[Repeatability of three-dimensional measurements based on cone-beam CT images].

Objective: To investigate the repeatability of three-dimensional (3-D) cephalometric measurements for the clinical application of 3-D cephalometry.

Methods: Forty-nine measurements that widely used in traditional cephalometric analyses were defined in 3-D cone-beam CT (CBCT) images. Three examiners identified landmarks on CBCT images of 17 subjects with normal occlusion, respectively, and 3-D measurements were exported automatically by software SimPlant. Inter-examiner reliability correlation coefficients (ICC) were obtained for all measurements.

Results: Repeatability of 36 measurements was high (ICC value greater than 0.9), including SNA, SNB. Repeatability of 11 measurements was moderate (ICC value between 0.8 and 0.9), including CoL-GoL, CoL-MSP. Repeatability of 2 measurements was low (ICC value lower than 0.8), including Gn-MSP and MPR-MSP.

Conclusions: Most 3-D cephalometric measurements based on CBCT had high repeatability. However, some 3-D cephalometric measurements had limited repeatability.