Three Dimensional Study on the Postoperative Stability after Advancement of Maxilla Using Le Fort I Osteotomy

Oh, Chul Jung; Hur, Jung Woo; Chung, Kwang; Cho, Min Sung; Jung, Seunggon; Park, Hong Ju; Oh, Hee Kyun; Ryu, Sun Youl; Kook, Min Suk

Abstract

PURPOSE
This study evaluated postoperative maxillary stabilities in patients with skeletal Class III malocclusion who were taken both maxillary advancement surgery and mandibular retrusive surgery, using Le Fort I osteotomy, through three-dimensional computed tomography.
METHODS
We selected 14 patients who were taken postoperative three-dimensional computerized tomography at the time before surgery, immediately after surgery, six months after surgery among the patients undergone both maxillary advancement surgery using Le Fort I osteotomy and mandibular retrusive surgery using bilateral sagittal split ramus osteotomy. We measured and compared the vertical distance of A-point and posterior nasal spine (PNS), the horizontal distance of A-point and PNS in transverse plane and coronal plane of the three-dimensional reconstructed images, respectively.
RESULTS
In transverse plane, the distance difference between immediately after surgery (S1) and immediately before surgery (S0) of A-point was -0.04+/-1.80 mm, S2 and S0 was -0.15+/-1.69 mm, and between S1 and S2 was 0.11+/-0.58 mm. There were no significant differences between these data (P>0.05). In transverse plane, the distance between S1-S0 of PNS was -3.87+/-2.37 mm, S2-S0 of PNS was -3.79+/-2.39 mm, and S1-S2 of PNS was -0.08+/-0.18 mm. There were significant differences between these data (P<0.05). In coronal plane, the distance between S1-S0 of A-point was 3.99+/-0.86 mm, S2-S0 was 3.57+/-1.09 mm, and S1-S2 was 0.42+/-0.42 mm. There were significant differences between these data (P<0.05). In coronal plane, the distance between S1-S0 of PNS was 3.82+/-0.96 mm, S2-S0 was 3.43+/-0.91 mm, and S1-S2 was 0.39+/-0.49 mm. There were significant differences between these data (P<0.05). In transverse plane, it was estimated that PNS has no statistical postoperative stability in the same direction. In coronal plane, it was estimated that both A-point and PNS had no statistical postoperative stability (P<0.05).
CONCLUSION
Clinically, the operation plan needs to take into account of the maxillary relapse.