• Maxillofacial Plastic and Reconstructive Surgery
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• 제13권4호
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• pp.412-420
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• 1991

Seventeen rigid screw fixation and sixteen nonrigid wire fixation cases of mandibular sagittal slit ramus osteotomy were selected to compare postoperative dental and skeletal changes. A constructed horizontal plane was drawn seven degrees under sella-nasion plane and detailed cephalometirc assessment was applied to serial radiographic films taken before surgery($T_0$), immediately after surgery($T_1$), and at least six months after surgery($T_2$). Linear and angular positional changes were measured and analyzed statistically using paired t-test method and percent of positional changes(amount of post-op change/amount of intra-op change)${\times}100$. The results were as follows; 1. It was 29.4% in rigid fixation cases and 37.5% in nonrigid fixation cases comparing the postoperative positional change of more than 2mm at point B. So rigid fixation method was slightly more stable. 2. In nonrigid fixation cases, the positional change might be caused by incomplete bony union at the osteotomy site and soft tissue tension acting on this site. 3. In rigid fixation cases, the positional change might be caused by interaction between relapse tendency of protracted condyle-proximal segment and neighboring soft tissue tension.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제40권
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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.

• Journal of Yeungnam Medical Science
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• 제21권2호
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• pp.242-250
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• 2004

In general, the skeletal class III has the characteristics of mandibular overgrowth with a normal maxillary growth or maxillary undergrowth with a normal mandibular growth And clinical and radiographic evaluations of the patient are needed. However, the treatment plan is not dependent on these evaluations alone, because patient's general condition and hope for aesthetics varies. The aim of this report is to consider the treatment of a medically compromised patient with an anterior open bite and skeletal class III, which showed a severe mandibular overgrowth. In 2003, a 17-year-old boy with epilepsy, mental retardation presented at our clinic complaining of concave profile. A clinical examination showed severe mandibular prognathism with an anterior open bite. The radiographic examination revealed a short cranial base, a moderate maxillary overgrowth, severe mandibular overgrowth and skeletal open bite tendency. In 2004, he was verified to have no potential of growth by hand-and-wrist radiographs and an endocrine examination. He completed the preoperative orthodontic treatment and orthognathic surgery (sagittal split ramus osteotomy, genioplasty). He was evaluated on the first visit, the preoperative period and the postoperative period with a clinical and radiographic examination. At the first visit, the patient showed moderate overgrowth of the maxilla, severe overgrowth of the mandible, and a subsequential skeletal open bite. After the preoperative orthodontic treatment (preoperative period), the patient showed the same skeletal problem as before and a decompensated dentition for orthognathic surgery. After orthognathic surgery, his profile had improved, but he had still a skeletal openbite tendency because the maxillary orthognathic surgery was not performed. Severe mandibular prognathism with a maxillary overgrowth and anterior open bite should be treated by bimaxillary orthognathic surgery. However, one-jaw orthognathic surgery on the remaining the skeletal open bite tendency was performed for his medical problem and facial esthetics. This subsequential open bite should be resolved with a postoperative orthodontic treatment.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제15권3호
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• pp.229-237
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• 1993

자자는 1991년 2월부터 1993년 2월까지 경북대학교병원 구강악안면외과에 하악전돌 및 개구교합을 주소로 내원하여 하악골 시상골절단술을 이용하여 악교정 수술을 받은 환자중 추적 조사가 가능했던 9명의 개구교합을 동반한 하악 전돌증 환자와 개구교합이 없는 하악 전돌증 환자 9명, 총 18명을 대상으로 두부 상사선 규격사진을 이용한 술후 재발에 관한 연구를 시행하여 다음과 같은 결과를 얻었다. 1. 비개구교합군에 비해 개구교합군에서 술전 전안면고경, 하악 하연 평면각 및 하악 우각부 값이 더 크게 나타났으나 유의성은 없었다.(p>0.05) 2. 개구교합군에서 수술시 SNB 값과 하악 하연 길이의 변화량이 하악의 재발과 통계적으로 유의한 상관 관계가 있었다.(p.<0.01) 3. 개구교합군에서 전안면고경은 술후 비교적 안정되어 있었다. 4. 개구교합군과 비개구교합군에서 수술에 의한 하악 하연 평면각의 변화와 하악의 수평 이동량은 재발과 상관 관계가 없었다.(p>0.01) 5.개구교합을 가진3급 부정교합 환자에서 하악골 시상골 절단술을 시행시 본 연구에서는 수직적 재발보다는 수평적 재발에 문제가 있었다.

• Journal of Yeungnam Medical Science
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• 제12권2호
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• pp.393-399
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• 1995

심한 하악 후퇴증은 교정치료만으로 성공적인 결과를 얻을 수 없으며 골절단술, 이부성형술등 외과적 교정이 고려되어야 한다. 설골상근의 장력에 의한 회귀현상을 최소화하기 위해 수술시 하악 체부를 전방회전시킴과 동시에 가능한 전방으로 overcorrection한다. 저자등은 구미인에 비해 발생빈도가 적은 하악 후퇴증을 주소로 내원한 환자를 양측성 하악골 시상절단술과 이부 성형술을 통하여 만족할만한 안모개선 및 교합관계 개선을 이루었기에 이에 보고하는 바이다.

• Imaging Science in Dentistry
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• 제54권2호
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• pp.181-190
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• 2024

Purpose: This study compared sequential changes in skeletal stability and the pharyngeal airway following mandibular setback surgery involving fixation with either a titanium or a bioabsorbable plate and screws. Materials and Methods: Twenty-eight patients with mandibular prognathism undergoing bilateral sagittal split osteotomy by titanium or bioabsorbable fixation were randomly selected in this study. Lateral cephalometric analysis was conducted preoperatively and at 1 week, 3-6 months, and 1 year postoperatively. Mandibular stability was assessed by examining horizontal (BX), vertical (BY), and angular measurements including the sella-nasion to point B angle and the mandibular plane angle (MPA). Pharyngeal airway changes were evaluated by analyzing the nasopharynx, uvula-pharynx, tongue-pharynx, and epiglottis-pharynx (EOP) distances. Mandibular and pharyngeal airway changes were examined sequentially. To evaluate postoperative changes within groups, the Wilcoxon signed-rank test was employed, while the Mann-Whitney U test was used for between-group comparisons. Immediate postoperative changes in the airway were correlated to surgical movements using the Spearman rank test. Results: Significant changes in the MPA were observed in both the titanium and bioabsorbable groups at 3-6 months post-surgery, with significance persisting in the bioabsorbable group at 1 year postoperatively (2.29°±2.28°; P<0.05). The bioabsorbable group also exhibited significant EOP changes (-1.21±1.54 mm; P<0.05) at 3-6 months, which gradually returned to non-significant levels by 1 year postoperatively. Conclusion: Osteofixation using bioabsorbable plates and screws is comparable to that achieved with titanium in long-term skeletal stability and maintaining pharyngeal airway dimensions. However, a tendency for relapse exists, especially regarding the MPA.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제29권4호
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• pp.340-352
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• 2007

In this systematic review on bone reduction procedures for the correction of the prominent mandibular angle, we collected and sorted the methods. The strength and weakness, indication, complication, and final esthetic result of each method were evaluated. After searching and filtering the literatures on the base of inclusion criteria, 9 eligible case series studies were included in this study. There were 3 types of curved ostectomies and 4 types of lateral cortical ostectomies. Surgical procedures for curved ostectomies were divided into 2 types. One was single curved ostectomy and the other was multistaged curved ostectomy. Lateral cortical ostectomies reported were all similar to sagittal split ramus osteotomy. The complications reported in the included studies were scarce, but curved ostectomies may be able to induce many complications. The prominent mandibular angle must be analyzed in the lateral dimension and frontal dimension, and curved ostectomy can reduce the mandibular angle laterally while lateral cortical ostectomy can reduce the bigonial distance frontally. Because curved ostectomies can induce complications and unnaturally large mandibular angle while can not reduce bigonial distance efficiently, the current trend for the angle reduction procedure is lateral cortical ostectomies.

• Archives of Plastic Surgery
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• 제42권4호
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• pp.419-423
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• 2015

Background Orthognathic surgery is required in 25% to 35% of patients with a cleft lip and palate, for whom functional recovery and aesthetic improvement after surgery are important. The aim of this study was to examine maxillary and mandibular changes, along with concomitant soft tissue changes, in cleft patients who underwent LeFort I osteotomy and sagittal split ramus osteotomy (two-jaw surgery). Methods Twenty-eight cleft patients who underwent two-jaw surgery between August 2008 and November 2013 were included. Cephalometric analysis was conducted before and after surgery. Preoperative and postoperative measurements of the bone and soft tissue were compared. Results The mean horizontal advancement of the maxilla (point A) was 6.12 mm, while that of the mandible (point B) was -5.19 mm. The mean point A-nasion-point B angle was $-4.1^{\circ}$ before surgery, and increased to $2.5^{\circ}$ after surgery. The mean nasolabial angle was $72.7^{\circ}$ before surgery, and increased to $88.7^{\circ}$ after surgery. The mean minimal distance between Rickett's E-line and the upper lip was 6.52 mm before surgery and 1.81 mm after surgery. The ratio of soft tissue change to bone change was 0.55 between point A and point A' and 0.93 between point B and point B'. Conclusions Patients with cleft lip and palate who underwent two-jaw surgery showed optimal soft tissue changes. The position of the soft tissue (point A') was shifted by a distance equal to 55% of the change in the maxillary bone. Therefore, bone surgery without soft tissue correction can achieve good aesthetic results.

• 대한치과교정학회지
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• 제36권1호
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• pp.63-73
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• 2006

악교정 수술 시행 시 연조직 변화에 대한 대부분의 연구는 II급 부정교합을 대상으로 하였다. 또한 수술 방법에 따른 연조직 변화에 대한 비교 연구가 부족하였다. 따라서 이 연구는 골격성 III급 부정교합자에서 상악골 전진술과 하악골 후퇴술을 동시에 시행한 양악 수술과 하악골 편악 수술 시행 시, 경조직과 연조직 측모 및 연조직 두께의 변화를 관찰하고, 수술 전후 변화의 상관성을 산출하며, 경조직 변화에 수반하는 연조직 변화의 비율을 산출하여 교정-악교정 수술 복합 치료 계획 수립과 결과의 예측에 이용하고자 시행되었다. 경희대학교 치과병원 교정과에 내원하여 골격성 III급 부정교합자로 진단받은 환자 52명을 대상으로 하여, Le Fort I osteotomy를 이용한 상악골 전방이동술과 시상분할골절단술을 이용한 하악골 후퇴술을 시행한 양악 수술군 26명과 하악골 후퇴술만을 시행한 편악 수술군 26명으로 구분하여, 수술 전후 측모두부방사선규격사진을 계측, 분석하여 다음과 같은 결과를 얻었다. 양악 수술군은 골격 변화량의 72.4% 비율로 상순 부위 연조직의 전방 이동을 보였으며, 편악 수술군은 통계적으로 유의한 변화를 보이지 않았다. 비순각은 양악 수술군에서 편악 수술군에 비해 더 크게 증가하였다. 이순각은 편악 수술군에서 더 크게 감소하였다. 하악골의 후방 이동에 따른 연조직 pogonion의 후방 이동은 양악 수술군에서 98%, 편악 수술군에서 109%로 편악 수술군에서 더 크게 나타났다. 양악 수술군에서는 편악 수술군에 비하여 경조직의 변화에 수반하는 상순에서의 큰 변화가 나타났다. 편악 수술군에서는 상순의 변화는 미약하였으며, 하순 및 이부의 변화가 양악 수술군에 비해 두드러지게 나타났다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제37권4호
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• pp.264-271
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• 2011

Purpose: This study evaluated retrospectively the postsurgical facial hard tissue profile of a Le Fort I osteotomy with/without posterior impaction and rigid internal fixation to correct mandibular prognathism. After observing a difference between the two groups, this measurement was used to prepare a treatment plan for 2-jaw surgery. Patients and Methods: Thirty patients who had undergone orthognathic surgery in Pusan National University Dental Hospital were enrolled in this study. Fifteen patients were treated using a Le Fort I osteotomy with posterior impaction and mandibular setback bilateral sagittal split ramus osteotomy, and the other fifteen patients were treated without posterior impaction. The preoperative (T0), immediate postoperative (T1) and six-month follow-up period (T2) cephalograms were taken and difference between T1-T0 and T2-T2 was analyzed. Results: Both groups was FH-ABp, SNB and ANB showed significant changes in the measurement, whereas only the posterior impaction group showed a change in the SN-U1, occlusal plane, posterior facial height, surgical movement difference from the L1 and B-point. There was no significant statistical change between the immediate postoperative (T1) and six-month follow-up (T2) hard tissue analysis in the two groups. Conclusion: A Le Fort I osteotomy with posterior impaction is considerable for patients with a flat occlusal plane angle, large posterior facial height, prominent B-point, pogonion and labioversed incisal inclination if the indications are well chosen.