title: Effects of ultrasound modes on mandibular osteodistraction.
abstract: Previous studies have shown that therapeutic pulsed ultrasound (pulsed) has superior stimulatory effect on bone fracture healing compared with continuous ultrasound (continuous). Our predictive hypothesis was that pulsed ultrasound can produce better bone formation during mandibular osteodistraction than continuous ultrasound. Thirty-six New Zealand rabbits were divided into 3 groups of 12. Osteodistraction was performed at 3 mm/day for 5 days. Group 1 received pulsed, group 2 received continuous ultrasound, and group 3 was the control group (distraction only). Bone formation was assessed by quantitative bone density (QBD), mechanical testing, and histological examination. In the first 2 wks post-distraction, group 2 showed enhanced bone formation more than group 1 (p < 0.05); however, in the 3rd and 4th wks, group 1 showed more bone formation than group 2 (p < 0.05). Earlier stages of bone healing were enhanced more by continuous, whereas late stages were enhanced more by pulsed, ultrasound.
authors.affiliation: Orthodontics and Biomedical Engineering, Faculty of Medicine and Dentistry, University of Alberta, Dentistry/ Pharmacy Centre, Edmonton, AB, Canada. telbialy@ualberta.ca
authors.forename: T H
authors.initials: TH
authors.lastname: El-Bialy
authors.forename: R F
authors.initials: RF
authors.lastname: Elgazzar
authors.forename: E E
authors.initials: EE
authors.lastname: Megahed
authors.forename: T J
authors.initials: TJ
authors.lastname: Royston
mesh_terms: D000818:Animals; D001861:Bone Regeneration / Q000502:physiology*; D008297:Male; D008334:Mandible / Q000601:surgery*; D019857:Osteogenesis, Distraction; D011817:Rabbits; D013997:Time Factors; D014464:Ultrasonic Therapy / Q000379:methods*