• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.50 no.4
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• pp.235-240
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• 2024

Lipomas, the most common soft-tissue mesenchymal neoplasms in adults, are characterized by the proliferation of mature white adipocytes without cytologic atypia. Lipomas are rarely observed in the head and neck region. We present a case of resection and orthognathic surgical removal of an intramuscular lipoma of the mandible with involvement of the mandibular ramus and condylar head and neck. An 18-year-old female patient was referred to our hospital for orthognathic surgery for the management of facial asymmetry and mandibular prognathism. The patient did not present with facial swelling, pain, or temporomandibular dysfunction; however, on radiographic examination, including cone-beam computed tomography and magnetic resonance imaging, an infiltrative fatty lesion was observed in the masticator space inside the right mandible, and the adjacent mandible exhibited bone thinning and deformity. Resection of the lipoma was performed along with orthognathic surgery, including a Le Fort I osteotomy for the maxilla and bilateral sagittal split ramus osteotomy (BSSRO). In this case, because the ramus was split using BSSRO, accessing the lipoma intraorally was easy. Consequently, aesthetic scarring was avoided, and no complications, such as unfavorable splitting or pathologic fracture, occurred. Although recurrence has not been observed about 1 year, long-term follow-up should be performed.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.27 no.3
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• pp.259-266
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• 2005

The function of the masseter and anterior temporal muscles was assessed by electromyography in 30 patients with mandibular prognathism (20 patients with facial asymmetry and 10 patients without facial asymmetry) before orthognathic surgery and 4weeks afterwards. Electromyogram(EMG) recordings were made during resting, clenching and swallowing. We compared with right-left difference of this recording and asymmetry index before and after orthognathic surgery. The result of this study was as follows. 1. There was no significant right-left difference in muscle activities of masticatory muscles both asymmetric groups and controls and many variable change after orthognathic surgery.(P>0.05) 2. The mean electric activity of the masticatory muscles was found to have decreased during more clenching than resting, but there was no statistically significant difference because of individual difference of measuring values.(P>0.05) 3. The asymmetry index of masticatory muscles in asymmetric groups was significantly greater during clenching compared with controls.(P<0.05) In conclusion, no right-left difference of muscle activities was found in patients with facial asymmetry before orthognathic surgery and 4weeks afterwards. Not only muscular functioning but also many other factors, such as occlusion, temporomandibular joint disorder and trauma, probably affect facial asymmetry and will be analyzed in future studies. And we will need long term follow-up after orthognathic surgery.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.40
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• pp.13.1-13.8
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• 2018

Background: We evaluated change in the mandibular condyle after orthognathic surgery using cone-beam computed tomography (CBCT) in patients with facial asymmetry. Methods: Thirty patients with skeletal class III malocclusion and mandibular prognathism or facial asymmetry were classified into two groups according to the amount of menton deviation (MD) from the facial midline on anteroposterior (AP) cephalogram: group A (asymmetry, MD ≥ 4 mm; n = 15) and group B (symmetry, MD < 4 mm; n = 15). Position and angle of condylar heads on the axial, sagittal, and coronal views were measured within 1 month preoperatively (T0) and postoperatively (T1) and 6 months (T2) postoperatively. Results: On axial view, both groups showed inward rotation of condylar heads at T1, but at T2, the change was gradually removed and the condylar head returned to its original position. At T1, both groups showed no AP condylar head changes on sagittal view, although downward movement of the condylar heads occurred. Then, at T2, the condylar heads tended to return to their original position. The change in distance between the two condylar heads showed that they had moved outward in both groups, causing an increase in the width between the two heads postoperatively. Analysis of all three-dimensional changes of the condylar head positions demonstrated statistically significant changes in the three different CBCT views in group B and no statistically significant changes in group A. Conclusions: There was no significant difference between the two groups in condylar head position. Because sagittal split ramus osteotomy can be performed without significant change in symmetrical and asymmetrical cases, it can be regarded as an effective method to stabilize the condylar head position in patients with skeletal class III malocclusion and mandibular prognathism or facial asymmetry.