Angiogenesis is enhanced by continuous traction in rabbit mandibular distraction osteogenesis.
BACKGROUND
Distraction osteogenesis is a controlled surgical procedure that initiates a regenerative process and uses mechanical strain to enhance the biological responses of the injured tissues to create new bone. To test the hypothesis that high frequency mechanical traction can enhance the angiogenesis in distraction regenerate, we compared the neo-vessel formation and gene expression of the angiogenic mediators between intermittent and continuous distraction osteogenesis.


METHODS
Eighty adult New Zealand white rabbits were randomly assigned to the continuous and intermittent distraction groups. Unilateral mandibular osteotomy was performed and custom-designed manual-driven or autodriven distractor was bridged over the osteotomy segments. Animals were sacrificed at day-6, day-10, day-14 and day-21 after osteotomy and examined with histology, immunohistochemistry and real-time polymerase chain reaction (PCR).


RESULTS
Histological examination showed a more advanced bone formation in the continuous distraction group associated with significantly increased micro-vascular density and up-regulated mRNA expression of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF).


CONCLUSIONS
We concluded that the high frequency traction provides a proper mechanical environment for angiogenesis contributing to the enhanced bone formation likely to be through up-regulation of the angiogenic mediators.
Discipline of Oral & Maxillofacial Surgery, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China.
Li Wu
LW
Zheng
Li
L
Ma
Lim Kwong
LK
Cheung
D000818:Animals; D001861:Bone Regeneration / Q000502:physiology*; D016222:Fibroblast Growth Factor 2 / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation / Q000502:physiology; D007150:Immunohistochemistry; D008334:Mandible / Q000098:blood supply* / Q000502:physiology / Q000601:surgery; D055806:Microvessels / Q000033:anatomy & histology / Q000254:growth & development / Q000378:metabolism; D018919:Neovascularization, Physiologic / Q000502:physiology*; D019857:Osteogenesis, Distraction / Q000295:instrumentation / Q000379:methods*; D012333:RNA, Messenger / Q000032:analysis; D011817:Rabbits; D011897:Random Allocation; D013997:Time Factors; D014143:Traction / Q000295:instrumentation* / Q000379:methods; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000378:metabolism; D014945:Wound Healing / Q000502:physiology
D012333:RNA, Messenger; D042461:Vascular Endothelial Growth Factor A; D016222:Fibroblast Growth Factor 2