Effects of Timing of Extracorporeal Shock Wave Therapy on Mandibular Distraction Osteogenesis: An Experimental Study in a Rat Model

Abstract

Distraction osteogenesis (DO) is an established method for bone lengthening in the craniofacial skeleton. Its major drawback is the long consolidation period with attendant morbidity and possible complications. Several methods have been suggested to shorten the consolidation period. We evaluated the timing and effects of extracorporeal shock wave therapy (ESWT) on bone mineralization and extracellular bone matrix proteins during mandibular DO. Twenty-seven rats underwent mandibular DO (latency period, 3days; distraction period, 10days; 0.5mm/day) and were divided into 3 groups according to the timing of ESWT application: group I (control) received no treatment, whereas groups II and III received ESWT (0.18mJ/mm2) before and after the active distraction period, respectively. The distracted mandibles were harvested after 4weeks of consolidation and analyzed radiographically, histologically, and immunohistochemically. Group III showed significantly increased mineral density, enhanced bone formation, a higher collagen orientation index, and greater expression of type I collagen and osteocalcin proteins. Application of ESWT after active distraction enhances bone maturation and mineralization.