How Thick Can A Cranial Implant Be?

Q: Dr. Eppley, I have some questions concerning adding implants to the top of the head. How thick can the implant be at most in your opinion? How is PMMA implants fixed to the top of the skull? Is there any risk of getting loose later and cause infection? Will it thin the skin?Thanks in advance.

A: The thickness of any skull augmentation that can be achieved is directly related to how much the scalp can expand over it. Short of a first-stage tissue expansion procedure, most scalps can stretch 5 to 7mms and have a tension free skin closure. Once you get anything over 10mm, a tension-free scalp closure may become more difficult. Anything cranial implant is secured by small titanium screws through a ‘rebar method’ when it comes to cranioplasty materials that are applied initially as liquid-powder or putty mixtures that then set up. Looseness or infection are two potential complications that I have not seen. There is always some slight tissue thinning around any body implant that expands the overlying tissue. But the scalp is very thick and any tissue thinning over a long time does not affect the skin or the hair follicles.

Dr. Barry Eppley

Indianapolis, Indiana