Maxillofac Plast Reconstr Surg.  2022;44(1):19. 10.1186/s40902-022-00350-w.

Does maxillomandibular fixation affect skeletal stability following mandibular advancement? A single-blind clinical trial

• Tabrizi R
• Sarrafzadeh A
• Shafiei S
• Moslemi H
• Dastgir R

• KMID: 2538641
• DOI: http://doi.org/10.1186/s40902-022-00350-w

Abstract

Background
The stability of the results remains a significant concern in orthognathic surgeries. This study aimed to assess the amount of relapse following mandibular advancement with/without maxillomandibular fixation (MMF).
Materials and methods
A single-blind clinical trial was conducted on patients with mandibular retrognathism who underwent BSSO for mandibular advancement and Lefort I maxillary superior repositioning. Patients were randomly divided into two groups of treatment (MMF) and control (no MMF). In the treatment group, MMF was performed for 2 weeks; meanwhile, MMF was not performed in the control group, and only guiding elastics were applied postoperatively. Lateral cephalograms were obtained preoperatively (T1), immediately after surgery (T2), and at 1 year postoperatively (T3). The distance from points A and B to the X and Y plane were measured to identify the amount of vertical and horizontal relapse in 1 year as a primary outcome. An independent t-test was applied in order to find differences in outcomes between the control and treatment groups.
Results
Fifty-eight patients were evaluated in two groups (28 patients in the MMF group and 30 in the no-MMF group). The magnitude of mandibular advancement following BSSO was 7.68±1.39 mm and 7.53±1.28, respectively, without significant difference among the groups (p= 0.68). The mean sagittal and vertical changes (relapse) at point B were significantly different between the two groups at 1-year follow-up after the osteotomy (p=0.001 and p=0.05, respectively).
Conclusion
According to the results of this study, patients with short-term MMF following BSSO for mandibular advancement benefit from significantly greater skeletal stability in the sagittal and vertical dimensions.

Keyword

Orthognathic surgery; Skeletal class II malocclusion; Bilateral sagittal split osteotomy