Several members of the transforming growth factor (TGF)-β superfamily are expressed in developing teeth from the initiation stage through adulthood. Of those, TGF-β1 regulates odontoblast differentiation and dentin extracellular matrix synthesis. However, the molecular mechanism of TGF-β3 in dental pulp cells is not clearly understood. In the present study, beads soaked with human recombinant TGF-β3 induced ectopic mineralization in dental pulp from fetal mouse tooth germ samples, which increased in a dose-dependent manner. Further, TGF-β3 promoted mRNA expression, and increased protein levels of osteocalcin (OCN) and type I collagen (COL I) in dental pulp cells. We also observed that the expression of dentin sialophosphoprotein and dentin matrix protein 1 was induced by TGF-β3 in primary cultured dental pulp cells, however, not in calvaria osteoblasts, whereas OCN, osteopontin and osteonectin expression was increased after treatment with TGF-β3 in both dental pulp cells and calvaria osteoblasts. Dentin sialoprotein was also partially detected in the vicinity of TGF-β3 soaked beads in vivo. These results indicate for the first time that TGF-β3 induces ectopic mineralization through upregulation of OCN and COL I expression in dental pulp cells, and may regulate the differentiation of dental pulp stem cells to odontoblasts.
The effect of preoperative external radiotherapy (XRT) on head and neck free‐flap reconstruction is still controversial. In this study, we aimed to determine the impact of preoperative XRT on the outcomes of head and neck microvascular free‐flap reconstruction. A systematic review and meta‐analysis was conducted in concordance with the Systematic reviews and Meta‐Analyses protocol. We searched several databases (PubMed, EMBASE, Web of Science, and Cochrane Library) to find published papers on the topic. The R program was used for data synthesis and statistical heterogeneity evaluation; then, fixed effect or random effect models were used. A total of 37 studies, involving 12 408 patients with 12 668 flaps, were included in this meta‐analysis. The overall flap success rate for all studies was 94.4%. Pooled analysis showed that patients with preoperative XRT were significantly associated with an increased risk of total flap failure (odds ratio [OR] = 1.80, 95% confidence interval [CI] = 1.45‐2.23, P < .001), partial flap failure (OR = 1.90, 95% CI = 1.07‐3.38, P = .029), and postoperative complication rates (OR = 2.22, 95% CI = 1.64‐2.72, P < .001). Our study suggests that preoperative XRT is associated with an increased risk of developing free‐flap failure and an increased postoperative complication rate.
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