• Maxillofacial Plastic and Reconstructive Surgery
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• v.36 no.5
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• pp.185-191
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• 2014

Purpose: Although there have been several studies of reduced airway space after mandibular setback surgery using the sagittal split ramus osteotomy technique, research on the risk factors for changes of the airway space is lacking. Therefore, this study was performed to examine airway changes and the position of the hyoid bone after orthognathic surgery, and to assess possible risk factors. Methods: In this retrospective study, 50 patients who underwent posterior displacement of the mandible by the bilateral sagittal split ramus osteotomy technique were included. Changes of the position of the hyoid bone and the airway space were analyzed over various follow-up periods, using cephalometric radiography taken preoperatively, immediately after surgery, eight weeks after surgery, six months after surgery, and one year after surgery. To identify risk factors, multiple regression analysis of age, gender, body mass index (BMI), posterior mandibular movement, and the presence of genioplasty was performed. Results: Inferor and posterior movement of the hyoid bone was observed postoperatively, but subsequent observations showed regression towards the anterosuperior aspect. The airway space also significantly decreased after surgery (P<0.05), and increased slightly up until six months after surgery. The airway space significantly decreased (${\beta}=0.47$, P<0.01) as the amount of mandibular setback increased. However, age, sex, BMI, and presence of genioplasty were not associated with airway reduction. Conclusion: The amount of mandibular set back was significantly associated with postoperative reduction of airway space. It is necessary to establish a treatment plan considering this factor.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.30 no.1
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• pp.100-107
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• 2008

First of all a good surgical access is considered among various approach methods to the cystic lesion. A poor surgical access can lead to a failure of the whole treatment. A sagittal split ramus osteotomy (SSRO) on the large cyst occurring in the mandibular ramus lets us not only reduce operation time, but can additionally contribute to a good visual field. In addition, a merit exists that it lets this operating method provide soft tissue adhesion for proximal and distal segment and decrease post operative necrosis. We experienced three cases of a large cyst on the mandibular angle and ramus. By employing a sagittal splitting of the mandible, it provided good surgical access and operation results without recurrence during a follow-up period. The surgical technique described may be helpful in treating similar large cysts.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.27 no.2
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• pp.160-163
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• 2005

This study was designed to assess skeletal stabilily after surgical correction of mandibular prognathism by bilateral saggital split ramus osteotomy(BSSRO) and fixation with absorbable screws. From July 2001 to September 2003, 30 patients with Class III malocclusion were treated with BSSRO and mandibular setback. They underwent fixation with Biosorb$^{TM}$ FX screws. Cephalograms were obtained preoperatibely, 2 or 3 days postoperatively, and about 12 months after the operation. Changes in the position of lower incisor tip, B point, and pogonion were examined on lateral cephalograms. The mean mandibular setback just after surgery was 10.6mm. 12 months after surgery, mean relapse at pogonion represented 17.9% and 15.1% at B point. Our results suggest that fixation of the bony segments with absorbable screws after BSSO may be used effectively in properly selected cases.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.32 no.6
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• pp.559-565
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• 2006

The aim of this study was to evaluate the amount and interrelationship of the soft and hard tissue changes after simultaneous maxillary clockwise rotation and mandibular setback surgery in skeletal class III malocclusion. The sample comprised of 16 adult patients who had anteroposterior skeletal discrepancy. These patients had received presurgical orthodontic treatment and surgical treatment which consisted of Le fort I Osteotomy and bilateral saggital split ramus osteotomy. The presurgical (T1) and postsurgical (T2) lateral cephalograms were evaluated. The computerized statistical analysis was carried out with SPSS/PC program. The results demonstrated a decrease in the vertical dimension in the soft and hard tissue. The nasolabial angle was increased and the mentolabial angle was decreased. The results showed also many statistically significant correlations(p<0.05). The lower lip closely followed the skeletal movement of the B- point in the horizontal plane. The double jaw rotation surgery can afford a good solution to solve the problems of class III malocclusion cases.