• The korean journal of orthodontics
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• v.26 no.3
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• pp.255-265
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• 1996

The purpose of this study was to investigate if there were a significant difference between cephalometric measurements of mandibular position derived from a centric occlusion tracing compared to those of a converted centric relation tracing in the Class III malocclusion. The sample consisted of 25 Class III malocclusion and 25 normal occlusion persons who had no orthodontic treatment. The records included an lateral cephalometrics in centric occlusion, centric relation and centric occlusion bite registration and diagnostic casts mounted on the SAM II articulator in CR. The amount of CR-CO discrepancy of condyle was recorded using a MPI(Mandibular Position Indicator, MPI $200^{(R)}$, Great Lakes Orthodontics, USA). The conversion of the CO cephalogram to CR using the MPI readings was performed on the Conversion work sheet. Measures of mandibular position were chosen for the purpose of this study. The comparison of the difference between CO and CR cephalometric measurements in the normal occlusion and Class III malocclusion group were studied. The results were as follows: 1. In the features of CR-CO discrepancy of the condyle, the condyle was displaced posterior and inferior when the teeth were in centric occlusion. The horizontal component(${\Delta}X$) in Class HI malocclusion group was greater than the vertical component(${\Delta}Z$) and also greater than the horizontal component(${\Delta}X$) in normal occlusion group. There was no statistically significant correlation between MPI measurements and the groups of normal occlusion and Class III malocclusion group. 2. In the comparison of the cephalometric measurements in each group, Normal occlusion group showed significant difference in measurements such as ANB, Facial angle, Facial convexity and ODI. Class HI malocclusion group showed significant difference in measurements such as ANB, Facial angle, Facial convexity, ODI, SNB, APDI, L1-FP and it had more significance than the normal occlusion group. 3. The Value of cephalometric measurements was significantly different between CO and CR but there were no differences between the groups of normal occlusion and Class III malocclusion. The results of this study suggest that if the discrepancies are greater than the amount of normal displacement from clinically captured centric relation, centric relation should be considered as the starting point for proper diagnosis and treatment planning.

• Journal of Oral Medicine and Pain
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• v.14 no.1
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• pp.81-88
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• 1989

저자는 정상 치열을 가지며 두개하악장애의 증상 및 병력이 없는 성인 21명을 대상으로 computerized occlusal analysis system인 T-Scan system을 이용하여 교합력에 따른 치아접촉수와 총치아접촉시간을 측정한 후 정량적인 분석을 시도하여 다음과 같은 결론을 얻었다. 1. 최대 측두근 전부 근활성도의 약 20%, 50%, 80% 수준의 교합력에서 치아접촉수의 평균은 각각 1.6개, 8.8개, 16.7개로 교합력이 증가할수록 유의하게 증가하였다. 2. 최대 측두근 전부 근활성도의 약 20%, 50%, 80% 수준의 교합력에서 치아당 치아접촉수이 평균은 대구치에서는 0.2, 1.4, 2.2 개였으며 소구치에서는 0.1, 0.5, 1.1개였고, 전치에서는 0.1, 0.2, 0.6개로 교합력이 증가함에 따라 유의하게 증가하였다. 3. 치아접촉분포로 구분된 대칭군과 비대칭군간의 총치아접촉시간에는 유의한 차이가 없었다.

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.2
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• pp.248-261
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• 1999

In order to define a current set of Korean children norm with mixed dentition, following study was done. The subjects were 102 healthy dentition contestants(48boys, 54girls). Standardized lateral head roentgenograms were taken, and Ricketts analysis was done. Results were as follows: 1. Length of anterior cranial base, posterior facial height, corpus length were longer in male than in female(p<0.05), and Porion was located posteriorly in male than in female(p<0.01). 2. Through facial depth, Pogonion of male was more forwardly positioned(p<0.05), mandible was significantly steeper in female, and maxillary anterior teeth were significantly tipped forward in male(p<0.05). 3. Variables such as length of anterior cranial base, upper molar position(p<0.01) and corpus length(p<0.05) were significantly changed by age. 4. Maxillary height, facial depth, mandibular plane angle, convexity were changed by age, but not significantly(p>0.05).

• The korean journal of orthodontics
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• v.27 no.4 s.63
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• pp.549-557
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• 1997

This study was designed to investigate the attrition pattern in Angle Class III malocclusion with facial asymmetry. The sample consisted of three groups, the 20 subjects of normal occlusion group(Group I), the 12 subjects of class III malocclusion without facial asymmetry group(Group II) and 17 subjects of Class III malocclusion with facial asymmetry group(Group III). Attrition areas from canine to second molar on both sides in upper and lower arch, totally twenty, was marked by pencil and mesured by computer system(INTERGRAPH CO. USA) 2 times and the average value was used for date processing. Attrition areas from canine to second molar on both sides in upper and lower arch, totally twenty, was marked by pencil and mesured by computer system(INTERGRAPH CO. USA) 2 times and the average value was used for date Processing. All attrition areas were measured 2 times and the average value was used for data processing The data were statistically analyzed by SAS program. The results of this study were as follows. 1. Total attrition area in Group I was larger than in Group II and III. 2. There was no significant difference in attrition area between right and left side in each group, but attrition area in Group III was larger than in Group I and II. 3. In Group I, Maxillary attrition area was larger than mandibular attrition area, but in Group ll and III, there was no significant difference in attrition area between maxilla and mandible. 4. In Group III, the attrition area of deviated side was target than undeviated side 5. There was no significant difference in attrition area between chewing side and non-chewing side in each group. 6. The total attrition area was unaffected by gender.

• The korean journal of orthodontics
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• v.28 no.5 s.70
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• pp.751-761
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• 1998

The purpose of this study was to find the characteristics of lateral crphalogram of skeletal class III malocclusion patients to whom orthognathic surgery was essential. For this study 37 patients with skeletal class III and going to treat or be treated orthognathic surgery(age 7-17) were selected to experimental group and 56 people with normal occlusion (age 8-13) were selected to normal group and the two groups were evaluated and statistically analyzed and the results were as follows 1. In comparison of experimental group and normal group in prepubertal group, there were significant differences in ANS-U1/Me-L1, Mx. Length/Mn. Length, S-N/Go-Me, Wits, ANB, SN-Pog, IMPA, Facial Convexity, APDI (p<0.05) 2. In comparison of experimental group and normal group in pubertal group, there were significant differences in ANS-U1/Me-L1, S-Go/N-Me, Mx.Length/Mn.Length, S-N/Go-Me, Wits, Saddle Angle, SNB, ANB, SN-Pog, IMPA, Interincisal Angle, Facial Convexity, APDI (p<0.05) 3. Among items showing characteristics of skeletal class III malocclusion, there were no significant differences between prepubertal group and pubertal group in other items except Mx. Length/Mn. Length,APDI (p<0.05) 4. The significant correlationship was the highest between Saddle Angle and SNB, SN-Pog and SNB, ANB and Facial Convexity in experimental group

• Journal of the korean academy of Pediatric Dentistry
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• v.39 no.3
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• pp.293-300
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• 2012

In case of treating the functional type of anterior cross bite, removing the cause in early stage prevents from turning to skeletal type, leads to perform normal function, and has improved facial appearance. Functional Regulator III (FR III), one kind of the Functional regulator(FR)s suggested by R$\ddot{o}$lf Fr$\ddot{a}$nkel in 1966, applied to patients with the functional and skeletal anterior crossbite in early mixed, and permanent dentition. This appliance improves unbalanced power condition by blocking abnormal muscle-power effect, so that normal growth can be expected. In this case report, favorable results were obtained by selecting clinical cases of children in their early mixed dentition with functional cross bite. 1. FR IIIs were applied to patients with anterior crossbite for 5~6 months. Anterior crossbite patients were corrected favorably, nevertheless they didn't show any horizontal skeletal-changes by buccal shields. 2. Normal occlusion and esthetic facial contour were achieved from dental movement of maxillary and mandibular anterior teeth while the mandible rotates to posterior and inferior direction.

• The korean journal of orthodontics
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• v.39 no.2
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• pp.112-119
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• 2009

Objective: To develop a mixed dentition analysis method in consideration of the normal variation of tooth sizes. Methods: According to the tooth-size of the maxillary central incisor, maxillary 1st molar, mandibular central incisor, mandibular lateral incisor, and mandibular 1st molar, 307 normal occlusion subjects were clustered into the smaller and larger tooth-size groups. Multiple regression analyses were then performed to predict the sizes of the canine and premolars for the 2 groups and both genders separately. For a cross validation dataset, 504 malocclusion patients were assigned into the 2 groups. Then multiple regression equations were applied. Results: Our results show that the maximum errors of the predicted space for the canine, 1st and 2nd premolars were 0.71 and 0.82 mm residual standard deviation for the normal occlusion and malocclusion groups, respectively. For malocclusion patients, the prediction errors did not imply a statistically significant difference depending on the types of malocclusion nor the types of tooth-size groups. The frequency of prediction error more than 1 mm and 2 mm were 17.3% and 1.8%, respectively. The overall prediction accuracy was dramatically improved in this study compared to that of previous studies. Conclusions: The computer aided calculation method used in this study appeared to be more efficient.

• The korean journal of orthodontics
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• v.28 no.3 s.68
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• pp.343-351
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• 1998

The purpose of this study was to investigate the pretreatment and posttreatment dentofacial characteristics of non-extraction patients with Class I malocclusion. And to compare this result with matched non-orthodontic normal occlusion and Class I premolar extraction patients. Such comparison might help identify morphologic characteristics of the non-extraction patients. Initial and final cephalometric evaluation were compared in a sample of 22 patients with Class I malocclusions treated in non-extraction manner with edgewise appliance and MEAW The mean age of the total population was 14 years 9 months and the average treatment time was 2 years 8 months. 32 landmarks were located and digitized on each cephalogram. From these landmarks, 24 linear and angular dimension were obtained. Student's t-test were used to compare the pretreatment - posttreatment results, Nonextraction - Normal groups, and nonextraction Extraction groups. Significance was predetermined at $p{\leq}0.05$. The results were as follows. 1. Before treatment, the mean value of the $ODI\;was\;69.9^{\circ},\;APDI\;was\;82.1^{\circ},\;CF\;was\;152^{\circ},\;EI\;was\;152^{\circ}$ in the non-extraction groups. 2. The skeletal pattern of the non-extraction groups were similar with non-orthodontic normal groupsr, but the non-extraction groups had larger interincisal angle. 3. Comparison between groups treated with and without extraction indicated at pretreatment, the extraction groups had more protrusive lips, smaller interincisal angle, and EI. 4. After treatment, there was no significant changes in the skeletal pattern of the non-extraction groups, but uprighting of the maxillary and mandibular first molar and decrease of the interincisal angle were seen.

• Journal of Dental Rehabilitation and Applied Science
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• v.40 no.2
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• pp.91-99
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• 2024

In the case of skeletal class III edentulous patients, the stability of dentures can be achieved by using a crossbite by considering the residual ridge relationship when fabricating complete dentures. Forming the anterior teeth in a normal occlusal relationship in a skeletal class III ridge relationship may reduce the stability of the denture by increasing the anterior cantilever. However, when patients use complete dentures, not only functional aspects but also aesthetic aspects are important. The aesthetics of complete dentures depends on how the anterior artificial teeth are arranged, and cases of complete denture fabrication using normal occlusion or edge-to-edge bite in edentulous patients with skeletal class III ridge relationships have been reported. In this case, complete dentures were fabricated for an edentulous patient with a skeletal class III edentulous patients by forming anterior edge-to-edge bite considering neutral zone in maxillary anterior teeth, and good aesthetic and functional results were obtained.

• The korean journal of orthodontics
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• v.12 no.2
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• pp.127-138
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• 1982

The present study was performed to establish the cephalometric norms and to study characteristics of craniofacial skeleton of Korean male and female with normal occlusion. The author studied and analyzed statistically vertical cephalometric measurements of the 52 adult male ranging in age from 18 to 26 years and 43 adult female ranging in age from 16 to 30 years with normal occlusion and acceptable profile. The results were as follows; 1. Cephalometric craniofacial norms and standard deviation chart were abtained about adult Korean male and female with normal occlusion. 2. Vertical dimensions of the craniofacial skeleton were larger in male than in female. 3. Lower face was more divergent in female than in male. 4. In simple correlation coefficients between vertical linear mesurements in male and female, high correlation were shown between ATFH and ALFH, PTFH and PLFH, ALFH and ALDH, PLFH and PLDH.