Treatment and posttreatment effects of a novel magnetic palatal expansion appliance with reactivation system in dogs.

INTRODUCTION: This study aimed to compare the effects of a novel magnetic palatal expansion appliance (MPEA) during the expansion and maintenance period with that of a screw expansion appliance. METHODS: Based on previous research, the MPEA had a reactivation system that was modified for a broader working range and more stable expansion. Thirty-six male beagle dogs were assigned to a magnetic expansion (ME; n = 12), screwed expansion (SE; n = 12) or control (n = 12) group. Half of the dogs from each group were evaluated only during 5 weeks of activation, whereas the rest were evaluated for 5 weeks of activation and 8 additional weeks of retention. Nonmagnetic metal marking implants were implanted on both sides of the midpalatal suture of all dogs. Three-dimensional assessment of treatment and posttreatment dental and skeletal effects were conducted using cone-beam computed tomography. The width of the midpalatal suture, mineralization and deposition rate of bone, and fluorescence integral optical density were calculated during the expansion and retention periods using tetracycline fluorescence labeling. RESULTS: There were increases in the value of all cone-beam computed tomography parameters in the SE and ME groups during the expansion period, and the increase was significantly greater than that of the control group (P <0.01). However, there was no significant difference in the values of any parameters during the retention period. The width of the midline sutures, mineralization and deposition rate of bone, and integral optical density in the 2 experimental groups were significantly higher than those of the control group (P <0.01), and there was no significant difference between the SE and ME groups. After the retention period, the values of all tetracycline fluorescence evaluation parameters of the experimental groups decreased significantly. CONCLUSIONS: The novel MPEA with a reactivation system was able to expand the midpalatal suture effectively. Dental and skeletal expansion effects are similar to those of the screw expansion appliance. Wearing the appliance as a retainer can effectively maintain the expansion effect. The new bone formation rate was accelerated during the expansion process and decreased to normal levels during the retention period.

LncRNA SNHG17 promotes the progression of oral squamous cell carcinoma by modulating miR-375/PAX6 axis.

BACKGROUND: The prognosis of patients with recurrent and/or metastatic oral squamous cell carcinoma (OSCC) remains poor, and its incidence is especially high in developing countries. Multiple long non-coding RNAs (lncRNAs) are recently identified as crucial oncogenic factors or tumor suppressors. This study aimed to probe into the role of lncRNA small nucleolar RNA host gene 17 (SNHG17) on the progression of OSCC. METHODS: The expression level of SNHG17 in OSCC samples was tested using quantitative real-time polymerase chain reaction (qRT-PCR). Human OSCC cell lines CAL-27 and Tca8113 were used in in vitro studies. Cell counting kit-8 (CCK-8) and BrdU assays were used to assess the effect of SNHG17 on OSCC cell proliferation. Flow cytometry was used to study the effect of SNHG17 on OSCC cell apoptosis. Transwell assay was conducted to detect the effect of SNHG17 on migration and invasion. Moreover, luciferase reporter assay was employed to confirm targeting relationship between miR-375 and SNHG17. Additionally, Western blot was used to observe the regulatory function of SNHG17 on PAX6. RESULTS: SNHG17 expression in OSCC clinical samples was significantly increased and was correlated with unfavorable pathological indexes. Its overexpression remarkably accelerated proliferation and metastasis of OSCC cells, while reduced apoptosis. Accordingly, knockdown of SNHG17 suppressed the malignant phenotypes of OSCC cells. Overexpression of SNHG17 significantly reduced the expression of miR-375 by sponging it, but enhanced the expression of PAX6. CONCLUSION: SNHG17 is a sponge of tumor suppressor miR-375 in OSCC, enhances the expression of PAX6 indirectly, and functions as an oncogenic lncRNA.