• Maxillofacial Plastic and Reconstructive Surgery
• /
• 제41권
• /
• pp.57.1-57.8
• /
• 2019

Background: The relationship between the lateral deviation of chin and the upper and middle facial third asymmetry is still controversial. The purpose of this study is to evaluate the correlation of upper and middle facial third asymmetry with lateral deviation of chin using 3-dimensional computed tomography. The study was conducted on patients who underwent orthognathic surgery from January 2016 to August 2017. A total of 40 patients were included in this retrospective study. A spiral scanner was used to obtain the 3-dimensional computed tomography scans. The landmarks were assigned on the reconstructed 3-dimensional images, and their locations were verified on the axial, midsagittal, and coronal slices. The Pearson correlation analysis was performed to evaluate the correlation between chin deviation and difference between the measurements of distances in paired craniofacial structures. Statistical analysis was performed at a significance level of 5%. Results: In mandible, the degree of chin deviation was correlated with the mandibular length and mandibular body length. Mandibular length and mandibular body length are shorter on the deviated-chin side compared to that on the non-deviated side (mandibular length, r = -0.897, p value < 0.001; mandibular body length, r = -0.318, p value = 0.045). In the upper and middle facial thirds, the degree of chin deviation was correlated with the vertical asymmetry of the glenoid fossa and zygonion. Glenoid fossa and zygonion are superior on the deviated-chin side than on the non-deviated side (glenoid fossa, r = 0.317, p value = 0.046; zygonion, r = 0.357, p value = 0.024). Conclusion: Lateral deviation of chin is correlated with upper and middle facial third asymmetry as well as lower facial third asymmetry. As a result, treatment planning in patients with chin deviation should involve a careful evaluation of the asymmetry of the upper and middle facial thirds to ensure complete patient satisfaction.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• 제33권1호
• /
• pp.55-61
• /
• 2011

Conventional slinding genioplsty has the risk of mental nerve injury after operation and difficult to correct vertical asymmetry of chin. So, authors propose a new genioplasty to correct asymmetry of chin. Switching genioplasty is a modification method of conventional genioplasty. Between mandibular right and left canine, osteotomy line of triangular shape make until mandibular lower border. In large side, osteotome line of wedge shape is added to reduction. After osteotomy, segment of wedge shape was separated from chin. Distal segment was rotated to reduction side. Because of rotation of distal segment, space is made in opposite side. Seperated segement of wedge shape from large side is switched this space to fill. So, stability of distal segment is achieved. Authors applied to swiching genioplasty the patients who was remained the chin asymmetry after both sagittal split ramus osteotome was done because mandible asymmetry. After operation, patient and operator were satisfied with excellent esthetic results without any other complication. The switching genioplasty is effective surgical technique for chin asymmetry because it has more advantages than conventional sliding genioplasty. First, other donor side does not need for bone graft. Second, the switching genioplasty can reduce infection, bone resroption, dehiscence, capsular contraction after allograft. Third, have little mental nerve damage. Forth, anteroposterior correction is possible. Fifth, operation time is less than other genioplasty for chin asymmetry.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• 제42권
• /
• pp.36.1-36.5
• /
• 2020

Background: Different genioplasty techniques are applied for the adjustment of chin area deformities such as chin deviation. Results: Thirty patients with simple facial asymmetry due to chin deviation underwent computer-assisted horizontal translational osseous genioplasty. In this technique, a surgical guide was used to cut a bone strip from the side where the chin should be transferred to; then, the same bone strip was used for the filling of the gap that was formed on the opposite side. Conclusion: According to the experience gained from this study, the authors believe that computer-assisted horizontal translational osseous genioplasty is a simple and reliable technique for patients with facial asymmetry due to chin deviation.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• 제31권3호
• /
• pp.266-273
• /
• 2005

Purpose: To assess the relationship between soft tissue reference line and hard tissue reference line using the standardized photographs and the posteroanterior cephalometric radiographs(P-A)in facial asymmetric patients and to compare the differences of angular measurement between normal group and asymmetry group. Methods: Normal group consisted of 44 persons with normal occlusion and normal facial morphology. Asymmetry group consisted of 90 patients with facial asymmetry. Standardized facial photographs and P-A were taken in all subjects. The horizontal reference lines were bipupillary line in photographs and latero-orbitale line in P-A respectively. The vertical reference line were the line from the midpoint of horizontal reference line perpendicularly. Angular measurement of otobasion canting, lip canting, nose deviation, chin deviation, and maxillary deviation were compared and analyzed in photographs. And angular measurement of mastoid canting, mandibular canting, nose deviation, chin deviation, and maxillary deviation were compared and analyzed in P-A. Results: 1. The variables of photographs and P-A were significantly related in the asymmetry group. 2. Significant differences between all variables except for PT2 and PA2 were shown in the asymmetry group and between PT1 and PA1, PT3 and PA3 in the normal group respectively. 3. Comparison measurement scores of angular difference between control group and experimental group concerning each variable showed significant difference except for PA1. Conclusions: Soft tissue components may not compensate for underlying skeletal imbalance in nose deviation and chin deviation. The horizontal reference lines in photographs were significant related with the P-A, but angular variables between the two studies show significant differences. Therefore, we do not recommend use photography in the assessment the facial asymmetry as complemented in the P-A.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• 제32권1호
• /
• pp.72-76
• /
• 2010

Osteochondroma is the one of the most benign tumors of the axial skeleton, but is rarely found in the facial bones. Typical facial features of condylar osteochondroma include striking facial asymmetry, malocclusion with openbite on the affected side, and prognathic deviation of the chin and crossbite to the contralateral side. In this case, twenty four year-old female showed facial asymmetry, chin deviation, openbite on the affected side but have no symptoms of pain or dysfunction. Concomitantly she had maxillary occlusal cant and hemimandibular hypertrophy. Panoramic radiograph showed radiopaque mass on right mandibular condyle extended along the lateral pterygoid muscle. Computed tomogram demonstrated enlarged condylar head and bony spur on posteromedial side of condyle and 99Tc bone scintigraphy showed a focal hot image. These findings were correspond with osteochondroma. The lesion was treated with condylectomy and residual facial asymmetry was corrected with 2-jaw orthognathic surgery. Herein, we report a case of osteochondroma of the mandibular condyle and accompanying facial asymmetry.

• Imaging Science in Dentistry
• /
• 제52권1호
• /
• pp.43-51
• /
• 2022

Purpose: The aim of this study was to evaluate the reliability of the Vectra M3 (3D Imaging System; Canfield Scientific, Parsippany, NJ, USA) in detecting chin asymmetry, and to assess whether the automatic markerless tracking function is reliable compared to manually plotting landmarks. Materials and Methods: Twenty subjects (18 females and 2 males) with a mean age of 42.5±10.5 years were included. Three-dimensional image acquisition was carried out on all subjects with simulated chin deviation in 4 stages (1-4 mm). The images were analyzed by 2 independent observers through manually plotting landmarks and by Vectra software auto-tracking mode. Repeated-measures analysis of variance and the Tukey post-hoc test were performed to evaluate the differences in mean measurements between the 2 operators and the software for measuring chin deviation in 4 stages. The intraclass correlation coefficient (ICC) was calculated to estimate the intra- and inter-examiner reliability. Results: No significant difference was found between the accuracy of manually plotting landmarks between observers 1 and 2 and the auto-tracking mode (P=0.783 and P=0.999, respectively). The mean difference in detecting the degree of deviation according to the stage was <0.5 mm for all landmarks. Conclusion: The auto-tracking mode could be considered as reliable as manually plotted landmarks in detecting small chin deviations with the Vectra^® M3. The effect on the soft tissue when constructing a known dental movement yielded a small overestimation of the soft tissue movement compared to the dental movement (mean value<0.5 mm), which can be considered clinically non-significant.

• 대한치과교정학회지
• /
• 제53권6호
• /
• pp.402-419
• /
• 2023

Objective: This study assessed the differences in soft tissue deviations of the nose, lips, and chin between different mandibular asymmetry types in Class III patients. Methods: Cone-beam computed tomography data from 90 Class III patients with moderate-to-severe facial asymmetry were investigated. The sample was divided into three groups based on the extent of mandibular rolling, yawing, and translation. Soft tissue landmarks on the nose, lips, and chin were investigated vertically, transversely, and anteroposteriorly. A paired t test was performed to compare variables between the deviated (Dv) and nondeviated (NDv) sides, and one-way analysis of variance with Tukey's post-hoc test was performed for intergroup comparisons. Pearson's correlation coefficient was calculated to assess the relationship between the soft and hard tissue deviations. Results: The roll-dominant group showed significantly greater differences in the vertical positions of the soft tissue landmarks between the Dv and NDv than other groups (P < 0.05), whereas the yaw-dominant group exhibited larger differences in the transverse and anteroposterior directions (P < 0.05). Moreover, transverse lip cant was correlated with the menton (Me) deviation and mandibular rolling in the roll-dominant group (P < 0.001); the angulation of the nasal bridge or philtrum was correlated with the Me deviation and mandibular yawing in the yaw-dominant group (P < 0.01). Conclusions: The three-dimensional deviations of facial soft tissue differed based on the mandibular asymmetry types in Class III patients with similar amounts of Me deviation. A precise understanding of soft tissue deviation in each asymmetry type would help achieve satisfactory facial esthetics.

• 대한치과교정학회지
• /
• 제26권3호
• /
• pp.241-246
• /
• 1996

턱은 인간의 성격을 나타내는 요소의 하나로 적절하게 돌출된 턱은 심미적인 안모를 위해 대단히 중요하다. 이부골성형술은 턱의 형태재형성을 목적으로 하며 이를 통해 교정치료 목적의 하나인 안모의 심미성 향상에 기여할 수 있다. 이부골성형술은 수직, 수평적으로 턱의 크기를 확대시키는 축조이부골성형술과 축소시키는 축소이부골성형술로 나눌수 있으며 그활용하는 예는 다음과 같다. 1. 후퇴된 턱의 전진 2. 전방 돌출된 턱의 후퇴 3. 수직고경의 조절 4. 비대칭의 개선

• 대한치과교정학회지
• /
• 제35권3호
• /
• pp.163-173
• /
• 2005

본 연구는 안면비대칭 환자에서 경조직의 비대칭 정도와 연조직 비대칭 정도의 차이를 3차원적으로 밝히고자 시행되었다. 안면비대칭으로 보이는 성인 남녀 34명을 대상으로 두경부 전산단층사진을 촬영하고 3차원 입체영상으로 재구성한 후 기준평면에 대해 비대칭을 나타내는 5개의 계측항목을 경조직에 설정하고, 이에 대응하는 연조직 계측항목을 각각 설정한 후 3차원 계측을 시행하고 경조직과 연조직의 계측항목간 차이를 비교하였다. 이부편위측과 반대측간의 계측치 차이를 비교한 결과, 경조직과 연조직 모두에서 좌우측 계측치간에 통계적으로 유의한 차이가 관찰되었으며 경조직과 연조직의 비대칭 계측항목을 비교한 결과, 6개의 계측항목 모두에서 통계적으로 유의한 차이를 나타내었다. 이부편위를 나타내는 chin deviation, 하악지와 하악골체를 나타내는 frontal ramal inclination difference, frontal corpus inclination difference 항목은 경조직의 비대칭 정도에 비하여 연조직 비대칭 정도가 작게 나타난 반면, 입술경사를 나타내는 lip cheilion height difference, lip canting은 maxillary height difference, occlusal plane canting보다 크게 나타나 입술부위의 비대칭 정도는 하부 경조직의 비대칭 정도보다 큰 것으로 나타났다. 안면비대칭자에서 경조직과 연조직간 비대칭 정도 차이를 규명한 본 연구 결과는 안면비대칭 평가 시 경조직 외에 연조직 계측항목을 이용한 비대칭 분석도 필요함을 시사하였다.

• 대한치과교정학회지
• /
• 제41권2호
• /
• pp.87-97
• /
• 2011

안면비대칭의 원인은 다양하며, 비대칭적 성장은 상악골과 하악골의 길이나 각도로 평가되어지곤 한다. 하지만 하악 과두의 비대칭적인 위치나 형태 또한 비대칭의 표현에 영향을 줄 것으로 생각된다. 따라서 본 연구는 하악 과두가 안면비대칭의 표현형인 이부 편위에 영향을 주는지에 대해 알아보고자 하였다. 50명의 골격성 III급 부정교합자 중 4 mm 이상의 menton point deviation을 보이는 비대칭군 30명, 4 mm 이하의 menton point deviation을 보이며 뚜렷한 안면비대칭이 없는 20명을 대칭군으로 하여, 두개저에 대한 좌우 하악 과두의 근원심적, 전후방적 위치를 평가하고, axial 평면에서 장축을 설정해 하악 과두의 최대 크기와 coronal plane에 대한 각도를 평가하였으며, sigmoid notch 상방 하악 과두의 길이와 부피를 측정하였다. 대칭군은 좌우 하악 과두의 위치, 각도, 크기, 길이, 부피에 있어 통계적인 차이가 없었다. 비대칭군은 이부 편위측과 비편위측으로 나누어볼 때, 이부 편위에 따른 좌우 하악 과두의 위치와 angulation 에서 통계적 차이는 없었으나, 하악 과두의 크기, 길이 및 부피에서는 비편위측 값이 컸고, 이부 편위량이 클수록 좌우 크기, 길이의 차이 및 편위측에 대한 비편위측 하악 과두의 부피비가 컸다. 또한 편위측에 대한 비편위측 하악 과두의 부피비가 이부 편위의 정도를 가장 잘 설명해주는 특성이었다. 이상의 결과를 통해 하악 과두의 비대칭이 안면비대칭의 발현에 영향을 주며, 비편위측 하악 과두가 편위측에 비해 크고 길다는 것을 알 수 있었다.