Evaluation of Sinonasal Change After Lefort I Osteotomy Using Cone Beam Computed Tomography Images

Orthognathic surgery including Le Fort I osteotomy involves changes in the nasal septum and maxillary sinus. This study assesses nasal septum changes after Le Fort I osteotomy using cone beam computed tomography images and evaluates mucosal changes in the maxillary sinus after the surgery.This was a retrospective study of 33 patients who underwent orthognathic surgery including Le Fort I osteotomy. To assess the maxillary sinus, changes in the mucosa of the maxillary sinus were analyzed by volume and geometry. We measured the air cavity per se and mucosal thickening of the maxillary sinus using SIMPLANT (Materialise, Belgium) software. And the geometry of the distribution of the mucosa was analyzed using cone beam computed tomography images.The septal angle was decreased after surgery, but not significantly (P > 0.05). The volume reduction of the air cavity per se and the volume increase associated with mucosal thickening were statistically significant (P < 0.05). Mucosal thickening was observed in the posterior-inferior direction.In this study, nasal septum deviation was not statistically significant after Le Fort I osteotomy. Decrease of the air cavity per se, decrease of the total volume of the maxillary sinus, and increase of mucosal thickening were prominent. Furthermore, the mucosal thickening that occurs after surgery appears to be mainly in the posterior lower part of the maxillary sinus.