A NOVEL NON-INVASIVE MODULATION OF ORTHODONTIC RELAPSE: INSIGHTS FROM A RABBIT MODEL.

Abstract

AIM: Low-intensity pulsed ultrasound (LIPUS), such as Exogen device, stimulates osteogenesis and angiogenesis without harmful thermal effects, enhancing bone strength and shortening recovery time. This experimental study evaluated the application of Exogen low-intensity pulsed ultrasound (LIPUS) device in promoting alveolar bone healing and reducing post-orthodontic relapse in rabbits model after induction of teeth movement by semi orthodontic appliance. MATERIALS AND METHODS: 12 adult rabbits underwent orthodontic tooth movement for lower anterior teeth, followed by appliance removal. Animals were randomly assigned to two groups: a control group with no LIPUS treatment, and an Exogen group that received daily low-intensity pulsed ultrasound (LIPUS) therapy for 20 days. Clinical measurements of relapse distance were recorded at days 0, 10, and 20 in mm. Histological and histomorphometric analyses were performed to assess osteoblast and osteoclast counts, vascular density, and periodontal ligament (PDL) width in both cervical and apical regions. RESULTS: showed that the Exogen group exhibited a significantly smaller relapse distance from day 10 onwards (p≤0.01) and approximately 35% less relapse at day 20 compared with controls. Histomorphometric data revealed higher osteoblast counts, lower osteoclast counts, increased vasculature, and narrower PDL width in the Exogen group, indicating enhanced bone formation, reduced bone resorption, and improved periodontal stability. Histological examination confirmed greater organization of lamellar bone, denser osteoblastic lining, and more pronounced vascularization in treated animals. CONCLUSION: These findings suggest that the Exogen LIPUS device may serve as an effective adjunct tool in orthodontics to accelerate alveolar bone healing and to achieve greater stability of teeth following orthodontic interventions.