ObjectivesThis study analyzed the differences in the upper airway of patients with skeletal Class III high-angle malocclusion with and without mandibular deviation, and further investigated the effects of orthognathic surgery on the upper airway in these two groups.
Material and Methods 15 patients with skeletal Class III high-angle malocclusion and mandibular deviation, and 15 patients without mandibular deviation were selected to explore the impact of mandibular deviation on the upper airway. Additionally, 16 patients with mandibular deviation undergoing orthodontic-orthognathic combined treatment, and 13 patients without mandibular deviation, were selected to investigate the effects of orthognathic surgery on the upper airway in these two groups.
ResultsIn patients with skeletal Class III high-anglemalocclusion, the mandibular deviation group showed significantly smaller sagittal diameter/maximum transverse diameter, cross-sectional area, volumes of oropharynx and hypopharynx, and total volume compared to the non-deviation group, with all differences being statistically significant. After orthognathic surgery, the postoperative sagittal diameter/maximum transverse diameter of the oropharyngeal airway increased in the mandibular deviation group, while it decreased in the non-deviation group. The postoperative reductions in cross-sectional area, volumes, and total volume of the oropharynx and hypopharynx were more pronounced in the non-deviation group.
ConclusionIn patients with skeletal Class III high-angle malocclusion, mandibular deviation results in narrowing of the lower portion of the upper airway. The orthognathic surgical correction of mandibular deviation compensates to some extent for the reduction in the cross-sectional area and volume of the upper airway caused by the surgery itself.
Clinical relevance For patients with skeletal Class III high-angle malocclusion with mandibular deviation, the upper airway space should be assessed before orthognathic surgery, and appropriate treatment plans should be developed based on the assessment results to achieve a balance between aesthetics and function.