Table 1.

Clinically Available Materials for Cranioplasty.

Source	Type	Vascularity	Defect Fit	Resorption	Extrusion	Infection	Resistance to hostile environments (radiation, previous infection)	Implant Cost	Reasons for Failure/ Reoperation	Ref.
Autologous	Banked Orthotopic Bone Graft (“Bone Flap”)	Requires neo-vascularization	Exact fit	↑↑↑	–	7–10%	↑↓	–	Resorption	[26–29]
	Heterotopic Bone Graft	Requires neo-vascularization	Requires intraoperative shaping	↑↓	–	–	↑↑	–	Low failure rates, Contour abnormalities secondary to resorption or initial operation	[24,27,31–33]
	Heterotopic Vascularized Bone Flap	Vascularized	Requires intraoperative shaping	–	–	–	↑↑↑↑	–	Low failure rates, Contour abnormalities secondary to resorption or initial operation	[24,30]
Allogenic	Cadaveric Bone Graft	Requires neo-vascularization	Requires intraoperative shaping	↑↑↑	–	13.2%	↓↓↓	↑↑	Infection, Resorption	[34,35]
Alloplastic	Titanium	–	Either intraoperative shaping or exact fit with 3D printing	–	↑↑↑	8.6– 29%	↓↓↓	↑↑	Extrusion, Infection	[44,45,48]
	Hydroxyapatite(Bone Cement)	–	Either intraoperative shaping or exact fit with 3D printing	–	↑	22–62.5%	↓↓↓	↑↑	Infection	[48]
	Methylmethacrylate	–	Either intraoperative shaping or exact fit with 3D printing	–	↑	13–42%	↓↓↓↓	↑↑	Infection	[140]
	Polyetheretherketone (PEEK)	–	Exact fit with 3D printing	–	? (insufficient time in clinical use)	7.6–13%	↓↓↓	↑↑↑↑↑	Infection	[49,50]

↑ denotes relative increase with multiple arrows denoting higher relative qualities (i.e. increased resorption or cost), ↓ denotes relative decrease with multiple arrows denoting lower relative qualities (i.e. decreased resorption or cost); ↑↓ denote equivocal depending on report; – denotes not applicable.