A STUDY ON THE ORTHODONTIC TOOTH MOVEMENT UNDER HALF SINE-WAVE PULSED ELECTROMAGNETIC FIELDS

Half sine-wave pulsed electromagnetic fields 내에서 교정력에 의한 치아 이동에 대한 연구

  • Kim, Young-Joon (Department of Dental Science, College of Dentistry, Yonsei University) ;
  • Ryu, Young-Kyu (Department of Dental Science, College of Dentistry, Yonsei University)
  • 김영준 (연세대학교 치과대학 치과교정학교실) ;
  • 유영규 (연세대학교 치과대학 치과교정학교실)
  • Published : 1994.12.01

Abstract

The biologic potential, which is different from the piezoelectric signals, relates tooth movement at least in part to changes in bone metaboliosm in bioelectric theory. The purpose of this experiment was to determine wheather the application of half sine-wave pulsed electromagnetic fields (HSPEMF) could increase both the rate and amount of orthodontic tooth movement. Forty-three male Hartley guinea pigs, weighting approximately 255g, were utilized in this study. The animals were 35 days old at the start of the study. Laterally directed orthodontic force was applied to the maxillary central incisors of 40 Hartley guinea pigs (20 experimental, 20 control). According to the amount of orthodontic force (6g, 12g), they were divided into two sub-groups (10 experimental I, 10 experimental II, 10 control I, 10 control II). During the experimental period, experimental animals were placed in plastic animal holders with their heads positioned in an area of uniform electromagnetic field. Control animals were placed in similar plastic holders that did not carry the electric apparatus. The results were as follows : 1. The application of a HSPEMF to the experimental groups significantly increase the final amount of orthodontic tooth movement observed over a 10-day experimental period. 2. The application of a HSPEMF to the experimental groups significantly increase the velocity of orthodontic tooth movement observed over a 10-day experimental period. 3. There was no significant difference in the final amount of orthodontic tooth movement at the fourth day to the eighth day, but there was significant difference in the final amount of orthodontic tooth movement at the nineth, tenth day during a 10-day experimental period. 4. After 10 days of HSPEMF exposure & orthodontic force, the experimental groups demonstrated more osteodasts in the pressure side than control groups.