• Maxillofacial Plastic and Reconstructive Surgery
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• 제18권2호
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• pp.177-183
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• 1996

With the increasing esthetic requirement in orthognathic surgeries, midfacial corrective surgeries were developed to improve the paranasal depression. Augmentation with autogenous bones has long been the standard in facial reconstruction, however limited graft availability, donor site morbidity, and difficulties in 3-dimensional shaping were led to limited use. Porous high density polyethylene$(Medpor{(R)})$ was introduced in the 1970s as an alloplastic implants. It can be used in various size and shapes, and shortend operation time. The purpose of this study is to determine, by means of cephalometrics, the degree of long term stability and gaining of the overlying soft tissue thickness. The results were as followings : 1. There was no evidence of foreign body reaction, infection, and tissue necrosis. 2. $(Medpor{(R)})$ implants had an advantage of clinical use ; easy to contour and adapt to obtain a precise 3-dimensional construction. 3. Cephalometric study of 16 cases of paranasal augmentation revealed an overall increase of soft tissue thickness of approximately 82.1% in 6-months following. 4. The successful results could be obtained under the aseptic handling.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제30권5호
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• pp.380-390
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• 2004

Bone healing plays an important role in orthognathic and craniofacial surgery. Bone tissue repair and regeneration are regulated by an array of growth and morphogenetic factors. Bone formation and remodeling require continuous generation of osteoprogenitor cells from bone marrow stromal cells, which generate and respond to a variety of growth factors with putative roles in hematopoiesis and mesenchymal differentiation. In this study, the efficacy of a single application of hepatocyte growth factor to promote bone regeneration in 5-mm experimental calvarial defects of adult male rats was assessed histologically and immunohistochemically. The result of the experimental site were compared with those of the contralateral contral side. None of the control and experimental bone defects demonstrated complete bone closure. Bone regeneration was found close th the margine and central part of the defects. At 1, 2 weeks, there were found much significant cellural mitotic activity and many inflammatory cells and osteoblasts on the experimental site than control site. At 4, 6 weeks, new bone apposition was founded in both site but, more apposition was seen at experimental site. At 8, 12 weeks, also, some differences was found that more apposition of new bone and collagen fiber was seen on experimental site. Our results have some possibility that HGF do a early positive role to repair the bone defect. More study will be needed.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제19권4호
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• pp.351-361
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• 1997

This study was performed to evaluate the change of the soft tissue facial profile after mandibular set back surgery during time intervals. For this study, 33 patient, 8 males and 25 females, were selected and their lateral cephalograms were taken and analyzed periodically. Hard and soft tissue changes during postoperative time intervals, correlation between surgical skeletal changes and postoperative soft tissue changes, and prediction for long-term soft tissue changes were established through varying statistical methods. The results were as follow : 1. There were meaningful changes of anteroposterior skeletal position at 6 months and 2 years after mandibular set back by mandibular ramus osteotomy. Two years postoperatively, there was 30%, 32%, 29% relapse on B point, pogonion, menton each. 2. Two years after the mandibular ramus osteotomy, the relative changes of the soft tissue to their osseous counterparts showed 76% on the lower lip and 91% on the pogonion. 3. The movements of the mandibular landmarks in correlation to anteroposterior position of the lower lip and soft tissue of the chin showed to be effective on a long-term basis. 4. Using surgical changes of pogonion, prediction of changes in soft and hard tissue pogonion was useful and the coefficient of determination was 0.46 each and their reliability decreased 2 years postoperatively. 5. The upper lip position after the mandibular set back surgery was somewhat anterior 2 years postoperatively, but that has no statistical meanings.

• 대한치과교정학회지
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• 제50권4호
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• pp.258-267
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• 2020

Objective: This study aimed to analyze the correlation of horizontal and sagittal planes used in two-dimensional diagnosis with lip canting by using three-dimensional (3D) analysis. Methods: Fifty-two patients (25 men, 27 women; average age: 24 years) undergoing treatment for dentofacial deformity were enrolled. Computed tomography images were acquired, and digital imaging and communication in medicine files were reconstructed into a 3D virtual model wherein horizontal and sagittal craniofacial planes were measured. Subsequently, the correlations of lip canting with these horizontal and sagittal planes were investigated. Results: The mandibular symmetry plane, the occlusal plane, Camper's plane, the mandibular plane, Broadbent's plane, and the nasal axis plane were correlated with the amount of lip canting (Pearson's correlation coefficients: 0.761, 0.648, 0.556, 0.526, 0.438, and 0.406, respectively). Planes associated with the lower part of the face showed the strongest correlations; the strength of the correlations decreased in the midfacial and cranial regions. None of the planes showed statistically significant differences between patients with clinical lip canting (> 3°) and those without prominent lip canting. Conclusions: The findings of this study suggest that lip canting is strongly correlated with the mandibular symmetry plane, which includes menton deviation. This finding may have clinical implications with regard to the treatment of patients requiring correction of lip canting. Further studies are necessary for evaluating changes in lip canting after orthognathic surgery.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제32권6호
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• pp.506-513
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• 2006

The purpose of this study was to examine the familial tendency of the patients with mandibular prognathism in three generations and to define the relationship between the familial tendency and the skeletal class III morphology. The probands of this study were 103 orthognathic surgery patients with skeletal Class III malocclusions who had undergone (48 men, 55 women) mandibular set-back surgery. A questionnaire was given to patients who sought surgical treatment for excessive mandibular length, and all answers were confirmed in interviews. Lateral cephalograms were analyzed in cranial base parameters, mandibular positional parameters and mandibular skeletal parameters. In the examined families, 58.3% had at least one member other than the proband who had mandibular prognathism. The affected ratio of total relatives was 4.5%, and the value was higher in first-degree (13.4%) than second-degree (5.9%) and third-degree relatives (1.7%). The affected ratio was 51.9% in the offsprings who had at least one affected father or mother. The comparison of the groups according to the familial tendency showed no significant craniofacial skeletal measurments. In conclusion, skeletal class III malocclusion showed high familial tendency, suggesting a significant genetic influence in the etiology. However, the patient's familial tendency did not show the special craniofacial patterns compare to the subjects without familial tendency.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제36권3호
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• pp.197-201
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• 2010

Introduction: In a surgery of the oral cavity, nasotracheal intubation is often carried out to secure the surgical field. By passing a tracheal tube through the nasal cavity to the pharynx, the nasotracheal intubation can lead to complications that do not occur with oral intubation, such as nasal bleeding and submucosal aberration etc. The purpose of this study is to examine the method of CT evaluation and pretreatment for a safe nasotracheal intubation. Materials and Methods: Among 30 patients who orthognathic surgery was performed at Chung-Ang University Hospital during the period August 2009 to October 2009, 30 patients were included. The 30 patients were divided into two groups; 15 patients intubated with CT evaluation with pretreatment, and the other 15 patients intubated with no pretreatment. We evaluated nasal bleeding of the two groups during nasotracheal intubation. Results: CT evaluation with pretreatment group had a significantly lower incidence of nasal bleeding than the group with no pretreatment. Conclusion: CT evaluation with pretreatment helps to minimize nasal bleeding during nasotracheal intubation.

• 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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• 제41권
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• pp.12.1-12.5
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• 2019

Background: Le Fort I osteotomy is one of the surgical procedures now routinely and safely performed. It is possible to move the maxilla in three dimensions, but it is necessary to separate the bones around the maxillary sinus. Therefore, with surgery, maxillary sinus mucosal thickening occurs. By knowing the changes in the sinus mucosa after surgery and the factors affecting it, it is possible to better predict the outcomes of surgery and contribute to safer surgery. In this study, thickening of maxillary sinus mucosa before and after surgery in Le Fort I osteotomy was evaluated using multidetector-row computed tomography (MDCT) images, and the changes in mucosal thickening and the related factors were examined. Methods: Using MDCT images, the maxillary sinus mucosa of 125 patients who had undergone Le Fort I osteotomy was retrospectively evaluated before surgery, 1 month after surgery, and 1 year after surgery. On the MDCT images, the maxillary sinus was judged as mucosal thickening and classified into three grades according to the proportion occupying the maxillary sinus. In the evaluation of factors related to mucosal thickening, the following eight factors were examined: sex, age, diagnosis, operating time, amount of postoperative bleeding, with/without bone graft, with/without multisegmental osteotomy, and with/without macrolide therapy after surgery. Results: The mean age at the time of surgery was 25.6 ± 8 years. Of all 125 patients, 66 had bilateral thickening, 19 had unilateral thickening, and 40 had no thickening. Factors that were significantly related to mucosal thickening were the operative time for the maxilla, bone grafts, and macrolide therapy after surgery. Conclusions: Operative time for the maxilla, bone grafts, and macrolide therapy after surgery were found to be related to mucosal thickening. In addition, MDCT scanning 1 month after surgery was considered to be appropriate for evaluation of maxillary sinus mucosal thickening.

• 대한치과교정학회지
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• 제25권1호
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• pp.101-110
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• 1995

악교정수술을 요하는 악안면 기형환자에서 술후 교정치료시기는 골 치유정도 또는 골편의 안정성과 환자의 악골운동 정도에 따라 결정된다. 근래에 악교정 수술시 이동골편의 고정에 miniplate나 screw등을 이용한 견고성 고정 방법이 증가하는 추세이고 이는 술후 악간 고정기간을 최소화하고 교정력에 의한 골편의 변위 가능성을 줄이므로써 술후 조기에 교정치료를 가능하게 하였다. 한편 술후 조기에 교정치료를 시행할 경우는 골 절단술에 의한 혈류량의 변화와 외과적 처치에 의한 치주조직의 염증반응과 대사작용의 증가 등으로 인해 일반적인 치아이동과는 골개조, 초자양 변성 및 치근흡수 등에서 다소 차이를 보일 것으로 예상된다. 이에 저자 등은 고양이의 상악골 협측 치근단 하부에 수평적 골절단술을 시행한 후 즉시 교정력을 가하여 초기의 치주조직 반응을 교정력만을 가했을 때의 조직반응과 비교 관찰함으로써 다음과 같은 결과를 얻었다. 골절단술 시행후 즉시 교정력을 가한 실험군에서 교정력만을 가한 대조군에 비해 1. 압박측에서 치조골면을 따라 보이는 파골세포의 수가 증가하였고 골흡수 양상도 보다 직접성으로 관찰되었다. 2. 압박측에서 초자양 변성정도는 보다 경미하게 관찰되었다. 3. 견인측에서 신생골 형성은 치조골면을 따라 균일하게 형성되었고 대조군에 비해 다소 증가된 양상으로 뚜렷한 휴지선이 관찰되었다. 4. 치근흡수는 양군 모두에서 관찰되지 않았다.

• 대한치과교정학회지
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• 제29권3호
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• pp.285-301
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• 1999

악교정 수술의 계획에 있어서 수술 후 경조직의 이동에 따른 연조직 변화 양상을 보다 정확히 예측하는 것은 매우 중요하다. 최근에는 측모 두부 규격 방사선 사진과 실제 측모 사진을 병합하여 수술 후 측모 변화에 대한 가시성을 높인 여러 종류의 video imaging 프로그램들이 개발되어 널리 사용되고 있다. 그러나 이들 프로그램의 정확도를 판단하는 연구는 아직 미비한 실정이며 특히 국내에서 많이 시행되고 있는 골격성 III급 부정교합 환자의 수술 후 변화 양상에 대한 연구가 임상적인 활용에 앞서 선행되는 것이 필요하다. 이에 저자는 video imaging프로그램의 하나인 Power $Ceph^{\circledR}$ (Power Soft Co. Ver 3.3)을 이용하여 국내에서 양악수술을 시행 받은 골격성 III급 부정교합 환자 30명(남 14명, 여 16명)을 대상으로 예측도와 실제 술후의 측모를 비교하여 정확도를 평가하였으며 정확도에 영향을 미치는 요인을 분석하기 위해 이동량 및 술식별로 분류 비교하여 다음과 같은 결론을 얻었다. 1. 예측치와 실제 계측치의 비교에서 24개의 계측항목 중 14개 항목에서 유의성 있는 차이를 보였다. 2. 계측항목 중 유의성 있는 차이를 보이는 항목은 대부분 상악에 관련된 연조직으로 하악에 관련된 연조직에 비해 다양한 차이를 나타내었다. 3.상악 및 하악의 이동량에 따른 비교에서 이동량이 적은 군이 이동량이 많은 군에 비하여 예측치와 실제 계측치 비교에서 유의성 있는 차이를 보인 항목이 적게 나타났다. 4. 이부 성형술 여부에 따른 비교에서 이부 성형술을 시행하지 않은 군에서 이부 성형술을 시행한 군에 비하여 예측치와 실제 계측치 비교에서 유의성 있는 차이를 보인 항목이 적게 나타났다. Video imaging(Power $Ceph^{\circledR}$ Ver 3.3)프로그램에 의한 예측치와 실제 계측치 비교시 그 차이는 대부분 2mm 이내로써 임상적으로 수용할 수 있는 수준이었다.