[Clinical effect of cortical incision with rapid maxillary expansion to assist orthodontic-orthognathic treatment of skeletal Class â ¢ malocclusion].

PURPOSE: To investigate the clinical effect of rapid maxillary expansion with cortical osteotomy combined with orthodontic- orthognathic treatment for skeletal Class Ⅲ malocclusion. METHODS: A total of 84 patients with skeletal Class Ⅲ malocclusion admitted to Jining Dental Hospital from March 2018 to May 2020 were randomly divided into experimental group and control group, with 42 cases in each group. The control group was treated with orthodontic-orthognathic treatment, while the experimental group was treated with orthodontic-orthognathic treatment with rapid maxillary arch expansion by cortical incision. The time of closing gap, alignment time, maxillary first molar and maxillary central incisor tooth movement distance in the sagittal direction were compared between the two groups. Before treatment and 4 weeks after treatment, the vertical distance from the end of the upper central incisor edge to the horizontal plane(U1I-HP), the distance from the apex of the upper central incisor to the coronal plane(U1I-CP), the vertical distance from the edge of the upper pressure groove to the coronal plane(Sd-CP), the vertical distance from the upper alveolar seat point to the horizontal plane(A-HP), the vertical distance from the point of the upper lip to the coronal plane(Ls-CP), and the vertical distance from the inferior point of nose to coronal plane(Sn-CP) were measured, and the relevant changes were calculated. During the treatment period, the complications of the two groups were compared. SPSS 20.0 software package was used for statistical analysis of the data. RESULTS: There was no significant difference in alignment time, A-HP change, Sn-CP change, maxillary first molar movement distance and maxillary central incisor movement distance between the two groups (P＞0.05). The closing interval in the experimental group was significantly shorter than that of the control group (P＜0.05). The changes of U1I-HP, U1I-CP, Sd-CP, and Ls-CP in the experimental group were significantly higher than those in the control group (P＜0.05). There was no significant difference in the incidence of complications between the two groups during treatment (P＞0.05). CONCLUSIONS: Rapid maxillary expansion of cortical incision assisted orthodontic-orthognathic treatment of skeletal Class Ⅲ malocclusion patients can shorten the closing gap time and improve the treatment effect, which has no obvious influence on the sagittal direction of the teeth.

Implantable zoledronate-PLGA microcapsules ameliorate alveolar bone loss, gingival inflammation and oxidative stress in an experimental periodontitis rat model.

The effect of implantable Zoledronate-PLGA microcapsules (PLGA-ZOL) in periodontitis remains unclear. In this study, we aimed to explore the potential role of PLGA-ZOL in protecting periodontitis and elucidate the underlying mechanism. A rat model of periodontitis was established by ligation the mandibular first molars, then PLGA-ZOL was implanted. The healing volume was scanned by cone-beam computed tomography. Cytokine levels in the gingival tissues were determined by ELISA and RT-PCR. Oxidative stress was indicated by detecting superoxide dismutase concentration and catalase activity. After periodontitis model was successfully established in rats, PLGA-ZOL treatment significantly attenuated alveolar bone loss, as indicated by the increased total healing volume, bone volume/tissue volume and osteoprotegerin level, as well as decreased sRANKL level. PLGA-ZOL treatment also suppressed the inflammatory activities by inhibiting pro-inflammatory cytokine production (TNF-α, IL-1ß) but increasing anti-inflammatory cytokine secretion (IL-10). Furthermore, PLGA-ZOL was found to ameliorate oxidative stress in gingival tissues. In conclusion, PLGA-ZOL microcapsules ameliorate alveolar bone loss, gingival inflammation and oxidative stress in an experimental rat model of periodontitis.

MiR-147 inhibits cyclic mechanical stretch-induced apoptosis in L6 myoblasts via ameliorating endoplasmic reticulum stress by targeting BRMS1.

Functional orthopedic treatment is effective for the correction of malformation. Studies demonstrated myoblasts undergo proliferation and apoptosis on certain stretch conditions. MicroRNAs (miRNAs) function in RNA silencing and post-transcriptional regulation of gene expression, and participate in various biological processes, including proliferation and apoptosis. One hypothesis suggested that miRNA was involved into the procedure via suppressing its target genes then triggered endoplasmic reticulum stress-induced apoptosis. Therefore, miRNAs play important roles in the regulation of the proliferation and apoptosis of myoblasts. In our study, the miR-147 has been explored. A cyclic mechanical stretch model was established to observe the features of rat L6 myoblasts. The detection of mRNA and protein levels was performed by qRT-PCR and western blot. L6 cell proliferation/apoptosis was checked by CCK-8 assay, DNA fragmentation assay, and caspase-3 activity assay. MiRNA transfections were performed as per the manufacturer's suggestions: (1) cyclic mechanical stretch induced apoptosis of L6 myoblasts and inhibition of miR-147; (2) miR-147 attenuated cyclic mechanical stretch-induced apoptosis of L6 myoblasts; (3) miR-147 attenuated cyclic mechanical stretch-induced L6 myoblast endoplasmic reticulum stress; (4) BRMS1 was a direct target of miR-147 in L6 myoblasts; (5) miR-147/BRMS1 axis participated in the regulation of cyclic mechanical stress on L6 myoblasts. MiR-147 attenuates endoplasmic reticulum stress by targeting BRMS1 to inhibit cyclic mechanical stretch-induced apoptosis of L6 myoblasts.