Objective This study was conducted to measure the mandibular incisive canal (MIC) by cone beam computed tomography(CBCT)and to assess 3?dimensional structure, course and adjacent structure of the MIC , in order to ensure safe region for surgery of the mandibular interforaminal area. Methods A total of the CBCT images from 83 patients were studied and measured. The detection rates of MIC were calculated The diameter of the MIC and the distances from MIC to the labial and lingual cortices and the inferior border of the mandible and tooth tips were measured at canines and lateral incisors. Results MIC was found in 67.8%of the patients. In the position of canine, the diameter of MIC, the mean distance of the MIC to the tips of the teeth, to the buccal border of the mandible , to the lingual border of the mandible and the inferior border of the mandible were (1.3±0.4), (8.9±2.9), (4.3±0.9), (5.2±1.1) and (8.6± 1.5) mm, respectively. In the position of the incisor, the distance of MIC, the mean distance of the MIC to the tips of the teeth, to the buccal border of the mandible , to the lingual border of the mandible and the inferior border of the mandible were (1.0 ± 0.3), (13.3 ± 4.0), (4.2 ± 0.9), (5.9 ± 0.9) and (8.9 ± 1.8) mm, respectively. Conclusion CBCT clearly show three dimensional structure, course and adjacent structure of the MIC. Preoperative CBCT can provide vital information for surgery of the mandibular interforaminal area.

调节性T（regulatory T，Treg）细胞是一类控制体内免疫反应性的T细胞亚群，在维持机体的免疫系统稳态和调节免疫 应答方面具有重要作用，并且发现在多种肿瘤类型中以较高比例存在，被认为是产生抗肿瘤免疫应答的主要障碍。Treg细胞在 其功能状态和稳定性方面存在异质性，通过多种机制发挥免疫负调控作用，目前在自身免疫和肿瘤免疫的研究中发现，特异性调 节不同Treg细胞群体可改善免疫疗效。但是，如何更加合理有效的以Treg细胞为靶点抑制肿瘤的进展仍需进一步探索。本文就 Treg细胞在肿瘤免疫中的作用机制及治疗应用新策略展开综述。