Background Clear aligner treatment has become popular over recent years. It is necessary to identify methods by which we could avoid the bowing effect in extractions with clear aligner. The present study was to identify the appropriate method to design torque movement involving the upper anterior teeth of extraction cases, in order to maintain or improve the axis and torque of the upper anterior teeth with a clear aligner during movement and closure of the extraction space. Results As the height of the power ridge increased, the rotation angle of the upper central incisor in the sagittal direction decreased gradually and the location of the rotation center changed significantly; the rotation center moved in the apical direction and then changed to the crown side. The highest von-Mises stress of the upper central incisor root, periodontal ligaments, and alveolar bone, showed little change as the power ridge height increased. When the axial inclination of the upper central incisor was normal (U1-SN = 105°), the tendency of movement for the upper central incisor approached translation with a power ridge height of 0.7 mm (corresponding distorted angle: 5.8415). When the axial inclination of the upper central incisor was oversized (U1-SN = 110°), the axial inclination of the upper central incisor reduced to normal following completion of the anterior segment retraction with a power ridge of 0.4 mm (corresponding distorted angle: 3.4265). Conclusion Analysis indicates that pure palatal tipping movement of the upper anterior teeth is generated without torque control, thus resulting in the bowing effect. The required torque control of the upper anterior teeth with oversize axial inclination is weaker than that of the upper anterior teeth with normal axial inclination because limited torque loss is expected for oversize axial inclination teeth. Variation sensitivity of the rotation center should be considered carefully due to biological problems when designing translation of the upper anterior teeth with normal axial inclination.

Preventive strategies for maxillofacial-oral injuries due to traffic accidents should be emphasized and promoted in the first hand, especially for males, rural residents and those aged between 18 and 59 years.

We investigate whether the expression of the receptor activator of nuclear factor kappa-B ligand (RANKL) and osteoprotegerin (OPG) in human dental follicle cells (HDFCs) regulated by colony stimulating factor 1 (CSF-1), parathyroid hormone-related protein (PTHrP) and bone morphogenetic protein-2 (BMP-2) contributes to osteoclastogenesis. Adolescent human impacted third mandibular molars were used to separate HDFCs. These cells were incubated with PTHrP (10 ng/ml), CSF-1 (25 ng/ml), or BMP-2 (100 ng/ml) for 0.5, 1, 3, 6 and 12 h. The expression of OPG and RANKL was investigated by immunohistochemistry and reverse transcription polymerase chain reaction (RT-PCR). Two co-culture systems and tartrate-resistant acid phosphatase (TRAP) staining were used to examine osteoclast formation. Scanning electron microscopy was utilized for the resorption pit assay. RANKL and OPG were expressed innately in HDFCs. Exogenous PTHrP, CSF-1 and BMP-2 chronologically regulated the expression of RANKL and OPG in HDFCs. PTHrP and CSF-1 had similar regulative patterns leading to the up-regulated expression of RANKL and the down-regulated expression of OPG and opposite for BMP-2. The number of TRAP-positive peripheral blood mononuclear cells (PBMCs) slightly increased in contacted co-culture of HDFCs and PBMCs, whereas secreted OPG from HDFCs inhibited osteoclastogenesis in the transwell co-culture system. Contacted co-culture of HDFCs and PBMCs exhibited small and shallow resorption pits, whereas in the transwell co-culture system, secreted OPG from HDFCs reduced the resorption pits, reflecting the difference in osteoclast production. Collectively, we found a dual action of HDFCs in osteoclastogenesis; moreover, PTHrP, CSF-1 and BMP-2 might influence osteoclastogenesis by regulating the expression of RANKL and OPG in HDFCs.

Background: Major depressive disorder (MDD) is a serious and common mood disorder with unknown etiology. Emerging evidence has demonstrated the critical roles of SIRT1 and microRNAs (miRNAs) in the progression of MDD. However, the underlying molecular mechanisms remain to be fully understood. Methods: In the present study, the expression level of miR-138 and SIRT1 were analyzed by RT-PCR or Western blotting in a chronic unpredictable mild stress (CUMS) model. The depressive-like behaviors were analyzed by forced swimming test (FST) and sucrose preference test (SPT) in mice injected with miR-138 and SIRT1 overexpression lentivirus. The luciferase reporter assay was used to assess the direct regulation of miR-138 on SIRT1 expression. Results: The upregulation of miR-138 was found in the hippocampus of the CUMS mice and correlated with decreased SIRT1 expression. C57BL/6J mice treated with SIRT1-and miR-138-expressing (miR-138) lentivirus showed increased depressive-like behaviors. In contrast, SIRT1 or si-miR-138 lentivirus treated C57BL/6J mice showed decreased depressive-like behaviors. Moreover, the Sirt1/PGC-1α/FNDC5/BDNF pathway was downregulated following miR-138 overexpression and increased upon miR-138 knockdown in hippocampus in CUMS mice and cultured primary neuronal cells. Mechanistically, luciferase reporter assay demonstrated that SIRT1 gene was a downstream transcriptional target of miR-138. Conclusion: Our data demonstrated the regulation role of miR-138 on SIRT1 gene expression, miR-138 increased depressive-like behaviors by regulating SIRT1 expression in hippocampus.

Background With the popularity of medical aesthetic programs, some female adults who will or are undergoing orthodontic treatment often wonder whether orthodontic treatment has adverse effects on the nasolabial folds (NLFs). The aims of the study were to investigate any potential changes in the NLFs and associated peripheral soft tissues after orthodontic treatment of female adults. Methods This study compared changes in the NLFs and peripheral soft tissues in female adults undergoing orthodontic treatment using the 3dMD Face system (3dMD, Atlanta, Ga). A total of 52 adult female patient cases (24 teeth extraction, 28 non-teeth extraction) were included to evaluate the effects of different orthodontic treatment regimens on the NLFs and peripheral soft tissues. Results In the NLFs area, the landmarks of the extraction group were all significantly negatively changed (P < 0.001; the NLF2s average value was − 0.72 mm), and the upper and middle parts of the landmarks were negatively changed in the non-extraction group (P < 0.05; the NLF2s average value was − 0.22 mm). Compared to the non-extraction group, the negative changes in the extraction group were more pronounced (P < 0.005). In the lip region, all landmarks in the extraction group were negative changes (P < 0.05; upper lip (ULP) = − 0.93 mm, lower lip (LLP) = − 1.46 mm), and most landmarks in the non-extraction group were positive changes (P < 0.01; ULP = 0.55 mm). In the cheek area, the left and right buccal of the extraction and non-extraction groups were all negatively changed (P < 0.05), and there was no significant difference between the two groups. Conclusion After orthodontic treatment, the NLFs showed negative changes, which were more obvious in the extraction group. The lip soft tissue had a negative change in the extraction group and a positive change in the non-extraction group, indicating that orthodontic treatment affected the soft tissue around the nasolabial sulcus, and that tooth extraction would lead to more negative changes.