Single versus triple daily activation of the distractor: no significant effects of frequency of distraction on bone regenerate quantity and architecture.
OBJECTIVE
To study the effect of two different frequencies of distraction on the quantity and architecture of bone regenerate using micro-computed tomography, and to determine whether radiographic and ultrasonographic bone-fill scores provide reliable predictive value for the amount of new bone in the distraction area.


METHODS
Twenty-six skeletally mature rabbits underwent three full days of latency, after which midface distraction was started. Low-frequency group (n=12): a distraction rate of 0.9 mm/d achieved by one daily activation for 11 days to create a 10mm distraction gap. High-frequency group (n=12): idem, but three daily activations were used instead of one. Control group (n=2) underwent no distraction. After 21 days of consolidation, bone-fill in the distraction area was assessed by means of ultrasonography and radiography. Micro-computed tomography was used to quantify new bone formation and bone architecture.


RESULTS
Relative bone volume (BV/TV) showed a tendency towards a difference (P=0.09) between the low and high-frequency groups. No significant differences were found for bone architecture. No significant correlation between BV/TV values and bone-fill scores was found.


CONCLUSIONS
An increase in rhythm from one to three activations daily does not create significantly more bone. Bone-fill score values provided no reliable predictive value for the amount of new bone formation.
Djasim
Urville Mardijanto
UM
Department of Oral and Maxillofacial Surgery, Erasmus MC, University Medical Center, Rotterdam, The Netherlands (Chair: Prof. K.G.H. van der Wal, DDS, MD, PhD). Electronic address: u.djasim@erasmusmc.nl.
Wolvius
Eppo Bonne
EB
Department of Oral and Maxillofacial Surgery, Erasmus MC, University Medical Center, Rotterdam, The Netherlands (Chair: Prof. K.G.H. van der Wal, DDS, MD, PhD).
Van Neck
Johan Wilhelm
JW
Department of Plastic and Reconstructive Surgery, Erasmus MC, University Medical Center, Rotterdam, The Netherlands (Chair: Prof. S.E.R. Hovius, MD, PhD).
Van Wamel
Annemieke
A
Department of Biomedical Engineering, Erasmus MC, University Medical Center, Rotterdam, The Netherlands (Chair: Prof. A.F.W. van der Steen, PhD).
Weinans
Harrie
H
Orthopaedic Research Laboratory of the Department of Orthopaedics, Erasmus MC, University Medical Center, Rotterdam, The Netherlands (Chair: Prof. H. Weinans, PhD).
Van Der Wal
Karel George Hendrik
KGH
Department of Oral and Maxillofacial Surgery, Erasmus MC, University Medical Center, Rotterdam, The Netherlands (Chair: Prof. K.G.H. van der Wal, DDS, MD, PhD).
D000818:Animals; D015519:Bone Density / Q000502:physiology; D001861:Bone Regeneration / Q000502:physiology*; D016267:External Fixators; D005260:Female; D007091:Image Processing, Computer-Assisted; D023421:Models, Animal; D009295:Nasal Bone / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D010012:Osteogenesis / Q000502:physiology; D019857:Osteogenesis, Distraction / Q000295:instrumentation / Q000379:methods*; D011237:Predictive Value of Tests; D011817:Rabbits; D011897:Random Allocation; D015203:Reproducibility of Results; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D014463:Ultrasonography