• The korean journal of orthodontics
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• v.24 no.3 s.46
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• pp.555-567
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• 1994

The purpose of this study is to observe the effect of high pull headgear on the craniofacial structures of mixed dentition with Class II malocclusion. The cephalometric headplates of 16 children treated by high pull headgeaar during 6 months and 18 children during 12 months were traced, digitized and statistically analyzed. The results were as follows. 1. Inhibition of foreward growth of maxilla was observed in both group. 2. Clockwise rotation of maxilla was observed in both group. 3. There were distal movement of maxillary 1st molar and inhibition of alveolar bone growth of maxilla. 4. There was compensatory extrusion on mandibular 1st molar. 5. The ratio of anterior facial height to posterior facial height was almostly not changed. In the treatment plan of C II malocclusion by high pull headgear, ire must prevent the mandibulasr 1st molar from extruding and for orthopedic effect, at least 6 months is needed.

• The korean journal of orthodontics
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• v.45 no.3
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• pp.121-129
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• 2015

Objective: This study aimed to assess three-dimensional changes in the temporomandibular joint positions and mandibular dimensions after correction of dental factors restricting mandibular growth in patients with Class II division 1 or division 2 malocclusion in the pubertal growth period. Methods: This prospective clinical study included 14 patients each with Class II division 1 (group I) and Class II division 2 (group II) malocclusions. The quad-helix was used for maxillary expansion, while utility arches were used for intrusion (group I) or protrusion and intrusion (group II) of the maxillary incisors. After approximately 2 months of treatment, an adequate maxillary arch width and acceptable maxillary incisor inclination were obtained. The patients were followed for an average of 6 months. Intraoral and extraoral photographs, plaster models, and cone-beam computed tomography (CBCT) images were obtained before and after treatment. Lateral cephalometric and temporomandibular joint measurements were made from the CBCT images. Results: The mandibular dimensions increased in both groups, although mandibular positional changes were also found in group II. There were no differences in the condylar position within the mandibular fossa or the condylar dimensions. The mandibular fossa depth and condylar positions were symmetrical at treatment initiation and completion. Conclusions: Class II malocclusion can be partially corrected by achieving an ideal maxillary arch form, particularly in patients with Class II division 2 malocclusion. Restrictions of the mandible in the transverse or sagittal plane do not affect the temporomandibular joint positions in these patients because of the high adaptability of this joint.

• The korean journal of orthodontics
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• v.19 no.1 s.27
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• pp.201-218
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• 1989

This study was focused on the distribution of different facial types of the Class II division I malocclusion groups and skeletal characteristics of the each group and those that anteropsterior relationship of the maxilla and mandible calculated from the analysis of ANB angle and Wits appraisal was quite different from each other, as well. Cephalometric headplates of 140 persons of Class II division 1 malocclusion whose mean age was 11.2 years and 69 persons of normal occlusion whose mean age was 12.2 years were utilize as materials. Measurements were recorded, tabulated and statistically analyzed employing the tracings of the lateral cephalograms, then Class II division 1 malocclusion group was divided into 9 Types according to the angle of SNA and SNB for the anteroposterior relationship of the maxilla and mandible, another 9 Types according to the FH-NPog and SN-MP for the horisontal and vertical relationship, and the other 9 Types according to the ANB and Wits appraisal for intermaxillary relationship as well, with which was based on $Mean{\pm}$ 1SD of those of normal occlusion. The result allowed the following conclusion: 1. $37.1\%$ of population demonstrated maxilla within nounal range and retrognathic mandible to the cranial base, $30\%$ for both maxilla and mandible within normal range, $20\%$ for retrognathic maxilla and mandible and $12.9\%$ of the rest were ananged in Class II division 1 maloccusion groups. 2. Retrognathic mandible and hyperdivergent face accounted for $30.7\%$, mesognathic mandible and neutrodivergent face for $29.3\%$, mesognathic mandible and hyperdivergent face for $16.4\%$, retrognathic mandible and neutrodivergent face for $13.6\%$, mesognathic mandible and hypodivergent face for $10\%$ of population were computed in Class II division 1 malocclusion groups. 3. It was suggested that skeletal Class II malocclusion might be due to anomaly in size and shape of cranial base, underdevelopment of mandible, retropositioning of mandible, underdevelopment of posterior face against anterior face, or any combination of these factors. 4. Population with underdevelopment and / or retropositioning of the mandible showed hyperdivergent tendency of facia profile. 5. The ANB angle and Wits appraisal did not coincide the severity of anteroposterior dysplasia in $35.7\%$ of Class II division 1 malocclusion group each other, and this inconsistency was suggested to be related with mandibular rotation, inclination of cranial base, and anteroposterior position of the maxilla.

• The korean journal of orthodontics
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• v.23 no.4 s.43
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• pp.633-644
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• 1993

There has been so much controversies about the position of upper and lower jaws, and their first permanent molars in normal occlusion and Angle's class $I{\cdot}II{\cdot}III$ malocclusions. So, the purpose of this study is to compare the position of upper and lower jaws, and their first molars in normal occlusion and Angle's class $I{\cdot}II{\cdot}III$ malocclusions by lateral cephalometric analysis. The sample consisted of one hundred and twenty girls(thirty in each group) who had completed growth. The findings of this study were as follows : 1. In class I malocclusion, both maxilla and mandible were slightly posterior position than normal occlusion, but they showed harmonious relationship. 2. In class II malocclusion, the mandible was greatly retruded, and the maxilla was also slightly retruded to the cranial base as compared with normal occlusion. 3. In class III malocclusion, the maxilla was significantly retruded to the cranial base, but no significant difference was found in mandibular position as compared with normal occlusion. 4. The maxillary first molar was located at posterior position in class II malocclusion, and anterior position in class III malocclusion to the cranium, so that the rotation of mandible was influenced by that. 5. The mandibular first molar showed constant relationship to the mandible in all four groups, but different position to the cranial base in direct proportion to the mandibular position. 6. On the treatment planning of class III malocclusion, it seems to be better to promote the mandibular horizontal growth by inhibiting the vertical growth of maxillary molar area, and on the treatment planning of class III malocclusion, it seems to be better to promote the antero-inferior growth of maxilla mi to promote the mandibular vertical growth by inducing the vertical growth of maxillary molar area.

• Journal of the korean academy of Pediatric Dentistry
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• v.24 no.4
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• pp.735-742
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• 1997

Class II malocclusion can be treated via early orthopedic, orthodontic treatment or orthognathic surgery with orthodontic treatment. In the mixed dentition, early orthopedic treatment can be used. Especially, in the case of mandibular retrognathism, the functional appliances can be used, and in the case of maxillary protrusion is combined, they can be used together with headgear. After using activator and activator combined with headgear to the class II malocclusion paitent in the mixed dentition, the results were as follows: 1. Lateral profile was improved, and lower face height was increaed. 2. Overjet was decreased, and molar relationship was changed to class I molar relationship. 3. Growth can be undisturbed, and the aggravation of malocclusion can be prevented to make the 2nd phase orthodontic treatment be much easier.

• The korean journal of orthodontics
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• v.25 no.1 s.48
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• pp.19-29
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• 1995

This study was performed to compare the size of soft palate, tongue and airway according to the types of the malocclusion and evaluate the correlation between the size of soft palate, tongue, airway and dentofacial skeleton respectively. The sample of this study was 98 malocclusion female patients between the ages 12 and 17 years. The lateral cephalometric radiographs were taken and the distance, angle, ratio and area of the dentofacial skeleton, soft palate, tongue and airway were measured and evaluated statistically. The results obtained were as follows: 1. There was significant difference in SNB, ANB, facial angle, facial convexity, A-B plane angel, Y axis to FH, SN-MP, Wits appraisal, ODI and APDI according to the types of malocclusion. 2. The hyoid bone was more posteriorly positioned in Class II malocclusion group than other two groups and superio-inferior position of the hyoid bone was not different according to the malocclusion types. 3. The nasopharyngeal area of Class II and Class III malocclusion group was smaller than that of Class I malocclusion group, and the pharyngeal area of Class II malocclusion group was smaller than that of Class I and Class III maocclusion group. There was no difference of the area of the soft palate, tongue, oropharynx and hypopharynx according to malocclusion types. 4. The ramal height and mandibular body length(Go-Me) showed positive correlation with the area of tongue, nasopharynx, oropharynx, and pharynx. SNA did not correlated with the area of tongue and airway but SNB showed positive correlation with the area of hypopharynx and pharynx. The anterior, posterior facial height, upper and lower central incisor position to facial plane showed positive correlation with tongue area.

• Journal of Yeungnam Medical Science
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• v.4 no.1
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• pp.151-156
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• 1987

A 25 year and 7 month old man patient who had Angle's classII division 2 malocclusion combined with anterior crowding of upper & lower part was treated by bioprogressive mechanism. After setting our objectives through the use of V.T.O., we programmed a sequence of mechanics. The possible objectives of treatment in the classII division 2 malocclusion can be listed as follows. 1) Relief of crowding & irregularities. 2) Relief of anterior gingival trauma & correction of interincisal inclination. 3) Correction of buccal segment relationship. We'd applied the classII intermaxillary elastics, Quad helix, utility arch wire and sectional arch wire in order to achieve anticipated objectives. As compared with pre & post treatment cephalogram, the result accomplished by this mechanics showed to us that interincisal angle was improved and favorable molar relationship was achieved.

• The korean journal of orthodontics
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• v.52 no.6
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• pp.432-438
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• 2022

Objective: To compare crown-root angulations of the permanent maxillary anterior teeth in skeletal Class I, Class II, and Class III Korean malocclusion patients using cone-bean computed tomography (CBCT) images. Methods: Sixty CBCT images were collected from orthodontic patients archive based on skeletal Class I (0˚< A point-nasion-B point angle [ANB] < 4˚), Class II (ANB ≥ 4˚), and Class III (ANB ≤ 0˚) to have 20 samples in each group. Mesiodistal crown-root angulation (MDCRA) and labiolingual crown-root angulation (LLCRA) were evaluated after orientation of images. Crown-root angulations were compared among Class I, Class II, and Class III groups and among the maxillary anterior teeth in each group. Results: LLCRAs of the maxillary central incisor and the lateral incisor were significantly lower in Class III group than those in Class I group. However, those of the canine showed no significant differences among groups. MDCRAs of the maxillary anterior teeth did not significantly differ among groups either. Conclusions: Our results suggest that skeletal Class III malocclusion might affect LLCRA of the maxillary incisors, especially the central incisor.

• The Journal of the Korean dental association
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• v.19 no.12 s.151
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• pp.1027-1030
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• 1981

2065 patients who visited orthodontic department form 1977. 7. 16. to 1981. 9. 30. were surveyed on the yearly tendency of patient distribution and the state of Angle's Classification. The results were as follows: 1. There was increased visiting rate of patient per year except the year 1980. 2. 8-13 age group was 55% in total visiting patient and 20 age over group was 11.0%. 3. Class I malocclusion was 42.3% in total visiting patient, more Class III malocclusion was prevalent than Class II malocclusion.

• The korean journal of orthodontics
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• v.21 no.1 s.33
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• pp.171-183
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• 1991

This investigation was designed to categorize Angle's class II malocclusion groups through analyzing horizontal and vertical components of craniofacial skeleton in Angle's class II malocclusion. The material selected for this study consisted in standard lateral cephalogram of two hundred and twenteen children, eighty eight boys and one hundred twenty four girls, aged 6 through 18 years, having Angle's class II malocclusion. On the basis of findings of this study, the following results were obtained. 1. In horizontal skeletal classifications, 16 groups were classified according to FMN-A-B, SE-FMN-A, Ba-SE-Me, Ba-Se/Ra P. The sequences that have relatively high frequency are as follows: a) Horizontal Group 16 b) Horizontal Group 12 c) Horizontal Group 13 d) Horizontal Group 9 & 15 2. In vertical skeletal classification, 8 groups were classified according to the PMV/PP, PMV/Occ. P. PMV/Mn. P. The sequences that relatively high frequency are as follows; a) Vertical Group A b) Vertical Group D c) Vertical Group C d) Vertical Group H 3. In vertical and horizontal skeletal classifications, the sequence that relatively high frequency are as follows; a) Group13-A b) Group16-A & 9-A c) Group12-A & 15-A d) Group16-C