Prevention of relapse following intraoral vertical ramus osteotomy mandibular setback: can coronoidotomy help?

Objective: Relapse after intraoral vertical ramus osteotomy (IVRO) is a subject of debate. The impact of the temporalis muscle on relapse has led to modifications, including liberating the temporalis muscle from the coronoid process or removing the coronoid process itself. The objective of this study was to evaluate the effect of coronoidotomy in preventing relapse after IVRO.

Study Design: Fifty-six patients with mandibular prognathism, selected for IRVO, were studied within a 21-month period. These patients were randomly divided into 2 groups. The patients were matched regarding cephalometric norms. The case group underwent the IVRO plus coronoidotomy, whereas the control group underwent the simple IVRO. Relapse ratio within the first year was compared between groups. Significant relapse was defined as relapse >30% of the primary setback.

Results: Twenty-seven patients in the study group and 29 patients in the control group were followed. The mean relapse ratio 1 year after surgery in B, menton, and pogonion points were greater in control subjects. The mean relapse ratio for ANB and SNB angle 1 year after surgery compared with the primary setback ratio was more in control subjects.

Conclusion: This study suggests that IVRO along with coronoidotomy was slightly better than IVRO without coronoidotomy for treatment of mandibular prognathism.