Morphological Characteristics of the Cranial Base in Different Vertical Facial Types

Abstract

Objectives: To compare cranial base morphology in different vertical facial types and explore their regularity. Methods: Sixty-nine Class I patients, aged 10-15 years, were selected from the Department of Orthodontics, School of Stomatology, China Medical University. They were divided into three groups: high angle group (12 males and 10 females), average angle group (11 males and 13 females) and low angle group (14 males and 9 females). Single factor analysis of variance, as well as paired t-test, was used to analyze the differences of the measurements among the three groups. Results: Significant differences could be found in cranial base angle, sella angle, Ba-SE-FMS angle, posterior cranial base angle and the length of SO-Ar. The gradual decrease of cranial base angle, sella angle and Ba-SE-FMS angle from low angle to high angle showed significant differences; moreover, the posterior cranial base angle and the length of SO-Ar gradually decreased and also showed significant differences. The length of posterior cranial base in the high angle group was shortest; however, there was no statistically significant difference between the average angle and low angle groups. The anterior cranial base angle of high angle patients increased; there was no statistically significant difference between the low angle and the average angle patients. Conclusions: The structure of the cranial base in different vertical facial types presents certain regularity and it could be considered that the growth of the cranial base is involved in the development of different vertical facial types. The posterior cranial base seems to have a significant influence on the formation of vertical facial types.