{Reference Type}: Journal Article
{Title}: Mandibular stability and condylar changes following orthognathic surgery in mandibular hypoplasia patients associated with preoperative condylar resorption.
{Author}: Wang M;Qian Y;Zhao H;Zhu M;Yu H;Shen SG;
{Journal}: Clin Oral Investig
{Volume}: 26
{Issue}: 12
{Year}: Dec 2022
{Factor}: 3.606
{DOI}: 10.1007/s00784-022-04668-7
{Abstract}: <B>OBJECTIVE: </B>To evaluate postoperative mandibular stability and condylar changes in patients with mandibular hypoplasia and preoperative condylar resorption (CR) undergoing orthognathic surgery.<BR><B>METHODS: </B>Fifty-four patients were included in this retrospective study. Computed tomography (CT) scans were acquired preoperatively (T0), 2-7 days immediate postoperatively (T1), and at least 1 year postoperatively (T2). Three-dimensional (3D) cephalometric analysis and measurements of condylar angle, volume, and position (joint spaces) were performed. A 2-mm mandibular relapse was deemed clinically acceptable. We also analyzed the correlations between relapse and postoperative CR and susceptible factors using a multivariate logistic regression model.<BR><B>RESULTS: </B>The results showed one year after the surgery, the average mandibular relapse was 1.0 mm (p < 0.05), and the average reduction of condylar volume was 152.4 mm3 (12.7%). Condyle-fossa relationships were improved immediately after the surgery, with a tendency of returning to their original state in the follow-up (p < 0.05). Anteroposterior advancement at point B (B-CP advancement) at T1 and superior joint space (SJS) at T0 were significantly correlated with mandibular relapse, and postoperative CR was mainly associated with vertical increasement at point B (B-AP increasement) at T1. The optimal cut-off values were as follows: 1.6 mm for SJS, 4.2 mm for B-CP advancement, and 1.8 mm for B-AP increasement. Concomitant advancement Genioplasty showed no significant correlation with relapse and postoperative CR.<BR><B>CONCLUSIONS: </B>While patients with mandibular hypoplasia and preoperative CR were vulnerable to further condylar resorption after mandibular advancement, the treatment outcomes were generally clinically acceptable. Postoperative relapse was associated with a larger than 4.2 mm of mandibular advancement measured at B-CP and a larger than 1.6 mm of superior joint space measured at SJS, and postoperative CR was associated with a larger than 1.8 mm of mandibular vertical increasement measured at B-AP.<BR><B>CONCLUSIONS: </B>The findings of this study suggested that the mandibular advancement might be limited to 5 mm for patients with preoperative CR. A concomitant advancement genioplasty might also be considered to achieve a better facial profile in these patients.