Working model with long fastening screws mounted on a milling machine. (a) Machine's guide pin is set parallel to the first implant's long fastening screw. (b) Inclination of long fastening screw (angle α in labiolingual direction). (c) Inclination of long fastening screw (angle β in mesiodistal direction). The angles are measured in relationship to the first implant's long fastening screw by the milling machine