Surgical Management of Laterognathia in Orthofacial Surgery.

INTRODUCTION: Each year around the world, various surgical procedures are carried out with the goal of correcting laterognathia; both the intraoral vertical ramus osteotomy (IVRO) and bilateral sagittal split ramus osteotomy (OSB) have been the most used techniques in mandibular surgery. These techniques have advantages and disadvantages; for example the advantages of the OSB include: increased coefficient of friction between bony segments, for both the forward and the retroposition, as well as decrease in the time of intermaxillary fixation (IMF). Disadvantages include injury to the inferior alveolar nerve (IAN), hemorrhage, bad split, among others. The advantages of IVRO include decrease of possibility of injury to the IAN, ease of implementation of the technique, a lower incidence of hemorrhage and the short duration of the surgical procedure. Their disadvantages include: lower coefficient of friction between bony segments, requires a relatively long period of IMF. The combination between the techniques of mandibular osteotomy for the correction of minor 10 mm laterognathia is the ideal treatment, since it avoids potential recurrence. MATERIALS AND METHODS: We describe two cases of patients with laterognathia greater than 6 mm associated with maxilla deformity, which were treated with combined osteotomies. At Maxillofacial Surgery Service, Specialty Hospital, National Medical Center XXI Century, we describe the advantages and disadvantages, pre and postoperative nosocomial, by comparing them with the reports of the literature. CONCLUSION: The combination of techniques in the correction of laterognathias greater than 4 mm (smaller than 10 mm) is the ideal treatment, eliminating problems of articular compression, recurrence and damage to the alveolar nerve.

"Modified Oblique Le Fort III Osteotomy" New Concepts.

INTRODUCTION: The purpose of this study is to demonstrate the surgical technique for the correction of midfacial deformities; vertical excess and posteroanterior hypoplasia. This situation obligates the need to move the whole osseous structure in an oblique posteroanterior movement that should correct both midfacial deformities. This should also correct the lip incompetence while improving the malar projection on a profile view of the patient. We also present a mathematical formula that gives the angulation needed for moving the midface complex in a simultaneous vertical and posteroanterior direction. Once given the correct angulation for the desired oblique movement, the surgeon can reproduce this angulation with custom made surgical guides over the stereolithographic model, that can then be used during surgery to achieve the desired movement accurately. This technique exemplified on this paper will give maxillofacial surgeons a new and affordable tool for the correction of midfacial deformities in an accurate and easily reproducible manner and amplifying the surgical repertoire. MATERIALS AND METHODS: Patients seen in the specialty hospital "Dr. Bernardo Sepulveda" National Medical Center XXI Century, IMSS, during the period from February 2013 to November 2014 with Modified Oblique Le Fort III osteotomies, with the application of two trigonometric formulas for the accuracy of the technique. CONCLUSIONS: The application of the formulas give accurate results as well as the enlargement of the upper airway and esthetic results.

Surgical Guides for Modified Oblique Le Fort III Osteotomy.

INTRODUCTION: The present work consists of the specific design of a surgical guide for modified oblique Le fort III osteotomy (MOLFIIIO), developed previously in the Stereolithography model of the patient. The guides are designed to perform an osteotomy for the orbital floor, zygoma and pterygomaxillary fossa. The fundamental objective of the malar guides will be: symmetrical orbitozygomatic osteotomies bilaterally. Regarding the guide of the orbital floor, it is of primary importance to begin the osteotomy 5 mm ahead of the inferior orbital fissure (IOF) in orbital antero posterior direction, crossing the orbital floor. The pterygomaxillary fossa guide, will cover the internal face of the malar bone exactly in the posterior portion of the butres (hidden portion) toward the IOF. This guide will be useful, revolutionize and make it easier and secure to access the osteotomy of the area for a lot of surgeons who fear manipulating the pterigomaxillary fossa in its upper third, due to the fear of damaging the internal maxillary artery, that will be reduced to a minimum with the guides. MATERIALS AND METHODS: Initially requires a CT scan, for designed the model patient stereolithography. The guides are prepared from self-curing acrylic and monomer. CONCLUSION: Surgical guides are very useful for MOLFIIIO, as being custom, manage to make a stable symmetrical bilateral cut, decreasing the possibility of injury to vascular structures and shorten the surgical time.