KOREASCHOLAR

Anchorage plays an important role in orthodontic treatment. Recently, some clinicians have tried to use skeletal anchorage system(titanium miniscrews and microscrews) in treatment due to their many advantages such as ease of insertion and removal, low cost, immediate loading, and the ability to place miniscrews in any area of alveolar bone. The purpose of this study was to investigate the histopathologic change of alveolar bone density around miniscrew under variable ortho -donticforceinyoung-adultdogs, throughthepolarizingmicroscopic findings. For this study, three young adult mongrel dogs(6-months in age) were used, 12 titanium miniscrews were inserted into the palatal bone(4 miniscrews placed in each dog), and then miniscrews were loadedwithorthodonticforce [50gm(F1),100gm(F2),250gm(F3), 500gm(F4)] immediately after implantation. After 1, 3 and 6 weeks, the animals were sacrificed. Then the miniscrews and surrounding bone of dogs were removed, respectively. The grinding samples along the long axis of miniscrew were made. The changes of bone density and thrombosis were examined under the polarizing microscope. Bone density was determined as color changes. The results of this study were as follows.
1. There was no thrombosis in the F1 group. But thrombosis was seen in 1 week of T side, 1, 3, 6 weeks of P side in
the F2 group, 1, 3 weeks of T side, 1, 3, 6 weeks of P side in the F3 group and 1, 3, 6 weeks of both P and T side
in the F4 group.
2. The changes of bone density decreased in P side more than T side in 1 week, while more decreased P side in 3
weeks than 1 week. In 6 weeks, bone density more increased in T side than P side along the middle & apex.
3. As orthodontic force increased, there was severe thrombosis, especially in cervical of P side. As it went up to 3, 6
weeks, thrombosis was decreased but remained.
4. As orthodontic force increased, bone density more severely decreased due to bone destruction in 1 and 3 weeks,
but more slowly increased due to bone formation in 6 weeks.
Based on the results of this study, in the practice, because of optimal orthodontic force for the most of tooth movement was less than 150gm, I thought that miniscrews could play role of use of skeletal anchorage immediately after implantation. In the more than 250gm & 500gm of orthodontic force, I thought that miniscrews would be delayed as use of skeletal anchorage after loss of bone was restored.

I. 서 론
 II. 실험 재료 및 방법
  1. 실험 재료
  2. 실험 방법
  3. 표본 제작
  4. 관찰 및 평가 방법
 III. 실험 결과
  1. 육안적 관찰
  2. 조직학적 소견
 IV. 총괄 및 고안
 참고 문헌

• 김상원(단국대학교 치과대학 교정학교실) | SangWon Kim
• 이진우(단국대학교 치과대학 교정학교실) | JinWoo Lee 통신저자
• 이종헌(구강병리학교실) | Chong Heon Lee