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 Burstone’s hard
and soft tissue, Steiner’s 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
