Since the application of Le Fort I osteotomy to orthognathic surgery in 1927 by Wassmund [10], improvements were made by many surgeons, and it became a surgical operation that was mostly established by Obwegeser [11]. Today, it is a procedure that is frequently performed due to its diversity of movement directions.
In Le Fort I osteotomy, the bone around the maxillary sinus is separated. Therefore, after surgery, blood accumulates in the sinus, and inflammatory changes (sinus mucosal thickening, edematous swelling) occur. It is also thought that the blood is absorbed with the progress of time, and the thickening of the sinus mucosa also disappears. It is easy to imagine that the risk of onset of maxillary sinusitis will be high if the blood reservoir or thickening of the mucosa persists for a long time. In the past, maxillary sinusitis has occurred, but fortunately, in the present evaluation period, there were no cases of maxillary sinusitis. Although mucosal thickening was not observed on the MDCT images of Le Fort I osteotomy after 1 year, mucosal thickening was observed in 68% in the first month after operation. Due to the characteristics of surgery, maxillary sinusitis may occur. Many reports on events after Le Fort I osteotomy are mostly related to abnormal fractures and bleeding [12,13,14,15]. However, to the best of our knowledge, there are very few reports on the incidence of maxillary sinusitis after Le Fort I osteotomy. Although Panula et al. [16] reported it in 6 of 655 patients, Kramer et al. [17] reported it in 11 of 1000 patients and Chow et al. [18] reported it in 3 of 125 patients; thus, the incidence and factors related to postoperative maxillary sinusitis have not yet been clarified.
In the present results, correlations with mucosal thickening were suggested, and factors that showed a significant difference were the operative time for the maxilla, bone grafts, and macrolide therapy after surgery. In 40 patients, no mucosal thickening was shown. One of the reasons for this may be that there was less blood retention in the maxillary sinus after surgery.
Due to the significant difference in operating time during Le Fort I osteotomy, it was suggested that a safer and faster procedure leads to the prevention of mucosal thickening. We believe that using the ultrasonic surgical method (piezoelectric surgery) and preoperative simulation by patient-specific 3D models made with a 3D printer contribute to safer and faster surgery [19]. Depending on the amount of movement of the maxilla, gaps between the bones may increase. Bone grafting promotes the formation of surrounding bone, and consequently, it was thought to contribute to the reduction of mucosal thickening. Furthermore, the results of this study support the role of postoperative macrolide therapy in reducing mucosal thickening. Opinions are divided on the timing of postoperative MDCT scanning to evaluate the maxillary sinus mucosa. Frequent MDCT scanning for the purpose of observation should not be done, since X-ray exposure should be avoided. Therefore, it is necessary to establish the validity of performing MDCT imaging. Currently, MDCT scanning is performed 1 month after surgery in our practice. Although it aims mainly to evaluate the condition of the bone, it also evaluates inflammatory changes of the maxillary sinus mucosa at the same time. If maxillary sinus mucosal thickening has been prolonged at that time, it is thought that the risk of infection remains high, and macrolide therapy is continued. Three-dimensional evaluation of the maxillary sinus by MDCT scanning is not performed to track the inflammatory changes of the maxillary sinus mucosa after scanning at 1 month postoperatively. If CT is performed, it is a two-dimensional evaluation such as Waters’ view. Therefore, it is difficult to demonstrate the dynamics over time. Therefore, while the period of continuing macrolide therapy is empirical, it is about 1 to 2 months. It is natural to observe the patient’s status carefully after surgery. In addition, it was demonstrated that MDCT 1 month after surgery looking for maxillary sinusitis can be helpful for deciding whether to continue postoperative macrolide therapy.