Orthodontic tooth movement at different stages of adolescent female menstrual cycle

Wang Bin; Yang Xi; Zhou Jian-ping; Feng Gang; Dai Hong-wei; Huang Lan

doi:10.3969/j.issn.2095-4344.2014.15.007

Abstract：BACKGROUND:Estrogen has an effect on orthodontic tooth movement. Currently, only animal experiments show that the lower estrogen levels, the greater the amount of orthodontic tooth movement;the higher estrogen levels are, the smal er the amount of orthodontic tooth movement is. <br> OBJECTIVE:To investigate effects of orthodontic force applied on orthodontic tooth movement at different stages of menstrual cycle among young female patients. <br> METHODS:Twelve young female patients were included in this study, aged 14-18 years old. They already have regular menstrual cycle, and need to extract the first premolar in the maxil a. By using self-control method, these female patients with their maxil ary canine at both sides were randomly divided into two groups:orthodontic force at ovulatory period and orthodontic force at menstrual period. Micro-implant anchorage was implanted to the distal y moving canine. Orthodontic force was given to the group of ovulatory period 2 weeks after the force was given at menstrual period. Dentition models were taken at day 0 and 28 after force, to prepare a superhard plaster model using silastic impression materials. Between these two groups, the distances of the canine distal movement were measured and statistical analysis was performed with GraphPad Prism5 software. <br> RESULTS AND CONCLUSIONS:The distances of the canine distal movement in the group of orthodontic force at menstrual period were greater than that in the other group (P<0.05). The orthodontic teeth with the application of orthodontic force at menstrual period move faster than that with the application of orthodontic force at ovulatory period, thus effectively shortening orthodontic treatment.