Objectives: To test the hypothesis that the sagittal position of the anterior teeth has no effect on pharyngeal airway dimension or hyoid bone position and to investigate the influence of orthodontic retraction of the anterior teeth on each section of pharynx and hyoid position. Materials and Methods: Forty-four Class I bimaxillary protrusion adults, treated with preadjusted appliances and maximum anchorage after extraction of four premolars, were divided into two groups according to their vertical craniofacial skeletal patterns. Pretreatment and posttreatment variables were compared using paired t-test, and the relationship between pharyngeal airway size and dentofacial variables was analyzed using Pearson correlation coefficient. The changes of pharyngeal airway size and hyoid position after treatment were compared between two groups using independent t-test. Results: Upon retraction of the incisors, the upper and lower lips were retracted by 2.60 mm and 3.87 mm, respectively. The tip of upper incisor was retracted by 6.84 mm and lower incisor retracted by 4.95 mm. There was significant decrease in SPP-SPPW, U-MPW, TB-TPPW, V-LPW, VAL, C3H, and SH (P , .05). No statistically significant different changes were observed in the dentofacial structures, pharyngeal airway, and hyoid position between the two groups after the treatment. There was a significant correlation between the retraction distance of lower incisor and the airway behind the soft palate, uvula, and tongue. Conclusions: The pharyngeal airway size became narrower after the treatment. Extraction of four premolars with retraction of incisors did affect velopharyngeal, glossopharyngeal, hypopharyngeal, and hyoid position in bimaxillary protrusive adult patients. (Angle Orthod. 2012;82:115-121.)

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.

Background and objective Periodontal ligament stem cells (PDLSCs) have potential for osteogenic differentiation and show a great foreground in treating bone diseases. Histone three lysine 27 (H3K27) demethylase lysine demethylase 6A (KDM6A) is a critical epigenetic modifier and plays an important role in regulating osteogenic differentiation. Multiple microRNAs have been found to play important roles in osteogenesis. The aim of this study was to explore the mechanisms underlying the roles of miR‐153‐3p and KDM6A in PDLSC osteogenesis. Methods The levels of the osteogenic markers alkaline phosphatase (ALP), runt‐related transcription factor 2 (Runx2), and osteopontin (OPN) were measured by western blotting. Osteoblast activity and mineral deposition were detected by ALP and Alizarin red S (ARS) staining. The levels of miR‐153‐3p and KDM6A were measured by quantitative real‐time PCR (qRT‐PCR). A luciferase reporter assay was used to confirm the interaction between KDM6A and miR‐153‐3p. Gain‐of‐function and loss‐of‐function assays were performed to identify the roles of miR‐153‐3p and KDM6A in the osteogenic differentiation of PDLSCs. Results In osteogenic PDLSCs, the expression of KDM6A, ALP, Runx2, and OPN was upregulated, whereas that of miR‐153‐3p was downregulated. miR‐153‐3p downregulation or KDM6A overexpression promoted the osteogenic differentiation of PDLSCs, as demonstrated by increases in ALP activity, matrix mineralization, and ALP, Runx2, and OPN expression. KDM6A was confirmed to be a target of miR‐153‐3p, and KDM6A overexpression reversed the inhibitory effect of miR‐153‐3p mimic on PDLSC osteogenesis. KDM6A promoted ALP, Runx2, and OPN expression through the demethylation of H3K27me3 on the promoter regions of these genes. Conclusion miR‐153‐3p inhibited PDLSC osteogenesis by targeting KDM6A and inhibiting ALP, Runx2, and OPN transcription. These findings provide latent hope for PDLSCs application in periodontal therapy.

Long non-coding RNA (LncRNA) AWPPH is a recently identified oncogenic lncRNA, while its role in other human diseases is still unknown. Blood samples from 80 periodontitis (periodontitis group) patients and 66 healthy controls (control group) who were admitted and treated by Peking University School and Hospital of Stomatology, expression levels of lncRNA AWPPH were detected by RT-PCR. In the present study, we showed that, before treatment, lncRNA AWPPH in plasma was up-regulated in periodontitis patients than in healthy controls. After treatment, expression levels of lncRNA AWPPH reduced significantly. Patients were followed up for 2 years to recorded recurrence. Compared with plasma levels of lncRNA AWPPH on the day of discharge, lncRNA AWPPH expression level increased significantly in patients with recurrence but not in patients without recurrence during follow-up. Based on Youden’s index, patients were divided into high and low lncRNA AWPPH groups according to its expression level on the day of discharge. It was observed that the recurrence rate of periodontitis is significantly higher in high lncRNA AWPPH group than in low lncRNA AWPPH group. LncRNA AWPPH overexpression predicts the recurrence of periodontitis.

Non-syndromic cleft lip with or without cleft palate (NSCLP) is the most common congenital craniofacial malformation, and its harmful influence on affected individuals is apparent. Despite many studies, the causative genes and their mechanisms are not completely clear. We recruited a Han Chinese NSCLP family and explored the causative variant in this pedigree. We performed whole-exome sequencing on two patients. Bioinformatics screening and analysis were used to identify the mutation. We also performed species conservation analysis, mutation function predictions, and homology protein modelling to evaluate the influence of the mutation. We identified a rare mutation in interferon regulatory factor 6 (IRF6) (c.26G>A; p.Arg9Gln) as a candidate of causative mutation. This mutation was predicted to be deleterious. The codon is conserved in many species. The residue change caused by this mutation would affect the structure of IRF6 to a degree. Our study suggested that the rare IRF6 variant is probably the pathogenic mutation in this family. Our result adds evidence that IRF6 variants play a role in the aetiology of orofacial clefts.