Morphological characteristics of the cranial base in Vietnamese children

Objectives: The objectives of this study were to evaluate the differences in selected morphological characteristics of the cranial base of 12 year-old Vietnamese children between skeletal class I and II and to determine their associations with maxillary/mandibular protrusion and mandibular growth. Methods: The cross-sectional study included 60 class I lateral head-films (ANB angle from 0 - 4 degrees ) and 60 class II ( ANB angle >=5 degrees). An expert examiner traced and measured saddle angle (Ba-S-N), anterior (S-N) and posterior (S-Ba) cranial base length . Independent sample t test and Pearson's correlation coefficient were applied. Results: There was a significant difference of Ba-S-N between the two classes (p<0.001), and of S-Ba between the two classes in females (p<0.05). No difference of S-N between class I and II was observed. Significant difference of S-Ba was found between male and female in class II (p<0.01), but not in class I. We also found a significant inverse correlation between Ba-S-N and S-N-A (class I: r=-0.54, p<0.001; class II: r=-0.51, p<0.001) as well as S-N-B (class I: r=-0.55, p<0.001; class II: r=-0.47, p<0.001). Ba-S-N and SN-GoGn showed a positive correlation in class II males (r=0.46, p<0.05). Neither S-N or S-Ba was correlated with S-N-A, S-N-B, SN-GoGn in either class. Conclusions: The study found significant differences in some characteristics between class I and II, between male and female based on lateral headfilms, and associations between these characteristics and maxillary/mandibular protrusion and mandibular growth.