• The korean journal of orthodontics
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• v.16 no.1
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• pp.167-177
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• 1986

This study was undertaken to compare the main differences and its effects of the 4 first bicuspid extraction on the face and dental arch of the class II div 1 malocclusion. The subjects consisted of twenty two class II div 1 malocclusion, four males, eighteen females, were 14 Years 2 Months old at the stan of the treatment 16 Year 3 Months old at the end of the treatment. (mean age) Twenty one variables were observed by comparing the statistical data of the pretreatment records with postteratment records, which were consited of eight varibles on the study model digitation, thirteen variables on the tracing of the lateral cephalogram. The following results were obtained. 1. No significant change was observed in the intercanine width. 2. Intercuspal widths of the 1st. premolar and 2nd. premolar were decreased. 3. Change of the overjet was dependant upon upper anterior rather than lower anterior. 4. No significant changes were observed in facial plane angle and ANB angle. 5. Uprighting of the lower 1st. molar had an effect on the increase of the facial height.

• 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.235-252
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• 1988

The quadrilateral analysis is a proportional analysis which evaluates the skeletal configuration of lower face on the relations between both jaws in the horizontal as we]1 as vortical dimensions. This study was undertaken to analyse the harmony and disharmony of quadrilateral patterns in normal occlusion and malocclusion. The present study was carried out on lateral cephalograms of 530 Korean children; the subjects consisted of 135 normal occlusions (63 male and 72 female), 105 Class II division 1 malocclusions (52 male and 53 female), 109 Class III malocclusions (50 male and 59 female), 91 hypodivergent facial types (44 male and 47 female) and 90 hyperdivergent facial types (45 male and 45 female). The following conclusions were reached: 1. Means and standard deviation in each group and sex were obtained from normal occlusion and malocclusion. 2. Quadrilateral mean diagram in normal occlusion was constructed for male and female, respectively. 3. In normal occlusion, 1:1 ratio exists between the maxillary base length (A' to Ptm') and mandibular base length (B' to J'), but lower facial height is targer than above. 4. Difference is effective to estimate the degrees of Class II and Class III malocclusion, and lower facial height (LFH) and sagittal angle is effective to recognize the hypodivergent and hyperdivergent facial type. 5. Quadrilateral analysis is able to visualize the anteroposterior and vertical dysplasia of lower face, and it is helpful to recognize certain problems in malocclusion.

• Archives of Craniofacial Surgery
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• v.25 no.5
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• pp.240-246
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• 2024

The severe gummy smile and a skeletal class II profile pose challenges in treatment. This case report outlines an effective alternative for addressing these problems in a patient with skeletal class II division 2, class II molar relationship, retroclination of upper incisors, and lip protrusion. Treatment objectives included normalizing the overjet and overbite, improving the gummy smile, and establishing a satisfactory occlusion. A three-dimensional simulation was performed to consult with the patient, assess possible results, and predict treatment biomechanics. The treatment involved the use of two zygomatic and one inter-radicular temporary anchorage devices, along with botulinum toxin. After the 2-year follow-up, a satisfactory dental occlusion, aesthetic improvement, and adequate function were achieved. This approach offers a viable alternative to orthognathic surgery for adults with skeletal class II malocclusion and a severe gummy smile due to hypermobile lip.

• Journal of Oral Medicine and Pain
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• v.19 no.2
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• pp.181-192
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• 1994

There have been many different theories on the etiology of temporomandibular disorders(TMDs). The objective of the study was to investigate the effects of occlusal fctors and recent life event changes as prediposing fctor on the development of temporomandibjlar disorders. To evaluate the above predisposing factor, the author used T-scan system(Tekscan Co. U.S.A.) for quantitative occlusal analysis, clinical examination for occlusal state and Social Readjustment Rating Scale(SRRS) for recent life event change units (LCU). 63 patients with TMDs and 57 patients with malocclusion presented at Wonkwang University Dental Hospital participated in this study. The subjects were grouped by Angle's classification and presence of absence of TMDs and parafunctional oral habits. Data gained with regard to contact number, contact force, contact time, occlusal state(number of total teeth and occluding teeth, overjet, overbite) and occlusal interferences (protrusive posterior contact, nonworking side interference, and RCP-ICP slide) and recent life event changes. The data were processed and analysed by SAS statistical package program, The results of this study were as follows : 1. There were no significant differences on both quantitative occlusal contact analysis and occlusal state between TMDs group and Angle's malocclusion group. Also, there were no differences among the Angle's classifications. But amount of overjet in TMDs group were more greater than that of malocclusion group. 2. There was no difference on protrusive posterior contact, and balancing contact between TMDs group and Angle's malocclusion group. Premature contact was more frequent in malocclusion group, but RCP-ICP slide was more frequent in TMDs group. And RCP-ICP slide was more freqent in Angle's class II malocclusion than Angle's I or III malocclusion. 3. Life changes units in TMDs group were higher than those in malocclusion group. And recent life change units in group with parafunctional oral habit were higher than those in group without parafunctional oral habits. Clenching was the most common habit among parafunctional oral habits.

• The korean journal of orthodontics
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• v.48 no.1
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• pp.11-22
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• 2018

Objective: The aim of this study was to determine cephalometric factors that help predict favorable soft-tissue profile outcomes following treatment with the Class II Twin-block appliance. Methods: Pre- and post-treatment lateral cephalograms of 45 patients treated with the Class II Twin-block appliance were retrospectively analyzed. Profile silhouettes were drawn from the cephalograms and evaluated by three orthodontists in order to determine the extent of improvement. Samples were divided into a favorable group (upper 30% of visual analogue scale [VAS] scores, n = 14) and an unfavorable group (lower 30% of VAS scores, n = 14). Skeletal and soft-tissue measurements were performed on the cephalograms and an intergroup comparison was conducted. Results: An independent t-test revealed that the following pre-treatment values were lower in the favorable group compared to the unfavorable group: lower incisor to mandibular plane angle, lower incisor to pogonion distance, point A-nasion-point B angle, sella-nasion line (SN) to maxillary plane angle, SN to mandibular plane angle, gonial angle, and symphysis inclination. The favorable group had a larger incisor inclination to occlusal plane. Moreover, the favorable group showed larger post-treatment changes in gonial angle, B point projection, and pogonion projection than did the unfavorable group. Conclusions: Class II malocclusion patients with a low divergent skeletal pattern and reduced lower incisor protrusions are likely to show more improvement in soft-tissue profile outcomes following Class II Twin-block treatment.

• The korean journal of orthodontics
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• v.15 no.2
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• pp.229-237
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• 1985

The Purpose of this study was to investigate the differences in soft tissue characteristics according to the dental or skeletal dysplasia. For this purpose, lateral cephalogram of 153 children (Hellman dental age IIIB: control group 32, Angle CIII. div. 1 malocclusion group 55, Angle Cl III group 66) were traced and measured. For these measurements, following conclusions were made. 1. FH A, FH Sn, FH UL, AA' of the Class III group were thicker than those of the normal and Class II group, but FH B, FH LL, BB' of the Class III group were not significantly different from those of the normal group. 2. FH B, FH LL, BB' of the Class II group were thicker than those of the normal and Class III group, but FH A, FH Sn, FH UL, AA' of the Class II group were not significantly different from those of the noraml group. 3. Ans-Sn, FH P were not significantly different in three groups, while PP' of the Class III group was thicker than those of the other groups. 4. The lower lips of the Class II group were more anterioly everted with respect to the lower incisor inclination than those of the other groups. 5. The severity of skeletal dysplasia was partly camouflaged by the soft tissue.

• The korean journal of orthodontics
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• v.32 no.3 s.92
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• pp.195-207
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• 2002

Numerous studies have revealed the similarities and discrepancies in two divisions of class II malocclusion, since these malocclusion groups have been postulated to be disparate criterion, much as classified under one diagnostic umbrella. This study was undertaken to describe the craniofacial configurations of class II division 1 and 2, and consequently to discriminate the morphologic differences between the two malocclusion groups in Korean sample. Lateral headfilms of 34 class H division 1 and 29 division 2 were employed, while those of 142 adults of normal occlusion served as a control. The landmarks were digitized and 26 variables were statistically analyzed for one way ANOVA. 1. There manifested no statistically significant difference in maxillary position anteroposteriorly. Normal occlusion group exhibited most anteriorly positioned mandible, whereas class II division 1 showed the most retroposition. Class II division 1 disclosed clockwise rotation tendency of mandible, which resulted in position of the chin Posteriorly. 2. Class II division 1 showed greater in SN to MP, SN to PP significantly than other groups. 3. Class II division 2 showed smaller genial angle and larger mandibular body length than other groups. 4. Class II division 1 revealed greater anterior lower face height than other groups, whereas division 2 dictated significantly greater posterior face height. 5. Class II division 2 expressed the most retroclined lower incisor, while division 1 manifested the most proclination. The largest interincisal angle resided in Class II division 2 group. There were no significant differences in upper molar position anteroposteriorly.

• The korean journal of orthodontics
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• v.15 no.2
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• pp.279-289
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• 1985

This study was undertaken to find out the factor highly correlated to the depth of overbite among the skeletal factors of the craniofacial complex using lateral roentgenocephalograms. The subjects cconsited of fifty normal occlusions, sixty Class I malocclusions, sixty Class II division I malocclustions and sixty Class III malocclusions. The results were as follows: 1. Ans-Go-Me angle and lower genial angle showed high correlation to the depth of overbite in the total malocclusion sample. 2. The mean values of Ans-Go-Me angle and lower goinal angle for the normal sample were $49.8^{\circ}\;and\;75.6^{\circ}$, respectively. 3. Ans-Go-Me angle above $56^{\circ}$ or lower gonial angle above $84^{\circ}$ indicated a tendency toward an openbite. Conversely, Ans-Go-Me angle below $48^{\circ}$ or lower goinal angle below $73^{\circ}$ indicated a tendency toward a deepbite.

• Journal of Technologic Dentistry
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• v.21 no.1
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• pp.131-138
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• 1999

As a society has developed, much concern has been put on appearances of people with development of economy. Accordingly malocclusion patients have been increasing. With this trend, it has become very important to investigate patients characteristics so as to cure the patients effectively. This study investigated 724 malocclusion patients who had been examined diagmosed and recorded well at Chong-a Dental Hospital for 5 years from 1994 to 1998. The results are as follows ; 1) The total number of orthodontic patients in 1998 increased about 79% than in 1994, and female orthodontic patients(68.1%) were more than male ones(31.9%). 2) Age distribution has shown more than 19 year-old group being the largest(48.9%) 3) Distributions in the types of malocclusion according to the Angle's classification have shown 42.5% for class I division, 21.5% for class II division, 35.9% for class III division, being class I division the largest. 4) 50.1% of the total patients were from Kang-nam Gu, So-cho Gu, and Song-pa Gu.