Emergence of Central Sleep Apnea Events After Maxillomandibular Advancement Surgery for Obstructive Sleep Apnea.

PURPOSE: Central sleep apnea (CSA) can develop after the treatment of obstructive sleep apnea (OSA) with continuous positive airway pressure (CPAP). No studies have identified whether treatment of OSA with maxillomandibular advancement surgery (MMA) can result in CSA. The purpose of our study was to determine the incidence and clinical significance of CSA emerging after MMA surgery to treat OSA. PATIENTS AND METHODS: A retrospective review was conducted of all patients who had undergone MMA surgery for OSA at the Department of Oral and Maxillofacial Surgery at the QEII Health Sciences Centre (Halifax, NS, Canada) from 1996 through 2016. All patients with preoperative level 1 polysomnography and follow-up level 1 study results available at least 6 months postoperatively were included the present study. The pre- and postoperative central apnea index (CAI) results were compared. RESULTS: A total of 113 patients (84 men and 29 women) with an average age of 44.0 years were included in the present study. In 35 patients (31.0%), the emergence of CSA events were recorded on postoperative polysomnograms. Only 2 of the 113 patients experienced the emergence of clinically significant postoperative CSA (CAI >5). In our patient cohort, gender (P = .085), patient age (P = .238), and preoperative (P = .716) and postoperative (P = .209) Apnea-Hypopnea Index (AHI) results correlated with the postoperative development of CSA events after MMA surgery. The mean AHI values had decreased from 41.4 to 8.7 in all patients treated with MMA in our study. CONCLUSIONS: The emergence of CSA events occurred in 31% of patients after OSA treatment with MMA surgery. The rate of clinically significant CSA events emerging after MMA surgery in our study was 1.8%. These findings help to support the use of MMA surgery for OSA as a reasonable treatment alternative for patients unable to tolerate CPAP.

A reliable and reproducible method for repositioning 3D images to calculate changes in facial volume after orthognathic surgery.

PURPOSE: An accurate, reproducible method to calculate post-operative facial swelling in patients who have undergone orthognathic surgery is important to evaluate the effects of different therapies and surgical techniques on edema. The purpose of this study was to describe such a method and assess its reliability. MATERIALS AND METHODS: A prospective study of patients undergoing orthognathic surgery was conducted. 3D facial photographs were taken on these patients immediately postoperatively, and again at least 21 days later using the 3DMD face system (3DMD LLC., Atlanta, GA, USA). These were cropped using specific anatomic points and the difference in facial volume between the photographs was calculated. Intra-rater reliability and inter-rater reliability were assessed using the Intraclass Correlation Coefficient (ICC). RESULTS: 30 patients were included in the study for analysis. When the difference in facial swelling was calculated twice by the same rater, the mean difference between the two measurements was 4.0 ± 4.2 mL. When calculated by two separate raters, the mean difference was found to be 5.0 ± 3.8 mL. The ICCs for intra-rater and inter-rater reliability were excellent at 0.979 and 0.981 respectively. CONCLUSION: This method allows for reproducible calculation of post-operative facial swelling and could be useful to evaluate the effects of different therapies used to limit swelling and to track the resolution of swelling. It can also potentially be used as a visual aid for patient counseling during the pre-surgical visits.