# Condylar Changes Following Mandibular Setback Using Manual Guidance
## 3 Results  
According to Table 2, the average movement of the condyle between T0 and T1 was 0.66 \(\pm\) 0.84 mm along the \(x\)-axis, \(-\)1.27 \(\pm\) 0.82 mm along the \(y\)-axis, and \(-\)0.20 \(\pm\) 0.69 mm along the \(z\)-axis. The linear distance covered was 1.77 \(\pm\) 0.87 mm. These changes were found to be statistically significant (\(p\) < 0.05). Comparing the condylar position at T1 with that at T0, there was a tendency for lateral, anterior, and inferior movement. The average movement of the condyle between T1 and T2 was \(-\)0.79 \(\pm\) 0.69 mm along the \(x\)-axis, 1.10 \(\pm\) 0.89 mm along the \(y\)-axis, and 0.16 \(\pm\) 0.71 mm along the \(z\)-axis, with a linear distance of 1.69 \(\pm\) 0.88 mm. At T2, the condyle showed a tendency to move in a direction opposite to that between T0 and T1. These changes were statistically significant (\(p\) < 0.05), except along the \(z\)-axis. On comparing the overall movement of the condyle between T0 and T2, there was no statistically significant difference, except along the \(y\)-axis (\(p\) < 0.05), but on average, the condyle moved medically, anteriorly, and inferiorly. There was no statistically significant difference in the extent of setback based on patient age, sex, the type of orthognathic surgery, and the degree of asymmetry (\(p\) > 0.05). Similarly, there was no statistically significant difference in the degree of asymmetry based on patient age, sex, and the type of orthognathic surgery (\(p\) > 0.05). Moreover, there was no significant change in the condylar position in any period or direction based on patient age and sex, as shown in Table 3.  
When comparing the movement between T1 and T2 according to the type of orthognathic surgery, statistically significant differences in condylar movement were observed (Table 3). Specifically, the condyle moved anteriorly in the bimaxillary surgery group and posteriorly in the mandibular surgery group during follow-up (\(p\) = 0.037: Table 3). Additionally, a statistically significant inferior movement of the condyle was observed in the mandibular surgery group compared to that in the bimaxillary surgery group between T0 and T2 (\(p\) = 0.003: Table 3). However, no statistically significant changes were found in other directions or periods (\(p\) > 0.05). When analyzing the extent of mandibular setback, patients with a mandibular setback of >8 mm showed a statistically significant inferior movement of the condyle only between T0 and T2 compared to that of those with a mandibular setback of \(\leq\)8 mm (\(p\) = 0.021: Table 3). No significant changes were observed in other directions or periods (\(p\) > 0.05). The degree of asymmetry was determined by the difference in mandibular setback between the left and right sides. Patients with a >3 mm difference showed a statistically significant anterior movement of the condyle between T0 and T1 compared to those with \(\leq\)3 mm difference (\(p\) = 0.003: Table 3). However, no significant changes were found in other directions or periods (\(p\) > 0.05). \begin{table}
\begin{tabular}{c c c c} \hline  & **Surgical Change** & **Postoperative Change** & **Total Change** \\  & **[T1–T0] (mm)** & **[T2–T1] (mm)** & **[T2–T0] (mm)** \\ \hline \(\Delta\)x & 0.66 \(\pm\) 0.84 * & \(-\)0.79 \(\pm\) 0.69 * & \(-\)0.14 \(\pm\) 0.57 \\ \(\Delta\)y & \(-\)1.27 \(\pm\) 0.82 * & 1.10 \(\pm\) 0.89 * & \(-\)0.17 \(\pm\) 0.48 * \\ \(\Delta\)z & \(-\)0.20 \(\pm\) 0.69 * & 0.16 \(\pm\) 0.71 & \(-\)0.05 \(\pm\) 0.68 \\ \(\Delta\)d & 1.77 \(\pm\) 0.87 * & 1.69 \(\pm\) 0.88 * & 0.85 \(\pm\) 0.57 \\ \hline \end{tabular}  
* \(p\) < 0.05, statistically significant. T0, before surgery; T1, within 1 week after surgery; T2, 6 months after surgery. \(\Delta\)d, a calculated value based on a formula that determines the distance between two points in spatial coordinates.  
\end{table} 
Table 2: Changes in condylar position after mandibular setback surgery with bioabsorbable mesh for mandibular fixation.