Biological evaluation of alveolar bone remodeling in methylprednisolone treated-rats during orthodontic tooth movement

Abstract EN

Background : Bone remodeling and metabolism associated with orthodontic tooth movement are regulated by a large number of local and systemic factors.

The widespread useof therapeutic corticosteroids (GCs) today raise concerns with regard to their effects on mineralized tissue metabolism.

This study aimed to investigate the effect of Methylprednisolone treatment on alveolar bone remodeling during orthodontic tooth movement. Materials and Methods : A twenty-six 12-weeks old male Wistar albino rats were divided into 2 groups; control group (n = 13) without any drug administration during the study and steroidal group (n = 13) which received 5 mg / kg / day of methylprednisolone for 3 weeks.

A split- mouth design was used performing orthodontic tooth movement on the upper right 1st molar by applying 20 g of mesial force using superelastic closed-coil spring attached to the incisors for 21 days while the upper left side served as the non-appliance side.

Orthodontic tooth movement was evaluated on weekly basis using digital caliber.

The rats were sacrificed after 3 weeks and alveolar bone remodeling process was evaluated by counting the number of osteoblast and osteoclast cells at the compression and tension sites at the coronal and apical levels of the mesiobuccal root of upper 1st molar in both appliance and non-appliance sides using digital microscope at 400× magnification.

At day of sacrifice serum measurements for alkaline phosphatase (ALP) and acid phosphatase (ACP) activity were carried out. Results : Showed that in the steroid group there was significantly greater amount of orthodontic tooth movement, greater reduction of bone formation and an increase in bone resorption with the presence of orthodontic appliance, increase in serum ACP activity and reduction of serum ALP activity as compared with the control group,(P ≤ 0.05). Conclusion : The Methylprednisolone therapy in low-medium doses elicits a noticeable change in the bone turnover rate during orthodontic tooth movement.