• The Journal of the Korean dental association
• /
• v.27 no.9 s.244
• /
• pp.861-867
• /
• 1989

• Journal of the korean academy of Pediatric Dentistry
• /
• v.29 no.3
• /
• pp.295-303
• /
• 2002

This study was performed to establish the cephalometric standards in Downs analysis and to compare them with other races. The lateral cephalograms of 88 Korean children (47 boys, 41 girls) with normal occlusion and acceptable profile between 7 and 11 years of age were taken and Downs analysis was done. Results were as follows: 1. Norms of Korean boys, girls and both sexes at 7, 9, 11 years of age by Downs analysis were established. 2. There were no statistically significant differences between boys and girls about ten measurements in each group, but significant differences in the occlusal plane angle, lower 1 to occlusal plane angle, interincisal angle, upper 1 to APog plane among 3 groups(p<0.05)(p<0.01). 3. Facial angle, AB plane angle, Y-axis, lower 1 to occlusal plane angle and lower 1 to mandibular plane angle showed increasing tendency whereas angle of convexity, mandibular plane angle, occlusal plane angle and interincisal angle did decreasing tendency according to aging. 4. In comparison among races, measurements in Korean children were generally larger than those of Caucasian and Greek except for small interincisal angle, but Korean were similar to Japanese, Chinese, Israeli, Negro about all measurements.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.28 no.3
• /
• pp.412-420
• /
• 2001

In the growing children with normal occlusion and class III malocclusion who need the early treatment to be helped to diagnose and to set up treatment plan by calculating the mean values of the lateral cephalometric measurements, cephalometric measurements by McNamara alalysis were achieved and compared on both the 84 elementary school children with normal occlusion and 83 class III malocclusion children at the age of 7 to 9 in Kwangju city and the results were as follows: 1. On the boys group, between normal occlusion and class III malocclusion, Effective maxillary length, Maxillomandibular differential, Facial axis, Nasion perpendicualr to pogonion, Point A perp to Mx 1, and A-Pog line to Mn 1 showed significant differences(p<0.05). 2. On the girls group, between normal occlusion and class III malocclusion significant differences were shown in Effective Maxillary length, Maxillomandibular differential, Mandibular plan angle, Nasion perpendicualr to Point A, Point A perp to Mx 1, A-Pog line to Mn 1(p<0.01). 3. There were no significant differences between normal occlusion and class III malocclusion of boys group but significant differences between them of girls group in Effective mandibular length(P<0.01). On the boys and girls group, Effective maxilla length of class III malocclusion was shorter than that of normal occlusion. 4. There were no significant differences between normal occlusion and class III malocclusion both in boys and girls at Anterior lower facial height. 5. There were significant differences between boys and girls both in class III malocclusion and normal occlusion at Anterior lower facial height and Mandibular plane angle(p<0.01).

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.29 no.4
• /
• pp.309-315
• /
• 2016

Recently, finite element analysis technique has been widely used for structural and mechanical understandings of human body in the dentistry field. This research proposed an effective finite element modeling method based on CT images, and parametric studies were performed for the occlusal simulation. The analyses were performed considering linear material behaviors and nonlinear geometrical effect, and validated with the experimental results. In addition, the skull models with two different molar relations such as Class I and full-CUSP Class II were generated and the analyses were performed using the proposed analytical method. As results, the relationships between the mandibular movement and occlusal force of both two models showed similar tendency in human occlusal force. However, stress was evenly distributed from teeth to facial bone in the skull model with Class I, while stress concentration was appeared in the model with full-CUSP Class II due to the changes of occlusal surfaces of the model.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.29 no.1
• /
• pp.45-58
• /
• 2013

The purpose of this study was to analyze the area of occlusal contact points using visual method. One subject was selected who had Angle Class I, normal dentition, without dental caries, periodontal disease and temporomandibular disorders. Forty times PVS impressions were taken and 10 pairs casts were fabricated using dental super hard stone. After mounting the casts with customized loading apparatus, 78.9kg/f force was loaded as a maximum biting force. In T-Scan method, occlusal contact points measurement was repeated twice. Then, using Photoshop program (Adobe photoshop CS3, Adobe. San Jose, USA), the pixels which indicated occlusal contact points by color was recognized, and the distribution of recognized pixels were calculated to area. In Add picture method, polyether bite material applied to the occlusal surface of the casts. Then, the image of the translucent areas was recorded and classified $0{\sim}10{\mu}m$, $0{\sim}30{\mu}m$, $0{\sim}60{\mu}m$ area by the amount of transmitted light. To acquire occlusal surface, the numbers of pixels from the photograph of the contact area indicated cast converted to $mm^2$. The mean occlusal contact area by two methods was statistically analyzed (paired t-test). Part of the red and pink area in T-Scan image were almost equivalent to the $0{\sim}10{\mu}m$, $0{\sim}30{\mu}m$, $0{\sim}60{\mu}m$ area in Add picture image. The distribution of occlusal contact points were similar, but the average area of occlusal contact points was wider in T-scan image (P<.05). Pink and red area in T-scan image was wider than $0{\sim}10{\mu}m$, $0{\sim}30{\mu}m$ area in Add picture image (P<.05), but similar to $0{\sim}60{\mu}m$area in Add picture image (P>.05). Occlusal contact points in T-scan image did not indicate real occlusal contact points. Occlusal contact areas in T-scan method were enlarged results comparing with those in Add picture method.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.30 no.2
• /
• pp.291-297
• /
• 2003

While making diagnosis and the treatment plan for the growing children who visited at Chonnam National University Hospital for orthodontic treatment, authors obtained 8 lateral cephalometric measurements in antero-posterior and vertical relationship such as APDI, WITS, ANB, SN-MP, ODI, PFH/AFH, Y-axis, SUM for children aged 7 to 9 with class III malocclusion and compared them with these of 73 children of elementary school aged 7 to 9 with proper profile and normal occlusion in Gwangju. The results were as follows: 1. Between normal occlusion and class III malocclusion, ANB, SN-MP, ODI, SUM, except PFH/AFH and Y-axis showed statistically significant differences(p<0.05). 2. Between mesurements to describe skeletal disorder of antero-posterior relationship such as APDI, WITS, ANB and skeletal disorder of vertical relationship such as SN-MP, ODI, PFH/AFH, Y-axis, SUM, all of them in both normal occlusion and Class III malocclusion showed significant correlation, except Y-axis, SUM correlation(p<0.01). 3. Wald' statistics of WITS, ANB and APDI expressing skeletal disorder of antero-posterior relationship showed 7.118, 5.148, 0.741, respectively and Wald' statistics of ODI, Y-axis, PFH/AFH, SN-MP, SUM were presented 28.348, 2.238, 1.376, 0.090, 0.089, respectively. Therefore, WITS and ODI could be considered as useful diagnotic measurements for class III malocclusion.

• The korean journal of orthodontics
• /
• v.29 no.3 s.74
• /
• pp.317-325
• /
• 1999

In proper diagnosis of skeletal Class III malocclusion, it was important to know the pattern of three dimensional skeletal & facial disharmony. The purpose of this study was to obtain P-A cephalometric characteristics in skeletal Class III malocclusion comparing with normal occlusion. The samples were consisted of 120 subjects, divided into four groups : Male normal occlusion, Female normal occlusion, Male skeletal Class III malocclusion, Female skeletal Class III malocclusion. Posteroanterior and lateral cephalogram were taken from the subjects with a x-ray apparatus (ASHAI CX90SP, Japan) and traced on acetate paper with routine manner. The transverse and vertical values from posteroanterior cephalometry, the sagittal values from lateral cephalometry and their ratio were obtained. The results were as follows: 1. The anteroposterior discrepancy in skeletal Class III group was not due to short maxillary length(Cd-A), but to longer mandibular length(Cd-Gn) than normal occlusion group. 2. The faces of skeletal Class III group were longer than normal occlusion group. It was not due to increase of upper face height(Cg-ANS) but to increase of the lower face height(ANS-Me) especially mandibular height(Cd-Me). 3. There was no difference in the facial width values between normal occlusion group and skeletal Class III group, except upper molar width(U6-U6), lower molar width(L6-L6) and mandibular width(Ag-Ag) of female skeletal Class III group which were larger than normal occlusion group. 4. The increase of mandibular length of skeletal Class III group was reflected in the increase of lower facial height but did not have an effect on the mandibular width.

• Journal of Oral Medicine and Pain
• /
• v.36 no.2
• /
• pp.107-115
• /
• 2011

We report 4 patients who developed change of occlusion which seemed to be related to anterior disc dislocation without reduction, but there was no distinct evidence of condylar destruction or collapse. They experienced sudden occurrence of occlusal change, anterior open bite in 2 patients, lateral CR-CO discrepancy in 1 patient, and anteroposterior CR-CO discrepancy in 1 patient. Also, this report is to find out if there is a relation between sudden occurrence of occlusal change and anterior disc dislocation without reduction.

• Journal of Oral Medicine and Pain
• /
• v.24 no.1
• /
• pp.49-58
• /
• 1999

저자는 하악의 위치변화가 저작근에 미치는 영향을 근전도학적으로 평가하고자, 측두하악장애의 징후와 증상이 없는 정상성인 28명을 대상으로 중심위 교합장치(centric relation splint), 중심교합위 교합장치(centric occlusion splint), 전방 재위치 교합장치(anterior repositioning splint)를 장착시킨 상태에서 하악의 중심의, 중심교합위, 전방위률 유도한 후 최대 이악물기 상태의 좌우측 교근 및 전측두근의 근전도를 채득, 분석, 평가한 결과 다음과 같은 결론을 얻었다. 1. 전측두근에서 하악의 위치변화에 따른 최대 근활성도의 차이가 나타났으나(p<0.05), 교근에서는 나타나지 않았다. 2. 전측두근의 경우 중심교합위에서 최대 이악물기 상태의 최대 근활성도는 교합 장치물을 장착하지 않은 경우 및 중심위에서와 비교하여 감소하였다(p<0.05). 3. 전측두근의 경우 전방위에서 최대 이악물기 상태의 최대 근활성도는 교합 장치물을 장착하지 않은 경우 및 중심위에서와 비교하여 감소하였다(p<0.001). 4. 교근과 전측두근의 좌우 비대칭지수(asymmetry index)는 하악의 위치변화에 따른 차이가 나타나지 않았다.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.30 no.2
• /
• pp.298-307
• /
• 2003

The purpose of this study was to investigate the distribution and differences of the cephalometric measurements between normal occlusion and the class III malocclusion. Kim's analysis was achieved and compared on both the 141 elementary school students with proper profile and normal occlusion and the class III malocclusion group at the age of 7 to 9, in Gwang-ju area and the results were as follows; 1. The ODI, APDI, IIA, UL showed statistically significant differences between normal occlusion and class III malocclusion(p<0.01). But, no significant difference existed in both CF and EI. 2. The mean value of ODI was 72.62, APDI 80.47 IIA 121.37 in normal occlusion. 3. The mean value of ODI was 64.45, APDI 87.31 IIA 129.89 in class III malocclusion. 4. ODI decreased as APDI increased, and the correlation coefficient was -0.576 in both normal occlusion and class III malocclusion. 5. The correlation coefficient related to EI was CF 0.777, LL -0.670, UL -0.588, IIA 0.485. It means that UL and LL were very sensitively reflected on EI.