Postoperative computed tomography study of pterygomaxillary separation during the Le Fort I osteotomy.

Computed tomography (CT) was used postoperatively to assess the pterygomaxillary region in 12 orthognathic surgery patients who had had a Le Fort I osteotomy. Although pterygomaxillary separation was successful in all cases, in only 41.6% of the sides did fractures of the plate not occur. The incidence of low pterygoid plate fracture was 37.5% and that of high pterygoid plate fracture was 25%; 4.2% of sides showed a maxillary tuberosity fracture. Multiple fractures were observed in 8.3% of separated plates. Of 17 pterygoid plates judged clinically to be intact, only 10 were intact as assessed by CT. The significance of these findings and application of CT to evaluation of modifications to the Le Fort I osteotomy is discussed.