Unit Twenty Seven Le Forte I osteotomy for correction of maxillary deformities [2]
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e. A: Typical dental, facial and skeletal characteristics of mandibular prognathism associated with maxillary retrusion. B, C: Horizontal incision through mucoperiosteum in the buccolabial aspect of depth of vestibule. Horizontal supraapical osteotomy of labial maxilla extending from piriform rim posteriorly to pterygomaxillary fissure. D: Separation of nasal septum from superior part of maxilla with osteotome; posterior lateral nasal wall sectioned with osteotome. E: Separation of maxilla from pterygoid plate with curved osteotome; surgeon’s finger is positioned below palatal mucosa to feel osteotome as it transsects bone. F: Maxilla in "downfractured" position. Mucoperiosteum has been detached and retracted away from entire superior surface of maxilla and horizontal plate of palatine bone; Posterior maxilla is separated from the pterygoid plates and perpendicular process of palatine bone with osteotome and bur. G: Repositioned maxilla fixed to the piriform rims and zygomatic buttresses with transosseous wires.
The collateral circulation within the maxilla and its enveloping soft tissue and the numerous vascular anastomoses in the anterior and posterior parts of the maxilla permit many variations of the total maxillary osteotomy technique. Intraosseous and intrapulpal circulation was not significantly altered by the buccal subapical osteotomies when bone cuts were made away from the apices of teeth and maximal attachment of the mucoperiosteum on the palatal and buccolabial gingiva of the mobilized maxilla was preserved. These results generated clinical confidence in performing total maxillary osteotomies. The current surgical technique was modified after these analogous investigations in animals and previously reported clinical techniques.
■ Anesthesia
The operation is performed in the hospital with the patient under general anesthesia delivered via the nasoendotracheal route. Successfully administered hypotensive anesthesia has reduced bleeding and facilitated surgical dissection. It is rarely necessary to use transfusions, although two units of packed cells are routinely available for use at the time of surgery if the need should arise. Reduced operative shocks and decreased postoperative nausea, vomiting, and edema is additional advantages of hypotensive anesthesia. Because submucosal oozing is decreased, postoperative wound healing may also be enhanced. Despite these significant advantages, the use of hypotensive anesthesia is justified only when it enables the surgeon to carry out the operation better than he could with conventional anesthetic techniques. The advantages to the patient and surgeon must be weighed against the increased risks. The technical skill and experience of the anesthesiologist must be of a high order.
■ Surgical Technique
(Fig l, A-G) A horizontal incision is made through the buccolabial mucoperiosteum above the mucogingival junction extending from one-second molar region to the other (Fig l, B). The incision is placed in the buccolabial aspect of the depth of the vestibule, at about the level of the apices of the teeth. The margins of the superior flap are raised to expose the entire lateral walls of the maxilla zygomatic crests, infraorbital foramens, and the piriform apertures. The inferior mucoperiosteal tissues are minimally elevated so that they provide additional vascular supply to the maxillary bone and teeth. Good visualization of the posterolate
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