Outfracture of the inferior turbinates during superior repositioning Le Fort I osteotomy with cone-beam computed tomographic analysis of the volume of the nasal cavity.

We have investigated the volumes of the nasal cavities of 35 patients treated with superior repositioning Le Fort I osteotomy by analysing cone-beam computed tomography (CT) data with a 3-dimensional reconstruction program to correlate changes in the volume of the nasal cavity that were associated with the maxillary superior repositioning and the role of outfracture of the inferior turbinates. The patients were treated at the Pusan National Dental Hospital during the 14-month period January 2011-March 2012.. The patients were divided into two groups, the first of which consisted of 20 patients who had superior repositioning of 4mm or more with a mean superior movement of 5.2mm and outfracture of the inferior turbinates (outfracture group). The second group consisted of 15 patients who also had more than 4mm impaction with a mean superior movement of 5.0mm and for whom outfracture was not done (no outfracture group). Nasal symptoms were investigated preoperatively and 6 months postoperatively using the Nasal Obstruction Symptom Evaluation (NOSE) scale, and 3-dimensional volumetric analysis was made using cone-beam CT data to assess changes in nasal volume. There were significant differences between the groups in volumetric changes (V1-V2) (p=0.001) but no significant differences between the sexes. The volume of the nasal cavity in the outfracture group decreased by 20% after superior repositioning, but that in the no outfracture group decreased by 33%. Among the 20 patients in the outfracture group not one complained of nasal symptoms postoperatively. We conclude that outfracture of the inferior turbinates should be considered when the amount of superior movement of maxilla is more than 4mm.