KUMJ | VOL. 14 | NO. 4 | ISSUE 56 | OCT.-DEC. 2016

Retrospective Study to Determine Stability of Mandibular Setback Surgery using Bilateral Sagittal Split Osteotomy Technique
Upadhyaya C, Chaurasian NK, Kafle D


Abstract:
Background Bilateral sagittal split osteototomy of mandible is one of the most commonly performed orthognathic surgical procedure performed in the mandible. According to hierarchy of stability, mandibular setback procedure is considered to be relatively unstable procedure and chances of relapse are higher. Objective We conducted this study to determine the skeletal stability of mandibular setback procedure using bilateral sagittal split osteotomy technique in Nepalese population. Method Lateral cephalograms of 14 patients who underwent mandibular setback using bilateral saggital split osteotomy were taken pre-operatively (P1), immediate postoperatively (P2) and eight months to one year post-operatively (P3). Cephalometric tracing was done for all the cephalograms. Various parameters of Burstoneís hard and soft tissue, Steinerís and McNamara analysis were used in the study to determine angular and linear changes following surgery. After tracing the cephalograms, changes between P1- P2, P1-P3 and P2-P3 were calculated. Mean difference in changes between P1-P2, P1-P3 and P2-P3 were compared using paired t test. P value less than 0.05 was considered to be significant. Data analysis was done using SPSS software version 20. Result Mean setback at Pogonion was 3.03 mm whereas at point B were 4.64 mm. Relapse at Pogonion was 0.03 mm and relapse at point B were 0.02 mm. Mean change in point A-Nasion-point B angle was 5.1 degrees whereas mean changes in NA-Pogonion angle were 4.69 degrees. Conclusion There were significant changes in angular as well as horizontal parameters at P2 but there were no significant changes in those parameters at P3. This is a preliminary study that we have carried out at our institution with smaller sample size thus we recommend a study with larger sample size and long term follow up.
Keyword : Bilateral sagittal split osteotomy, mandibular setback, stability