VEGF expression during orthodontic tooth movement under hypomineralization conditions: A preliminary study

Abstract

Objective: To study the expression of vascular endothelial growth factor (VEGF) during tooth movement in a model of hypomineralization.

Methods: 8 female Wistar rats (80±10g) were used, divided into two groups: Control and HIP. The HIP group received disodium etidronate (20mg/kg, i.p., 5 times/week) for 4 weeks, while the control group received physiological solution. At week 3 of the trial, an experimental orthodontic device was placed on the lower left first molar, exerting 25gF mesially. After 6 days, the animals were anesthetized, euthanized, and the jaws were removed. Digital radiographs were taken and the initial and final distances between the first and second molars were determined. Samples were processed for histological (H&E, picro sirius red) and immunohistochemical analysis with anti-VEGF antibody. The VEGF+ area (%) in the pulp of mesial and distal roots was quantified by digital imaging (ImageJ). Data were analyzed with Student's t-test (p<0.05).

Results: The HIP group showed significantly less tooth displacement (p<0.05) at all levels evaluated with respect to the control. In addition, it showed a tendency to increase the VEGF+ area in the root pulp, more marked in the mesial root (C: 2.9±1.2%; HIP: 7.89±2.39%) than in the distal root (C: 0.67±0.55%; HIP: 3.65±1.99%) (p>0.05).

Conclusion: The hypomineralization condition induces an increase in VEGF expression during orthodontic tooth movement.