The implant has an expansion element (1) with a guide unit (2), and jaws (4,4') that are provided along guide unit that is longitudinally and displaceably mounted. Bearing surfaces (43) are designed at spaced seminal outer sides of the jaws for the lamina of human, and a back stop portion is provided for the jaws. An alignment structure is arranged at the jaws, for variable orientation of the bearing surface relative to the guide unit.
