• Journal of International Society for Simulation Surgery
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• 제1권2호
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• pp.71-74
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• 2014

Purpose The prominent mandible angle, otherwise known as "square face", has been recognized as an aesthetic problem that needs correction by many in the Asian community. Many surgeons considered that mandible angle ostectomy alone, brings about hypotrophy of the masseter muscle. However, it was only proven indirectly (by clinical experience and histological animal experiments) and not objectively. In this study, we evaluated the volume of masseter muscle to prove the effect, objectively. Materials and method Computed tomography (CT) images were used to measure the masseter muscle volume of normal female group (n=6), and of female patient group n=8, preoperative and early & late postoperative volumes) presenting the symptom of prominent mandible angle. The data was analyzed statistically by two-sample t-test and paired t-test using SAS (version 8.2). Results In normal female group, volume average was $16,142{\pm}2,829.8mm^3$. In patient group, preoperative volume averaged $24,447{\pm}4,544.5mm^3$ (p<0.0001), early postoperative volume measured average of $31,966{\pm}50,421mm^3$ which is a 30% increase from the preoperative volume (p<0.0001). Late postoperative measurement was $20,202{\pm}4,092.3mm^3$, which is a 20% decrease from the preoperative volume (p<0.0006). Conclusion The bone reduction of prominent mandible angle induce the hypotrophic effect of masseter muscle after long term follow up (5 more months). This result mean that the result of mandible angle contouring surgery can be considered as combined effect of bony angle reduction and subsequent masseter muscle hypotrophy.

• 대한치과교정학회지
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• 제4권1호
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• pp.13-19
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• 1974

In orthodontic view points, there were a few attempts to describe on the mandibular rest position with roentgenocephalometric studies for the persons with malocclusion. The purpose of the present study was to evaluate and interpret the difference in each of the Angle's classification of the malocclusion. The author has selected 115 malocclusion patients of the both sexes as subjects, whose dental ages were from III A. Two lateral cephalometric head films were taken mandible at rest and with the teeth in occlusion utilizing the Broadbent-Bolton cephalometer. Their linear and angular measurements were made directly. The author obtained the following results: 1) The change in the incisal overbite was of $-2.32\~-3.36mm$, and the overjet decreased similiarly in each class of the malocclusion. 2) The range of free-way space was of $1.97\~3.56mm$, and showed prominent in the Angle's class III malocclusion. 3) In the rest position, the mandible showed backward displacement, and it was prominent in the Angle's class III malocclusion. 4) In the change of Ar-Gn, the class I and II showed more increase of distance-than the class III. 5) In the change of ${\angel}SNL_1L_1'$, the class III showed smaller angle than the class I and II. 6) There was no significant difference between the male and female in each class of the malocclusion.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제37권
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• pp.26.1-26.4
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• 2015

We experienced a patient of subcondylar fracture who had a squared contour of the lower face with prominent angle of the mandible and masseter hypertrophy. Our patient was increasingly seeking esthetic improvement of the lower third of the face. But she did not want multi-stage operations. Thus, we decided and performed a one-stage mandibular angle ostectomy with fracture management. We have a stable and esthetic result simultaneously despite fractures of the fixation plates during follow-up period, so report a case.

• Journal of International Society for Simulation Surgery
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• 제2권2호
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• pp.80-82
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• 2015

The mandibuloplasty for the facial aesthetic reason has been the one of the most popular procedures in aesthetic facial bone surgery in East Asia. Most East Asian women prefer smaller-looking and smooth-shaped facial contour. Prominent mandible angle which are common in Asia would be the main problem for smooth facial contour. In addition, recently, the mandibular body and broad chin shape also are known to be remodeled in order to get the ideal smooth facial shape. However, mandibuloplasty is not that easy to cut because many patients has inward mandibular angle and the visual field in operation is limited. The aim of this trial is to try to provide the prefabricated cutting guide for the symmetric and appropriate mandibuloplasty with the surgeons. Preoperative computed tomography(CT) data were processed for the patient and computer simulation model was produced. Then, mandibuloplasty was done on the computer simulation screen. Based on this data, customized cutting guide was made. This prefabricated cutting guide was used in real mandibuloplasty bilaterally. Premade cutting guide for the mandibuloplasty based on the computer simulation turned out to be very successful in this patient. Individualized approach for each patient could be an ideal way to manage the patients in near future.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제29권4호
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• pp.226-231
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• 2003

The contour of mandibular angle is important for facial esthetics in the oriental population, because the wide and square face is thought to have had an unhappy life. A prominent mandibular angle produces a characteristics quardrangle, coase, and muscular appearance. So, uni- or bi-lateral mandibular angle reduction is usually performed. However, there is little guideline for bi-lateral angle reduction. So, this study was to investigate the pattern of Korean mandibular angle for bi-lateral mandibular angle reduction as guideline. This study was included 66 adult men and women over 19 years old who are having the normal mandibular angle. We measured the posterior border, angle, and inferior border of mandible using cephalometric view. The results of study was as followed : 1. The ratio of posterior mandible was 96.6, 97.3% in male, and 103.0, 106.0% in female. 2. The ratio of mandibular angle(R1-Go/R1-R2) was 120.2% in male, and 117.3% in female. 3. The ratio of inferior mandible(D5, 6, 7, E, F, G/D4) was 97.3, 90.9, 79.5, 65.2, 57.8, 46.9% in male, and 98.5, 91.2, 80.5, 67.6, 59.1, 50.2% in female. The results of this study should be useful to decide accurate amount of reduction.

• 대한치과의사협회지
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• 제19권1호통권140호
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• pp.67-71
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• 1981

This study was undertaken to find out the characteristic craniofacial morphology of Class II Division 2 malocclusions in children by means of roentgenocephalometry. The subjects consisted of twelve boys and thirteen girls with Class Ii, Division 2, thirty seven boys and fifty three girls with Class II, Division 1, and forty six boys and eighty one girls with normal occlusion, ranged from 10 years old to 18 years old. The following results were obtained; 1. The anteroposterior relationship of the maxilla to the cranium in the Class II, Division 2 malocclusion similar to the normal occlusion, but the mandible was the posterior position in th the cranial anatomy. 2. There were no significant differences in the anteroposterior relationship of the maxilla and the mandible between Class II, Division 1 and Class II, Division 2 malocclusions. 3. In Class II, Division 1 the axes of maxillary incisors showed labial inclination, but lingual inclination in Class II, Division 2 malocclusions. 4. Overbite was prominent one in Class II, Division 2, on the other hand overjet was distinguished in Class II, Division 1.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제27권3호
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• pp.258-265
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• 2001

A prognathic mandible and prominent gonial angle are considered to be unattractive in the Orient because it gives the face a square and muscular appearance. Requests for contouring of the mandibular angle are rare in the other race but are much more common in Korea and, through out the Orient. So, we often encounter a patient with a prognathic mandible and squarish or broad face who wishes to have his or her facial size reduced minimally or to acquire a round or slender appearance. But, mandibular angle is located in the deepest part of the operative field and the strong tension of the lateral soft tissue makes retraction difficult. It is extremely difficult to reduce the gonial angle with sagittal split ramus osteotomy by intraoral approach at the same time. We apply the method of gonial angle reduction during SSRO and had satisfactory results. We will present our results and hope to give some useful information for management of mandibular deformity.

• 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.

• 대한치과교정학회지
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• 제19권1호
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• pp.187-200
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• 1989

The purpose of this study was to find out the craniofacial skeletal characteristics and to establish standards in facial patterns of Korean adolescences with normal occlusion. The subjects consisted of 54 males and 71 females ranging in age from 12 to 16 years. To classify facial patrons, number the clinical deviations from the normal five key measurements: the facial axis, facial angle, mandibular plane angle, lower face height, mandibular arc, are added and averaged with the proper sign to divide subjects into three groups ; brachyfacial, mesofacial dolichofacial groups. For the comparison of each group, a total of 43 morphologic variables were employed and the data were analyzed by statistical methods. The findings of this study can be summerized as follows; 1. The mesofacial group was $54.4\%$, the brachyfacial group was $29.6\%$ and the dolichofacial group was $16.0\%$ in this subjects. 2. There were no significant differences in size and shape of cranial base among each groups. 3. The brachyfacial group manifested the forward positioned maxilla and mandible to anterior cranial base, smaller cant of the mandibular plane, square shaped mandible, and prominent symphysis as compared with dolichofacial group. 4. There were no significant differences in the cant of the maxilla to the anterior cranial base among each groups. 5. Ramal height and madibular body length of brachyfacial group were larger than those of dolichofacial group. 6. Brachyfacial group indicated the smallest degree in divergency of maxilla and mandible while dolichofacial group showed the largest degree.

• 대한치과교정학회지
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• 제30권3호
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• pp.355-365
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• 2000

악교정수술에 관한 치료계획은 치료결과에 관한 정확한 예측을 바탕으로 수립되는 것이 바람직하며 이는 심미적인 결과를 얻기 위한 가장 중요한 요소 중에 하나이다. 성인에서 골격성 하악전돌증의 치료는 하악골후퇴술을 이용한 악교정수술법이 주로 이용되는데, 술후 턱끝의 돌출도가 과도하게 감소되어 하악전진이부성형술을 추가로 시행해야 하는 경우 하악골과 턱 부위의 연조직 변화방향이 상이하게 나타나므로 술후 연조직 변화를 정확히 예측하는데 한계가 있다. 본 연구에서는 골격성 하악전돌증을 주소로 악교정수술을 시행한 성인을 대상으로, 상행지시상분할골절단술(BSSRO)만을 시행한 경우(A군) 11명 과 하악전진이부성형술(advancement genioplasty)도 같이 시행한 경우(B군) 9명의 경조직과 연조직 변화의 상관관계를 알아보기 위하여, 수술 8개월 이후에 채득된 측모두부계측방사선사진을 비교하여 다음과 같은 결과를 얻었다. 1. E-line에 대하여 상순은 더 돌출되고 하순은 더 후퇴되어 입술의 형태가 개선되었으며, 하악전진이부성형술을 병행한 경우 하순의 돌출도는 더 개선되었다. 2. 두 군 모두에서 상순은 후방이동하고 비순각은 증가하였다. 3. 술후 B점에 대한 연조직 POGs점의 변화율은 A군에서 $84\%$, B군에서 $66\%$로 나타났으며 두 군간에 통계적 유의성이 있었다. 4. 경조직과 계측점의 수직변화량은 A군에서 감소하였다.