Table 4.

Factor expression in variable distraction rates and rhythms of distraction osteogenesis.

Factor	Distraction protocol	Model	Outcome	Reference
BMP-2/4/7 (protein)	0.9 mm/day versus 2.7 mm/day	Mandibular DO in rabbits	Increased Expression of BMP-2/4 in 0.9 mm/day group	Cheung et al. (83)
			No BMP-7 in both groups
FGF/VEGF/PDGF (protein)	0.5 mm/day versus 1.5 mm/day	Femur DO in rats	Increased expression of VEGF, FGF and PDGF in 0.5 mm/day group	Schiller et al. (26)
Endothelial cells antigen (protein)	Four varying rates (0.3, 0.7, 1.3, and 2.7 mm/day)	Tibia DO in rabbits	The vascularization process was maximally stimulated at distraction rates of 0.7 and 1.3 mm/day. While impaired in 0.3 mm/day and not maximally stimulated in 2.7 mm/day	Li et al. (24, 38)
Collagen type 4 (protein)	Four varying rates (0.3, 0.7, 1.3, and 2.7 mm/day)	Tibia DO in rabbits	Collagen type 4 expression was highest at rates of 0.7 mm/day and 1.3 mm/day	Li et al. (24, 38)

DO, distraction osteogenesis; BMP, bone morphogenic protein; VEGF, vascular endothelial growth factor; FGF, fibroblast growth factor; PDGF, platelet-derived growth factor.