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Estrous-cycle-dependent Variation in Orthodontic Tooth Movement

2002; SAGE Publishing; Volume: 81; Issue: 6 Linguagem: Inglês

10.1177/154405910208100610

1544-0591

Naoto Haruyama, Kaoru Igarashi, Shu Saeki, M. Otsuka-Isoya, Hisashi Shinoda, H. Mitani,

Estrogen and related hormone effects

Sex hormones, including estradiol, play important physiological roles in bone metabolism. The purpose of this study was to investigate whether there is estrous-cycle-dependent variation in orthodontic tooth movement, and, if so, to determine the mechanism. Ten-week-old female Wistar rats were used. They received repeated orthodontic force during specific phases in the estrous cycle. Tooth movement in animals that received force principally in estrus was about 33% greater than that in animals that received such force principally in pro-estrus (p < 0.05). Serum estradiol levels also varied according to the estrous cycle, with a peak during pro-estrus and a nadir during estrus, and were inversely related to tooth movement. Furthermore, there were negative correlations between estradiol and both serum TRAP activity and pyridinoline (r = -0.42, p < 0.05; r = -0.59, p < 0.001). These results suggest that cyclic changes in the estradiol level may be associated with the estrous-cycle-dependent variation in tooth movement through its effects on bone resorption.