Mandibular stability and condylar changes following orthognathic surgery in mandibular hypoplasia patients associated with preoperative condylar resorption

Long-term Stability Over 2 Years After Isolated Maxillary Orthognathic Surgery Combined With Mandibular Autorotation in Risk Patients for Condylar Resorption

“…11 Although the preoperative factors here are similar to the aforementioned patient risk factors and the intraoperative factors are almost identical to the surgical risk factors, joint compression and/or articular damage belong uniquely to the postoperative factors category. 5,[7][8][9][10][11][12][13]16,17 All surgical risk factors are caused by mandibular surgery with bilateral sagittal split ramus osteotomy (BSSRO) with or without maxillary surgery. 4,5,[7][8][9][10][11][12][13][14][15][16][17] Therefore, it is logical to suppose that isolated maxillary orthognathic surgery with mandibular autorotation would be a better surgical maneuver for the correction of malocclusion among patients with risk factors for pICR, if these individuals do not show mandibular asymmetry or severe mandibular retrognathism.…”

“…1 However, patients with preoperative idiopathic condylar resorption (ICR) or patients with risk factors such as high mandibular plane angle and anterior open bite often showed progressive relapse and condylar resorption with temporomandibular joint (TMJ) disorder following orthognathic surgery, which lead to unwanted esthetic results. [2][3][4][5] The earliest clinical or radiological signs of postoperative ICR (pICR) with occlusal disturbance or condylar resorption can occur 6 months after surgery; however, pICR is often observed instead at 1 or 2 years after surgery in most patients 4,[6][7][8][9][10][11][12] and ultimately leads to long-term relapse with decreased posterior facial height, progressive mandibular retrusion, and anterior open bite. [5][6][7][8][9][10][11][12][13][14][15][16][17] The pathophysiology of pICR is still not well understood.…”

“…[2][3][4][5] The earliest clinical or radiological signs of postoperative ICR (pICR) with occlusal disturbance or condylar resorption can occur 6 months after surgery; however, pICR is often observed instead at 1 or 2 years after surgery in most patients 4,[6][7][8][9][10][11][12] and ultimately leads to long-term relapse with decreased posterior facial height, progressive mandibular retrusion, and anterior open bite. [5][6][7][8][9][10][11][12][13][14][15][16][17] The pathophysiology of pICR is still not well understood. The main risk factors are suggested to be sex hormones and mechanical overloading on TMJ after orthodontic treatment, orthognathic surgery, trauma, internal derangement, occlusal therapy, or parafunctional habits.…”

“…5,[7][8][9][10][11][12][13]16,17 All surgical risk factors are caused by mandibular surgery with bilateral sagittal split ramus osteotomy (BSSRO) with or without maxillary surgery. 4,5,[7][8][9][10][11][12][13][14][15][16][17] Therefore, it is logical to suppose that isolated maxillary orthognathic surgery with mandibular autorotation would be a better surgical maneuver for the correction of malocclusion among patients with risk factors for pICR, if these individuals do not show mandibular asymmetry or severe mandibular retrognathism. Isolated Le Fort I osteotomy is usually indicated to reduce the anterior facial height by the correction of the anterior open bite, and concomitant mandibular autorotation holds an advantage with consequent forward chin movement.…”

“…The surgical risk factors are large mandibular advancement, counterclockwise rotation of the proximal and distal mandibular segments, and surgically induced condylar displacement 15 . Elsewhere, the risk factors were subclassified into preoperative factors, intraoperative factors, and postoperative factors 11 . Although the preoperative factors here are similar to the aforementioned patient risk factors and the intraoperative factors are almost identical to the surgical risk factors, joint compression and/or articular damage belong uniquely to the postoperative factors category 5,7–13,16,17 …”