Protective Role of Magnesium Oxide Against Orthodontically Induced Apical Root Resorption: An Experimental Rabbit Study

Background: Root resorption origin by orthodontic treatment (OIRR) is a frequent side effect. Thus, preservation of cementum and remodeling of the ligament (PDL) are critical in preventing such resorption. Magnesium (Mg2+) a mineral that have a dramatic role in mineralization, cell growth and regulating inflammation, however its function, in OIRR is not investigated. This study aimed to investigate the impacts of magnesium oxide (MgO) supplementation on apical root resorption, cementum and PDL. Materials and Methods: Twenty adult male albino rabbits were randomly allocated into four groups (n = 5): negative control (no applied orthodontic force) positive control (orthodontic force applied only) low-dose MgO group (40 Mg2+/kg/day) and high-dose MgO group (80 Mg2+/kg/day). Orthodontic tooth displacement was initiated on the incisors through modified fixed orthodontic devices exerting a 40 g force over a period of three weeks. MgO was given orally once each day. Histomorphometric evaluation measured of cementoblasts, cementoclasts, fibroblasts and fibrocytes, the thickness of the cementum and PDL. Statistical analysis employed ANOVA followed by Tukey post hoc tests (p ≤ 0.05). Results: The positive control group exhibited cementum reduction, elevated cementoclast quantities diminished cementoblast levels and thinner PDL relative, to the negative control (p < 0.05). Both MgO-treated groups presented thicker cementum and PDL and fewer cementoclasts compared to the positive control with the high-dose group displaying the strongest protective impact. The number of fibroblasts significantly increased in the MgO groups. Conclusion: MgO supplementation diminished OIRR with preserving cementum and PDL structure, suggested a potential protective role for magnesium during orthodontic treatment.