Correlation between the cranial base, mandible, and hyoid bone in Class II skeletal individuals- A cephalometric study

Abstract

The aim of this study was to assess the relationship between the cranial base, mandible, and hyoid bone in Class II skeletal individuals. The retrospective study included lateral cephalograms of 40 Skeletal Class II subjects divided into maxillary prognathism (n=20) and mandibular retrognathism(n=20) based on Burstone’s N⊥A and N⊥B values. The angular measurements using 10 variables were used to determine the relationship between the cranial base, mandible, and hyoid bone in Class II subjects. Statistical analyses were performed using IBM SPSS Statistics for Windows, Version 25.0. Armonk, NY: IBM Corp. An Independent t-test was used to compare the two groups and a p-value less than 0.05 was considered statistically significant. Post-Hoc Bonferroni was applied to examine any changes among any two groups that were found to differ statistically. NSAr, C3HyD, SArHy, and NSHy angles were measured in both groups. NSAr and NSHy angles showed significance between the two groups of skeletal class II whose p-value <0.05 whereas C3HyD and SArHy angles did not show any significance. The condylar position was anterior in maxillary prognathism compared to mandibular retrognathism of Skeletal Class II. The hyoid bone was positioned forward and upward in maxillary prognathism individuals and downward and backward in mandibular retrognathism individuals belonging to skeletal class II.