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ral portion of the maxilla is essential and is accomplished by positioning the tip of a curved cheek retractor at he pterygomaxillary suture (Fig l, B). Another cheek retractor is placed anteriorly to facilitate visualization of the anterolateral portion of the maxilla. Direct visualization and palpation of the bone encasing the apices of the teeth assess the length of the teeth. These findings are correlated with measurements taken from panoramic or lateral cephalometric radiography or both. So that a horizontal line can be etched in the bone 3 to 5 mm above the apices of the teeth.
Horizontal supraapical osteotomies of the lateral portions of the maxillas are made from the lateral part of the piriform rim posteriorly across the canine fossa and through the zygomatic maxillary crest to the pterygo maxillary fissure using a fissure bur in a straight hand piece or a high speed reciprocating saw. In some cases, depending on the existing facial deformify, greater augmentation of the midfacial region will result from placement of the anterior osteotomy more superiorly. Ideally, the supraapical bone cuts are made 3 to 4 mm or more above the apices of the maxillary teeth.
The mucoperiosteum is elevated from the anterior floor of the nose, nasal septum, and lateral walls of the nasal cavity to facilitate separation of the maxilla from these structures. A nasal septal osteotome is positioned above the anterior nasal spine parallel with the hard palate and malletted to separate the nasal sepum from the maxilla (Fig l, D). The anterior later nasal wall is sectioned transantrally with a fissure bur in a straight handpiece. The posterior lateral nasal wall is sectioned with a sharp osteotome above the level of the nasal floor. In many instances, however, this bone is m thin that does not have to be osteotomized. Finally, sharp pterygoid osteotome is malletted into pterygomaxillary suture to separate the maxillary from the pterygoid plates (Fig l, E). Digital pressure on the palatal mucosa in the region the hamulus permits the surgeon to feel osteotome as it transects the bone without frallmatizing the underlying mucoperiosteum. The osteotome is positioned inferiorly to minimize danger to the vascular structures in the ptetygo maxillary fissure. By manipulation of the curved osteotome and manual pressure against the tuberosities, the maxilla is made partially mobile.
At this point, downward movement fractures the maxilla. Gradually increasing into pressure on the anterior portions of the maxilla facilitates visualization of the superior surface of the maxilla and lateral nasal walls (Fig l, F). The mucoperiosteum is elevated and retracted away from the entire superior surface of the maxilla, horizontal plate of the palatine bone, and lateral nasal walls. Transection of the greater palatine vessels is of no practical consequence. Digital pressure gradually completes fracturing of the maxilla, without the use of disimpaction forceps. The downward position of the maxilla provides excellent access for completely separating the maxilla from the pterygoid plates and perpendicular process of the palatine bone (Fig l, F). This can be accomplished with a bur or an osteotome. By careful manipulation of the osteotome and forward pressure against the tuberosities and lower part of the maxilla, the maxilla is made completely mobile and moved into the planned position. The maxilla must be made so mobile that it can be moved with on