Does Maxillomandibular Counterclockwise Rotation Affect Surgical Stability in Class III Skeletal Patients with High Plane Angle? A Retrospective Longitudinal Study.

Abstract

In class III, skeletal patients with high plane angle, counterclockwise rotation of maxillomandibular units is necessary. The study was aimed to evaluate the long-term stability of the change of mandibular plane in patients with class III deformity. This is a retrospective longitudinal clinical study. Patients with class III skeletal deformity and high plane angles who underwent maxillary advancement and superior repositioning with mandibular set back were studied. The change of mandibular plane (MP) was predictive factors of the study. Age, gender, the amount of movement of the maxillary advancement, and mandibular set back following orthognathic surgeries were variables. The amount of relapse at the A and B points 12months after orthognathic surgeries was outcomes of the study. Pearson correlation test was used to determine any correlation between relapse at the A and B points following bimaxillary orthognathic surgery. Fifty-one patients were studied. The mean of MP changes immediately after osteotomies was 4.66 (1.64) degrees. The horizontal relapse at B point 12months after surgeries was 1.08 (0.81) mm, and the vertical relapse was 1.38 (0.44) mm. There was a correlation between the horizontal and vertical relapse with MP change (P = 0.001). It seems that the counterclockwise rotation of maxillomandibular units in patients with class III skeletal deformity and high plane angle may be associated with the vertical and horizontal relapse that was noticed at the B point.