The Effect of Trans-Sutural Distraction Osteogenesis on Nasal Bone, Nasal Septum, and Nasal Airway in the Treatment for Midfacial Hypoplasia in Growing Patients

The purposes of this study were to analyze the effect of trans-sutural distraction osteogenesis (TSDO) on nasal bone, nasal septum, and nasal airway in the treatment of midfacial hypoplasia. A total of 29 growing patients with midfacial hypoplasia who underwent TSDO by a single surgeon were enrolled. The 3-dimensional measurement of nasal bone and nasal septum changes was performed using computed tomography (CT) images obtained preoperatively (T0) and postoperatively (T1). One patient was selected to establish 3-dimensional finite element models to simulate the characteristics of nasal airflow field before and after traction. After traction, the nasal bone moved forward significantly (P<0.01). The septal deviation angle was lower than that before traction (14.43±4.70 versus 16.86 ±4.59 degrees) (P<0.01). The length of the anterior and posterior margin of the vomer increased by 21.4% (P<0.01) and 27.6% (P<0.01), respectively, after TSDO. The length of the posterior margin of the perpendicular plate of ethmoid increased (P<0.05). The length of the posterior inferior and the posterior superior margin of the nasal septum cartilage increased (P<0.01) after traction. The cross-sectional area of nasal airway on the deviated side of nasal septum increased by 23.0% after traction (P<0.05). The analysis of nasal airflow field showed that the pressure and velocity of nasal airflow and the nasal resistance decreased. In conclusion, TSDO can promote the growth of the midface, especially nasal septum, and increase the nasal space. Furthermore, TSDO is conductive to improve nasal septum deviation and decrease nasal airway resistance.