3D cephalometry: influence of patient scanning position

Method: The study consisted of five CBCT scanning (KODAK 9500 Cone Beam 3D System unit) in five different positions of a dry skull. The data were imported in SIMPLANT OMS Software version 13.0. Fifteen 3D cephalometric measurements were calculated; moreover the mean, the standard deviation, the maximum/minimum delta and the maximum/minimum delta percentage were calculated. The statistical analysis was performed by an indipendent sample ttest to evaluate differences between the five scans.

Result: No differences were found in the 3D cephalometric measurements, but, twelve of the fifteen measurements showed a delta above 1.5, seven of the fifteen measurements showed a delta above 2 and nine of the fifteen showed a delta percentage above 5%. 

Conclusion: Considering the importance of the precision of the data evaluated, the differences founded within the measurements in the five positions of the skull are to be considered significant from a clinical point of view. The preliminary results suggest that the 3D cephalometric analysis is influenced by patient scanning position.