• The korean journal of orthodontics
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• v.42 no.1
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• pp.23-31
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• 2012

Objective: The purpose of this study was to determine the soft tissue thickness of male and female orthodontic patients with different skeletal malocclusions. Methods: Soft tissue thickness measurements were made on lateral cephalometric radiographs of 180 healthy orthodontic patients with different skeletal malocclusions (Class I: 60 subjects, Class II: 60 subjects, Class III: 60 subjects). Ten measurements were analyzed. For statistical evaluation, one-way ANOVA and Kruskal-Wallis tests were performed. Least significant difference (LSD) and Dunnet T3 post hoc tests were used to determine the individual differences. Results: Soft tissue thicknesses were found to be greater for men than for women. Statistically significant differences among the skeletal groups were found in both men and women at the following sites: labrale superius, stomion, and labrale inferius. The thickness at the labrale superius and stomion points in each skeletal type was the greatest in Class III for both men and women. On the other hand, at the labrale inferius point, for both men and women, soft tissue depth was the least in Class III and the greatest in Class II. Conclusions: Soft tissue thickness differences among skeletal malocclusions were observed at the labrale superius, stomion, and labrale inferius sites for both men and women.

• The korean journal of orthodontics
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• v.20 no.1
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• pp.123-133
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• 1990

The work was undertaken to evaluate the calcification of the second and the third molars in skeletal Class II and III malocclusions. The differences in the calcification stages between skeletal Class II and III malocclusion were evaluated and statistically analysed from panoramic radiographs of 202 males and females ranging in age from 11 to 15 years old. The results were as follows, 1. The calcification stages of the second and the third molars were not different between the skeletal Class II and III malocclusions in each age groups of both sexes. 2. The calcification stages of lower second and third molars of the skeletal Class III malocclusion are more advanced than those of the skeletal Class II malocclusion in male. 3. The clacification stages of upper second and third molars are more advanced than those of lower second and third molars in skeletal Class II malocclusion. 4. The calcification stages of lower second and third molars are more advanced than those of upper second and third molars in skeletal Class III malocclusion.

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.4
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• pp.599-612
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• 2007

The present study was designed to compare the morphological and structural differences of craniofacial structures among 146 children with Class I and Class III malocclusions. The results below were obtained from the study. 1. Sphenoethmoidal synchondrosis continues to grow later in Class III. 2. Anteroposterior length of the nasomaxillary complex was significantly shorter in Class III, but the height of the nasomaxillary complex was similar. 3. Mandibular length and mandibular body length were longer in Class III, but had no statistical significance. Lower anterior facial height was shorter in Class III, but had no statistical significance. 4. Dentoalveolar height was similar between Class I and Class III. 5. In Class I, anterior cranial base took part in the anteroposterior length of the nasomaxillary complex and the mandible. 6. In Class III, anterior cranial base and middle cranial base had higher correlation with the mandible with aging. These results suggest that there exist a little differences between Class I and Class III malocclusions at age $7{\sim}11$, but growth patterns are mostly similar. Therefore it is necessary to correct Class III malocclusions at an early age before skeletal differences appear.

• The korean journal of orthodontics
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• v.17 no.1
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• pp.107-117
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• 1987

The study was designed to examinate the discrimination rate of 4 antero-posterior cephalometric measurements from Angle's malocclusion groups. The material was 246 cephalometric radiographs taken from 42 Normal occlusions, 83 Class I malocclusions, 64Class II Division I malocclusions, 57Class III malocclusions. ANB angle, APDI, AB/OP angle, and Wits appraisal as measurements of antero-posterior skeletal relationship were measured on the cephalometric radiographs and statistically analyzed by the Canonical Discriminant Function. The results of this study were as follows: 1. ANB angle, APDI, AB/OP angle, and Wits appraisal were clinically useful measurements for the evaluation of the antero-posterior skeletal relationship. 2. The rates that discriminate actual malocclusion groups were $77.45\%$ in Wits appraisal, $74.02\%$ in AB/OP angle, $71.08\%$ in ANB angle, and $70.59\%$ in APDI. 3. The discrimination rate of actual Class III malocclusion show above $93\%$, but actual Class I and Class II division I malocclusions were relatively low.

• The korean journal of orthodontics
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• v.50 no.2
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• pp.98-107
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• 2020

Objective: The aim of this study was to compare posterior tooth inclinations, occlusal force, and contact area of adults with different sagittal malocclusions. Methods: Transverse skeletal parameters and posterior tooth inclinations were evaluated using cone beam computed tomography images, and occlusal force as well as contact area were assessed using pressure-sensitive films in 124 normodivergent adults. A linear mixed model was used to cluster posterior teeth into maxillary premolar, maxillary molar, mandibular premolar, and mandibular molar groups. Differences among Class I, II, and III groups were compared using an analysis of variance test and least significant difference post-hoc test. Correlations of posterior dental inclinations to occlusal function were analyzed using Pearson's correlation analysis. Results: In male subjects, maxillary premolars and molars had the smallest inclinations in the Class II group while maxillary molars had the greatest inclinations in the Class III group. In female subjects, maxillary molars had the smallest inclinations in the Class II group, while maxillary premolars and molars had the greatest inclinations in the Class III group. Occlusal force and contact area were not significantly different among Class I, II, and III groups. Conclusions: Premolar and molar inclinations showed compensatory inclinations to overcome anteroposterior skeletal discrepancy in the Class II and III groups; however, their occlusal force and contact area were similar to those of Class I group. In subjects with normodivergent facial patterns, although posterior tooth inclinations may vary, difference in occlusal function may be clinically insignificant in adults with Class I, II, and III malocclusions.

• The korean journal of orthodontics
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• v.15 no.1
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• pp.85-92
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• 1985

This investigation was designed to compare the craniofacial morphology of Class III malocclusions with that of normal occlusions using PM line. The subjects consisted of forty-four normal occlusions (twenty-three males and twenty-one females) and sixty-nine Class III malocclusions (thirty males and thirty-nine females), aged eight through ten. Using the tracings of the standard lateral cephalograms, various angles, linear measurements and linear ratios of counter-part were recorded and analyzed by t-test. The following characteristics of craniofacial morphology of Class III malocclusion were obtained by this study. 1. Maxillary anteroposterior position was balanced with Nasion but was not balanced with mandible because maxillary bony arch was small and positioned posteriorly and mandibular corpus was large and positioned relatively anteriorly. 2. Upper and lover alveolar bony arch were not balanced each other in its size. 3. In counterpart analysis, Class III malocclusion was more horizontally unbalanced than normal occlusion. 4. Class III malocclusion was divided into 11 groups by maxillary and mandibular bony arch position, size and alveolar bony arch size. Unbalanced bony size of the maxilla and mandible was a major characteristics of Class III malocclusion.

• The korean journal of orthodontics
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• v.13 no.1
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• pp.45-62
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• 1983

To recognize the problems in malocclusion by roentgenocephalograms, the author designed a new pentagonal frame based on maxillary and mandibular bones. The subjects consisted of 44 normal occlusions (20 male and 24 female), 44 Class II division 1 malocclusions (15 male and 29 female) and 67 Class III malocclusions (31 male and 36 female). The results are as follows; 1. In normal group, the maxillary and mandibular skeletons of female we placed more closely to FH plane, so more anteriorly and upward than those of male. 2. In normal group, the posterior vertical height is longer in male than in female and the upper anterior teeth of female are in more labioversion than those of male. 3. By the X, Y coordinate values in pentagonal frame, it is helpful to recognize certain problems in malocclusions. 4. The posterior vertical height is a good indicator in detecting Angle's Class III malocclusion. 5. The maxillary and mandibular body length, the anterior point of maxillary and mandibular body length and the axial inclination of upper and lower anterior teeth can be useful in discerning Angle's Class II & Class III malocclusion.

• The korean journal of orthodontics
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• v.20 no.1
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• pp.157-168
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• 1990

This study was undertaken to investigate the interrelationships between the degrees of skeletal maturity of cervical vertebrae and the hand-and-wrist in skeletal Class III malocclusions. In 185 skeletal Class III malocclusions (male 62, female 123) having the lateral cephalogram and hand-wrist radiogram which were taken on the same day, 6 skeletal maturity stages of cervical vertebrae were compared with 11 skeletal maturity indicators of the hand-and-wrist. On the basis of findings of this study, the following results were obtained: 1. The stages of cervical vertebral maturity are one of the methods possible to assess the individual maturity. 2. Mean ages of male and female were obtained in each cervical vertebral stage. 3. Cervical vertebral stages 1 and 2 are considered to the accelerative growth phase, cervical vertebral stages 3 and 4 are corresponded to the peak height velocity, and cervical vertebral stages 5 and 6 were observed to occur during the decelerative phase of growth after peak height velocity in both sexes. 4. In cervical vertebral stages 1, 2, 3, 4, and 5, the degrees of skeletal maturity of cervical vertebrae in males were more retarded than females. 5. There was the high correlation between the degrees of skeletal maturity of cervical vertebrae and hand-and-wrist.

• Proceedings of the Korea Contents Association Conference
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• 2019.05a
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• pp.275-276
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• 2019

The purpose of this study was to assess condylar size in volumetric 3D imaging in patients with class I, class II, class III malocclusions. To evaluate the differences among the three experimental groups, the condylar values of men were analyzed. There was a significant difference in the measured values of height. Among the three experimental groups, the condylar measurements in women showed significant differences in height and width. This study is expected to be used for determining the connection between malocclusion and condyle as a base line data.

• Imaging Science in Dentistry
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• v.50 no.2
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• pp.105-115
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• 2020

Purpose: This study investigated the position of the hyoid bone and its relationship with airway dimensions in different skeletal malocclusion classes using cone-beam computed tomography (CBCT). Materials and Methods: CBCT scans of 180 participants were categorized based on the A point-nasion-B point angle into class I, class II, and class III malocclusions. Eight linear and 2 angular hyoid parameters(H-C3, H-EB, H-PNS, H-Me, H-X, H-Y, H-[C3-Me], C3-Me, H-S-Ba, and H-N-S) were measured. A 3-dimensional airway model was designed to measure the minimum cross-sectional area, volume, and total and upper airway length. The mean crosssectional area, morphology, and location of the airway were also evaluated. Data were analyzed using analysis of variance and the Pearson correlation test, with P values <0.05 indicating statistical significance. Results: The mean airway volume differed significantly among the malocclusion classes(P<0.05). The smallest and largest volumes were noted in class II (2107.8±844.7 ㎣) and class III (2826.6±2505.3 ㎣), respectively. The means of most hyoid parameters (C3-Me, C3-H, H-Eb, H-Me, H-S-Ba, H-N-S, and H-PNS) differed significantly among the malocclusion classes. In all classes, H-Eb was correlated with the minimum cross-sectional area and airway morphology, and H-PNS was correlated with total airway length. A significant correlation was also noted between H-Y and total airway length in class II and III malocclusions and between H-Y and upper airway length in class I malocclusions. Conclusion: The position of the hyoid bone was associated with airway dimensions and should be considered during orthognathic surgery due to the risk of airway obstruction.