• Maxillofacial Plastic and Reconstructive Surgery
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• 제16권1호
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• pp.51-62
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• 1994

The sagittal split osteotomy of the mandibular ramus is a common procedure which has been used in the correction of mandibular deformities for a few decades. Although the technical improvements have increased the reliability and stability of SSRO procedure, the postoperative relapse is imperative and clinically more significant than any other complication. One of the major causes of the relapse is due to the displacement of the proximal segment during SSRO procedure, which is well documented in the literature. Therefore it is important to preserve the original position of the proximal segment during SSRO proced and maxillofacial fixation period. In the case of mandibular asymmetry, if one side of mandible is advanced and the other side of mandible is setback during SSRO procedure, the proximal segment in the advancement site will rotate laterally and the proximal segment in the setback site will rotate medially. For the prevention of the lateral rotation or flaring of the proximal segment in the advancment site. we deliberately fracture the posterior protion of the distal segment in green-stick fashion during SSRO procedure, and there is no need to fix the fractured lingual segment. We fix the two osteotomized bony segments in the buccal cortex area rigidly with adjustable monocortical plates and screws. During SSRO procedure the lingual fracture technique was applied to nine patients with severe mandibular asymmetry who underwent orthognathic surgery in our hospital since march, 1992. These clinical experiencies enable us to find the lingual fracture technique has the following advantages. 1. The proximal segment is displaced minimally. 2. The osteotomized bony segments are contacted intimately. 3. The postoperative relapse and the healing period are decreased.

• 대한치과교정학회:학술대회논문집
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• 대한치과교정학회 2005년도 제38회 학술대회
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• pp.152.1-152.1
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• 2005

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제41권2호
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• pp.102-108
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• 2015

In surgery for facial asymmetry, mandibles can be classified into two types, rotational and translational, according to the required mandibular movements for surgery. During surgery for rotational mandibular asymmetry, a bilateral sagittal split ramus osteotomy (BSSRO) may cause a large bone gap between the proximal and distal segments as well as condylar displacement, resulting in a relapse of the temporomandibular joint disorder, especially in severe cases. The intraoral vertical ramus osteotomy has an advantage, in this respect, because it causes less rotational displacement of the proximal segment on the deviated side and even displaced or rotated condylar segments may return to their original physiologic position. Unilateral intraoral vertical ramus osteotomy (UIVRO) on the short side combined with contralateral SSRO was devised as an alternative technique to resolve the spatial problems caused by conventional SSRO in cases of severe rotational asymmetry. A series of three cases were treated with the previously suggested protocol and the follow-up period was analyzed. In serial cases, UIVRO combined with contralateral SSRO may avoid mediolateral flaring of the bone segments and condylar dislocation, and result in improved condition of the temporomandibular joint. UIVRO combined with contralateral SSRO is expected to be a useful technique for the treatment of rotational mandibular asymmetry.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제19권2호
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• pp.130-134
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• 1997

본 저자는 하악지시상분할법이 측두하악관절장애와 관련되어 교합의 개선과 과두의 위치적변화에 어떤영향을 미치는가에 관해 연구하고자하여 다음과 같은 결과를 얻었다. 측두하악관절증상은 약 80%에서 개선되었으며 이는 아마도 부정교합의 개선으로 일어난 것이 아닌가 생각된다. 하악지 시상분할술에 있어 측두하악관절의 구조적 변화가 야기되는데 이것이 관절의 기능에 어떤 변화를 주어 측두하악관절증상과 관련해서 발생되는 것으로 추정되고 단기 추적조사와 비교해 볼 때 장기추적조사 결과 하악두위치변화에도 불구하고 Range of adaptation이 환자 개개인에 존재하는 것이 아닐까 생각된다. 이와 같은 결과를 종합해볼 때 경미한 측두하악관절증상을 동반한 하악전돌증환자에서 악교정수술을 시행함에 있어 개인의 하악두의 위치를 지켜주어 부정교합의 개선과 정상적인 관절기능을 유지시켜주는 것이 회귀성향과 관련하여 중요한 요소가 아닌가 생각되며 회귀성향과 하악두의 위치관계 또 측두하악의 증상등을 연관하여 더 진행된 연구가 필요하리라 사려된다.

• 대한치과교정학회지
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• 제43권6호
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• pp.263-270
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• 2013

Objective: To evaluate condylar head remodeling after mandibular set-back sagittal split ramus osteotomy (SSRO) with rigid fixation in skeletal class III deformities. The correlation between condylar head remodeling and condylar axis changes was determined using cone-beam computed tomography (CBCT) superimposition. Methods: The CBCT data of 22 subjects (9 men and 13 women) who had undergone mandibular set-back SSRO with rigid fixation were analyzed. Changes in the condylar head measurements and the distribution of the signs of condylar head remodeling were evaluated by CBCT superimposition. Results: The subjects showed inward rotation of the axial condylar angle; reduced condylar heights on the sagittal and coronal planes; and resorptive remodeling in the anterior and superior areas on the sagittal plane, superior and lateral areas on the coronal plane, and anterior-middle and anterior-lateral areas on the axial plane (p < 0.05). Conclusions: The CBCT superimposition method showed condylar head remodeling after mandibular set-back SSRO with rigid fixation. In skeletal class III patients, SSRO with rigid fixation resulted in rotation, diminution, and remodeling of the condylar head. However, these changes did not produce clinical signs or symptoms of temporomandibular disorders.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제29권2호
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• pp.187-191
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• 2007

An ameloblastoma is one of the most common odontogenic tumors. Ameloblastoma is cytologically a benign tumor, but is clinically characterized by infiltrative growth and high recurrency. The treatment of ameloblastoma has been controversial. The aim of this paper is to consider effectiveness of curettage and enucleation after SSRO in the small-sized multilocular intraosseous ameloblastomas that have been treated more frequently by radical treatment. They were radiographically characterized by the cortical bone that was expanded or eroded locally and histopathologically by solid multilocular ameloblastomas. It is considered that curettage and enucleation after SSRO and long-term follow-up enable the small-sized multilocular intraosseous ameloblastomas that were characterized by almost destroyed cancellous bone and expanded cortical bone to treat minimizing facial disfigurement and masticatory dysfunction and sociopsychological impact produced by radical treatment. We recommend that the small-sized multilocular intraosseous ameloblastomas without involvement to the surrounding soft tissues be first treated by curettage and enucleation after SSRO.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제33권2호
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• pp.190-197
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• 2011

The management of mandibular prognathism was revolutionized by the advent of the of sagittal split ramus osteotomy (SSRO) technique as described by Obwegesser and Trauner in 1957. Facial nerve palsy following SSRO is a rare but serious problem. In the event of post-operative facial palsy, careful clinical and neurophysiological investigations such as a nerve condunction test for facial function is mandatory. The authors examined patients with facial palsy following SSRO. Patients recovered after 3~4 months and we had performed clinical examinations with electromyography and nerve conduction tests during follow-up period.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제18권4호
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• pp.563-569
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• 1996

Skeletal and dental changes were examined in 38 patients of mandibular prognathism who been treated by a bilateral sagittal split osteotomy(SSRO) and internal fixation using titanium mini-screws. All patients were followed up for over 8 months after the surgeries, and postoperative cephalometric measurements were compared at 2 months and at 8 months. Linear measurements of the "Pog-most posterior screws" and angular measurementsts of "SN-Pog'were compared to figure out the change of bony fragments. The significancy of data were tested by unpaired T-test. The results were as follows : 1. The fixation screws were changed in cephalometric position as little as $0.32{\pm}2.51mm$ in SSRO and $0.15{\pm}1.00mm$ in SSRO & Le Fort I Osteotomy.(P<0.05) 2. Mandibular set-back over 5mm resulted in less stability of the fixation screws and higher relapse tendency. 3. The internal fixation using two screws along the inferior border and one on the superior ridge is considered to be very resistant to postoperative relapse of the repositioned bony segments.

• 대한치과교정학회지
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• 제53권2호
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• pp.99-105
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• 2023

Objective: The study aimed to evaluate the changes in mandibular width after sagittal split ramus osteotomy (SSRO) in patients with mandibular asymmetric prognathism using cone-beam computed tomography (CBCT). Methods: Seventy patients who underwent SSRO for mandibular setback surgery were included in two groups, symmetric (n = 35) and asymmetric (n = 35), which were divided according to the differences in their right and left setback amounts. The mandibular width was evaluated three-dimensionally using CBCT images taken immediately before surgery (T1), 3 days after surgery (T2), and 6 months after surgery (T3). Repeated measures analysis of variance was applied to verify the differences in mandibular width statistically. Results: Both groups showed a significant increase in the mandibular width at T2, followed by a significant decrease at T3. No significant difference was observed between T1 and T3 in any of the measurements. No significant differences were found between the two groups (p > 0.05). Conclusions: After mandibular asymmetric setback surgery using SSRO, the mandibular width increased immediately but returned to its original width 6 months after surgery.

• 대한치과의사협회지
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• 제34권3호통권322호
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• pp.158-159
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• 1996