Interface between titanium miniplate/screw and human calvaria

This study demonstrates interfacial changes of titanium miniplate/screw wit h normal calvaria and nonvascularized calvarial bone graft ensued from cran iectomy in a 53-year-old female. In 18 months after operation, a right pari etal bone containing an L-shaped miniplate with screws, 5mm long and 2mm in external diameter, was harvested, fixed, and embedded in methylmetacrylate . Fifteen micrometer thick sections were made by an EXAKT cutting-grinding system (Exakt Company, Hamburg, Germany), and reviewed under the bright fie ld light microscope. The mean of the bone-contacting surface ratio (BCSR) i n six screwed bone was 64.1%; 69.3% in normal bone, and 60.4% in grafted bo ne. The trabecular bone areas in 10x5mm (50mm(2)) rectangular area of diplo e surrounding the screws was 43.02mm(2); 45.25mm(2) in normal calvaria; and 41.82mm(2) in grafted bone. The mean Ca/P peak-height ratio of the plated and screwed calvaria was 1.47 in a 9mm wide zone around each screw; 1.37 in normal calvaria; and 1.51 in grafted calvaria. We concede that the effect of direct contact of titanium with screws onto the bone is as much as an os seous integration (osseointegration).