Comparing Pharyngeal Airway Dimensions in Cephalograms of Patients with Different Skeletal Patterns

     Background and purpose: Respiratory function of patients is a major part of orthodontic diagnosis and treatment planning. It is affected by the dimensions of the pharyngeal airway. In this study, these dimensions were compared in patients with different skeletal patterns. Materials and methods: This cross-sectional descriptive-analytical study was performed studying the cephalograms of patients attending the Orthodontic Clinic affiliated with Mazandaran University of Medical Sciences 2016-17. After tracing, 144 cephalograms were divided into three groups: class I, II, and III (n= 48 per group) based on the ANB angle. The nasopharyngeal, oropharyngeal, and hypopharyngeal dimensions were measured. Data were analyzed using SPSS V24. Results: The highest mean dimensions amongst nasopharyngeal, oropharyngeal, and hypopharyngeal spaces were found in class I (21.25mm), III (10.49mm), and III (15.89mm), respectively. There was no significant difference between class I and II in the nasopharyngeal space (P=0.108). There were significant differences in the mean dimensions of all three spaces studied between class I and III and class II and III (P <0.05). Conclusion: Airway dimensions seem to vary among different classes of sagittal malocclusion. The dimensions of oropharyngeal and hypopharyngeal airways decrease with increase in ANB angle, but the dimensions of the nasopharyngeal airway are not associated with the changes in ANB angle and are higher in people with class I skeletal occlusion.