Abstract
Objective: In Le Fort I osteotomy, accidental pterygoid process fracture (ppfx) in case of pterygomaxillary disjunction is associated with occasional severe hemorrhage, so it is important to predict ppfxs before Le Fort I osteotomy. From the results of a detailed analysis of preoperative quantitative evaluation of morphometric values, we have reported four risk factors of ppfx: a thinner pterygomaxillary junction, a longer maxillary tuberosity, male and high age. Therefore, we prospectively examined whether the risk factors are applicable to cases of not only maxillary retrusion but also facial asymmetry with deformation reaching the maxilla, as well as the characteristics of high-risk cases of ppfx.
This study aimed to identify the high-risk group of ppfx, using the four risk factors obtained from our previous research.
Study Design: Clinical and anatomical data from preoperative computed tomography images were obtained. The correlation between these data and ppfx was examined. We divided the four groups based on the number of risk factors, then classified the high-risk group of ppfx.
Results: The group of pterygomaxillary junction thickness less than 2.6mm had a significantly higher risk of ppfx. In addition, cases having more than three or four factors were classified as the high-risk group.
Conclusions: In this study, a newly discovered high-risk group of ppfx was proposed. Prediction of frangible pterygoid plates by preoperative quantitative evaluation of morphometric values is likely to be useful for selecting safe procedures.
