Effects of 13-cis-retinoic acid on orthodontic tooth movement in rats

Abstract

Orthodontic tooth movement is the result of a cascade of inflammatory responses stimulated by a physical element that is the force generated by orthodontic devices, involving the remodeling of the alveolar bone, changes in the periodontal ligament and sometimes in the root cementum. Vitamin A or Retinol, is a micronutrient belonging to the group of fat-soluble vitamins that play a central role in the modulation of various cellular events such as proliferation, differentiation and apoptosis. Retinoic acid or tretinoin is an oxidized form of Vitamin A that is obtained in the intracellular medium during its metabolism. Isotretinin (13-cis-retinoic acid) is part of the most common retinoids of approximately 1500 synthesized, and its use is high in individuals undergoing orthodontic treatment. In this study, we will use an animal models to observe the effects of 13-cis-retinoic acid on orthodontic tooth movement in rats. Seventy adult male Wistar rats will be divided into 7 groups: Group 1 - 10 animals without any type of treatment (Control); Group 2 - 10 animals submitted to orthodontic tooth movement for 7 days and then sacrificed (MDI7); Group 3 - 10 animals submitted to orthodontic tooth movement for 14 days and then sacrificed (MDI14); Group 4 - 10 animals submitted to 13-cis-retinoic for 14 days and then sacrificed (ISO14). Group 5 - 10 animals that will be submitted to 13-cis-retinoic for 21 days and then sacrificed (ISO21). Group 6 - 10 animals that will be submitted to 13-cis-retinoic for 14 days and orthodontic tooth movement for 7 days and then sacrificed (MDI-ISO14). Group 7 - 10 animals that will be submitted to 13-cis-retinoic for 21 days and orthodontic tooth movement for 14 days and then sacrificed (MDI-ISO21). After euthanasia, the animals' jaws will be surgically extracted and subjected to histological examination and analysis by Micro-CT. Specific statistical tests will be used to analyze whether there will be a difference in bone repair and remodeling of animals submitted to isotretinoin and concomitantly to orthodontic tooth movement. This study will allow us to better understand the relationship of bone repair and remodeling in animals submitted to orthodontic tooth movement that are under treatment with isotretinoin. (AU)