MiR-146a-5p Promotes Dental Stem Cells Osteo/odontogenic Differentiation through NF-Kappa B Signaling Pathway by Targeting TRAF6.

OBJECTIVE: To screen miRNAs that could simultaneously regulate osteo/odontogenic differentiation of multiple stem cells, including dental pulp stem cells (DPSCs), stem cells from the apical papilla (SCAPs) and periodontal ligament stem cells (PDLSCs). METHODS: Differentially expressed miRNAs analysis on three miRNA microarrays data of dental stem cells undergoing osteo/odontogenic differentiation (GSE138180, GSE154466 and GSE159508) was performed, and miR-146a-5p were identified by bioinformatic prediction, dual-luciferase reporter assay and quantitative real-time polymerase chain reaction (PCR). In addition, differentially expressed genes between miR-146a-5p overexpressed group and control group (GSE79341) were applied for KEGG pathways enrichment analysis. RESULTS: MiR-146a-5p expression increased in the osteo/odontogenic differentiation of DPSCs, SCAPs and PDLSCs. Tumour necrosis factor receptor (TNFR)-associated factor 6 (TRAF6) was identified as the target gene of miR-146a-5p. Furthermore, miR-146a-5p could influence the NF-Kappa B signalling pathway. CONCLUSION: This study suggests that miR-146a-5p could promote differentiation in multiple dental stem cells through the NF-Kappa B signalling pathway by targeting TRAF6.

[Changes of the upper airway in children with Class â ¡ mandibular retrusion and snoring during night before and after functional treatment by sagittal-guidance Twin-block appliance].

PURPOSE: To study the changes of dimension and morphology of upper airway in children with ClassⅡ mandibular retrusion after functional treatment by sagittal-guidance Twin-block appliance. METHODS: Cone-beam CT (CBCT) data of upper airway of the subjects were measured by Dolphin 11.5 software and Mimics 17.0 software , and the changes of dimension and morphology of upper airway before and after functional treatment with sagittal-guidance Twin-block(SGTB) appliance were compared. SPSS 16.0 software package was used for data processing. RESULTS: After functional treatment，the volume of total upper airway，nasopharynx airway, oropharynx airway, the sectional area of tip of the epiglotti(TE), the lateral diameter of TE, the base of the epiglottis(EB) significantly increased (P<0.05) in children with SGTB appliance. CONCLUSIONS: SGTB functional treatment is effective in the treatment of skeletal ClassⅡ mandibular retrusion of children by increase of the upper airway and improvement of respiration．.

[Morphological characteristics of upper alveolar bone around central incisor in Class II division 1 and division 2 malocclusion on cone-beam CT].

PURPOSE: During orthodontic treatment, the incisors in patients with Class II division 1 and division 2 malocclusion showed different clinical features, which determine the different ways to move the teeth to the suitable position. This study analyzed the morphology of alveolar bone around upper central incisor with cone-beam CT (CBCT). METHODS: The sample consisted of 20 normal malocclusion and 40 patients with Class II malocclusion （division 1 20 cases and division 2 20 cases）. CBCT images before orthodontic treatment were reconstructed by INVIVO 5.0 image processing software. Paired t test was used for statistical analysis with SPSS 19.0 software package. RESULTS: At the upper central incisors, the alveolar thickness between normal malocclusion and Class II division 1 and division 2 malocclusion had significant difference except the palate thickness between normal malocclusion and Class II division 2 malocclusion (P<0.05). CONCLUSIONS: Orthodontist should consider the relationship between the teeth position and alveolar bone shape comprehensively, choose the correct plan in order to avoid root desorption, alveolar bone loss, fenestration and other adverse reactions.

[A study on the thickness of buccal bone in the mandible of different vertical facial type in adults using cone-beam CT].

PURPOSE: To provide some references of using micro-implant anchorage in clinical orthodontic treatment, the thickness of buccal bone of mandible of different vertical facial type in adults with cone-beam CT (CBCT) were measured. METHODS: Initial 3-dimensional images of 45 adult patients (15 men, 30 women)were reoriented by using a standardized protocol, and divided into 3 groups by angle of mandibular plane (G1: high angle, 15 patients; G2: average angle, 15 patients; G3: low angle, 15 patients). After signing the informed consent form, three measurement points were defined at 4, 6, and 8mm from the alveolar crest in each measurement area. Statistical analysis was performed with SPSS11.0 software package. RESULTS: The thickness of buccal bone in mandible was thinner in G1 than in G2, and was thinnest in G3. The cortical bone thickness was thickest at the 8 mm level and thinnest at the 4mm level. CONCLUSIONS: The study suggested that the cortical bone thickness at 4mm level from the alveolar crest was safe for implantation. It is more stable when the distance of implants was more away from the alveolar crest. Patients with low mandibular plane angle should use self-tapping micro-implant anchorage. Supported by Nantong Science and Technology Fund (HS2013033).