Malocclusion is an oral disease with a high prevalence. The goal of orthodontic treatment is health, aesthetics, function and stability. The transmission straight wire appliance and technique is an innovative orthodontic system with independent intellectual property rights invented by Professor Jiuxiang Lin′s team based on decades of clinical experience, which provides a new solution for the non-surgical correction of skeletal malocclusions, especially class Ⅲ malocclusion, and it is also a good carrier for the implementation of the concept of healthy orthodontics. Due to the lack of guidelines, how to implement standardized application of transmission straight wire technique remains a problem to be solved. This technical specification was formed by combining the guidance from Professor Jiuxiang Lin and joint revision by a number of authoritative experts from the Orthodontic Special Committee, Chinese Stomatological Association, with reference to relevant literatures, and combined with abundant clinical experience of many experts. This specification aims to provide reference to standardize the clinical application of transmission straight wire technique, so as to reduce the risk and complications, and finally to improve the clinical application level of this technique.

Objective To study the friction between brackets and archwires and the influential factors. Methods To test the friction of six combinations of canine bracket and stainless steel archwire, and to calculate the critical contact angles for each combination. Results The friction maintains stability with slight changes when the contact angle is smaller than the critical contact angle. The friction increases linearly when the contact angle is larger than the critical contact angle. The friction of different combinations of bracket-archwire are different and the critical contact angles are also different. Conclusion The critical contact angle influences the friction between bracket and archwire significantly. The critical contact angle is relevant to both the structure of the bracket and the size of the archwire.

With the continuous development of bioinformatics technology and precision medicine, genetic mechanism investigations of genetic diseases including cleft lip and palate (CLP) have been getting more and more attention. Researchers have focused on the coding sequence of the genome and successfully found many CLP causative mutations, but there still remain some unsolved questions. In recent years, researchers′ vision has gradually shifted to non-protein coding region of the genome. This article reviews several coding sequence mutations, non-protein coding variants and their genetic mechanisms discovered in CLP researches.

The isolated type of orofacial cleft, termed non-syndromic cleft lip with or without cleft palate (NSCL/P), is the second most common birth defect in China, with Asians having the highest incidence in the world. NSCL/P involves multiple genes and complex interactions between genetic and environmental factors, imposing difficulty for the genetic assessment of the unborn fetus carrying multiple NSCL/P-susceptible variants. Although genome-wide association studies (GWAS) have uncovered dozens of single nucleotide polymorphism (SNP) loci in different ethnic populations, the genetic diagnostic effectiveness of these SNPs requires further experimental validation in Chinese populations before a diagnostic panel or a predictive model covering multiple SNPs can be built. In this study, we collected blood samples from control and NSCL/P infants in Han and Uyghur Chinese populations to validate the diagnostic effectiveness of 43 candidate SNPs previously detected using GWAS. We then built predictive models with the validated SNPs using different machine learning algorithms and evaluated their prediction performance. Our results showed that logistic regression had the best performance for risk assessment according to the area under curve. Notably, defective variants in MTHFR and RBP4, two genes involved in folic acid and vitamin A biosynthesis, were found to have high contributions to NSCL/P incidence based on feature importance evaluation with logistic regression. This is consistent with the notion that folic acid and vitamin A are both essential nutritional supplements for pregnant women to reduce the risk of conceiving an NSCL/P baby. Moreover, we observed a lower predictive power in Uyghur than in Han cases, likely due to differences in genetic background between these two ethnic populations. Thus, our study highlights the urgency to generate the HapMap for Uyghur population and perform resequencing-based screening of Uyghur-specific NSCL/P markers.
Asian Continental Ancestry Group ; genetics ; China ; ethnology ; Cleft Lip ; genetics ; Cleft Palate ; genetics ; Genome-Wide Association Study ; Humans ; Infant ; Logistic Models ; Machine Learning ; Methylenetetrahydrofolate Reductase (NADPH2) ; genetics ; Polymorphism, Single Nucleotide ; Retinol-Binding Proteins, Plasma ; genetics ; Risk Assessment

Inflammatory bowel disease (IBD) is an intestinal immune-dysfunctional disease worldwide whose prevalence increasing in Asia including China. It is a chronic disease of the gastrointestinal tract with unknown cause. Exosomes are small vesicles in various body fluids. They have diameters of 40-120 nm, and one of their functions is long-distance transfer of various substances. In this study, we investigated the contents of salivary exosomes in patients with IBD and in healthy controls to explore a new biomarker in patients with IBD. In this study, whole saliva was obtained from patients with IBD (ulcerative colitis (UC), n = 37; Crohn's disease (CD), n = 11) and apparently healthy individuals (HC, n = 10). Salivary exosomes were extracted from samples, and the proteins within the exosomes were identified by liquid chromatograph-mass spectrometer (LC-MS/MS). The results showed that more than 2000 proteins were detected in salivary exosomes from patients with IBD. Through gene ontology analysis, we found that proteasome subunit alpha type 7 (PSMA7) showed especially marked differences between patients with IBD and the healthy controls, in that its expression level was much higher in the CD and UC groups. This exosomal protein is related to proteasome activity and inflammatory responses. So we conclude that in this research, salivary exosomal PSMA7 was present at high levels in salivary exosomes from subjects with IBD. It can be a very promising biomarker to release the patients from the pain of colonoscopy.
Animals ; Biomarkers ; metabolism ; Female ; Humans ; Inflammatory Bowel Diseases ; metabolism ; Male ; Proteasome Endopeptidase Complex ; metabolism ; Salivary Proteins and Peptides ; metabolism

SUMMARY Regenerationofbonetissue,aswellasothertissues,requiresinvolvementandinteraction of cells,scaffolds and relevant growth factors,among which growth factors play a crucial role in maintai-ning the stability of microenvironment.Nel-like-type 1 molecule (NELL-1 ),a novel growth factor in tis-sue engineering,has been studied intensively in recent years.Researches mainly covered gene and pro-tein structure and their expression profiling,biological function,molecular mechanisms and disease rele-vance.NELL-1 expressed in embryonic tissue is essential for growth and development of bone tissue. NELL-1 presents excellent abilities of inducing bone and cartilage regeneration,especially with high spe-cificity to chondrocyte lineage.Compared with classic osteogenic growth factor bone morphogenetic pro-tein 2 (BMP-2),the process of osteogenesis interacted with NELL-1 exhibits stronger specificity,higher bone density and fewerside effects.Furthermore,a recent study shows synergistic effects of NELL-1 and BMP-2.NELL-1 enhances the osteogenic reaction induced by BMP-2 of cells and notably declines in-flammation response caused by BMP-2.This review evaluates the current research progress of the function and application of NELL-1 by the systematic method of evidence-based medicine.

Objective To propose a new three-dimensional method or grading scale in the evaluation of the secondary alveolar bone grafting,thus modifying the Bergland grading scale.Methods A total of 40 patients (26 male,14 female) with unilateral cleft lip and palate (UCLP),who underwent secondary alveolar bone grafting at least 3 months ago,were enrolled.Regional cone-beam CT(CBCT) scans were taken to evaluate the height and thickness of the postoperative bone bridges.A new three-dimensional grafting scale was established,including four grades respectively in alveolar height and thickness.Results According to the new three-dimensional scale in this study,15 grafted sites were rated grade T-Ⅰ or T-Ⅱ in the alveolar thickness among 18 sites of grade H-Ⅰ in height,and 10 among 15 of grade H-Ⅱ in height.Therefore,25 grafted sites were considered as clinical success in the alveolar thickness (grade T-Ⅰ or T-Ⅱ) among 33 sites with clinical success in alveolar height (grade H-Ⅰ and H-Ⅱ).There were 24％ of 33 sites with clinical success in height,which were considered as clinical failure in the alveolar thickness.Conclusions It is necessary to establish a new three-dimensional method or grading scale for evaluating the secondary alveolar bone grafting.The three-dimensional scale can take comprehensive view of the bone-grafted alveolar clefts and thus modify the Bergland grading scale.

The accuracy and repeatability of computer aided cervical vertebra landmarking (CACVL) were investigated in cephalogram. 120 adolescents (60 boys, 60 girls) aged from 9.1 to 17.2 years old were randomly selected. Twenty-seven landmarks from the second to fifth cervical vertebrae on the lateral cephalogram were identified. In this study, the system of CACVL was developed and used to identify and calculate the landmarks by fast marching method and parabolic curve fitting. The accuracy and repeatability in CACVL group were compared with those in two manual landmarking groups [orthodontic experts (OE) group and orthodontic novices (ON) group]. The results showed that, as for the accuracy, there was no significant difference between CACVL group and OE group no matter in x-axis or y-axis (P>0.05), but there was significant difference between CACVL group and ON group, as well as OE group and ON group in both axes (P<0.05). As for the repeatability, CACVL group was more reliable than OE group and ON group in both axes. It is concluded that CACVL has the same or higher accuracy, better repeatability and less workload than manual landmarking methods. It's reliable for cervical parameters identification on the lateral cephalogram and cervical vertebral maturation prediction in orthodontic practice and research.

The accuracy and repeatability of computer aided cervical vertebra landmarking (CACVL) were investigated in cephalogram.120 adolescents (60 boys,60 girls) aged from 9.1 to 17.2 years old were randomly selected.Twenty-seven landmarks from the second to fifth cervical vertebrae on the lateral cephalogram.were identified.In this study,the system of CACVL was developed and used to identify and calculate the landmarks by fast marching method and parabolic curve fitting.The accuracy and repeatability in CACVL group were compared with those in two manual landmarking groups [orthodontic experts (OE) group and orthodontic novices (ON) group].The results showed that,as for the accu racy,there was no significant difference between CACVL group and OE group no matter in x-axis or y-axis (P＞0.05),but there was significant difference between CACVL group and ON group,as well as OE group and ON group in both axes (P＜0.05).As for the repeatability,CACVL group was more reliable than OE group and ON group in both axes.It is concluded that CACVL has the same or higher accuracy,better repeatability and less workload than manual landmarking methods.It's reliable for cervical parameters identification on the lateral cephalogram and cervical vertebral maturation prediction in orthodontic practice and research.

To investigate the longitudinal sagittal growth changes of maxilla and mandible according to the quantitative cervical vertebral maturation (QCVM) for adolescents with normal occlusion,mixed longitudinal data were used.The samples included 87 adolescents aged from 8 to 18 y old with normal occlusion (32 males,55 females) selected from 901 candidates.Sequential lateral cephalograms and hand-wrist films were taken once a year,lasting for 6 y.The longitudinal sagittal growth changes of maxilla and mandible according to QCVM were measured.There were some significant differences between maxilla and mandible according to QCVM.The sagittal growth change of maxilla showed a trend towards high velocity→decelerating velocity→completing velocity from QCVM stage Ⅰ to stage Ⅳ.The sagittal growth change of mandible showed a trend towards accelerating velocity→high velocity→decelerating velocity→completing velocity from QCVM stage Ⅰ to stage IV.With sagittal relationship,growth magnitude was almost the same between maxilla and mandible at QCVM stage Ⅰ.At stage Ⅱ the growth of mandible exceeded that of maxilla and growth in mandible continued at stages Ⅲ and Ⅳ,while the maxilla ceased to grow.Growth magnitude was greater and the growth duration was longer with male mandible.It is concluded that the longitudinal sagittal growth changes of maxilla and mandible on the basis of QCVM is of value in the orthodontic practice.