• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.3
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• pp.420-426
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• 2009

The purpose of this study was to evaluate skeletal and soft tissue changes that occur after using a facemask for treatment of skeletal class III malocclusion, and to assess the relapse pattern when no retention appliance was used. Fifteen skeletal class III malocclusion patients were treated with a facemask for an average of 12 months. No retention appliance was used during the 1 year follow-up period. Cephalograms were taken during pretreatment, posttreatment, and the 1 year follow-up. Cephalograms were traced, analyzed, and the results were compared between cephalograms. All patients showed significant sagittal skeletal changes after treatment, but they also showed a significant relapse during the 1 year follow-up period when no retention appliance was used. Despite the relapse, the sagittal skeletal changes that remained were still significant. Vertical skeletal change was also significant after treatment, but the total change was not significant after a 1 year follow-up due to relapse. In soft tissue changes, facial convexity and upper lip position improved after treatment and this change remained significant after the 1 year follow-up period. Facemask therapy is therefore an effective method for treatment of skeletal class III malocclusion, however, retention is imperative to maintain the treatment effect.

• The korean journal of orthodontics
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• v.28 no.2 s.67
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• pp.189-201
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• 1998

The purpose of this study was to evaluate the characteristics of craniofacial skeleton on orthognathic surgical cases with skeletal Class III malocclusion. For this study, 74 students at the dental college of Chosun University volunteered as a normal occlusion group. They had well-balanced faces and good occlusions with acceptable Class I molar relationship. They had not received orthodontic treatment and had no signs or symptoms of temporomandibular joint dysfunction. 45 malocclusion patients enrolled for orthognathic surgical treatment with skeletal Class III malocclusion at the Department of Orthodontics, College of Dentistry, Chosun University. On the basis of this study. the results of this study were as follows: 1. Skeletal Class III malocclusion was largely due to the overgrowth of mandible in man and the undergrowth of maxilla in woman. 2. The mandible was antero-inferiorly overgrown by large MP-HP angle and large genial angle in orthognathic surgical cases with skeletal Class III malocclusion. And also, upper incisors were severely labioversioned, but on the other hand lower incisors were linguoversioned. 3. In female, lower-third facial height was characteristically shortened in comparison with middle-third facial height and also, lower facial throat angle was small in male.

• The korean journal of orthodontics
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• v.22 no.3 s.38
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• pp.627-646
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• 1992

The purpose of this study was to investigate the relationship among the activity of the craniofacial muscle and craniofacial form and occlusal state. In this study, subjects were consisted of 23 male adults with skeletal Class III malocclusion and 30 male adults with normal occlusion. The measurements in oral exam, lateral ceghalogram, and E.M.G. recordings of anterior temporal, masseter, and upper lip muscles at rest position, clenching in centric occlusion, chewing of gum, swallowing of juice, were analyzed with SPSS system. The results were as follows: 1. At rest position upper lip muscle activity of skeletal Class III group was significantly higher than that of normal group. 2. Both clenching and chewing masseter and temporal muscle activity of normal group were significantly higher than that of skeletal Class III group. 3. During swallowing of juice, upper lip muscle activity of skeletal Class III group were significantly higher than that of normal group. 4. The activities of masseter and anterior temporal muscle during clenching and chewing were significantly correlated with hypodivergent facial form and number of occluded teeth. 5. The activity of upper lip during swallowing had positive correlation with mandibular prognathism.

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.1
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• pp.126-132
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• 1999

This article describes the use of an activator with anterior high pull headgear to treat a skeletal Class II malocclusion in children in the mixed-dentition phase. A combination of headgear-activator appliance can inhibit forward and downward growth of the maxillary complex while stimulating mandibular growth. The correction of Class II malocclusion can be achieved by careful case selection of a motivated patient with a favorable growth pattern. The patients who have skeletal Class II malocclusions were treated by means of activator with anterior high pull headgear and the following results were observed; 1. Forward and downward growth of the maxillary complex were inhibited 2. Mandibular growth was stimulated and counterclockwise rotation of the mandible was observed. 3. Large overjet and deep overbite were corrected.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.32 no.6
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• pp.506-513
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• 2006

The purpose of this study was to examine the familial tendency of the patients with mandibular prognathism in three generations and to define the relationship between the familial tendency and the skeletal class III morphology. The probands of this study were 103 orthognathic surgery patients with skeletal Class III malocclusions who had undergone (48 men, 55 women) mandibular set-back surgery. A questionnaire was given to patients who sought surgical treatment for excessive mandibular length, and all answers were confirmed in interviews. Lateral cephalograms were analyzed in cranial base parameters, mandibular positional parameters and mandibular skeletal parameters. In the examined families, 58.3% had at least one member other than the proband who had mandibular prognathism. The affected ratio of total relatives was 4.5%, and the value was higher in first-degree (13.4%) than second-degree (5.9%) and third-degree relatives (1.7%). The affected ratio was 51.9% in the offsprings who had at least one affected father or mother. The comparison of the groups according to the familial tendency showed no significant craniofacial skeletal measurments. In conclusion, skeletal class III malocclusion showed high familial tendency, suggesting a significant genetic influence in the etiology. However, the patient's familial tendency did not show the special craniofacial patterns compare to the subjects without familial tendency.

• The korean journal of orthodontics
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• v.21 no.2 s.34
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• pp.457-468
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• 1991

This investigation was designed to categorize Angle's class III malocclusion groups through analyzing horizontal and vertical components of craniofacial skeleton in Angle's class III malocclusion. The material selected for this study consisted in standard lateral cephalogram of one hundred and fifty five children, seventy four boys and eighty one girls, aged 6 through 15 years, having Angle's class III malocclusion. On the basis of findings of this study, the following results were obtained. 1. In horizontal skeletal classifications,16 groups were classified FMN-A-B, SE-FMN-A according to the Ba-SE-Me, Ba-SE/R. 2. The sequences that have relatively high frequency are as follow; a) Horizontal Group l b) Horizontal Group 3 c) Horizontal Group 5 d) Horizontal Group 9 e) Horizontal Group 4 3. In vertical skeletal classification, 8 groups were classified according to the PMV/PP, PMV/OP, PMV/MP. 4. The sequences that relatively high are as follows; a) Vertical Group 1 b) Vertical Group 3 c) Vertical Group 4 d) Vertical Group 8.

• 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.

• The korean journal of orthodontics
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• v.18 no.1 s.25
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• pp.141-154
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• 1988

This study was designed to investigate the difference between craniofacial characteristics of the normal occlusion and those of Class II Div. 1 malocclusion. The sample was divided into 2 groups, the 50 subjects of Normal occlusion, the 50 subjects of Class II Div. 1 malocclusion in both sexes. Both groups aged from 11 to 14 years. The results of this study were as follows; 1. No significant difference was observed in cranial base shape between both groups, but anterior cranial base size of Class II Div. 1 malocclusion group was larger than that of normal group. 2. No significant difference in antero-posterior position of Maxilla to cranial base was founded between both groups. 3. No difference in Mandibular shapes and Mandibular plane angles to the cranial base was observed between Class II Div. 1 malocclusion and normal occlusion, but Mandibular position in Class II Div. 1 malocclusion was posterior to that of normal group. 4. Antero-posterior relationship of Maxilla and Mandible was significant difference between both groups, but vertical relationship of those was no difference. 5. Maxillary incisor position to cranial base of Class II Div. 1 malocclusion was anteior to normal occlusion, and Maxillary posterior teeth was posterior. Mandibular incisor and mandibular posterior teeth position was no difference. 6. Upper and lower lip position to esthetic line of Class II Div. 1 malocclusion was anterior to normal occlusion.

• The korean journal of orthodontics
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• v.28 no.4 s.69
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• pp.581-589
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• 1998

In order to correct a maxillofacial-skeletal disharmony successfully and achieve a favorable facial profile, orthodontic treatment must begin at pubertal growth spurt. Therefore predicting the pubertal growth pattern and evaluating the growth potential is very important. For an orthodontist, estimating skeletal maturity in relation to one's personal growth spurt is essential and it must be considered into the treatment. The objective of this study was to find out whether there was a difference in menacheal age among different malocclusion groups and to evaluate the skeletal maturity at menarche. The subjects were 64 Class I malocclusion patients, 51 Class II patients and 38 Class III patients. Skeletal maturity was estimated from handwrist radiographs of these patients. Handwrist radiographs were taken between 3 months before and after the menarche. The results were as follows. 1. The mean chronologic age of menarche was $12.50{\pm}1.01$ years. 2. For the Class I malocclusion group the mean age of menarche was $12.36{\pm}1.04$ years, for Class II $12.81{\pm}1.03$ years and for Class III $12.32{\pm}0.82$ years. According to these results Class II malocclusion patients started mensturation later than Class I and Class III malocclusion patients. 3. No difference was found considering the skeletal maturity at menarche among the malocclusion groups. 4. The skeletal maturity index at menarche was SMI 7 for $45.10\%$, SMI 8 for $27.25\%$, SMI 9 for $10.46\%$, SMI 6 for $7.84\%$, SMI 10 for $7.84\%$ and SMI 5 for $1.31\%$ patients. 5. Statistically there was a significant correlation between skeletal maturity estimated by handwrist radiographs and menacheal age(p<0.05, r=0.25430).

• Journal of Yeungnam Medical Science
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• v.18 no.2
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• pp.208-214
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• 2001

Background: When we make treatment plan of class III malocclusion children, it is difficult to determine whether we treat it with orthognathic surgery or without orthognathic surgery. To determine that, we must consider many factors, such as cephalometric analysis, growth pattern, family history, and skeletal age. A Harvold cephalometric analysis is useful in determining the amount of discrepancy by comparing the maxillary unit length with mandibular, unit length. We tried this study to help the decision of treatment planning in class ill malocclusion children by comparison in class III malocclusion and normal occlusion children using a Harvold analysis. Materials and Methods: The materials for this study consisted of 20 class III malocclusion children. Cephalometric tracing and measurements were performed by one investigator. The control group consisted of 18 normal occlusion children and lateral cephalograms were obtained from 8.5 to 14.5 years old children biannually. The relationships between class III malocclusion group and normal occlusion group were evaluated statistically. Results: The lower anterior facial heights between two groups were not significantly different, although the lower anterior facial heights of class III malocclusion group was higher than those of normal occlusion group in all age groups. The Maxillary-mandibular unit length differences of class III malocclusion group were significantly higher than those of normal occlusion group(p<0.05). Conclusion: A Harvold analysis was useful to make treatment planning for class III malocclusion children.