Occurrence of a ‘bad’ split and success of initial mandibular healing: a review of 524 sagittal ramus osteotomies in 262 patients

Complications associated with orthognathic surgery

“…Although no statistically significant difference was found between the two groups, the rate of mandibular fracture was higher among patients who underwent extraction six months before SSRO. Posnick et al15 reported no ‘bad splits’ following extraction of impacted third molars performed during SSRO and claimed that the extraction of impacted teeth does not increase the rate of ‘bad’ splits and delay bone healing.…”

The Low Medial Horizontal Osteotomy in Patients With Atypical Ramus Morphology Undergoing Sagittal Split Osteotomy

“…However, the lack of a significant risk to the IAN or unfavorable fractures should make this technique applicable to mandibles with typical ramus morphology. Posnick et al 19 reported on the results of the SSO with the low medial cut in 524 osteotomies during a 9-year period, excluding patients with jaw deformities related to syndromes, clefts, previous trauma, repeat osteotomies, and pathologic features. They reported no unfavorable splits within this large sample, 40% of whom had undergone simultaneous third molar removal.…”

“…They reported no unfavorable splits within this large sample, 40% of whom had undergone simultaneous third molar removal. 19 Additionally, the overall risk of an unfavorable split of the proximal segment is very low using the traditional medial horizontal osteotomy design (<2 to 5%). 14,15,19,29,30 Our results are consistent with this prevalence, with no unfavorable splits noted.…”

“…To reduce the frequency of unfavorable osteotomy propagation toward the condyle, Posnick has described modification to the medial horizontal osteotomy, keeping the cut ''low'' or close to the mandibular occlusal plane and ' 'short' ' or terminating anterior to the lingula. 9,10,19 This modification allows for successful ramus osteotomies, with the posterior osteotomy progressing into the retrolingular fossa below the lingula, potentially decreasing the likelihood of propagation toward the condyle. 9,10,19 One consequence of keeping the medial ramus osteotomy low is that the IAN might be more likely to be contained within the proximal segment or injured.…”

“…9,10,19 This modification allows for successful ramus osteotomies, with the posterior osteotomy progressing into the retrolingular fossa below the lingula, potentially decreasing the likelihood of propagation toward the condyle. 9,10,19 One consequence of keeping the medial ramus osteotomy low is that the IAN might be more likely to be contained within the proximal segment or injured. 9,10,19,20 In an analysis of a large series of SSOs in patients with primary dentofacial deformities without associated craniofacial anomalies, Posnick et al 19 reported no unfavorable splits of the proximal segment when using a low medial horizontal osteotomy.…”