• 대한소아치과학회지
• /
• 제28권1호
• /
• pp.95-105
• /
• 2001

두개저의 길이와 폭경 그리고 굴곡의 정도는 그 하부 구조물인 상악골을 포함한 비상악복합체 및 하악골의 길이와 폭경 그리고 전후방적 위치를 결정짓는 중요한 요인으로 역할하며, 이에 따른 안면골의 다양한 구조물들 간의 구조적 관계는 각기 다른유형의 부정교합관계를 형성하는 것으로 알려져 있다. 측두방사선 계측학에서 두개저의 열리고 닫힘을 표현하는 계측치로 흔히 사용되는 안장각(N-S-Ba, N-S-Ar) 또는 중두개저각$({\angle}MCF)$ 등과 I급과 III급 부정교합을 보이는 어린이들의 안면골 계측치 간의 구조적 관계를 평가하여 두개저의 굴곡정도가 안면골을 구정하는 각 구조물과 부정교합 유형과의 관계를 구명하고자 하였다. 이를 위하여 $7\sim12$세 사이의 I급과 III급 부정교합을 보이는 어린이의 측두 규격방사선사진(208매)을 계측하여 통계적으로 비교, 평가한 결과, 안장각보다는 중두개저각이 안면골의 구조과 부정교합의 유형과 밀접한 관계를 지니고 있으며, 특히 III금 부정교합 어린이의 중두개저각과 안면골의 각 구조물들은 $9\sim11$세 사이에 뚜렷한 변화를 나타내는 것으로 가늠된다.

• 대한치과교정학회지
• /
• 제13권1호
• /
• pp.7-14
• /
• 1983

Serial cephalometric roentgenorgams of 40 Korean children (25 males, 15 females) were employed to study the growth changes of the cranial bases. As a result of this study, the following conclusions can be made: 1. The mean size of the cranial bases in males was larger than the females, especially at the age of 13. 2. In both sexes, growth of the cranial bases was seen from 6 to 13 years of age and the growth of the posterior cranial base (S-Ba) was larger than the anterior cranial base (S-N). 3, Variation in the changes of the saddle angle (Ba-S-N) was exhibited with males showing a marked tendency toward a decrease in saddle angle size.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• 제33권6호
• /
• pp.483-489
• /
• 2011

Purpose: Craniofacial structure form results from the adaptation to morphologic and functional changes in their neighboring structures for a mutual balance. The purpose of this study is classification of maxillomandibular complex growth pattern follow by cranial base growth pattern. And this study is identifying the correlation between maxilla-mandibular complex growth pattern and orthodontic criteria. Methods: 142 Class III malocclusion patients had orthognathic surgery at Wonkwang University Dental Hospital during April 2004 to October 2010. Patients were divided into 4 groups and the correlation between cranial base and maxillomandibular growth patterns were evaluated. Results: There was a correlation between cranial base and maxillomandibular growth patterns. Positive relationships were found between the occlusal plane, Incisor mandibular plane angle, mandibular plane, positioning of pogonion and the saddle angle, indicating maxillary growth patterns. Negative relationships were found between SNA, SNB, maxillary incisor angle and saddle angle. Positive relationships were found between the ratio of the anterior and posterior cranium, positioning of pogonion and the percentage of cranial depth indicating mandibular growth patterns. Negative relationships were found between the occlusal plane, maxillary incisor angle, mandibular plane, mandibular angle and cranial depth. Conclusion: Cranial base and maxillofacial growth patterns were correlated and the classification should be adjusted before orthognathic surgery.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2013년도 춘계학술대회 논문집
• /
• pp.1445-1446
• /
• 2013

• 대한치과교정학회지
• /
• 제20권3호
• /
• pp.519-539
• /
• 1990

It is the aim of this study to observe the distribution of various facial types in class III malocclusion and to characterize the craniofacial features of the very facial types. Cephalometric headptates of a hundred and ten persons showing bilateral class III malocclusion whose mean age was 12.51 years and sixty nine persons of normal occlusion whose mean age was 12.23 years were measured and statistically analyzed. The following summary and conclusions were drawn. 1. Affording the bases for SNA and SNB, $35.45\%$ of sample showed normally positioned maxilla and protruded mandible, $30.00\%$ for retruded maxilla and normally positioned mandible, $15.45\%$ for retruded maxilla and protruded mandible, $10.90\%$ for both maxilla and mandible within normal range and $8.20\%$ for miscellaneous types were arranged in class III malocclusion. 2. $52.72\%$ of sample showed neutrodiveigent, $35.45\%$ for hyperdivergent and $11.81\%$ manifested hypodivergent mandible in class III malocclusion. 3. Providing the bases for facial and mandibular planes, $33.63\%$ of sample showed prognathic and neutrodivergent, $20.90\%$ for mesognathic and hyperdivergent, $17.27\%$ for prognathic and hyperdivergent and $15.45\%$ for mesognathic and neutrodivergent were arranged in class III malocclusion. 4. The class III malocclusion brought out shorter cranial base, smaller saddle angle, and larger articular and genial angle. It showed retropositioned maxilla and forward positioned mandible in spite of no significant differences in linear measurements of mandible. Anterior lower facial height was significantly larger in class III malocclusion, while posterior total facial and anterior total facial heights exhibited no significant differences. 5. It is suggested class III malocclusion was attributed to shorter cranial base, smaller saddle angle, maxillary deficiency and/or retrusion, mandibular excess and/or protrusion, excessive vertical growth of the anterior lower face, and their complex as well.

• 대한기계학회논문집
• /
• 제8권5호
• /
• pp.401-407
• /
• 1984

본 연구에서는 구속공구 및 정상공구에 대하여 공구경사면의 전단응력과 수직 응력을 해석하고 칩 유동시의 마찰계수분포를 검토하였다.

• 대한치과교정학회지
• /
• 제37권4호
• /
• pp.260-271
• /
• 2007

본 연구는 악교정 수술을 필요로 하는 골격성 III급 부정교합자의 두개안면형태와 교합평면이 어떤 관련성을 가지고 있는 지를 알아보기 위하여 악교정 수술을 시행하기로 계획된 골격성 III급 부정교합자 90명의 초진 시 측모 두부 방사선계측사진을 대상으로 연구를 하였다. 전치부 피개량에 따라서 positive overbite (PO) group, edge to edge bite (EO) group, negative overbite (NO) group의 세 군으로 분류를 하였으며, 각 군의 골격관계와 상하악 제1소구치와 제1대구치의 교두의 접촉점을 연결한 기능교합평면과의 관계에 대한 항목을 계측하여 상관관계 분석과 회귀 분석을 시행하였다. 연구 결과, 각 군 간의 분류와 상관없이 전치부 피개 교합의 변화에 대해서 saddle angle, articular angle, Y axis, AFH, SN-FH, SN-Mn, FH-Mn 항목이 유의성 있는 차이를 보였다. 특히, 상악 전치부는 기능교합평면에 대한 각도에서 유의성 있는 차이를 보였으며, 하악 전치부는 FH 평면에 대한 각도에서 각 군 간에 유의성 있는 차이를 보였다. 안면 골격 계측 항목과 상하악골에 대한 기능교합평면의 각도 항목들과의 상관관계에서는, 상하악골의 이개 정도를 나타내는 Mx-Mn 항목이 모든 군에서 유사한 정도로 기능교합평면 각도와 가장 높은 상관관계를 보였다. 이를 이용하여 Mx-Mn 항목의 변화에 따라서 FH-Occ, Mx-Occ, Mn-Occ 항목이 어느 정도의 변화를 일으키는지를 알아보고자 회귀분석을 시행한 결과, 결정계수가 각각 0.714, 0.560, 0.677로 나타났다. 따라서 본 연구를 통해서 골격성 III급 부정교합자의 기능교합평면의 형성은 상하악골의 골격적인 수직이개 정도와 깊은 관련성이 있음을 알 수 있었다.

• 대한기계학회논문집B
• /
• 제25권10호
• /
• pp.1355-1364
• /
• 2001

Characteristics of secondary vortices is topologically investigated in the near-wake region of a circular cylinder, where the Taylor's hypothesis does nut hold. The three-dimensional flow fields in the wake-transition regime were measured by a time-resolved PIV for various planes of view. The convection velocities of the Karman and secondary vortices are evaluated from the trajectory of the vortex center. Then, saddle points are determined by applying the critical point theory. It is shown that the inclination angle of the secondary vortices agrees well with the previous experimental data. The flow fields in a moving frame of reference have several critical points and the mushroom-like structure appears in the streamline patterns of the secondary vortices. Since the distributions of fluctuating Reynolds stresses defined by triple decomposition are closely related with the existence of secondary vortices, the physical meaning of them is explained in conjunction with the vortex center and saddle point trajectories.

• 대한기계학회논문집B
• /
• 제22권1호
• /
• pp.12-24
• /
• 1998

The paper presents the mechanism of secondary flows and the associated total pressure losses occurring in turbine cascades with turning angle of about 127 and 77 degree. Velocity and pressure measurements are taken in seven traverse planes through the cascade passage using a prism type five hole probe. Oil-film flow visualization is also conducted on blade and endwall surfaces. The characteristics of the limiting streamlines show that the three dimensional separation is an important flow feature of endwall and blade surfaces. The larger turning results in much stronger contribution of the secondary flows to the loss developing mechanism. A large part of the endwall loss region at downstream pressure side is found to be very thin when compared to that of the cascade inlet and suction side endwall. Evolution of overall loss starts quite early within the cascade and the rate of the loss growth is much larger in the blade of large turning angle than in the blade of small turning angle.

• 대한치과교정학회지
• /
• 제23권3호
• /
• pp.341-358
• /
• 1993

This study was investigated to evaluate the morphologic characteristics of deepbite tendency as multiple factors. The subjects consisted of 60 control subjects(male 25, female 35) and 137 deephite patients(68 male, 69 female). The deepbite group was composed of 4 subgroups(Class I 44, Class II div. 1 40, Class II div. 2 13, Class III 40). The mean age was 21.57 year for the control group 21 year for deepbite group lateral cephalograph in centric occlusion were taken, traced, and digitized for each subject. The statistically computerized analysis was carried out with SAS program. The results were as follows ; 1. In deepbite group, saddle angle is lesser than that of normal group. 2. The vertical dysplasia is prominent on anterior lower face and is closely related with mandibular form and inclination. 3. Without consideration of sagittal relationship, the dental factors such as curve of Spee, interincisal angle, U1 to upper lip length were prominent in the deepbite group. 4. Although there were individual variances in the perioral soft tissue profile, the lip presented more protruded pattern. 5. There was no significant difference in hyoid bone position and inclination between normal and deepbite group. 6. The multivariate discriminant analysis between normal and Class I deepbite group showed that curve of Spee, AB-MP angle, interincisal angle, articular agnle were critical in the determination of deepbite as multiple factors.