Overview: Feature of the surgical treatment of patients with different classes of dentofacial anomalies is the movement of a tissues complex for achieving an optimal balance with function and aesthetics. Result of these movements is the difference in ratio between the anatomical structures of the naso- and oropharynx that lead to changes in the size and volume of the upper airway.

Objective: To analyze changes which occur in the upper airway during the orthognathic surgery in a group of patients with malocclusion and to assess the possibility to predict this changes during planning of upcoming surgery.

Materials and methods: There were 25 participants (19 patients with class III malocclusion and 6 with class II) who underwent orthognathic surgery. Le Fort I osteotomy and BSSO were used in all cases. Pre-surgical and 6 month post-surgical computed tomography was performed. For measurement of the upper airway’s volume we used Sinus/Airway kit of Dolphin Imaging 11.5 software based on the original DICOM files. Special soft and hard tissue landmarks were localized to create borders of the upper airway’s space for getting the area of interest. We have measured airway volume, maximal area in saggital plane and minimum axial area. All data were analyzed.

Results: Patients with class III malocclusion have had one-way changes of all measured data in nearly 50% of cases. Increasing of the airway volume was observed in 42.1% where is the decreasing in 57.9%. In patients with class II malocclusion we have observed 100% unilateral changes of all measured data with markedly more cases (83.3%) of increasing of the airway volume.

Conclusions: Orthognathic surgery leads to the hardly predictable changes in anatomy of the upper airway through the shifting of the hard and soft tissues causing the volume changes from 0.2% up to 57% in some cases.

Key words: upper airway; upper airway volume; upper respiratory tract; orthognathic surgery