Unilateral sagittal split ramus osteotomy: an alternative for some cases of asymmetric mandibular prognathism.

The objective of this study was to propose a treatment protocol for patients with lateral prognathism based on the unilateral sagittal split ramus osteotomy (USSRO). This was a prospective study involving 31 patients with lateral prognathism, who required a bilateral sagittal split ramus osteotomy (BSSRO). Two groups were formed using the proposed protocol, with specific inclusion criteria for each group: BSSRO (n=17) and USSRO (n=14). Occlusal parameters (dental midline deviation, overbite, and overjet) were measured preoperatively (T0), at model surgery (T1), 1 month postoperative (T2), and 1year after surgery (T3) and compared. P-values of <0.05 were considered significant. No significant difference was found between the USSRO and BSSRO groups for all occlusal parameters (T0, T1, T2, and T3). In both groups, there was a significant difference between T0 and T1 and no significant difference between T1 and T2 or T1 and T3 in all of the occlusal parameters; the exception was overbite between T1 and T2 in the BSSRO group, which showed a significant difference. No patient in either group showed signs or symptoms of temporomandibular joint dysfunction at T0 or T3. USSRO was found to be a stable alternative in patients with asymmetric mandibular prognathism. At the same time, it reduced the operating time and morbidity when compared to BSSRO.

Stability of unilateral sagittal split ramus osteotomy for correction of facial asymmetry: long-term case series and literature review.

Bilateral sagittal split ramus osteotomy is considered a standard technique in mandibular orthognathic surgeries to reduce unexpected bilateral stress in the temporomandibular joints. Unilateral sagittal split ramus osteotomy (USSO) was recently introduced to correct facial asymmetry caused by asymmetric mandibular prognathism and has shown favorable outcomes. If unilateral surgery could guarantee long-term postoperative stability as well as favorable results, operation time and the incidence of postoperative complications could be reduced compared to those in bilateral surgery. This report highlights three consecutive cases with long-term follow-up in which USSO was used to correct asymmetric mandibular prognathism. Long-term postoperative changes in the condylar contour and ramus and condylar head length were analyzed using routine radiography and computed tomography. In addition, prior USSO studies were reviewed to outline clear criteria for applying this technique. In conclusion, patients showing functional-type asymmetry with predicted unilateral mandibular movement of less than 7 mm can be considered suitable candidates for USSO-based correction of asymmetric mandibular prognathism with or without maxillary arch surgeries.

Stability of unilateral sagittal split ramus osteotomy for correction of facial asymmetry: long-term case series and literature review

Bilateral sagittal split ramus osteotomy is considered a standard technique in mandibular orthognathic surgeries to reduce unexpected bilateral stress in the temporomandibular joints. Unilateral sagittal split ramus osteotomy (USSO) was recently introduced to correct facial asymmetry caused by asymmetric mandibular prognathism and has shown favorable outcomes. If unilateral surgery could guarantee long-term postoperative stability as well as favorable results, operation time and the incidence of postoperative complications could be reduced compared to those in bilateral surgery. This report highlights three consecutive cases with long-term follow-up in which USSO was used to correct asymmetric mandibular prognathism. Long-term postoperative changes in the condylar contour and ramus and condylar head length were analyzed using routine radiography and computed tomography. In addition, prior USSO studies were reviewed to outline clear criteria for applying this technique. In conclusion, patients showing functional-type asymmetry with predicted unilateral mandibular movement of less than 7 mm can be considered suitable candidates for USSO-based correction of asymmetric mandibular prognathism with or without maxillary arch surgeries.