title: The effect of pulsed ultrasound on mandibular distraction.
abstract: This study evaluated the effect of pulsed ultrasound on tissue repair and bone growth during mandibular osteodistraction. Twenty-one rabbits were divided into three groups of 7. The distraction started 72 h after surgically severing both sides of the mandible and proceeded at a rate of 1.5 mm/12 h for 5 days. Group I received pulsed ultrasound (nominally 200 micros pulse of 1.5 MHz at a 1.1 kHz pulse repetition frequency, 30 mW/cm2) for 20 min on both sides of the mandible every other day (alternating sides). Group 2 received the same pulsed ultrasound treatment on one side of the mandible every day for 20 min. Group 3 did not receive any ultrasound treatment. Bone formation at the distraction site was assessed by photodensitometry on head radiographs, a vibratory coherence test across the distraction site, a postmortem three-point bending mechanical stiffness test, and a postmortem histological examination. Statistical analyses performed using analysis of variance revealed that pulsed ultrasound enhanced bone formation at the distraction site with a high level of significance when assessed by the increase in new bone photodensity (p = 0.001), vibratory coherence (p = 0.001), mechanical stiffness (p = 0.003), and qualitative histological studies, especially when the pulsed ultrasound treatment was directly applied daily.
authors.affiliation: Tanta University, Egypt and Department of Bioengineering, University of Illinois at Chicago, 851 South Morgan Street, M/C 063, Room 212, Chicago, IL, USA.
authors.forename: Tarek H
authors.initials: TH
authors.lastname: El-Bialy
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Royston
authors.forename: Richard L
authors.initials: RL
authors.lastname: Magin
authors.forename: Carla A
authors.initials: CA
authors.lastname: Evans
authors.forename: Abd El-moneim
authors.initials: Ael-M
authors.lastname: Zaki
authors.forename: Leon A
authors.initials: LA
authors.lastname: Frizzell
mesh_terms: D000818:Animals; D015519:Bone Density; D003131:Combined Modality Therapy / Q000379:methods; D004548:Elasticity; D008297:Male; D008334:Mandible / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology / Q000601:surgery; D008337:Mandibular Fractures / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology* / Q000628:therapy*; D019857:Osteogenesis, Distraction / Q000379:methods*; D011817:Rabbits; D011859:Radiography; D013314:Stress, Mechanical; D016896:Treatment Outcome; D014464:Ultrasonic Therapy / Q000379:methods*