The role of muscular traction in the occurrence of skeletal relapse after advancement bilateral sagittal split osteotomy (BSSO): A systematic review

Correlation between condylar repositioning, resorption, and mandibular relapse post-orthognathic surgery with the straight locking miniplate technique in patients with Class II and III malocclusion: a retrospective study

This study investigated the relationship between condylar position, condylar volume, and mandibular relapse following orthognathic surgery in which the proximal segments were temporarily fixed with a positioning device to maintain the condylar position. Computed tomography data (pre-surgery, immediately post-surgery, and 1 year post-surgery) from 12 patients with Class II malocclusion and 20 with Class III were analysed. Condylar volume was significantly lower in Class II patients than in Class III patients at all time-points (P < 0.001), and only Class II patients showed a significant volume reduction from immediately post-surgery to 1 year post-surgery (P < 0.001). Three-dimensional condylar movements from pre-surgery to immediately post-surgery and from pre-surgery to 1 year post-surgery were significantly greater in Class II patients than in Class III patients (both P < 0.001). Additionally, Class II patients exhibited more restoration movements to the preoperative position from immediately post-surgery to 1 year post-surgery, correlating with the volume reduction (r = -0.53, P = 0.007), which in turn correlated significantly with mandibular relapse (r = 0.63, P < 0.001). These findings suggest an association between preoperative volume, intraoperative movement, condyle movement restoration, volume reduction, and postoperative mandibular relapse, particularly in the Class II group. Accurate condylar positioning appears crucial for mitigating mandibular relapse in Class II cases.

Changes in masseter muscle morphology after surgical-orthodontic treatment in patients with skeletal Class III malocclusion with mandibular asymmetry: The automatic masseter muscle segmentation model

INTRODUCTION

This study evaluated the masseter muscle changes after surgical-orthodontic treatment in patients with a skeletal Class III malocclusion using automatic segmentation.

METHODS

Images of 120 patients with skeletal Class III malocclusion were obtained and reconstructed at T0 (pretreatment), T1 (presurgery), and T2 (6-12-month postsurgery). The patients were divided into symmetrical and asymmetrical groups. The volume, major axis length, maximum cross-sectional area, horizontal cross-sectional area 5 mm above the mandibular foramen (CSAF), and orientation were calculated automatically.

RESULTS

In the asymmetrical group, the volume and major axis length on the deviated side were lower than on the nondeviated side at T0, T1, and T2 (P <0.05). There were no significant differences in maximum cross-sectional area and CSAF bilaterally. The orientation was coronally more vertical and sagittally more forward on the deviated side (both P <0.001). In the symmetrical group, there were no significant bilateral differences at T0, T1, and T2. The volume, major axis length, and CSAF decreased, and the coronal orientation was more vertical on the nondeviated side at T2 than at T0 in both groups (P <0.05). The coronal plane orientation was more inclined on the deviated side at T2 than at T0 in the asymmetrical group (P <0.05).

CONCLUSIONS

The smaller volume on the deviated side at T2 indicates the need for myofunctional training after surgery. The masseter muscle volume and the cross-sectional area did not recover to the preorthodontic levels. Studies with longer follow-up durations are needed to confirm these findings.

Exploring the relationship between the number of systematic reviews and quality of evidence: an orthognathic surgery-based study

OBJECTIVE

We analyzed the quality and quantity of systematic reviews (SRs) of orthognathic surgery, the most frequently published topic in maxillofacial surgery.

STUDY DESIGN

We searched the PubMed database for SRs of orthognathic surgery with no restriction on the language of publication date. We assessed the certainty of evidence presented according to the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocol and the Leiden Manifesto using the Grading of Recommendations Assessment, Development, and Evaluation approach. We analyzed the data using descriptive statistics, Pearson´s correlation test, and linear regression.

RESULTS

Of the 171 SRs evaluated, approximately one fifth presented evidence with a high level of certainty. The number of orthognathic surgery SRs has been increasing, and many SRs were published after very similar topics had already been published. There is no relationship between the impact factor and the certainty of evidence.

CONCLUSIONS

An excessive number of SRs of orthognathic surgery are published, and many SRs are superfluous, simply reporting previous findings. Clinicians should not base treatment decisions solely on the evidence presented in SRs, and journal editors and reviewers should evaluate these SRs more critically, particularly when they address topics that have already been covered in the literature.

Craniofacial Distraction Osteogenesis

Distraction osteogenesis (DO) of the craniofacial skeleton has become an effective technique for the treatment of both nonsyndromic and syndromic conditions. The advent of craniofacial DO has allowed for earlier intervention in pediatric patients with less complication risk and morbidity compared to traditional techniques. In this review, we will discuss current application and technique for craniofacial DO by anatomical region and explore future applications in craniofacial surgery.