Three Cases of Coronoid Process Transplantation to Fill Maxillary Bone Fragment Gap for Orthognathic Surgery−Each Case of a Maxillary Protrusion, a Maxillary Retrusion and Vertical Maxillary Excess, a Vertical Maxillary Deficiency
Le Fort I osteotomy is performed commonly to promote occlusal relations and midface profile harmony. However the cases that the larger amount of maxillary segment movement were predicted anteroposteriorly and /or vertically would often show the significant gap between bone fragments. The gap disrupts a rigid fixation of maxilla and decrease the skeletal stability. We underwent three cases filling coronoid process to the gap and we report the graft procedure and the stability after surgery.
Case and Methods
Three case were performed double jaw surgery and removed bilateral coronoid process during biSSRO for transplantation and filled to the gap according to maxillary movement. Case1; 41-year-old Japanese woman with skeletal class III. The case was performed on-lay graft to the maxillary segment by Le Fort I osteotomy as filling the gap. Case2; 36-year-old Japanese woman with skeletal class II and short lower facial height. The case was performed sandwich graft between maxillary segments. Case3; 37-year-old Japanese man with facial asymmetry and vertical maxillary excess. The case was performed on-lay graft to the maxilla of immobile as filling the gap.
Result
All case improved facial profile and achieved an acceptable occlusion. No relapse of the maxillary position were observed. After Six months, three cases showed new bone formation and reduced the gap and regenerated bone at the donor-site of bilateral coronoid process.
Conclusion
The case that bone fragment gap by Le fort I osteotomy appear 3-5mm or more should be needed filling the gap for postoperative stability. Although the one of autogenous bone graft is iliac bone, our procedure of coronoid process transplantation was performed at the same operation field as double jaw surgery and rigid maxillaly fixation.