Long-term experience with methylmethacrylate cranioplasty in craniofacial surgery.

Cranioplasty is a procedure commonly performed by plastic surgeons involved in craniofacial surgery, in which it is generally accepted that the ideal reconstructive material is autogenous bone. When this is not available or when its use is inappropriate, alloplastic materials are the next best option. A retrospective analysis was carried out to review the senior author's experience of 98 cranioplasties with methylmethacrylate (MM) from 1980 to 2001. The site and size of the implant and complications thereof were recorded and an assessment of the quality of the final result made. The patients were divided into two groups: Group 1: Methylmethacrylate as a full thickness inlay. Group 2: Methylmethacrylate as an onlay only. In group 1 there were 32 patients for whom the average follow up was 8.2 years (range 2-16 years). In group 2 there were 66 patients with an average follow up of 7.1 years (range 2-20 years). After a minimum follow up of 2 years, 89 out of 98 of the patients retained their implants. Nine implants in total were removed. Of the 89 patients retaining their implants, 85 had excellent or good results at long-term follow up. The infection and implant removal rate was very high if nasal or frontal sinus tissue was in direct contact with the implant during the operative procedure. The keys to the successful use of methylmethacrylate are discussed and representative case examples are presented. There is increasing evidence that the long term results of newer alternatives to methylmethacrylate for cranioplasty such as hydroxyapatite cement are disappointing and do not justify their expense. Methylmethacrylate is cheap, readily available and easy to use and it remains the alloplastic material of choice for cranioplasty in our hands.