Histological changes of periodontal tissue by anti-tumor agents, and study on effective management of dental caries

近年来，在儿童癌症患者中经常观察到抗肿瘤治疗的晚期效应。环磷酰胺（cyphosphamide， CY）是儿童癌症治疗中常用的细胞抑制剂之一。本研究旨在探讨CY对小鼠牙齿发育的影响。用CY （100 mg/kg, ig）治疗12日龄ICR小鼠。侧位软x线片。计算第一磨牙的根冠长度（R/C）比。从第一磨牙上制备一系列矢状面切片，进行组织形态学和免疫组织化学（细胞角蛋白）研究。27 d时，实验组的根长约为对照组的60%。实验组Hertwig上皮根鞘自20 d起消失。我们的研究结果表明，CY可以诱导HERS的缺陷并改变其功能，而上皮鞘的破坏会抑制其增殖和根的形成。

Recently,late effects of antineoplastic treatment are frequently observed in childhood cancer patients. Cyclophosphamide (CY) is one of the cytostatic drugs commonly used for cancer treatment in children. This study aimed to evaluate the effect of CY on dental development in mice. We treated 12-day-old ICR mice with CY (100 mg/kg, i.p.). Soft X-ray radiographs were obtained in lateral projection. The root / crown length (R/C) ratio of the first molar was calculated. Serial sagittal sections were prepared from the first molars and histomorphological and immunohistochemical (cytokeratin) studies were performed. At 27 days, the root length in the experimental group was approximately 60% of that in the control group. The Hertwig's epithelial root sheath in the experimental group disappeared from 20 days onwards. Our results indicate that CY can induce a defect in and alter the function of HERS and disruption of the epithelial sheath inhibits proliferation and root formation.