抄録
In intraoral vertical ramus osteotomy (IVRO), the important issue is how to decide the initial point of the osteotomy to avoid injuring the mandibular nerves. We had developed a simple technique to transfer the initial point of the osteotomy determined by the preoperative panoramic radiograph to the actual ramus. This technique was recently modified. The aim of the present study was to introduce this modified technique and to confirm its better reproducibility.
IVRO using our technique was performed in seven mandibular prognathism cases. A highly experienced surgeon in this technique performed the surgery on the right side, while seven oral surgeons who had had no experience of IVRO performed it on the left side. Positional accuracy of the initial point of osteotomy was compared between the experienced surgeon and the unexperienced surgeons.
The maximum discrepancies between the scheduled and performed osteotomy points were 1.1mm anteriorly, 1.3mm posteriorly for the highly experienced surgeon, and 1.1mm anteriorly, 1.7mm posteriorly for the unexperienced group. The median and interquartile range of the absolute discrepancies were 1.1mm and 0.3mm for the experienced surgeon, and 0.8mm and 0.6mm for the unexperienced group, respectively. No significant differences were found between the two groups. In this series, transient hypesthesia of one side of the lower lip was documented in a case who underwent IVRO with genioplasty. It was not clear whether the hypesthesia was related to IVRO or geni oplasty.
This study shows the efficacy and safety of this modified technique even when performed by less experienced surgeons.
