Kyomen S, Tanne K
Department of Orthodontics, Hiroshima University School of Dentistry, Japan.
Angle Orthod. 1997;67(1):67-72. doi: 10.1043/0003-3219(1997)067<0067:IOACIP>2.3.CO;2.
This study was designed to investigate the influences of aging changes in the proliferative activity of PDL cells during experimental tooth movement in rats. Young (6-week-old) and adult (14-week-old) Wistar strain rats were used as experimental animals. Light (10 g) or heavy forces (40 g) were applied to the maxillary first molars for periods of 1, 3, 7, or 14 days. Proliferative activity of the PDL cells was evaluated immunohistochemically in terms of the ratio of the number of labeled cells to the total number of PDL cells (labeling index) or the number of labeled cells. In the controls, cellular activity was significantly greater in the young than in the adult group (P < 0.05). Significant differences in the proliferative activity between young and adult groups were found in the tension and pressure areas during early stage of tooth movement (P < 0.05), which indicated a delay of biologic responses to orthodontic stimuli in adult rats. It is shown that aging changes substantially influence proliferative activity of the PDL cells and subsequent tooth movement during the initial phase in particular.
本研究旨在调查大鼠实验性牙齿移动过程中，牙周膜（PDL）细胞增殖活性的衰老变化所产生的影响。选用年轻（6周龄）和成年（14周龄）的Wistar品系大鼠作为实验动物。对上颌第一磨牙施加轻力（10 g）或重力（40 g），持续1、3、7或14天。通过免疫组织化学方法，根据标记细胞数与PDL细胞总数的比例（标记指数）或标记细胞数，评估PDL细胞的增殖活性。在对照组中，年轻组的细胞活性显著高于成年组（P < 0.05）。在牙齿移动早期，年轻组和成年组在张力区和压力区的增殖活性存在显著差异（P < 0.05），这表明成年大鼠对正畸刺激的生物学反应延迟。结果显示，衰老变化尤其在初始阶段对PDL细胞的增殖活性及随后的牙齿移动有显著影响。
