The aim of this study was to explore how mandibular distraction osteogenesis influences morphological changes in the oropharynx and laryngopharynx.This was a retrospective study of airway parameter measurements in CFM patients undergoing mandibular distraction osteogenesis treatment. The indication for surgical treatment was the obvious facial asymmetry. Mimics 17.0 (Materialise Inc., Belgium) was used to build 3D models of the oro- and laryngopharynx. The minimum cross-sectional area (CSA), mean CSA, volume, length, and surface area were measured in the 3D models. All data were entered into SPSS v. 23.0 (SPSS Inc. USA), with statistical differences assessed pre- and postoperatively using the Wilcoxon test.Thirty-two patients diagnosed with CFM were included in this study. Five were classified as type IIa, 21 as type IIb, and six as type III, using the Pruzansky–Kaban classification. The average age of the patients was 8.34 years; 14 were females and 18 were males. The average traction time was 35.59 days and the average length of traction was 35.81 mm.The total volume of the airway was significantly increased after MDO (p = 0.001). In the oropharynx and laryngopharynx segments, the mean CSA, minimum CSA, and surface area were statistically significantly different. According to the results, expansion of oropharynx and laryngopharynx were evident after MDO.Mandibular distraction osteogenensis (MDO) can expand the volume of the oropharynx and laryngopharynx. Therefore, MDO can be considered a clinically useful treatment for changing the structure of the oropharynx and laryngopharynx.