Influence of a Proposed Micro-Osteoperforation Approach on the Root Resorption During Orthodontic Tooth Movement: An Immuno-Histochemical Study in a Rabbit Model

The purpose of the current study was to investigate the impact of a new proposed micro-osteoperforation (MOP) with 2 other MOP approaches on orthodontically-induced root resorption (OIRR) that accompanies orthodontic tooth movement (OTM) in rabbits. Our study included forty-five (of age 24 weeks) albino adult male rabbits which were divided into 3 groups equally regarding the tested 3 MOP approaches; the first new approach (OTM+MOP/2H&1V), the second approach (OTM+MOP/1V), and the third approach (OTM+MOP/3H), which were performed for the first group by 2 horizontal (2H) MOP plus 1 vertical (1V) MOP plus OTM, for the second group by 1 vertical (1V) MOP plus OTM, and for the third group by 3 horizontal (3H) MOP plus OTM, respectively. All approaches were performed in front of the first premolar of mandibular right side of rabbit (RMP1), while the positive (+ve) control (C) group was the same tooth, but on left (LMP1) receiving OTM only (OTM/+veC). Each premolar was protracted by a closed coil spring delivering a (50g) force. After 1, 2, and 3 weeks of OTM, certain interleukines (ILs) biomarkers, named the IL-1 alpha (IL-1α) and IL-10 were detected the OIRR through the immunohistochemistry (IHC) of the compression mesial side of both premolars root regions (cervical, middle and apical thirds). The results revealed a significant increase in the expression of IL-1α and IL-10 which were confirmed in the compression side of the MOP groups (P<0.001 to = 0.041). Also, the results indicated that the middle and cervical third regions were significantly higher (P < 0.05) than the apical third in all groups. Besides, the results depicted that the new approach, the (OTM+MOP/2H&1V) group showed a moderate ILs expression between the higher, the (OTM+MOP/1V) group and the lower, the (OTM+MOP/3H) group. The study concluded that all MOP approaches could induce OIRR at the compression side of PDL during OTM, but with a different range. The current study concludes that the new approach, the (OTM+MOP/2H&1V) group might be the preferred approach for stimulating faster OTM because it causes a moderate OIRR after the less inducing group, the (OTM+MOP/3H) when examined in rabbits.