• 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.

• The korean journal of orthodontics
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• v.25 no.1 s.48
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• pp.87-100
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• 1995

Distributions and trends were examined in 2155 malocclusion patients who had been examined and diagnosed at Deparment of Orthodontics in Youngdong Severance Hospital over a 10 year-period from 1984 to 1993. The results were as follows ; 1. The number of patients per you had nearly quadrupled during the 10 year-period, with females($58.3\%$) outnumbering males ($41.7\%$). 2. Age distribution had shown 7-12 year-old group being the largest($53.3\%$), but percentages of 7-12 year-old and 13-18 year-old groups had been decreasing while that of above-19 patients had gradually incresed. 3. Distributions in the types of malocclusion according to the Angle's Classification had shown $27.8\%$ for Class I, $22.6\%$ for Class II division 1, $7.9\%$ for Class II division 2, and $41.6\%$ for Class III. Percentages of Class I patients had decreased while percentages of Class II and III patients had increased. 4. Non-extraction cases ($75.4\%$) had outnumbered extraction cases ($24.6\%$), with a general trend toward fewer extraction cases over the 10 year period. 5. Patients who had orthognathic surgery had been increasing, with Class I, II, and III cases comprising $8.8\%,\;16.9\%\;and\;74.3\%$, respectively. There had been three times as newly 2-jaw operations as 1-jaw operations. 6. Nearly $4\%$ of the subjects had facial asymmetries, with Class III cases being the most frequent. 7. Patients with TMD symptoms comprised $4.6\%$, with an increasing trend. The symptoms had occurred more frequently in older patients and in females. 8. Geograpic distributions showed majority (3/4) of patients from the nearby areas, namely Gangnam-gu, Seocho-gu and Songpa-gu.

• The korean journal of orthodontics
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• v.49 no.3
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• pp.161-169
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• 2019

Objective: To evaluate the effectiveness of the Frog appliance in three dimensions by using cone-beam computed tomography (CBCT) images. Methods: Forty patients (21 boys and 19 girls), averaged 11.7 years old, with an Angle Class II division 1 malocclusion were included in our study. They had either late mixed dentition or early permanent dentition, and the maxillary second molars had not yet erupted. All patients underwent CBCT before and after the treatment for measuring changes in the maxillary first molars, second premolars, central incisors, and profile. Paired-samples t-test was used to compare the mean difference in each variable before treatment and after the first phase of treatment. Results: The maxillary first molars were effectively distalized by 4.25 mm (p < 0.001) and 3.53 mm (p < 0.05) in the dental crown and root apex, respectively. The tipping increased by $2.25^{\circ}$, but the difference was not significant. Moreover the teeth moved buccally by 0.84 mm (p < 0.05) and 2.87 mm (p < 0.01) in the mesiobuccal and distobuccal cusps, respectively, whereas no significant changes occurred in the root apex. Regarding the anchorage parts, the angle of the maxillary central incisor's long axis to the sella-nasion plane increased by $2.76^{\circ}$ (p < 0.05) and the distance from the upper lip to the esthetic plane decreased by 0.52 mm (p = 0.01). Conclusions: The Frog appliance effectively distalized the maxillary molars with an acceptable degree of tipping, distobuccal rotation, and buccal crown torque, with only slight anchorage loss. Furthermore, CBCT image demonstrated that it is a simple and reliable method for three-dimensional analysis.

• The korean journal of orthodontics
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• v.31 no.2 s.85
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• pp.283-300
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• 2001

With socioeconomic development and change of esthetic recognition, the demand for orthodontic treatment and number of orthodontic patients has been increasing so rapidly. And frequency of malocclusion was changed. So this study was done in an attempt to provide an epidemiologic study so that we can accomodate their orthodontic needs adequately and to obtain the reliable quantitative information regarding the characteristics of orthodontic patients. Distribution and trends were examined in 3,070 malocclusion patients who had been examined and diagnosed at Department of Orthodontics, Dental Hospital, Chosun University over 10 year-period from 1990 to 1999. The results were as follows : 1. The number of patients per year was increasing trend and higher visiting rate in female(56.5%) than in male(43.5%). 2. Age distribution had shown 7${\sim}$ 12 year-old group being the largest(37.9%) and each percentage of 13${\sim}$18, 19${\sim}$24, above-19, 0${\sim}$6 year${\sim}$old group was 32.0%, 19.6%, 7.1%, 3.4%. 3. Hellman dental age IVa which is completion of the permanent dentition showed the highest percentage in male and female. 4. Geographic distribution showed a majority of patients in Kwang Ju(71.0%). Group within the distance 10km from Chosun Dental Hospital was 56.3% and group within 20km was 14.7%. 5. Anterior cross bite showed the highest percentage in chief complaints and percentage of Mn. prognathism and protrusion of Mx. teeth was 12.6%, 12.2%. 6. Distribution in the types of malocclusion according to the Angle's classification had shown; 38.9% for Class I, 20.7% for Class II division 1, 2.0% for Class III division 2, 38.4% for Class III. 7. In the dental vertical dysplasia according to the Angle's classification, deep bite was the most frequent in Class II div.1 and div. 2(24.3%, 56.7%) and open bite in Class III(21.4%). 8. In the skeletal sagittal dysplasia, 39.3% of skeletal Class II was due to the undergrowth of the mandible and 46.3% of skeletal Class III was due to the overgrowth of the mandible. 9. Distribution in orthodontic treatment acceding to the extraction and nonextraction had shown 66.9% for nonextraction case, 33.1% for extraction case, and four first bicuspids have been extracted in the highest percentage(38.6%). 10. Patients who had orthognathic surgery comprised 7.9%, with an increasing trend.

• The korean journal of orthodontics
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• v.25 no.3 s.50
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• pp.247-261
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• 1995

The purpose of this study was to quantitate differences in the nature of the correction of Angle's Class II div 1 malocclusion dependent on the patient's age at the time of treatment. The sample consisted of 27 female patients in the adolescent group with a mean initial records age of 11.8 years and 25 female patients in the adult group with a mean starting age of 21.1 yrs. Lateral cephalometric head films were taken before and after orthodontic treatment with four bicuspid extraction. The results were obtained as follows. 1. None of maxillary skeletal parameters exhibited a significantly different in treatment change between adolescents and adults. But, in mandibular skeletal measurements, there were significant differences between two groups. (P<0.05) 2. Measures of vertical dimension in the adults remained unchanged during treatment, reflecting the effective absence of growth. 3. The steepness of occlusal plane in the adults changed significantly.(P<0.05) In contrast, the adolescents displayed stability of the occlusal plane. 4. According to the Johnston analysis, there was a significant difference in the total molar correction between two groups.(P<0.05) 5. According to the Johnston analysis, differential mandibular growth in the adolescents contrubuted $63\%$ of the total molar correction, with orthodontic tooth movement accounting for the remaining $37\%$. In the adults, dental movement comprised $99\%$ of the correction.

• The korean journal of orthodontics
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• v.26 no.4
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• pp.401-413
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• 1996

Facial vertical dyscrepancies is decided on the relationship between the anterior vertical facial height and posterior vertical facial height. Thus this study was conducted to determine the factors that affect the FHI, and classify the Class II div.1, malocclusion, which success is dependent on the vertical control according to the FHI, which is the ratio of antero-inferior facial height, posterio-inferior facial height ratio, and to use this as a guideline for treatment. Angle between palatal plane and Mandibular plane were in the order of RH, ID. Thus showing that interrelated angle was more inportant than the independent angle of both, palatal plane and Mandibular plane. The tendency of Cl II div.1. Malocclusion according to FHI, showed the Low group to have Mx. protrusion, prominent development of Mn. ramus, and the Mn. body length and ant. post. position was normal. The Normo group showed slight protrusion of the Maxilla,. The development of the ramus was less than normal and the Mn. was in a slight retruded position. The High group showed the Mx. in a normal position, the development of the Mn. ramus and body was the lowest, and the Mn. was in a posterior position. In observation of the factors affecting the FHI between each groups of Cl II div.l, malocclusion; In the Low group the MP- PP angle was very small, the ID was smililar to the normal group, but the RH was very large thus the FHI was increased. In the Normo group, the PP-MP angle was normal, ID was slightly smaller than the normal group and the RH was slightly smaller than the normal group, thus maintaining a normal FHI ratio. In the High group the PP-MP angle was very large, the ID was similar to the normal group, but the RH was smaller than the normal group thus the FHI was small.

• The korean journal of orthodontics
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• v.47 no.6
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• pp.375-383
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• 2017

Objective: The purpose of this study was to evaluate the dental and skeletal effects of the modified C-palatal plate (MCPP) for total arch distalization in adult patients with Class II malocclusion and compare the findings with those of cervical pull headgear. Methods: The study sample consisted of the lateral cephalograms of 44 adult patients with Class II Division 1 malocclusion, including 22 who received treatment with MCPP (age, $24.7{\pm}7.7years$) and 22 who received treatment with cervical pull headgear (age, $23.0{\pm}7.7years$). Pre- (T1) and post-treatment (T2) cephalograms were analyzed for 24 linear and angular measurements. Multivariate analysis of variance was performed to evaluate the changes after treatment in each group and differences in treatment effects between the two groups. Results: The mean amount of distalization at the crown and root levels of the maxillary first molar and the amount of distal tipping was 4.2 mm, 3.5 mm, and $3.9^{\circ}$ in the MCPP group, and 2.3 mm, 0.6 mm, and $8.6^{\circ}$ in the headgear group, respectively. In addition, intrusion by 2.5 mm was observed in the MCPP group. In both groups, the distal movement of the upper lip and the increase in the nasolabial angle were statistically significant (p < 0.001). However, none of the skeletal and soft tissue variables exhibited significant differences between the two groups. Conclusions: The results of this study suggest that MCPP is an effective treatment modality for total arch distalization in adults.

• The korean journal of orthodontics
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• v.27 no.1
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• pp.65-78
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• 1997

This study was carried out in order to determine soft tissue response to incisor movement and mandibular repositioning and to determine feasibility of predicting vertical and horizontal changes in soft tissue with hard tissue movement. For this study, cephalometric records of 41 orthodontically treated adult females who had Angle's Class II division 1 malocclusion were selected and stepwise multiple regression analysis was employed. Following conclusions were obtained by analysing the changes of soft tissue and hard tissue before and after treatment. 1. Hard tissue measurements that showed significant changes before and after treatment were horizontal and angular changes of maxillary incisor, horizontal,vertical and angular changes of mandibular incisor, overjet, overbite, interincisal angle, mandibular repositioning, A,B, skeletal convexity and soft tissue measurements that showed significant changes were horizontal, thickness and angular changes of upper lip, horizontal and angular changes of lower lip, interlabial angle, nasolabial angle labiomental angle, Sri, Ss, Si and soft tissue convexity(P<0.05). 2. All Soft tissue measurements changed significantly before and after treatment had between one and four hard tissue independent variables at statistically significant level, indicating that all soft tissue changes were direct relationship with hard tissue changes 3. Ova jet, horizontal change of maxillary incisor, horizontal change of maxillary root apex and horizontal change of pogonion entered into prediction equations most frequentely indicating that they were more significant variables in prediction of vertical and horizontal changes in the soft tissue with treatment, but vertical changes of mandibular incisor not entered any prediction equations, indicating that it was not considered a good predictor for soft tissue changes with maxillary incisor retraction. 4. Horizontal and vertical changes in subnasale were found to have most independent variables, significant at the 0.05 level in prediction-equations(${\Delta}$Sn(H):Ur, Is(H), Pg(H), UIA,${\Delta}$Sn(V): Is(H), Pg(H), overjet, A), indicating that subnasale changes are influenced by complex hard tissue interaction. 5. Multiple correlation coefficient($R^2$) of the soft tissue prediction equations ranges from 0.2-0.6.

• Journal of Dental Rehabilitation and Applied Science
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• v.24 no.1
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• pp.29-40
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• 2008

The purpose of this study was to evaluate the prevalence of symptoms and signs of temporomandibular joint dysfunction (TMD) and malocclusion in 10-12 year old children and to determine if a relationship exists between symptoms and signs of TMD and malocclusion. The subjects were composed of 465 school children (233 boys and 232 girls). Each subject was evaluated with simplified questionnaire and clinical examination to measure symptoms and signs of TMD and malocclusion. The results showed an elevated prevalence of headache (34.6%), which were more frequent in girls than boys. The most common cardinal sign of TMD was clicking (32.9%), which increased with age. TMJ lateral tenderness was present in 18.1% of the subjects and had a tendency to increase with age. Masseter muscle tenderness was found to be sensitive in 15.1%of the subjects and had a tendency to increase with age. Restriction of mandibular mobilitywas present in 30.3% of the subjects and had a tendency to increase with age. There was no significant difference in the prevalence of TMD signs between sex. The occlusal status showed Class I malocclusion in 73.3%, Class III in 12.9%,Class II division 1 in 11%, Class II division 2 in 2.8%. There was no significant difference in malocclusion traits between sex. There was statistically significant relationship between TMD signs and symptoms and class II division 1 and Class III malocclusion(p<0.05). The results indicate that the prevalence of TMD symptoms and signs in children is high, and the evaluation of TMD in children seems to be important.

• Restorative Dentistry and Endodontics
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• v.12 no.1
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• pp.119-129
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• 1986

The purpose of this study was to evaluate the marginal leakage of glass ionomer cement with different cavosurface margins. 192 class V cavities were prepared on freshly extracted non-carious teeth and glass ionomer cement were inserted according to the manufacturer's instructions. Cavity preparations for this investigation were performed in four groups. The experimental specimens were made by packing the glass ionomer cement (Fuji Ionomer Type II G-C Co. Japan) into the prepared 192 cavities of four groups with different modes: Group I. - The 48 cavities with $90^{\circ}$ butt-joint cavosurface preparation and restored with glass ionomer cement. Group II. - The 48 cavities with butt-joint preparation modified by $135^{\circ}$ beveling the cavosurface in the dentin and restored with glass ionomer cement. Group III. - The 48 cavities with butt-joint preparation modified by cutting a chamfer in the dentin and restored with glass ionomer cement. Group IV. - The same 48 cavities as group I, and overfilled with glass ionomer cement beyond the cavosurface angle. And four groups above described divided into three subgroups by means of conditioning the cavity walls: Control group. - Glass ionomer cement filled in the prepared 64 cavities after being cleaned with a stream of tap water. Phosphoric acid treatment group. - Glass ionomer cement filled in the prepared 64 cavities after being conditioned with a 50% phosphoric acid. Citric acid treatment group. - Glass ionomer cement filled in the prepared 64 cavities after being conditioned with a 50% citric acid. All 192 specimens were immersed in the 2.0% basic fuchsin solution and subjected to thermal stress at one-minute intervals ($4{\pm}2^{\circ}C$ to $60{\pm}2^{\circ}C$) for 70 minutes before exposure to the dye. The specimens were sectioned ecclesiologically through the center of the restorations for different periods of immersion time, 24 hours, 7 days, 14 days 30 days. The sections were examined under a stereoscopic microscope. The results were as follows: 1. The degree of marginal leakage in group II and III was greater than that in group I and IV. 2. The degree of marginal leakage in phosphoric acid treatment group was similar with that in control group. 3. The degree of marginal leakage in citric acid treatment group was less than that in control group. 4. In all groups, the degree of marginal leakage in phosphoric acid treatment group was greater than that in citric acid treatment group. 5. There is no statistical difference of the degree of marginal leakage according to the immersion time in the dye solution.