Table 2.

Factor expression in acute versus gradual distraction osteogenesis in rat mandibles.

Factor	Outcome	Reference
ERK 1/2, BMP 2/4 (protein)	GD → ↑ ERK1/2+ ↑ BMP2/4	Rhee et al. (51)a
	AD → no ERK1/2
VEGF/FGF (protein)	GD → ↑ VEGF and FGF	Fang et al. (77)b
	AD → absence of GF
Osteocalcin, collagen type 1, TIMP-1, VEGF (mRNA)	GD → ↑ osteocalcin Collagen type 1 and TIMP-1 compared to AD Both protocols had no effect on VEGF	Warren et al. (25)c

DO, distraction osteogenesis; GD, gradual distraction; AD, acute distraction; ERK1/2 extracellular signal-related kinase; BMP, bone morphogenic protein; VEGF, vascular endothelial growth factor; FGF, fibroblast growth factor; GF, growth factors; TIMP-1, tissue inhibitor metalloproteinase’s-1.

^aGradual distraction group (distraction of 0.6 mm/day for 8.5 days), Acute distraction groups (intra-operative separation of 2.1 mm in group 1 and 5.1 mm in group 2).

^bGradual distraction group (distraction of 0.5 mm/day for 8 days) and acute distraction group (intra-operative separation of 4 mm).

^cGradual distraction group (distraction of 0.5 mm/day for 6 days) and acute distraction group (intra-operative separation of 3 mm).