Stability of clockwise rotation of the maxillary occlusal plane in skeletal Class III patients treated with two‐jaw surgery

Abstract

Introduction: To investigate the post-surgical stability of clockwise rotation of the maxillary occlusal plane (MXOP) after Le Fort I osteotomy for posterior impaction and advancement in skeletal Class III patients who had undergone two-jaw orthognathic surgery (2J-OGS).Materials and methods: Sample set consisted of 46 patients [18 males and 28 females]. Using lateral cephalograms taken at the initial (T0), before 2J-OGS (T1), after (T2), and at debonding (T3), The amount of MXOP change (criterion: 2° in ΔMXOP between T2-T3) was used to assign patients to Group1[G1, high relapse, 3.09°] or Group2 [G2, low relapse, -0.99°]. Statistical analyses were then performed.Results: Compared to G2, G1 exhibited more severe skeletal Class III relationships and a atter MXOP at T0, a greater increase in ΔANB, and more clockwise rotation of ΔMXOP and ΔFMA during T1-T2, as well as a greater decrease in ΔANB, higher counterclockwise rotation of ΔMXOP, and upward movement of U1 during T2-T3. Regression analysis resulted in formulation of the following equation: MXOP(ΔT2-T3) = -0.37 X MXOP(ΔT1-T2) -0.43.Conclusions: The higher the clockwise rotation of the MXOP during 2J-OGS in skeletal Class III patients, the greater the relapse (counterclockwise rotation) in the MXOP.

The prediction of sagittal chin point relapse following two-jaw surgery using machine learning

“…The second limitation is that Pog was the only measurement. Other measurements, such as the maxillary occlusal plane 27 , vertical bony step 28 and points A, B, etc., should be addressed in future studies.…”