• The Journal of Korean Academy of Prosthodontics
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• v.46 no.4
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• pp.420-430
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• 2008

Statement of problem & Purpose: Articulators are very important for education and overall clinical situation in the field of prosthodontics, however preexisting articulators are designed and built based on maxillofacial structures and mean values of mandibular movement of Western people. Purpose of this research is to find out a adequate basis for applicating these articulators, presently used for clinical education, for Korean. Material and methods: 59 Korean adults (41 males, 18 females), aged between 24 to 41, where selected for this study. Two pairs of both maxillary and mandibular models were made for each examinee. These models where attached to both KaVo PROTARevo 7 and Hanau Modular semiadjustable articulators by using facebow transfer, than sagittal condylar inclination, occlusal plane inclination and position of mandibular on the articulator where measured. Result and conclusion: 1. Mean sagittal condylar inclination for KaVo PROTAR semiadjustable articulator was $33.75^{\circ}$(standard deviation $12.46^{\circ}$) meanwhile Hanau Modular semiadjustable articulator showed $40.72^{\circ}$(standard deviation $12.09^{\circ}$) for mean sagittal condylar inclination. 2. Mean occlusal plane inclination for KaVo PROTAR semiadjustable articulator was $-2.76{\circ}$(standard deviation $3.63^{\circ}$) meanwhile Hanau Modular semiadjustable articulator showed $11.87^{\circ}$ (standard deviation $3.63^{\circ}$) for mean occlusal plane inclination. 3. On the average center of the mandibular dentition were in the range of 5 to 7 mm of the central position of the articulator. Both anterior and posterior dentition were positioned at the center of the articulator vernacularly for KaVo PROTAR semiadjustable articulators, meantime for Hanau Modular semiadjustable articulator, anterior dentition was positioned 5 mm downwards and 3mm upwards for posterior dentition from vertically central position of the articulator.

• The korean journal of orthodontics
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• v.34 no.5 s.106
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• pp.380-393
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• 2004

The Purpose of this study was to investigate the dentoalveolar compensation according to anteroposterior skeletal discrepancy in normal occlusion and to evaluate cephalometric parameters that quantitatively describe dental compensations. The study consisted of 90 subjects (50 males. 40 females) who were selected among specimens of normal occlusion at Seoul National, University Dental Hospital, Dept. of Orthodontics. Lateral cephalograms in centric occlusion were traced and digitized for each subject. According to the anteroposterior skeletal pattern the sample was divided into three groups. Cephalometric data were analyzed for the three groups using the SPSS program. Independent t-test, correlation analysis and regression analysis were carried out. The results were as fellows: Dentoalveolar compensation was found in upper and lower incisor inclination and occlusal plane inclination. As the mandible located anterior to the maxilla, the maxillary incisors incisors more labially. the mandibular incisors more lingually, and the occlusal plane continued to flatten. The dental parameters most correlated with anteroposterior skeletal discrepancy were L1 to SN and L1 to FH. Among the compensatory dentoalveolar changes, lower incisor inclination was strongly related to the anteroposterior jaw relationship and played au imposrtant role in obtaining a normal incisor relationship U1 to PtGn and L1 to APog were constant irrelevant to anteroposterior skeletal discrepancy.

• The korean journal of orthodontics
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• v.37 no.3 s.122
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• pp.182-191
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• 2007

Objective: The purpose of this study was to evaluate the validity of midsagittal reference (MSR) planes constructed in maxillofacial 3D images. Methods: Maxillofacial computed tomography (CT) images were obtained in 36 normal occlusion individuals who did not have apparent facial asymmetry, and 3D images were reconstructed using a computer software. Six MSR planes (Cg-ANS-Ba, Cg-ANS-Op, Cg-PNS-Ba, Cg-PNS-OP, FH${\perp}$(Cg, Ba), FH${\perp}$(Cg, Op)) were constructed using the landmarks located in the midsagittal area of the maxillofacial structure, such as Cg, ANS, PNS, Ba and Op, and FH plane constructed with Po and Or. The six pairs of landmarks (Z, Fr, Fs, Zy, Mx, Ms), which represent right and left symmetry in the maxillofacial structure, were selected. Statistically significant differences of the right and the left measurements were examined through t-test, and the difference of the right and the left measurement was compared among the six MSR planes. Results: The distances from the right and the left landmarks in each pair to each MSR plane did not show a statistically significant difference. The reproducibility of the landmark identification was excellent. Conclusion: All the six planes constructed in this study can be used as a MSR plane in maxillofacial 3D analysis, particularly, the planes including Cg and ANS.

• The korean journal of orthodontics
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• v.35 no.3 s.110
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• pp.238-249
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• 2005

The contemporary two-jaw surgical approach usually involves a Le Fort osteotomy of the maxilla and a ramal osteotomy of the mandible with 3-dimensional repositioning of the jaws as well as the occlusal planes. After making the surgical treatment plan. the surgical movements are duplicated in the model surgery. During this procedure, reference poings and lines are drawn on the base of the models over the dental arch and sawcuts are mads according to these marked osteotomy lines. This technique, however, has been found to be inexact. especially when the laws are moved in several dimensions simultaneously. To overcome this. different methods have been developed for an accurate repositioning of the jaws as planned. A new appliance. Surgical Jaw Relater, has been devised by th8 author for the simple 3-dimensional relocation of the upper and lower models, resulting in the easy construction of the splints such as centric relation splint, intermediate and final splint. This article describes an introduction and a clinical application of this appliance. Through the application of this system to the orthognathic cases including two-law surgery. it is proved that the row device is very clinically useful.

• Archives of Craniofacial Surgery
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• v.9 no.2
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• pp.105-109
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• 2008

Temporomandibular joint(TMJ) and dental occlusion are important in functional aspect as well as in cosmetic aspect for craniofacial surgery such as orthognathic and traumatic surgery. During these operations, appropriate maxillomandibular fixation(MMF) is especially necessary to conserve or reconstruct, dynamic TMJ and functional occlusion. Arch bar is one of the most popular method to gain proper MMF. Seventeen patients including 5 patients with mandibular fracture, 12 patients with orthognathic surgery(6 patients had relatively normal occlusion, however 6 patients had facial anomalies such as hemifacial microsomia with irregular occlusal plane.) were joined in this study. Arch bar was contoured on the dental cast, which was prepared for model surgery, prior to apply it on the facial anomaly patient. On using pre-contoured arch bar, patients felt better during the procedure and surgeons saved time. Moreover, well-contoured arch bar promises precise transmission of force on the bone, which implies surgeons do not need to worry about the occlusion while fixing bony structures. Authors suggest how to apply arch bar to satisfy basic theories about dental row and occlusion based on the experience. In addition, it is proposed to contour arch bar on the dental impression prior to apply it on the patient who has irregular and complex occlusal plane.

• The korean journal of orthodontics
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• v.41 no.4
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• pp.224-236
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• 2011

Objective: The purpose of this study was to analyze the dental and basal arch forms in patients with normal occlusion using the computed tomography (CT) imaging method. Methods: CT images were taken from 27 normal occlusion subjects (male, 15; female, 12) and these images were reconstructed into three-dimensional models. A 3D-coordinate system was formed by setting the middle of the facial axis (FA) point of the maxillary central incisors as the origin. The morphology of the maxilla and mandibular dental and basal arches were analyzed by sectioning parallel to the maxillary occlusal plane. Results: There was no significant difference between A point and B point and between the maxillary 1st molars in both sides of the maxillary and mandibular basal bone. The dental arch was located more labially than the basal arch in the anterior portion. The bucco-lingual crossover of the dental arch and basal arch was formed at the molar region in the maxilla, and at the premolar region in the mandible. Conclusions: This study will help provide three-dimensional diagnostic information about the relationship between basal and dental arches in patients who have severe dental compensation and inappropriate jaw relationships.

• The korean journal of orthodontics
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• v.34 no.2 s.103
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• pp.153-163
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• 2004

The purpose of this study was to evaluate the postretention change of class II malocclusion treatment and to examine which factors were related to the relapse. Seventy-eight treated cases were divided into two groups according to the stability of treatment results. Various measurements in pre-treatment and post-treatment lateral cephalograms were evaluated and comparisons were drawn between the stable and relapse group by t-test and correlation analysis. 1. There were only a row differences in the skeletodental relationship in the pre-treatment phase between the stable and the relapse group. 2. Mandibles in the stable group were repositioned mote anteriorly than those in the relapse group. 3. Mandibular incisors were more uprighted to the basal bone and maxillary incisors were less lingualized in the stable group than in the relapse group. 4. Occlusal plane was inclined forward and downward in the relapse group.

• The korean journal of orthodontics
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• v.28 no.5 s.70
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• pp.865-875
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• 1998

The purpose of this study was to investigate the angle formed by the Sella-Nasion(SN) plane and Frankfort-Horizontal(FH) plane and evaluate the correlation and difference of the FH plane to other horizontal reference planes. Through this study we hope to present a basis for selecting a horizontal reference plae which can be implemented in cephalometric studies and in surgical orthodontic treatment planning. 600 subjects were chosen following a clinical examination md lateral cephlometric X-rays were taken. According to cephalometric analysis the subjects were classified into 3 groups , Skeletal Class I malocclusion or normal occlusion group(male 50, female 50), Skeletal Class II malocclusion group(male 50, female 65) and Skeletal Class III malocclusion group(male 50, female 50). The results were as follows. 1. The angle formed by the SN plane and FH plane showed no difference among the malocclusion groups, but there was a significant sex difference. For males the angle measured was $7.47^{\circ}{\pm}2.40^{\circ}$ whereas for females it was $8.93^{\circ}{\pm}2.72^{\circ}$. 2. The angle formed by the SN plane or FH plane and Mandibular plane was higher in females for all malocclusion groups. This angle in the Skeletal Class I malocclusion group was lower than in the other two groups. 3. There was no difference among the sexes or malocclusion groups considering the angle formed by the FH plane and Palatal plane. 4. The genial angle in the Skeletal Class III malocclusion group was higher than in the Skeletal Class I and Class II malocclusion groups in both sexes.

• The korean journal of orthodontics
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• v.34 no.1 s.102
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• pp.93-107
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• 2004

Enlow's counterpart analysis explains the complex with anatomic and developmental characteristics where craniofacial aspect of Individuals has been developed. Counterpart analysis does not compare individual measurement with the normal value from the average of majority but analyzes by comparison of values that each individual has. In this study we examined surgical changes in skeletal Class III malocclusion patients(male 40, female 40) and compared them with normal occlusion patients using counterpart analysis. The results indicated that : 1. Skeletal anterior-posterior discrepancy was relieved by shortening of the ramus width(B3). 2. The ramus alignment(R3, R4) was displaced posteriorly and the occlusal plane angle(R5) was rotated clockwise. 3. Skeletal Class III pattern was relieved in the post-operative group, but differences in the level of the cranium(R1, R2) was remaining compared to the normal occlusion patients. 4. In the comparison of surgery methods, the two-jaw surgery group presented changes In the maxillary length(A4), ramus alignment(R3, R4) and occlusal plane angle(R5) compared to the one-jaw surgery group, but the differences were not significant. In the past study about Korean skeletal Class m patients, the skeletal characteristics are upward backward rotation of the cranial base, posterior displacement of the maxilla, forward inclination of the ramus and lengthening of the mandibular body, but in this study, skeletal Class m pattern was relieved by shortening of the ramus width and maxillary advancement by orthognathic surgery, because orthognathic surgery is usually performed on limited areas in the maxilla and the mandible.

• The Journal of Korean Academy of Prosthodontics
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• v.33 no.4
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• pp.705-717
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• 1995

In clinical prosthetic dentistry the occlusal planes were represented to the dental arch form sagittally and composed of the occlusion morphologically. From now on the determinations of the occlusal planes were done through the facebow transfer and the cephalometric radiography, but they were not exact method for the diagnosis of the stomagnathic function. The purpose of this study is to examine the sagittal characteristics of occlusal planes using panoramic view between the normal subjects and the subjects with stomatognathic dysfunction. 60 normal subjects and 16 subjects with stomatognathic dysfunction were slectec for this investigation. We measured the inclination of occlusal planes to Frankfurt Horizontal plane. The occlusal planes were divided into 4 groups : 1) The plane between the midpoint of upper central incisor and the mesiobuccal cusp of upper 1st molar, 2) The plane between the midpoint of upper central incisor and the mesiobuccal cusp of upper 2nd molar, 3) The plane between the midpoint of upper central incisor and the distobuccal cusp of upper 2nd molar, 4) The plane between the mesiobuccal cusp of 1st molar and the distobuccal cusp of 2nd molar. The results were as follows : 1) The occlusal planes could be determined very easy by using panoramic view, 2) Among the angles between the occlusal planes and the FH plane, the angles related with the 2nd molar were more steep than those of the 1st molar. The angle between the 1st molar and the 2nd molar is the most steep in the other angles. 3) In the angles between occlusal planes and FH plane, the subjects with stomatognathic dysfunction were more significant steep(p<0.05) than the normal subjects.