Research
3d Evaluation of Soft Tissue Changes Following Class III Orthognathic Surgery– A Systematic Review
Background: The principle goal of orthognathic surgery is to establish a balanced and stable dento-skeleto facial complex.This mandates the surgeon and the orthodontist to be able to predict the soft tissue changes to the orthognathic surgery precisely, which is accurately possible using 3-D imaging. Aims: To evaluate the soft tissue changes following class III orthognathic surgery using 3-D imaging. Settings and Design:Systematic review. Methods and Material: This review was conducted according to Preferred Reporting Items for Systematic Reviews and meta-Analyses guidelines systematically searching the six databases including PubMed, Cochrane, Google Scholar, LILACS, Directory of Open Access Journals, and OpenGrey. Statistical analysis used: Not applicable. Results: This systematic review comprises of most UpToDate evidence from eleven articles answering the review questions. Conclusion: Le Fort I advancement shows significant increase in the alar width, alar cinch, upper lip, chelion, labiale superius, crista philtri,pronasale and subnasale. Mandibular setback shows significant backward movement of soft tissue point B, labialeinferius and subnasale and chin.
Evaluation of the Pharyngeal Airway Space Before and after Bi-Lateral Sagittal Split Osteotomy Surgery using Three-Dimensional Cone Beam Computed Tomography
Objectives: To evaluate the changes in the pharyngeal airway space (PAS) before and after bi-lateral sagittal split osteotomy (BSSO) surgery using a threedimensional cone-beam computed tomography (3D-CBCT). Material and Methods: The sample consisted of patients (n=7), aged between 21-30 years, having a skeletal Class II with retrognathic mandible and orthognathic maxilla who underwent orthodontic treatment and were advised for BSSO advancement surgery. Pre-surgical CBCT scans were taken a week before the surgery (T0) and the post-treatment records, three months after the surgery (T1). The 3D PAS was reconstructed from the CBCT scans, and the volumetric changes were evaluated. Result: The PAS volume was derived, and the pre-surgical values (T0 mean=14083.19mm3) were compared with the post-surgical values (T1 mean=18067.26mm3), and a significant increase by 28.29% in the volume was evident (t=4.51, p=0.04 < 0.05) for a mean mandibular advancement of 4.7mm. Conclusion: Our findings suggest that bilateral mandibular advancement surgery in patients with retrognathic mandible increases the PAS volume anatomically and enhances the breathing functionally.
