A comparative assessment of orthodontically induced root resorption and alveolar bone changes in adolescent...

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.

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.

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.

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.