• 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.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제28권1호
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• pp.1-6
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• 2002

When bilateral sagittal split ramus osteotomy or mandibular angle reduction are carried out, we have to consider the position of inferior alveolar nerve. For bone splitting or resection using a saw or an osteotome, the bucco-lingual position of the inferior alveolar nerve plays an important role in the preventing perioperative complications such as paresthesia or anesthesia. Because it is rare to find literatures concerning the mean anatomic position of the inferior alveolar nerve in Koreans, we investigated 30 patients who underwent to take CT and orthopantomogram for implant surgery, and evaluated the bucco-lingual position and vertical relationship of the inferior alveolar nerve at the mandible. The results showed that the distance between inferior alveolar nerve and buccal plate was the farthest at mandibular second molar ($7.1{\sim}7.4mm$) and the nearest at mandibular angle area ($4.4{\sim}4.8mm$). But it was no statistical relationship between the bucco-lingual postion of inferior alveolar nerve on the CT and its vertical position on the OPT. In conclusion, the results suggest that a careful surgical procedure is needed at the mandibular angle area to avoid a nerve damage and there are sufficient bone materials at the mandibular second molar are for bilateral sagittal split ramus osteotomy or mandibular angle reduction or plate fixation. And OPT is not usefull for the evaluation of a relative bucco-lingual position of inferior alveolar nerve in relation to its vertical postion on the OPT.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제38권3호
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• pp.139-144
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• 2012

This study was performed in order to evaluate the occurrence of temporomandibular joint disorder after surgical correction of skeletal class II malocclusion. Materials and Methods: This study included 21 patients who underwent orthognathic surgery for the correction of dentofacial deformities by a single surgeon at Mokdong Hospital, Ewha Womans University from 2000 to 2010. They underwent bilateral sagittal split ramus osteotomy for the treatment of undesirable mandibular advancement. The temporomandibular disorder (TMD) symptoms prior to surgery were recorded and the radiographic evaluation (panorama, bone scan, and magnetic resonance imaging [MRI]) of the post-surgery temporomandibular joint (TMJ) were assessed in order to evaluate condylar resorption, remodeling and disc displacement. The minimum follow-up period, including orthodontic treatment, was 12 months. Orthognathic procedures included 1-jaw surgery (n=8 patients) and 2-jaw surgery (n=13 patients). The monocortical plate was used for bilateral sagittal split ramus osteotomy fixation. Results: Among class II malocclusion patients with TMD symptom, clicking improved in 29.1%, and maximum mouth opening increased from $34.5{\pm}2.1$ mm to $37.2{\pm}3.5$ mm. The differences were not statistically significant, however. Radiographic changes in bone scan improved slightly based on the report by radiologist but not in TMJ dynamic MRI. Conclusion: No particular improvements were found in patients with joint sound only. Patients with limitation of mouth opening showed an increase in the degree of opening, but the difference was not statistically significant (P>0.05).

• 대한치과교정학회지
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• 제54권4호
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• pp.247-256
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• 2024

Objective: This retrospective study evaluated the mandibular condyle position before and after bimaxillary orthognathic surgery performed with the mandibular condyle positioned manually in patients with mandibular prognathism using cone-beam computed tomography. Methods: Overall, 88 mandibular condyles from 44 adult patients (20 female and 24 male) diagnosed with mandibular prognathism due to skeletal Class III malocclusion who underwent bilateral sagittal split ramus osteotomy (BSSRO) and Le Fort I performed using the manual condyle positioning method were included. Cone-beam computed tomography images obtained 1-2 weeks before (T0) and approximately 6 months after (T1) surgery were analyzed in three planes using 3D Slicer software. Statistical significance was set at P < 0.05 level. Results: Significant inward rotation of the left mandibular condyle and significant outward rotation of the right mandibular condyle were observed in the axial and coronal planes (P < 0.05). The positions of the right and left condyles in the sagittal plane and the distance between the most medial points of the condyles in the coronal plane did not differ significantly (P > 0.05). Conclusions: While the change in the sagittal plane can be maintained as before surgery with manual positioning during the BSSRO procedure, significant inward and outward rotation was observed in the axial and coronal planes, respectively, even in the absence of concomitant temporomandibular joint disorder before or after the operation. Further long-term studies are needed to correlate these findings with possible clinical consequences.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제22권2호
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• pp.184-190
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• 2000

Objective : To compare two different methods of rigid fixation in postoperative stability after mandibular setback. Material and Methods : 28 patients with Class III malocclusion were treated by bilateral sagittal split ramus osteotomy(BSSRO) and mandibular setback were selected for this study. Group A(n=14) had the bone segments fixed with monocortical miniplate on the lateral side of the mandibular body and Group B(n=14) had three noncompressive bicortical screw inserted at the genial area through a transcutaneous approach. Cephalograms were taken preoperatively, postoperatively within 1 weeks and at a follow-up period (mean 8.9 months after surgery) and the amount of setback and postoperative change were measured. Results : Postoperative relapse between two groups was minimal in setback of the mandible. Statistical analysis showed no significant difference in postoperative relapse. Conclusion : This study suggests that both methods of skeletal fixation investigated give comparable postoperative stability and their use in mandibular setback appears to be a fairly stable clinical procedure .

• Maxillofacial Plastic and Reconstructive Surgery
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• 제40권
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• pp.36.1-36.5
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• 2018

Background: Botulinum toxin-A (BTX-A) injection into muscle reduces muscular power and may prevent post-operative complication after orthognathic surgery. The purpose of this study was (1) to evaluate BTX-A injection into the masseter muscle on the prevention of plate fracture and (2) to compare post-operative relapse between the BTX-A injection group and the no injection group. Methods: Sixteen patients were included in this study. Eight patients received BTX-A injection bilaterally, and eight patients served as control. All patients received bilateral sagittal split ramus osteotomy for the mandibular setback and additional surgery, such as LeFort I osteotomy or genioplasty. Post-operative plate fracture was recorded. SNB angle, mandibular plane angle, and gonial angle were used for post-operative relapse. Results: Total number of fractured plates in patients was 2 out of 16 plates in the BTX-A injection group and that was 8 out of 16 plates in the no treatment group (P = 0.031). However, there were no significant differences in post-operative changes in SNB angle, mandibular plane angle, and gonial angle between groups (P > 0.05). Conclusions: BTX-A injection into the masseter muscle could reduce the incidence of plate fracture.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제33권3호
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• pp.276-280
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• 2011

BSSRO (bilateral sagittal split ramus osteotomy) is an effective surgical method for maxillofacial deformities. Rigid fixation using a plate and screws can stabilize bony segments and induce early mouth opening. Though this procedure has a low complication rate, normal function and esthetic recovery is achieved through proper and early management of the complications. Complications consisting of temporomandibular disorders, sensory disturbances due to inferior alveolar nerve damage, open bite, malunion or nonunion, and facial nerve palsy occur, but these rarely develop. Facial nerve palsy causes the muscles involved in facial expression to depress, which results in ocular dryness or retinal damage. When facial nerve palsy develops, early management involving steroid medication and physical therapy is effective. In the case of severe damage, surgical intervention should be considered. A 20-year-male patient came to the oral and maxillofacial surgery department for orthognathic surgery. The mandible was set back by BSSRO under general anesthesia. Facial nerve palsy was observed on the left side of the face: steroid and vitamins were administered early and physical therapy was performed daily. These forms of management can aid in function and allow for gradual esthetic recovery. Presumed causes were excessive soft tissue retraction or soft tissue injury by the osteotome at the horizontal osteotomy of the ramus. Careful dissection, retraction and a precise osteotomy are needed for protection of the facial nerve. If nerve damage is observed, early management can help in the recovery of facial nerve function and esthetics.

• 대한치과교정학회지
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• 제40권6호
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• pp.383-397
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• 2010

본 연구는 상순돌출을 동반한 골격성 III급 부정교합에서 전방분절골절단술(anterior segmental osteotomy, ASO)을 병용한 상행지시상분할골절단술(bilateral sagittal split ramus osteotomy, BSSRO)과 Le Fort I 골절 단술을 병용한 상행지시상분할골절단술(BSSRO) 후 상악의 경 연조직 변화 및 경조직 변화에 대한 연조직 변화율을 비교하였다. A군은 ASO/BSSRO를 시행한 군 14명, B군은 Le Fort I/BSSRO를 시행한 환자 중 상악의 후방부가 상방으로 이동(posterior impaction)된 15명으로 구성되었다. 수술 전 2개월 이내와 수술 후 6개월 이후에 촬영한 측모두부방사선사진을 분석하여 다음과 같은 결과를 얻었다. 두 군 모두 수술 후 상악 전방부 경조직과 연조직이 후방이동되었고, A군에서 더 큰 변화량을 보였다. A point의 후방이동에 따른 superior labial sulcus의 변화율은 A군에서 79%, B군에서 15%를 보였고, supradentale에 대해 labrale superious는 A군에서 80%, B군에서 68%의 비율로 후방이동하였다. 교합평면각은 B군에서 증가한 반면, A군에서는 통계적으로 유의성 있는 변화가 없었다. 이상의 연구결과 골격성 III급 부정교합의 양악수술 시 상악 수술은 상악 전방부와 상순의 돌출이 심한 경우에는 ASO를 시행하고 교합평면각의 증가가 필요한 경우에는 posterior impaction을 동반한 Le Fort I 골절단술을 시행하는 것이 바람직하다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제23권2호
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• pp.169-173
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• 2001

본 교실에서는 조선대학교 구강악안면외과에 내원한 중안면성장부전을 동반한 하악전돌증소견을 보이는 22세 여자 환자의 치료에 있어서 변형 LeFort III 골절단술과 양측 하악지 시상분할골절단술 그리고 자가 장골 이식술을 동시에 시행하여 기능적 심미적으로 만족할 만한 결과를 얻었기에 보고하는 바이다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제31권6호
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• pp.485-491
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• 2009

Postoperative skeletal stability was evaluated in combination of Le Fort I and U-shaped osteotomies for superior repositioning of maxilla in bi-maxillary surgeries in 30 consecutive patients. The fifteen patients underwent Le Fort I osteotomy alone and the other fifteen patients underwent Le Fort I and U-shaped osteotomies. In all patients, the maxilla was first osteomized and fixed with absorbable plates system. A bilateral sagittal split ramus osteotomy (BSSRO) of the mandible was then carried out and fixation was performed using absorbable plates. Maxillo-mandibular fixation with rubber ring was used for two weeks post-operatively in all patients. Lateral cephalograms were obtained pre-operatively, 1 day post-operatively, 6 months after surgery. The changes in anterior nasal spine (ANS), point A, upper incisior (U1), and point of maxillary tuberosity (PMT) were examined. The maxillas in the fifteen patients of both examination group were repositioned nearly in their planned positions during surgery and no significant post-operative changes in the examined points of the maxilla were found. These results suggest that a combination of a Le Fort I and U-shaped osteotomy is a useful technique for reliable superior repositioning of the maxilla. The post-operative change in the maxilla using this combination osteotomy was comparatively stable.