Modified Anterior Z Le Fort III Osteotomy.

Introduction: Surgery of the midface for non-syndromic patients with maxillo-malar hypoplasia exclusively has had many breakthroughs lately. The surgical techniques for midface surgery are varied and must be selected according to the patient's problem.

Purpose: The technique is a modification of the Z Osteotomy, the Modified Anterior Z Le Fort III Osteotomy (MAZLFIIIO), is used to correct posteroanterior midface deficiency of 6 mm at most. It can be combined simultaneously with a Le Fort I osteotomy if a greater maxillary advance is needed. MAZLFIIIO advances midface without grafts or distraction osteogenesis. The anterior reposition of the midface is calculated in millimetres and depends on the relation of the eye's most inferior point, as well as the orbital's hard and soft tissues. It is a predictable osteotomy, only for patients without vertical excess of the midface. The osteotomy planned is drawn over a stereolithographic model, and then Z-shaped surgical splints are fabricated over it. Transverse midface deficiencies of no more than 4 mm can also be corrected during the malar osteotomy. A great number of patients are operated exclusively with Le Fort I osteotomies, leaving behind an undesirable step between the upper part of the midface and the Le Fort I osteotomy.

Methods: The Modified anterior Z Le Fort III Osteotomy (MAZLFIIIO) was performed in seven patients, from 2016 to 2018.

Results: The results obtained with the proposed osteotomy notably improve the appearance of the patient and provide a better protection of the lower part of the eye, while widening the maxillary sinus.

Conclusion: We consider that maxillo-malar hypoplasias are very common; the surgeon pretends not to give importance to the deformity, exclusively using an advance Le Fort type osteotomy, with both functional and aesthetic treatment being limited. In this article, we give all the elements to perform this Le Fort III Modified Osteotomy in anterior Z, and that it is a combined and routine procedure in midface surgery.