英语论文网

. Maxilla is superimposed over maxilla; mandible is superimposed over anterior potion et mandible. G: Surgical treatment plan. Simultaneous maxillary advancement by Le Forte I osteotomy and retraction of mandible by body ostectomies (maxillary surgical technique illustrated in Figure l).
Although the maxilla and mandible were positioned as planned, the final alignment of the arches was compromised by lack of patient cooperation (retention appliances were not worn as prescribed after the orthodontic appliances were removed). When the patient was seen again ten months after jaw surgery, the anterior teeth were end to-end; the posterior teeth were in crossbite and slight open bite. Coordinated study of the before-and-after cephalometric radiographs and study models showed slight proclination of lower incisors, interdental spacing of the maxillary and mandibular premolars, and a 6 - mm increase in the width of the mandibular dental arch in the interpremolar region. Occlusal balance was achieved after the maxilla was surgically advanced 3 mm and widened 5 mm in the interpremolar region.
■ Complications
Wound Healing - The incisional wounds healed without discernible vascular ischemia, infection, or dehiscence. Postoperative studies have shown minimal bone loss ill the interdental osteotomy sites and no periodontal problems.
Stabilty- Significant occlusal and skeletal relapse has been discernible in only one patient whose maxilla was advanced without bone grafting (case 8, Table). This patient with a cleft lip and cleft palate was an impressive illustration of the need for bone grafting. It is beyond the scope of this paper to discuss small positional changes of the surgically repositioned maxillas that occurred in some patients after fixation appliances were removed. Clinically, however, such changes appeared minimal.
Esthetica- In a patient with previously repaired cleft lip and cleft palate (case 4, Table), the nasal esthetics was compromised by obvious splaying of the alar base of one side of the nose after maxillary advancement. In another patient, there was bilateral splaying of the alar bases and buckling of the cartilaginous nasal septum after the maxilla was raised 10 mm (case 13, Table). In both patients, facial balance was achieved after rhinoplasty. Because Le Forte I osteotomy for anterior or superior repositioning of the maxilla will probably alter nasal esthetics favorably or unfavorably, to a lesser or greater degree, the preoperative coordination of treatment is essential. Prospective patients must be apprised of the possible need for rhinoplasty after the maxilla is advanced or raised. Although the operation has not yet been used to lengthen the midfacial region, it is interesting to speculate on the results of such a procedure. On the basis of our clinical observations to date, the nasal and molar regions might be expected to decrease in prominence. The use of such procedures in the treatment of patients with deep bites and low mandibular plane angles is a fruitful field for further clinical research and for experiments in animals; it is also another fertile meeting place for orthodontists and oral surgeons.
■ Summary
With proper planning, execution, and follow-up care, the maxilla can be surgically repositioned into a stable relationship with the mandible. Complete mobility, preservation of viability by proper design of the bony and soft tissue incisions a