[Comparation of anterior maxilla and whole maxilla clockwise rotation to improve paranasal aesthetic defects of skeletal Class Ⅲ maxillofacial deformity].

OBJECTIVE

To compare the aesthetic effects of anterior maxilla clockwise rotation combined with segmental Le Fort Ⅰ osteotomy and whole maxilla clockwise rotation on improving paranasal concavity in patients with Class Ⅲ maxillofacial deformity.

METHODS

A non-randomized controlled trial was designed, and 21 patients diagnosed with skeletal Class Ⅲ maxillofacial deformity were included. In the study, 11 patients in the test group were treated by segmental Le Fort Ⅰ osteotomy combined with anterior maxilla clockwise rotation, and 10 patients in the control group were treated by whole maxilla clockwise rotation. The CBCT and 3D photography of preoperative (T0), 2 weeks postoperative (T1), and 6 months postoperative (T2) were collected respectively, and the three-dimensional cephalometry was carried out. The differences of specific parameters between the two groups were compared by independent sample t-test, including saggital displacement of the cheek mass point (CK) and subalare point (SA), nasolabial angle, occlusal plane angle and labial inclination angle of the upper incisor.

RESULTS

There were no significant differences of the parameters on T0 between the two groups. The average sagittal displacement of the upper incisors of the test group was (-0.71±1.67) mm and smaller than that of control group [(2.26±1.68) mm], t=-4.052, P < 0.05. The average angle of the occlusal plane clockwise rotation of the test group was 1.46°±2.38° and smaller than that of the control group (4.31°±1.83°), t=-3.047, P < 0.05. The angle of anterior maxilla clockwise rotation was 11.73°±2.81° during the surgery. The average saggital displacement of the paranasal soft tissue landmarks of the test group from T0 to T2 was larger than that of the control group [CK point, (4.96±1.18) mm vs. (2.01± 1.50) mm, P < 0.05;SA point, (5.19±1.17) mm vs. (2.69±1.45) mm, P < 0.05]. The labial inclination angle of the upper incisor of the test group was 112.15°±5.40° in T2 and significantly smaller than that of the control group (122.38°±8.83°), t=-3.237, P < 0.05. The nasolabial angle of the test group was 106.54°±12.82° in T2 and significantly larger than that of the control group (93.90°±12.46°), t=2.288, P < 0.05.

CONCLUSION

Compared with whole maxilla clockwise rotation, anterior maxilla clockwise rotation combined with segmental Le Fort Ⅰ osteotomy can increase the saggital displacement of the paranasal soft tissue, correct labial inclination of the upper incisors and the acute naso-labial angle and better improve the paranasal aesthetic defects in patients with Class Ⅲ maxillofacial deformity with less changing on the saggital orientation of the upper incisors and the occlusal plane angle.