Bakker V M, Johnston L E
J Dent Res. 1985 Jan;64(1):44-7. doi: 10.1177/00220345850640010801.
Full-time Class II elastic forces were applied to eight rats in order to evaluate their effects on the growth of the snout and the mandible. Eight animals served as controls. Lateral cephalograms were taken at the start of the experiment and again at the end, 23 days later. The pre- and post-treatment tracings were superimposed on the cranial base to measure alterations in snout growth, and on metallic implants to measure differences in mandibular growth. As judged by t tests, Class II elastic forces caused a significant antero-posterior growth inhibition both in the snout and in the mandible.
为了评估二类弹性力对大鼠口鼻部和下颌骨生长的影响，对八只大鼠施加了全日制二类弹性力。八只动物作为对照。在实验开始时和23天后实验结束时分别拍摄侧位头影测量片。将治疗前和治疗后的影像重叠在颅底上以测量口鼻部生长的变化，并重叠在金属植入物上以测量下颌骨生长的差异。通过t检验判断，二类弹性力在口鼻部和下颌骨均引起了显著的前后向生长抑制。
