A comparative assessment of orthodontically induced root resorption and alveolar bone changes in adolescent orthodontic patients undergoing Micro-Osteoperforations assisted canine retraction: A Split-Mouth randomized controlled trial.

Abstract

Introduction: Micro-osteoperforation (MOP) is a minimally invasive technique aimed at accelerating orthodontic tooth movement (OTM) by stimulating localised bone remodelling. However, its impact on root resorption, alveolar bone levels, and inflammatory mediators such as interleukin-4 (IL-4) requires further investigation. This study assessed root resorption, alveolar bone changes, canine angulation, rate of retraction, and IL-4 expression associated with MOP-assisted canine retraction.

Methods: A randomised split-mouth controlled clinical trial was conducted on 20 patients (mean age: 19.70 ± 2.38 years). Patients were randomised according to the SNOSE criteria, with one side receiving MOPs distal to the canine; the contralateral side served as control for both maxillary and mandibular dentition. Retraction was performed using 9 mm NiTi closed coil springs with 150 g force for 7.6 ± 1.2 months. Pre- and post-retraction CBCT scans evaluated linear root resorption and alveolar bone changes. Digital models assessed canine movement and angulation. Gingival crevicular fluid was collected at four intervals and analyzed for IL-4 using ELISA.

Results: Maxillary and mandibular canines showed relatively greater root resorption (1.03 mm and 0.57 mm, respectively) and crestal bone loss (0.893 mm and 0.56 mm, respectively) on the MOP side (p < 0.05). The rate of canine retraction was higher with MOP (maxilla: 1.28 ± 0.17 mm/month; mandible: 1.36 ± 0.16 mm/month) compared to control (p < 0.001) with increased canine tipping noted on MOP side. IL-4 levels showed a transient decline post-MOP, recovering by day 28.

Conclusions: MOP effectively accelerates OTM but increases the risk of root and alveolar bone resorption. The associated reduction in IL-4 may contribute to enhanced osteoclastic activity. Clinical application should be case-dependent, with caution in patients at risk of periodontal or root compromise.