Correlating Cranial Base Flexure And Posterior Cranial Base Length With Vertical Skeletal Patterns

Abstract

Background: The cranial base has pivotal role in development of craniofacial structures. Both anterior and posterior cranial bases and the angle between the two affect the position of maxilla and mandible. Objectives: To evaluate the effect of cranial base angle and posterior cranial base length in various vertical facial types. Methodology: The study sample consisted of pre-treatment lateral cephalogram of 135 subjects (63 males and 72 females, age 14-21 years) with skeletal class I pattern. These were divided into three groups of normodivergent, hypodivergent and hyperdivergent facial types with 45 subjects in each group. Two angular parameters i.e Saddle angle (NSAr) and Articular angle (SArGo) and one linear parameter Posterior cranial base length (SAr) were used in cephalometric analysis. Inter-group comparison of means of all measurements were studied using ANOVA with Bonferroni’s correction for multiple group comparison. Results: Saddle angle and articular angle did not show significant difference across three study groups. Highly significant difference in posterior cranial base length was observed between hypodivergent and hyperdivergent groups. Saddle angle and Posterior Cranial base length showed significant positive correlation in hypodivergent whereas Saddle angle and Articular angle showed significant negative correlation in hypodivergent and hyperdivergent groups. Conclusion: The cranial base angle does not affect the vertical facial patterns but posterior cranial base length does affect the hyperdivergent and hypodivergent facial types. Cranial base angle found to correlate with posterior cranial base in hypodivergent facial pattern whereas Saddle angle correlated negatively with articular angle in both hyperdivergent and hypodivergent facial types.