How much variation exists amongst experienced surgeons in orthognathic surgical planning?

Abstract

Discussions of orthognathic planning are often dogmatic, however, it is a subjective science. The aim of this study was to quantify the variation in orthognathic surgery planning in a group of experienced orthognathic surgeons. A cross-sectional study was designed, and an identical presurgical orthognathic case provided to 13 surgeons. Statistical analysis was performed using descriptive statistics, Fisher's exact test, and MANOVA with p < 0.05 considered significant. The mean (SD) anterior-posterior (AP) movement of the upper incisors was 5.8 (1.5) mm anterior (range 3.0-7.0 mm), and 0.7 mm (-0.7 (1.9) mm; range -2.9 to 4.0 mm). The mean (SD) AP movement of pogonion was 0.6 mm posterior (-0.6 (2.2) mm; range 5.5 mm posterior to 2.1 mm anterior). The standard deviations in movement (AP and superior-inferior) were greatest at pogonion (2.3 mm and 1.9 mm), followed by B-point (1.9 mm and 2.0 mm), maxillary incisor (1.5 mm and 1.9 mm), then A-point (1.4 mm and 1.8 mm). This study shows that significant variation exists in surgical planning among a group of experienced orthognathic surgeons at the level of pogonion and B-point, with less variation at the maxillary central incisor and A-point. Future studies may compare these results with surgeons with less orthognathic expertise, or non-OMS trained surgeons.