Validation of a fully automatic three-dimensional assessment of orthognathic surgery

The aim of the present study was to propose and validate FAST3D: a fully automatic three-dimensional (3D) assessment of the surgical accuracy and the long-term skeletal stability of orthognathic surgery. To validate FAST3D, the agreement between FAST3D and a validated state-of-the-art semi-automatic method was calculated by intra-class correlation coefficients (ICC) at a 95 % confidence interval. A one-sided hypothesis test was performed to evaluate whether the absolute discrepancy between the measurements produced by the two methods was statistically significantly below a clinically relevant error margin of 0.5 mm. Ten subjects (six male, four female; mean age 24.4 years), class II and III, who underwent a combined three-piece Le Fort I osteotomy, bilateral sagittal split osteotomy and genioplasty, were included in the validation study. The agreement between the two methods was excellent for all measurements, ICC range (0.85–1.00), and fair for the rotational stability of the chin, ICC = 0.54. The absolute discrepancy for all measurements was statistically significantly lower than the clinical relevant error margin (p < 0.008). Within the limitations of the present validation study, FAST3D demonstrated to be reliable and may be adopted whenever appropriate in order to reduce the work load of the medical staff.