Evaluation of pharyngeal airway space changes after bimaxillary orthognathic surgery with a 3-dimensional simulation and modeling program

Gokce S. M., GÖRGÜLÜ S., Gokce H. S., Bengi A. O., KARAÇAYLI Ü., Ors F.

American Journal of Orthodontics and Dentofacial Orthopedics, cilt.146, sa.4, ss.477-492, 2014 (SCI-Expanded, Scopus)

Özet

Introduction: The aims of this study were to use 3-dimensional simulation and modeling programs to evaluatethe effects of bimaxillary orthognathic surgical correction of Class III malocclusions on pharyngeal airway spacevolume, and to compare them with the changes in obstructive sleep apnea measurements frompolysomnography. Methods: Twenty-five male patients (mean age, 21.6 years) with mandibular prognathismwere treated with bilateral sagittal split osteotomy and LeFort I advancement. Polysomnography and computedtomography were performed before surgery and 1.4 ± 0.2 years after surgery. All computed tomography datawere transferred to a computer, and the pharyngeal airway space was segmented using SimPlant OMS(Materialise Medical, Leuven, Belgium) programs. The pretreatment and posttreatment pharyngeal airwayspace determinants in volumetric, linear distance, and cross-sectional measurements, and polysomnographychanges were compared with the paired samples t test. Pearson correlation was used to analyze theassociation between the computed tomography and polysomnography measurements. Results: The resultsindicated that setback procedures produce anteroposterior narrowing of the pharyngeal airway space at theoropharyngeal and hypopharyngeal levels and the middle and inferior pharyngeal volumes (P <0.05). Incontrast, advancement of the maxilla causes widening of the airway in the nasopharyngeal and retropalataldimensions and increases the superior pharyngeal volume (P <0.05). Distinctively, bimaxillary orthognathicsurgery induces significant increases in the total airway volume and the transverse dimensions of all airwayareas (P <0.05). Significant correlations were found between the measurements on the computedtomography scans and crucial polysomnography parameters. Conclusions: Bimaxillary orthognathic surgeryfor correction of Class III malocclusion caused an increase of the total airway volume and improvement of polysomnographyparameters. A proposed treatment plan can be modified according to the risk of potential airwaycompromise or even to improve it with 3-dimensional imaging techniques and polysomnography.