The behaviour of the maxilla in vertical movements after Le Fort I osteotomy.

In 15 cases of ordinary Le Fort I osteotomy with simultaneous vertical displacement, the behaviour of the maxilla in respect to vertical movement was examined. It was observed that out of 12 maxilla which had been tilted downwards, 10 moved upwards again. One maxilla remained stable and another one moved further downwards. Of 3 cases with upward movement, two remained stable whereas one moved further upwards. Therefore, the authors conclude that the downward displacement especially is unstable and that one has either to overcorrect or search for possibilities of stabilization other than wiring suspension. Since these movements occur during postoperative intermaxillary fixation, no occlusal changes are observed.