosa were observed,the mucosal tissue lesions were examined by HE,Masson and immunofluorescence staining,the expression of TNF-α and IL-1β were detected by qPCR and ELISA respectively,and the body conditions such as diet and body weight of the rats were observed,the pain,dis-tress and discomfor of the rats were evaluated by MORTON&Griffits Guidelines.Results:40％and 60％GAA,20 mm2 and 30 mm2 friction damage and ionizing radiation of 12 Gy or greater may induce oral mucosa ulcer with a diseas coruse of 6-7 d in SD rats.TNF-α and IL-1β mRNA expression in the damaged tissue,the related protein expression in blood serum of the rats were in-creased.MORTON&Griffits Guidelines analysis showed 40％GAA,20 mm2 friction damage and 12 Gy ionizing radiation induced the lowest scores of pain,distress and discomfort of the rats with compatible oral mocosa ulcere induced by the relevat treatment.Conclusion:40％GAA,20 mm2 of friction damage and 12 Gy of ionizing radiation can reliably establish oral mucosa ulcer models and minimize adverse effects on SD rats,and accord with ethical standards of 3R for laboratory animal.

The advancement of surgical techniques enables effective treatment for many patients with oral and maxillofacial tumors.How-ever,post-surgery problems such as chewing,swallowing and speech difficulty may arise due to the defects in speech organs and inade-quate compensatory function of tissue flap repair.Speech disorders,in particular,isolate patients by making it difficult for them to com-municate with others,not only impact their quality of life but also potentially lead to psychological problems and social interaction disor-ders.Although the decline in life quality and other related issues caused by speech dysfunction due to surgery and radiotherapy or chemo-therapy have been widely recognized,there is currently no standardized and universally applicable assessment method and standardized re-habilitation treatment management guideline or consensus for speech disorders following oral and maxillofacial tumor surgery at home and abroad.Based on previous clinical practice,combined with the characteristics of speech disorders in patients after oral and maxillofacial tumor surgery,the clinical experience of the experts in maxillofacial tumor surgery and rehabilitation and the relevant domestic and foreign literature,relevant experts organized discussions and modifications,reach a consensus on core content such as the assessment of speech disorders and the implementation plan for early rehabilitation treatment management,providing a reference for clinical practice,in order to improve patients'speech-related life quality and enhance the assessment and rehabilitation treatment techniques for speech disorders after oral and maxillofacial tumor surgery.