# Evaluation of Deviations Produced by Soft Tissue Fitting in Virtually Planned Orthopathic Surgery
## 3 Results  
A total of 16 patients between the ages of 20 and 50 were recruited for the study after surgery during the follow-up period. Five patients did not comply with the study protocol and questionnaire and were therefore excluded. The reasons for noncompliance were not clear due to great difficulty in communicating with these patients, so they were considered as miscommunication and lack of interest in participation. Therefore, the final study included 11 successfully treated patients, divided into 6 patients with Class II malocclusion and 5 patients with Class III malocclusion. All patients showed functional and aesthetic disorders for orthognathic surgery. Consequently, the motivation for surgery was considered functional and aesthetic for all patients. Data from the cohort are described in Table 1.  
Postoperative measurements showed that in five patients the surgeon followed the VSP exactly, demonstrating good precision and limiting deviations. On the other hand, six patients were considered modified from VSP and showed that SI and Pg advancement were always more conservative than planned according to the surgeon's criteria. Pg position showed more variability between cases than SI. All Class II patients also required less advancement than originally planned for both pogonion and superior incisive displacements, and only one of them was strictly adapted to VSP. Table 2 shows the final displacements and total surgical deviation. In addition, Figure 1 shows deviation maps for each surgery for SI and Pg displacements. In addition, Figure 2A illustrates the deviation of all considered procedures combined with Pg and SI deviation maps, which are categorized by dentofacial deformity class. The accuracy of Pg anteroposterior positioning showed significant differences between Class II and III deformities (\(p\)-value = 0.017), suggesting that VSP performed better in predicting Class III patients. This is also consistent with the higher number of Class II patients for whom intraoperative planning modifications were considered. It was also reproducible for SI in Class II anteroposterior (\(p\)-value = 0.0117) and vertical (\(p\)-value = 0.0252) positioning operations. On the other hand, Pg vertical deviations were similar (\(p\)-value = 0.654). \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Patient Characteristics** & **Class II** & **Class III** & **Overall** \\ \hline Final SI Ap displacement—mean mm (SD) & 2.04 (2.37) & 5.03 (2.23) & 3.34 (2.37) \\ Final Pg Ap displacement—mean mm (SD) & 8.16 (5.67) & 1.86 (5.87) & 5.30 (5.67) \\ \hline Final SI V displacement—mean mm (SD) & 0.75 (2.09) & 0.92 (1.82) & 0.83 (2.09) \\ Final Pg V Displacement—mean mm (SD) & \(-\)1.18 (2.76) & 0.50 (2.29) & \(-\)0.42 (2.75) \\ \hline Overall SI deviation—mean mm (SD) & \(-\)2.30 (2.25) & 0.63 (2.27) & \(-\)0.96 (2.4) \\ Overall Pg deviation—mean mm (SD) & \(-\)4.37 (3.05) & 1.02 (3.05) & \(-\)1.92 (3.05) \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Final displacements and overall surgical deviation. Empirically measured displacements for all procedures performed based on postoperative CT imagery. Overall SI and Pg deviations from VSP-defined displacement and final empirical measures. Figure 2: (**A**) Mean deviations and SDs for anteroposterior (Ap) and vertical (V) displacements of surgery results compared with VSP proposal for each anatomical marker (Pg and SI) and grouped by dentofacial deformity class. (**B**) Mean deviations and SDs for Ap and V displacements of final surgery result compared with VSP proposals for Class II patients for Pg and SI grouped by VSP following groups. “On VSP” represents those patients for whom VSP was followed; “Mod. VSP” represents those patients for whom the surgeon decided to modify the positioning from VSP. (**C**) Mean deviations and SDs for Ap and V displacements of final surgery results compared with VSP proposals for Class III patients for Pg and SI grouped by VSP following groups. *: \(p<0.05\). Figure 2A,B show the deviations for Class II and Class III patients, respectively.