gms | German Medical Science

Objective: Bone autografts and alloplastic prostheses used for craniomaxillofacial bone repair are associated with resorption, infection and extrusion, which may limit their use in difficult cases. The purpose of this study was to examine the clinical outcomes of using customized implants with unique calcium phosphate composition for this indication.

Method: Twenty-five patients with various cranial or maxillofacial defects were treated with customized implants comprising ceramic tiles interconnected by titanium mesh manufactured by molding technique (CranioPSI, Ossdsign Sweden). The defect sizes measured from 15 to 320 cm². The follow-up times were from 1 to 42 months.

Results: Twenty-three out of 25 patients displayed successful clinical results without signs of acute or long-term complications. [¹⁸F]-fluoride PET-CT scans performed in two patients 27 and 29 months after surgery indicated bone formation. One patient had an early postoperative infection that required removal of the implant. Another patient was unsatisfied with the aesthetical result with flat contour of the reconstructed frontal bone. A new implant was therefore inserted 9 months after surgery. The explant was histologically examined and analyzed with rtPCR showing intra-membranous bone growth adjacent to the ceramic discs and the expression of osteocalcin and osteopontin, respectively.

Conclusions: The use of bone stimulating implants may be required to successfully repair difficult cranial bone defects. The calcium phosphate-based implant, as presented, was shown to stimulate bone growth. The long-term healing effects were excellent, also in patients where previous implants had failed. These results encourage the use of the implant for cranial repair, particularly in therapy-resistant cases.