Does osteotomizing the lower border of the mandible affect the lingual split pattern in a sagittal split ramus osteotomy?

Abstract

Aim The purpose of this study was to evaluate the effect of adding a fourth osteotomy at the lower border of the mandible on the lingual cortical fracture pattern in bilateral sagittal split ramus osteotomies. Patients and methods The sample of the study consisted of 20 patients (12 male and 8 female, with a mean age of 26.79 ± 7.12 years) with mandibular deformities who needed bilateral sagittal split ramus osteotomy. One side underwent a traditional sagittal split ramus osteotomy, and the procedure was modified on the other side by adding a 1 cm horizontal osteotomy at the lower border of the mandible, just distal to the caudal end of the vertical buccal osteotomy cut. A 3D CBCT was used to identify the split pattern. Results In the total sample, 40% of the lingual splits ran vertically toward the lower border of the mandible (LSS1), 20% of the splits passed horizontally to the posterior border of the mandible (LSS2), 32.5% of the splits took place along the inferior alveolar canal (LSS3), and 7.5% of the splits were unfavourable fractures (LSS4). On the inferior border osteotomy sides, the distribution of LSS1, LSS2, LSS3, and LSS4 was 10 (25%), 6 (15%), 4 (10%), and 0 (00), respectively. Their distribution on the sides without inferior border osteotomy was 6 (15%), 8 (20%), 13 (32.5%), and 3 (7.5%), respectively. Statistical analysis revealed a significant difference between the two groups (p < 0.05). Conclusion Inferior border osteotomy tends to direct the lingual split fracture line toward the lower and posterior borders of the mandible and minimizes bad splits; however, further studies are needed to confirm our findings.

Is inferior border osteotomy beneficial in bilateral sagittal split osteotomy? A retrospective clinical study

“…The distribution of type 1, type 2, type 3, and type 4 fracture types in the regions where an additional fourth osteotomy was performed on the mandibular border after BSSO was 10 (25%), 6 (15%), 4 (10%), and 0 (0%), respectively. The authors noted that lower border osteotomy tends to direct the lingual fracture line towards the inferior and posterior margins of the mandible and minimizes the risk of bad splits (9). The conventional BSSO group in this study had the greatest percentage of type 1 fractures (68.8%), followed by type 3 fractures (18.8%) and type 2 fractures (12.5%) in term of lingual fracture pattern.…”

“…The BSSO procedure, which is regrarded as one of the most established technique of orthognathic surgery, has been used for many years for the correction of skeletal deformities in the lower jaw. Several modi cations have been made to the original approach since it was published in the literature to reduce the risk of perioperative complications, avoid recurrence, hasten bone healing, and better control the split procedure (9,15). The inferior border osteotomy, which Wolford et al rst reported in the literature, is one of these modi cations.…”

“…They have also reduced the frequency of intraoperative and postoperative complications and improved the stability and predictability of postoperative outcomes. Despite these developments, BSSO demands technical accuracy, and complications still occur (1,8,9). Injuries to the inferior alveolar nerve (IAN) constitute one of the most common and widely documented complications of BSSO.…”

“…Injuries to the inferior alveolar nerve (IAN) constitute one of the most common and widely documented complications of BSSO. Permanent nerve damage in the IAN can occur in approximately 5-10% of patients after BSSO surgery (9)(10)(11). Due to the IAN injury, permanent anesthesia, hyperesthesia, or allodynia could appear in the lower lip and chin area after the surgery.…”

“…In the literature, there are a limited number of ex vivo and in vivo studies examining the advantages and disadvantages of lower border osteotomies (9,15,16). The rst hypothesis for the study was that patients who underwent lower border osteotomy of the mandible would be more prone to type 1 fracture patterns after splitting.…”