Table 2.

Classification of fusion grades according to Bridwell et al. [14] and fusion type according to Vavruch et al. [91]

Grade	Definition
Fusion grades
I	Fused with remodeling and trabeculae
II	Graft intact, not fully remodeled and incorporated, no luciencies
III	Graft intact with definite lucency at the top or the bottom of the graft
IV	Graft definitely not fused with graft resorption and collapse

Type	Definition
Fusion types
1A	Bridging bone anterior and through the disc space
1B	Bridging bone anterior but not through the disc space
2A	Bridging bone not anterior but through the disc space
2B	No bridging bone at all