A histologic and autoradiographic study on the early changes in the movements of rat incisors.
- Author:
Ki Whan YOO
1
;
Sang Cheol KIM
;
Yoon A KOOK
Author Information
1. Department of Orthodontics, College of Dentistry, Wonkwang University, Korea.
- Publication Type:Original Article
- Keywords:
Tensile force;
[3H]-thymidine;
laser irradiation;
New Bone formation
- MeSH:
Animals;
Bone Resorption;
Capillaries;
Dilatation;
Hyalin;
Incisor*;
Osteogenesis;
Periodontal Ligament;
Rats*
- From:Korean Journal of Orthodontics
1993;23(2):199-216
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
The purpose of this study was to quantify the biologic effects of the tensile forces from helical springs across the maxillary incisors on the periodontal tissues of rats. 39 Sprague-Dawlely rats were divided into a control group(3 rats) and three experimental groups(36 rats)-group 1, pressured with a light force(50-75g), group 2, with a heavy force(250-300g) and group 3, with a heavy force(250-300g) plus laser irradiation. Autoradiographic and histopathologic observations were performed in 12, 24, 48 and 96 hours after force application. The result were as follow: 1. Hyalinized zone of periodontal ligament began to appear at pressure side in 12 hours in group 2 and group 3 ; all decreased in 96 hours except in group 2. 2. Alveolar bone resorption began to appear in 12 hours in group 2 and group 3 ; Group 2 showed more resorption than group 1 and no difference to group 3. 3. Tearing of periodontal ligament and vascular dilatation began to appear at tension side in 12 hours in all groups ; Group 2 showed more changes than group 1 and no difference to group 3 ; Decrease began to appear in 96 hours. 4. New bone formation began to appear at tension side in 12 hours and increased more and more; No differences were shown of groups 5. New capillary proliferation began to appear at pressure side in 12 hours; The changes were the greatest in group 3, group 2, group 1, in that order. 6. Positive reaction of cells to [3H]-thymidine was the greatest in 24 hours of all groups and decreased with times ; Group 2 showed more reaction than group 1 and no difference to group 3.
