Implantable screw: MatrixMANDIBLE, MatrixNEURO, MatrixMlDFACE and MatrixORTHOGNATHlCS.Manufactured by Synthes GmbH.Specific lot numbers affected.The affected screws were first distributed in July 2007. Each screw is held within a clip that has a number etched on it, corresponding to the length of the screw.