Clinical Evaluation of Le Fort I With Horseshoe Osteotomy in Bimaxillary Surgery
Le Fort I with horseshoe osteotomy has the distinct advantage of allowing superior elevated repositioning of the maxilla, especially in the posterior portion, without trimming of the bone around the descending palatine artery. We have performed a single segmental Le Fort I osteotomy to achieve increased movement with 5.0 mm at the point of maxillary tuberosity. However, more recently we have experienced more cases which require Le Fort I with horseshoe osteotomy. In the current study, we have evaluated the accuracy of this technique in bimaxillary surgery.
2. Subjects
The subjects were 8 adult patients (8 female, age: 18 - 35 years, median age 21 years) who had undergone Le Fort I with horseshoe osteotomy within 132 cases of bimaxillary surgery from 2009 to 2014. Lateral cephalograms were obtained preoperatively, 1 week postoperatively, and subsequently 3 and 6 months later.
3. Results
The cases included two gummy smiles, one asymmetry, one open bite, two gummy smiles with asymmetry and two open bites with asymmetry. In the case of mandibular movement, intraoral ramus vertical osteotomy (IVRO), IVRO with genioplasty, and sagittal splitting ramus osteotomy (SSRO) were carried out to six, one, and one patient respectively. The mean superior movement of upper incisor (U1) and upper molar mesial cusp tip (UMT) were 2.9 mm (range -2.0 - 8.0mm) and 4.8 mm (range 3.0 - 8.0 mm) respectively. There were no severe complications observed such as intraoperative hemorrhage, avascular necrosis of the maxilla (partial or total), devitalization of teeth and oroantral or oronasal fistulas in any of the cases. The average blood loss was 247ml and average operation time was 370 min. In one case, the horseshoe osteotomy was added to the high Le Fort I osteotomy, which was planned for superior movement of 3.0 mm at UMT and 5.0 mm at posterior nasal spine (PNS) with clockwise rotation of the maxilla owing to the interferences of posterior maxillary bones. In two cases, which were planned for both superior movement and posterior setback (one is 4.0mm at U1, 5.0mm at UMT impaction, and 3.0mm posterior setback; the other is 8.0mm at U1 and UMT impaction, and 5.0mm posterior setback), there was a discrepancy between prediction and actual horizontal movement. It was suggested that this was the result of the larger interference between the dentoalveolar component and palatal component and insufficient of trimming of the maxillary tuberosity, posterior palatal wall and anterior pterygoid plates.
4. Conclusions
Superior movement could be obtained with accuracy by application of this technique, regardless of the amount of superior impaction. However, in regard to posterior repositioning, it is suggested that not only 3D model operation should be evaluated before surgery with a double splint technique intraoperatively, but that computer assisted navigation should be implemented where possible as excess trimming of the bone may also be required to achieve the planned positioning of the dentoalveolar component.
References
- Harada K, Sumida E, Enomoto S, Omura K. Post-operative stability of the maxilla treated with Le Fort I and horseshoe osteotomies in bimaxillary surgery. Euro J Orthodont. 24, 471-476, 2002.
- Yoshioka I, Khanal A, Kodama M, Habu M, Nishikawa T, Iwanaga K, Kokuryo S, Basugi A, Sakoda S, Fukuda J, Tominaga K. A novel modification in combined Le Fort I and horseshoe osteotomy for posterior repositioning of the maxilla. Asian J Oral Maxillofac Surg. 23, 172-176, 2011.