A comparative morphometric analysis of pharyngeal airway spaces among subjects with different sagittal craniofacial patterns

Aim: The aim of the present study was to investigate the inter-relationship between  pharyngeal airway widths, velum morphology and hyoid bone position in patients with different skeletal sagittal craniofacial pattern. Material and methods: The sample comprised of 75 digital lateral cephalograms of adult individuals in age range of 16-25 years. Sagittally the total sample was divided into three Groups i.e Group Ia with normal anteroposterior positioning of maxilla and mandible, Group Ib with Skeletal class II malocclusion with Prognathic maxilla and retrognathic mandible i.e. SNA angle  >840 SNB angle <780 and Group Ic with Skeletal class II malocclusion with Normal maxilla and retrognathic mandible i.e.SNA angle 80-840 SNB angle <780. The groups were compared for each of the 9 factors i.e width of nasopharynx, width of oropharynx, width of hypopharynx , width of the deep pharynx, PNS-UT, U-Ang, U-max, H-A,H-B,H-C3,H-MP. Since the data was normal, one way ANOVA test was used followed by complementary Tukey test. Results: The groups were compared for pharyngeal dimensions at various levels, velum morphological parameters and position of hyoid bone with respect to craniofacial structures. It was found that nasopharyngeal and oropharyngeal spaces were more in class II malocclusion subjects with prognathic maxilla and retrognathic mandible and smallest in class II malocclusion subjects with normal maxilla and retrognathic mandible., Soft palate / velum length and thickness was found to be more in class II malocclusion subjects. Conclusion: It was concluded that evaluation of maxillo-mandibular sagittal positioning plays an important role especially in determining morphology of pharyngeal airway space widths and soft palate and also positioning of hyoid bone.