Three-Dimensional Tomographic Analysis of the Dimensions of the Nasal Cavity and Nasal and Upper Pharyngeal Airway Space in Subjects Submitted to Surgically Assisted Rapid Maxillary Expansion

Poster Session utilized the scans to create three-dimensional models of the upper airway. Amount of mandibular dental advancement measuring incisor over-jet and degree of vertical dimension of occlusion (VDO) pre- and postMRD were recorded. Methods of Data Analysis: CFD was used to analyze airway characteristics and correlate predicted results with clinical observations with and without the use of MRD. The effects of different MRDs and design characteristics were compared. Patient satisfaction with the MRD was assessed via questionnaire and Likert scale. Results: A total of 81 patients were treated with a MRD at the SFVA. Average mandibular advancement was 70% of maximal protrusive movement and similar amongst the different MRDs. Of the 31 patients who have pre- and post-MRD PSG results, 28 showed an improvement in OSA severity based on the apnea-hypopnea index (AHI) (p= 0.009363). 9 patients have undergone CT scan with and without MRD, and CFD of these patients showed increase in minimum airway area, increase in minimum wall static pressure, decrease in maximum air speed, and decrease in airway resistance in all three types of MRDs utilized. However, the greatest improvement was seen in the Narval MRD. Patient satisfaction was also reported to be the greatest with the Narval MRD. The degree of VDO increase was also the least in the Narval MRD. Outcomes Data: CFD analysis showed that the greatest affect of the MRD on the airway was in the region of the tongue base and to a lesser degree in the velum. Limiting the increase in the VDO leads to better treatment outcomes with the MRD. Conclusions: CFD analysis showed improved airway characteristics in patients treated with MRDs and depicted the significance in limiting the increase in VDO. CFD can be utilized as a predictive model in determining the optimal design of a MRD necessary to provide ideal airway manipulation in a specific patient manor in order to alleviate OSA symptoms. References: 1. De Backer, et. al. Functional imaging using computational fluid dynamics to predict treatment success of mandibular advancement devices in sleep-disordered breathing. Journal of Biomechanics 40 (2007) 3708–3714 2. Glupker, et. al. Three-dimensional computed tomography analysis of airway volume changes between open and closed jaw positions. American Journal of Orthodontics and Dentofacial Orthopedics, April 2015. Vol 147, Issue 4

ORTHOGNATHIC SURGERY POSTER 20 Three-Dimensional Tomographic Analysis of the Dimensions of the Nasal Cavity and Nasal and Upper e-382

Pharyngeal Airway Space in Subjects Submitted to Surgically Assisted Rapid Maxillary Expansion E. S. Gonc¸ales: Bauru Dental School - S~ao Paulo University, A. G. Gonc¸ales, V. Tieghi Neto, E. S. Fiamoncini, V. A. Pereira Filho The main objective of the surgically assisted rapid maxillary expansion (SARME) is to increase the transversal dimension of the upper dental arch in individuals with maxillary atresia. Its effects are not restricted to the maxilla, also acting on the nasal cavity and pharyngeal airway. The present study aimed to evaluate the occurrence of dimensional changes in the nasal cavity and nasal and upper pharyngeal airway space in individuals submitted to surgically assisted maxillary expansion using 2 different osteotomies. Nasal and pharyngeal airway space structures were analyzed by pre-and post-operative cone beam computed tomography scans of 29 adult subjects submitted to surgically assisted maxillary expansion. Volumetric measurement of the nasal and upper pharyngeal airway and linear measurements of the nasal cavity were performed using Dolphin Imaging 11.7 software. The data were tabulated and submitted to statistical analysis by ANOVA analysis of variance and Tukey test (p <0.05). The results showed that both osteotomies were effective in correcting transverse maxillary deficiency and presented similar effects on the nasal cavity and pharyngeal air space, the pharyngeal air space presented increased volume also in the hypopharynx region, which allowed to conclude that the EMCA promotes an increase in the floor width of the nasal cavity after expansion, and, consequently, increase in volume of the nasal cavity itself and nasal airway space, as well as pharyngeal air space. Keywords: Cone-Beam Computed Tomography; Maxillary Expansion; Airway Remodeling

References: 1. Pereira-Filho VA, Monnazzi MS, Gabrielli MAC, Spin-Neto R, Watanabe ER, Gimenez CMM, et al. Volumetric upper airway assessment in patients with transverse maxillary deficiency after surgically assisted rapid maxillary expansion. Int J Oral Maxillofac Surg. 2014;43(5): 581–6 2. Salgueiro DG, Rodrigues VHLO, Tieghi Neto V, Menezes CC, Gonc¸ales ES, Ferreira J unior O. Evaluation of opening pattern and bone neoformation at median palatal suture area in patients submitted to surgically assisted rapid maxillary expansion (SARME) through cone beam computed tomography. J Appl Oral Sci. 2015; 23(4): 397–404

Thanks to Fundac¸~ao de Apoio a Pesquisa do Estado de S~ao Paulo (FAPESP) for their financial support. AAOMS  2017