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the buccal vestibule through three vertical incisions and the septum and horizontal part of the palate are maintained intact.
The surgical treatment plan must be flexible. Techniques using both incisions have been used successfully and provide the surgeon more latitude in correcting maxillary deformities than has been possible with previously reported techniques.
■Results
Since 1971, the Le Forte I "downfracturing" Technique has been used to advance, retract, raise, narrow, or expand the maxilla in 15 patients (Table). Complex dentofacial problems (Fig 5-7) such as maxillary retrusion, skeletal type anterior open bite, maxillary asymmetry, bilateral buccal or palatal crossbite, maxillary dento-alveolar protrusion, and maxillary alveolar hyperplasia have been successfully corrected. The surgical and orthodontic principles used in treating thew deformities are illustrated by three case reports (case numbers correspond with those in the Table).
CASE l - Figure 5 shows how maxillary retrusion associated with mandibular prognathism in a 16 year-old boy was corrected by maxillary advancement (surgical technique illustrated in Fig l) and orthodontic treatment. A widening of the alar bases of the nose and a decrease of the nasolabial angle produced a pronounced improvement of the patient' s overall facial balance (Fig 5 B, D, F, G). Interocclusal harmony was likewise attained (Fig 5 H-J).
- Comment. All obtuse nasolabial angle is probably the single most important diagnostic criterion for total maxillary advancement. The upper lip - nose balance can be significantly improved by reduction of such an angle.

Fig 6 - Case 2. A, B, 21-year-old woman with short upper lip, contour-deficient chin, narrow nasal alar beses, and lack of prominence in midfacial region before treatment (repose position). C, D: Improved facial balance, widening of nasal alar bases, and increased prominence in zygomxaticomaxillary and nasomaxillary regions after maxillary surgery (technique shewn in part G). E: Preoperative cephalometric tracing showing high mandibular plane, 7 mm overjet, and skeletal-type Class Ⅱmalocclusion and unilateral palatal crossbite. G: Diagrammatic plan of maxillary surgery. Simultaneous anterior and posterior maxillary osteotomies in reposition maxilla superiorly and facilitate maxillomandibular arch alignment. H: Postoperative occlusion. I: Composite cephalometric tracings before (solid line - 21 year, 3 months) and three months after surgery (broken line - 21 years, 6 months) showing autorotation of mandible, reduction of anterior facial height, restoration of chin contour, improved upper lip line-inciser relationship, and functional overbite and overjet. Maxilla is superimposed over anterior portion of maxilla; mandible is superimproved over mandible. (Dr. Craig Williams, resident in oral surgery, Parktand Memorial Hospital, Dallas, was responsible for the primary care of this patient.)
CASE 2 - A 21 - year - old woman sought treatment to decrease the "prominence" of her maxillary teeth and to improve the contour of her face (Fig 6 A - B). Clinical and cephalometric analyses disclosed a high mandibular plane angle, total maxillary alveolar hyperplasia, a high palatal vault, short upper lip, contour - deficient chin, and lack of prominence in the midfacial region (Fig 6 A, B, E). Her Class n malocclusion was associated with a unilateral palatal cross bi