[Lefort 1 osteotomy. The proposal of an outline modification].

A modified outline of Lefort 1 osteotomy using an "inverse step" design is proposed which ensures simple and effective down-fracture and pterygo-maxillary separation. Osteosynthesis of the mobilized fragment is facilitated due to the improved contact of bone surfaces, particularly laterally. Combined rigid and supple osteosyntheses allow some degree of post-operative adjustment.