Recently, distraction or compression osteogenesis has been used to treat jaw deformities. The anterior alveolar segment of the maxilla and mandible is moved posteriorly en bloc using a skeletal anchorage device combined with corticotomy to shorten the treatment period for maxillary or mandibular protrusion in adults. This method has many advantages. For example, the invasiveness of surgery is slight and the treatment period can be greatly shortened.
We studied the effects of orthodontic treatment combined with/without corticotomy for maxillary protrusion compared to that using the three-dimensional finite element method. Three-dimensional models were developed based on the geometrical model reconstructed from computed tomography. To evaluate the mechanical characteristics of these methods, the following three items were compared: 1) the displacement of the anteriortooth, 2) the displacement of the anterior alveolar segment, and 3) the distribution of the stresses. Greater displacement of anterior tooth and segment were achieved with corticotomy, and the stresses concentrated at the region of corticotomy. These findings suggest that orthodontic treatment combined with corticotomy is useful.

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This study investigated risk factors for obstructive sleep apnea hypopnea syndrome (OSAHS) induced by orthognathic surgery for malocclusion, by analysis of preoperative and postoperative examination findings. In this first report, we discuss the relationship between the findings from the polysomnographic record and the direction of jaw movement during orthognathic surgery. The postoperative Apnea Hypopnea Index was significantly decreased in the group that underwent maxillaryadvancement with or without mandibular movement; however, there was no significant difference between the groups that underwent mandibular movement with and without maxillary movement. Mandibular morphology is frequently considered when evaluating the relationship between the maxillofacial structure and sleep-disordered breathing; our findings also indicated that maxillary morphology is an important factor. Hence, we advocate orthognathic surgery to treat malocclusion when necessary and to take sleep-disordered breathing into consideration. Additionally, we considered that the findings of this study provide important evaluation criteria for determining the indications for orthognathic surgery to treat OSAHS.

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We investigated risk factors for obstructive sleep apnea hypopnea syndrome (OSAHS) induced by orthognathic surgery for the treatment of malocclusion, and analyzed preoperative and postoperative findings. In Part 1, we reported on the relationship between polysomnographic findings and direction of jaw movement before and after orthognathic surgery. In this study (Part 2), we investigated the relationship between the pharyngeal airway space on lateral cephalometric radiographs and polysomnographic findings in the cases studied in Part 1 As a result, the pharyngeal airway space was influenced more by mandibular movement than by maxillary movement. Further, there was no correlation between changes in the pharyngeal airway space and polysomnographic findings. Therefore, to determine the relationship between orthognathic surgery and sleep-disordered breathing, we consider it important to evaluate functional change rather than morphological change.

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The purpose of this study was to investigate the morphological changes of the inharmonious growth of mandible in rats.
We investigated a rat (6-week-old, male) mandibular asymmetry model to assess the growth changes in morphological study after removal of lateral guide plane. A mandibular lateral guide plane (shift to the left side) was applied to the upper incisors of rats for 8 weeks (0, 1, 2, 4, 8 weeks after removal of lateral guide plane). After mandibular asymmetry was recongnized, the mandible was observed.
In morphological measurement, there were no diferences in mandibular height and mandibular body length until the 8th week between left and right sides after removal of the lateral guide plane. However, the mandibular length of the left side was significantly shorter than that of the right side. After 4 weeks there was no difference between the left and right sides. Moreover, the deformity of condyle in the left side recovered after removal of the lateral guide plane. These results suggested that the early treatment of mandibular shift is necessary to treat mandibular asymmetry.

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The present study was designed to three-dimensionally evaluate the morphological asymmetry of maxillofacial complexes such as the maxilla and the mandible, and the state of the maxillary and mandibular deviation in the craniofacial complex of jaw-deformity patients with facial asymmetry. Based upon the results obtained, we tried to classify the states of asymmetry and/or deviation in the cases showing diverted jaw.
The subjects comprised 15 patients (10 males and 5 females; 16 years and 6 months old on average) diagnosed as mandibular prognathism with facial asymmetry. All subjects exhibited more than 4-mm deviation of the mandible from the midline on the frontal cephalogram. Pretreatment CT images were taken as data for precise diagnosis in all subjects. Then, sliced CT data were forwarded to 3D reconstruction software Medical Viewer INTAGE 3.1 in order to form the MPR images. After that, 3D-CT images were constructed using the volume rendering (VR) method. After these images were obtained, the three-dimensional ratio of morphological asymmetry of the maxilla and the mandible was analyzed. The three-dimensional ratio of the maxillary and mandibular deviation was also examined.
As a result, various types of asymmetry and/or deviation existed and the cases examined were divided into the following eight types: 1. Symmetrical maxilla without deviation in the craniofacial complex, 2. Almost symmetrical maxilla with deviation in the craniofacial complex, 3. Asymmetrical maxilla without deviation, 4. Asymmetrical maxilla with deviation, 5. Asymmetrical maxilla with deviation but complementary to each other, 6. Symmetrical mandible without deviation, and 7. Asymmetrical mandible with deviation, 8. Asymmetrical mandible with deviation but complementary to each other.
The present method for three-dimensional evaluation made it possible to classify the state of asymmetry and/or deviation of the maxilla and the mandible in cases with diverted jaw. This VR method may be helpful in determining a more suitable treatment plan for jaw-deformity patients with deviation.

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Accuracy and postoperative stability were evaluated in a combination of Le Fort I and horseshoe osteotomy for superior repositioning of the maxilla.
Superior repositioning was performed in a total of 13 cases. Le Fort I osteotomy was performed in 6 cases (Le Fort I group) where the planned superior movement was less than 3.5mm. Combination of Le Fort I and horseshoe osteotomy was performed in 7 cases (combination group) where the planned superior movement was more than 4mm. In the Le Fort I and combination groups, the discrepancy between the planned and measured superior repositioning of the maxilla was 0.26 and 0.33mm, respectively. At one year after surgery, combination osteotomy had excellent stability. When superior repositioning of the maxilla is indicated, horseshoe osteotomy combined with Le Fort I is a useful method for accuracy and postoperative stability.

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Congenital factor VII deficiency is a rare hemorrhagic disorder with an autosomal recessive pattern of inheritance and incidence of approximately 1 in every 500000 live births. We report a case of sagittal splitting ramus osteotomy (SSRO) in congenital factor VII deficiency with mandibular prognathism.
The patient was a 20-year-old male. Congenital factor VII deficiency had been diagnosed during preoperative investigation for orthodontic surgery. The serum level of factor VII was 40%. We prepared fresh frozen plasma (FFP), recombinant factor VII, for abnormal bleeding during operation and prevention of delay in homeostasis while we were performing SSRO to set back the mandible. SSRO was done without recombinant factor VII and FFP, and hemostasis was achieved with the application of cold and continuous suction drainage. The amount of blood loss was 75ml. He was discharged on the 11th day after the surgery.

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