Relationship between cranial base and jaw base in different skeletal patterns

Purpose

To determine the relationship between the cranial base and both jaw bases in different skeletal patterns.

Materials and methods

Lateral cephalometric radiographs of 180 adult patients of all three malocclusion groups were evaluated and analyzed. A group of linear and angular measurements were measured and compared among all study groups to assess the existence of any relationship between the cranial base and both jaw base discrepancies.

Results

Significant differences were found in the cranial base angle (NSBa) and both jaw base lengths among all three malocclusion groups, while no significant differences were found in the cranial base lengths. As for angular measurements, an inverse correlation was found between the cranial base angle and both SNA and SNB angles in both Class II and Class III malocclusion groups. Concerning linear measurements, a significant correlation was found between the total cranial base length and the total facial height among all malocclusion groups.

Conclusion

The cranial base angle affects the anteroposterior orientation of both maxilla and mandible with a minimal contribution to the appearance of different vertical skeletal patterns. Meanwhile, the cranial base length affects minimally the anteroposterior orientation of both the maxilla and the mandible. However, a significant link was found between it and the total facial height, thus contributing to the appearance of different vertical skeletal patterns.