# Condylar Changes Following Mandibular Setback Using Manual Guidance
###### Abstract  
The purpose of this retrospective study was to analyze changes in the position of the condyles following mandibular setback surgery with manual guidance. The study included 28 patients with mandibular pragnathism who underwent mandibular setback surgery using manual guidance with a bioabsorbable mesh for mandibular fixation, and changes in the position of the center of the condylar head were compared at three time points: before surgery (T0), within 1 week after surgery (T1), and 6 months after surgery (T2). The results showed significant lateral, anterior, and inferior movements of the condyle at T1 compared to T0, with an average movement of 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, with a 1.77 \(\pm\) 0.87 mm linear distance (\(p<\) 0.05). At T2, the condylar position had mainly changed inferiorly along the \(y\)-axis (\(-\)0.17 \(\pm\) 0.48 mm) (\(p<\) 0.05) compared to that at T0. The change in the position along the \(x\)-axis (\(-\)0.14 \(\pm\) 0.57 mm), \(z\)-axis (\(-\)0.05 \(\pm\) 0.68 mm), and linear distance (0.85 \(\pm\) 0.57 mm) at T2 was not significantly different from that in the condylar position at T0 (\(p>\) 0.05). The study suggests that significant anterior-lateral-inferior condylar movement occurs within 1 week after mandibular setback surgery using manual guidance, but the condyle returns to its original position over time, which is clinically acceptable.  
orthagentic surgery; condylar position; accuracy; sagittal split ramus osteotomy; con-beam computed tomography +
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been controversial. The permissible movement of the condyle right after surgery should be defined as the ability to return to its pre-surgery position during the follow-up period. Any technique showing the physiologic range of condylar position may be acceptable. Manual guidance involves the surgeon manually guiding and holding the jaw in the desired position during surgery using their hands. Although this approach can be effective in some cases, it may not consistently offer the same degree of accuracy and stability as a condyle repositioning device can [12; 15; 16]. To evaluate the manual guidance technique, precise analysis of postoperative condylar change is required.  
Assessing condylar position changes after orthognathic surgery can be achieved by analyzing lines and angles between anatomical landmarks on lateral, frontal, and submental-vertical cephalosporams and computed tomography (CT) scans [17; 18; 19; 20]. However, different observers may identify variations in these landmarks' localization on the scans [21; 22]. Recently, a novel automatic superimposition method using two CT images has been introduced, proving more accurate than manual landmark setting [12; 15]. Employing this method allows for more precise analysis of condylar positional changes following orthognathic surgery.  
The aim of this study was to investigate changes in condylar position after mandibular setback surgery using manual guidance in patients with mandibular prognathism. The null hypothesis stated that there would be no significant alterations in condylar position after the surgery. As a result, the preoperative condylar position served as the control. Moreover, the study analyzed variations in condylar position influenced by factors such as patient age, sex, the type of orthognathic surgery, the extent of mandibular setback, and the degree of asymmetry.