Evaluation of Maxillary Stability in Simultaneous Downward Repositioning and Expansion With Miniplates, Screws, and Allograft

Maxillary expansion and downward repositioning are among the least stable movements in orthognathic surgery. However, they are often necessary for functional and aesthetic purposes. Although combining these movements can reduce the need for multiple surgical procedures, it increases the risk of instability and requires stabilization techniques to prevent relapse. A multitude of approaches have been described, yet the literature remains limited in optimal strategies to enhance long-term outcomes. This retrospective study evaluated patients who underwent simultaneous maxillary expansion and downward repositioning using segmental Le Fort I osteotomy over a 24-month follow-up period. All patients underwent orthodontic preparation, followed by miniplate stabilization and interpositional bone grafting with tibial allogenic blocks. Data collected included surgical movements performed, dental cast measurements, postoperative imaging, and clinical assessment. Overall, 23 patients (mean age: 41.1±10.3 years) were included. All patients underwent maxillary advancement (3-9 mm) with inferior repositioning (2-9 mm), while 19 patients (82.6%) had concomitant mandibular procedures. Intercanine widths increased from 24.0±2.2 mm to 27.5±2.1 mm ( p <0.001), while intermolar widths increased from 33.0±0.6 mm to 38.7±0.7 mm ( p <0.001). Over 24 months, no complications were reported, including dehiscence, graft exposure, gingival recession, root injury, or relapse. Aesthetic improvement was evident in exposure of the incisors, and radiographs confirmed stable bone healing. When using current surgical methods and interdisciplinary coordination, this technique can be executed as a single-stage procedure with safety and reliability, minimizing patient morbidity and eliminating the need for additional interventions.