Prefabricated Zirconia Crowns and Preformed Metal Crowns in the Treatment of Severely Childhood Caries and Anterior Crossbite in a Child with Autistic Spectrum Disorder.

Crowns have been recommended to treat decayed teeth and rebuild teeth function. The dental management of children with autism is a tremendous challenge for pediatric dentists due to the impaired behaviors and communication disorders. In this context, a 5-year-old boy with autism was treated to solve carious lesions under the assistance of general anesthesia. The posterior occlusal function was restored, and the crossbite existing in the primary anterior teeth was approached merely by NuSmile® zirconia crowns (ZCs) rather than orthodontic intervention. We conducted an 18-month period. Throughout the long-term follow-up, the boy's masticatory efficiency was remarkably improved and the anterior teeth had transferred into the correct position with adequate overbite to maintain the new relationship, thus ameliorating the appearance of tissue on the labial surface and enhancing his quality of life and oral health.

The effect of phenytoin on the proliferative ability of periodontal and gingival ligament fibroblasts in cell culture medium.

Periodontal ligament fibroblasts (PDLFs) play a vital role in the period of periodontal regeneration. In addition, studies show that diphenylhydantoin (phenytoin) increases the growth of gingival fibroblasts. If this effect is also present in the periodontal ligament (PDL) fibroblasts, it may be used to regenerate periodontal tissues. Accordingly, this study aimed to compare the effect of phenytoin on the growth rate of gingival fibroblast cells and PDL in the cell culture medium. In this regard, 10 Wistar rats were selected. The gingival specimen was obtained from the area between the upper teeth, and the PDL specimen was obtained from the middle third of the lower teeth root. After transferring the samples to a suitable culture medium for culturing PDL and gingival fibroblasts, each sample was divided into two experimental and control groups. In the experimental group, 20 mg/ml phenytoin dissolved in sodium hydroxide was added to Dulbecco's modified Eagle's medium (DMEM). After 48 hours, fibroblast cell proliferation was assessed through a 1-WST cell proliferation kit by ELISA. The proliferation of gingival fibroblast cells and PDL in both test and control groups were statistically analyzed by the independent t-test. The results showed that the effect of phenytoin on the proliferation of gingival fibroblast cells and PDL fibroblast cells is significant. Also, the proliferation of PDL cells was significantly different from gingival cells in the experimental group (P <0.001) and was higher in PDL cells. In general, in this study, it was found that phenytoin in vitro, like in vivo, is able to increase the proliferation of gingival fibroblast cells, and this phenytoin effect is also present in PDL fibroblast cells.

Interacting C/EBPg and YBP regulate DNA methyltransferase 1 expression in Bombyx mori embryos and ovaries.

DNA methylation is an important epigenetic modification. DNA methyltransferases (Dnmts), which catalyze the formation of 5-methylcytosine, play a role in ovarian and embryonic development in some insects. However, the underlying mechanism of Dnmt in mediating ovarian and embryonic development remains unclear. In this study, the regulation and function of Bombyx mori Dnmt1 were investigated. By progressively deleting the sequence upstream of Dnmt1, a region located between -580 and -560 region from the transcription initiation site was found to have the most transcriptional activity. Electrophoretic mobility shift assay and chromatin immunoprecipitation demonstrated that transcription factor Y box binding protein (YBP), a homolog of human Y box binding protein 1 (YBX1), bound to the -580 to -560 region. YBP knockdown and overexpression in a Bombyx cell line indicated that YBP activates Dnmt1 expression. Furthermore, GST-pulldown and co-immunoprecipitation demonstrated that YBP and ovarian CCAAT/enhancer binding protein (C/EBPg) could bind each other. Simultaneous knockdown of C/EBPg and YBP was more effective than single-gene RNAi in inhibiting Dnmt1 expression and reducing the hatching rate. These results demonstrated that the interaction of C/EBPg and YBP activated Dnmt1 expression. Correlated with the expression profiles of the studies genes, our results suggest that high-level expression and interaction of C/EBPg and YBP in ovaries and embryos enhance the expression of Dnmt1, thus ensuring high reproduction rate in B. mori.

Intragenic DNA methylation regulates insect gene expression and reproduction through the MBD/Tip60 complex.

DNA methylation is an important epigenetic modification. However, the regulations and functions of insect intragenic DNA methylation remain unknown. Here, we demonstrate that a regulatory mechanism involving intragenic DNA methylation controls ovarian and embryonic developmental processes in Bombyx mori. In B. mori, DNA methylation is found near the transcription start site (TSS) of ovarian genes. By promoter activity analysis, we observed that 5' UTR methylation enhances gene expression. Moreover, methyl-DNA-binding domain protein 2/3 (MBD2/3) binds to the intragenic methyl-CpG fragment and recruits acetyltransferase Tip60 to promote histone H3K27 acetylation and gene expression. Additionally, genome-wide analyses showed that the peak of H3K27 acetylation appears near the TSS of methyl-modified genes, and DNA methylation is enriched in genes involved in protein synthesis in the B. mori ovary, with MBD2/3 knockdown resulting in decreased fecundity. These data uncover a mechanism of gene body methylation for regulating insect gene expression and reproduction.

DNA methylation suppresses chitin degradation and promotes the wing development by inhibiting Bmara-mediated chitinase expression in the silkworm, Bombyx mori.

BACKGROUND: DNA methylation, as an essential epigenetic modification found in mammals and plants, has been implicated to play an important role in insect reproduction. However, the functional role and the regulatory mechanism of DNA methylation during insect organ or tissue development are far from being clear. RESULTS: Here, we found that DNA methylation inhibitor (5-aza-dC) treatment in newly molted pupae decreased the chitin content of pupal wing discs and adult wings and resulted in wing deformity of Bombyx mori. Transcriptome analysis revealed that the up-regulation of chitinase 10 (BmCHT10) gene might be related to the decrease of chitin content induced by 5-aza-dC treatment. Further, the luciferase activity assays demonstrated that DNA methylation suppressed the promoter activity of BmCHT10 by down-regulating the transcription factor, homeobox protein araucan (Bmara). Electrophoretic mobility shift assay, DNA pull-down and chromatin immunoprecipitation demonstrated that Bmara directly bound to the BmCHT10 promoter. Therefore, DNA methylation is involved in keeping the structural integrity of the silkworm wings from unwanted chitin degradation, as a consequence, it promotes the wing development of B. mori. CONCLUSIONS: This study reveals that DNA methylation plays an important role in the wing development of B. mori. Our results support that the indirect transcriptional repression of a chitin degradation-related gene BmCHT10 by DNA methylation is necessary to keep the proper wing development in B. mori.