[Harmonisation of the middle level of the face by Lefort type I osteotomy (author's transl)].

Elongation of the middle level of the face which is characterised by a short upper lip and exposure of the superior alveolar process is an indication for resection of a boney segment of the maxilla. Planning of this operation and the surgical technique are described and it is shown that osteosynthesis using a miniplate makes it possible to avoid intermaxillary block but requires a strict surgical technique and a very careful therapeutic plan.