Volumetric and cephalometric evaluation of the upper airway of class III patients submitted to maxillary advancement

Abstract Introduction Anteroposterior maxillary deficiency can be associated with a decrease of upper airway volume. Maxillary advancement can improve the upper airway space. Aim To correlate cephalometric (2D) and volumetric (3D) measurements of the upper airway in class III patients treated by maxillary advancement. Material and method This retrospective transversal study was performed in ten adult patients submitted to maxillary advancement for correction of class III deformity secondary to maxillary anteroposterior deficiency. The Cone beam tomography files included in the medical records were used: (T1) pre-operative and (T2) 6 to 8 months postoperative. The DICOM files were imported and reconstructed for volumetric and cephalometric evaluation of the upper airway, as divided into nasopharynx, oropharynx and hypopharynx (Arnett & Gunson FAB Surgery). Result Age ranged from 26 to 55 years with a mean of 36.3±9.2 years. There were no statistically significant differences for cephalometric and volumetric parameters of the three pharyngeal regions between T1 and T2 periods. This was due to the small amount of maxillary advancement necessary to correct the maxillary deformity in the studied patients (4.7±1.89mm). The correlation between area and volume was not statistically significant only for preoperative measurements of the nasopharynx (r=0.30, p=0.40). It was significant for the other regions and evaluation periods (p<0.05). Conclusion Small maxillary advancements do not result in significant increases in airway dimensions.