• 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.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.

• Journal of the korean academy of Pediatric Dentistry
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• v.47 no.3
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• pp.235-247
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• 2020

The purpose of this study was to evaluate the skeletal and dentoalveolar effects and optimal timing for treatment of class II malocclusion with functional appliances in children and adolescents. A group of 30 patients with class II malocclusion were divided into 3 groups according to their use of functional appliance: Twin block, Activator, Fränkel appliance. The group was also divided into 2 groups according to the cervical vertebrae maturation method. Lateral cephalometric radiographs were analyzed pretreatment (T0) and posttreatment (T1). Among the functional appliances, treatment with Twin block and Activator showed significant increase in the length of the mandible (Co-Gn) and the lower anterior facial height (ANS to Me), whereas the overjet and overbite were significantly reduced. Treatment with Fränkel appliance showed significant improvement in the relationship of maxilla and mandible. In addition, if the functional appliance was used during the period of pubertal growth peak, there was a significant increase in mandibular length, improvement in the relationship of maxilla and mandible, labial inclination of lower incisors and decrease in overjet compared to the treatment before pubertal growth peak. Therefore, this study indicates that using functional appliances for patients with class II malocclusion is effective and the optimal timing for using functional appliances is during pubertal growth peak.

• The korean journal of orthodontics
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• v.27 no.3 s.62
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• pp.473-479
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• 1997

This author tried to find if the size of the frontal sinus can be used as a diagnostic aid to predict the manldibular growth pattern in growing Patients in lateral cephalogram utilizing the fact the the frontal sinus completes its growth in earlier stage but the mandible continues to grow until later. At this study, the 228 samples were divided into 3 groups as skeletal Class I, II, III malocclusions and three indicies(ANB, APDI, Wits) were measured which indicate the mandibular body length and the antero-posterior relationship of maxilla and mandible to evaluate their relations with frontal sinus. And results were obtained as followings 1. The size of frontal sinus is highly related to ANB, APDI, Wits and mandilar body length.(p<0.001) 2. the size of the frontal sinus of the Cl III malocclusion group was on the lateral cephalogram larger than Cl I and Cl II group.

• The korean journal of orthodontics
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• v.39 no.4
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• pp.257-272
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• 2009

This case report describes the treatment of an adult patient with a Class I canine and molar relationship but a convex profile with a retrognathic mandible and marked lip protrusion, as well as an excessive lower anterior facial height and reduced transverse width on both arches due to a nasal airway obstruction. The constricted arches were expanded by surgically-assisted rapid palatal expansion and the application of a Schwarz appliance to the maxilla and mandible. Acceptable facial balance was obtained using contemporary directional force technology with microimplant anchorage (MIA), which provided horizontal and vertical anchorage in the maxillary and mandibular posterior teeth, as well as intrusion and torque control in the maxillary anterior teeth, resulting in a favorable counterclockwise mandibular response. The total treatment period was 29 months and the results were acceptable for 13 months after debonding.

• The korean journal of orthodontics
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• v.37 no.1 s.120
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• pp.44-55
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• 2007

Objective: Previous studies have reported that morphological features of the first cervical vertebra (atlas) have been associated with mandibular growth direction. The purpose of this study was to show the possible positional and morphological changes of the Atlas from activator treatment in Class II malocclusion patients. Methods: Lateral cephalometric radiograph tracings were made at initial, middle and final stages of treatment. Angular and linear measurements of skeletal and morphological features were measured on the anatomical landmarks and reference planes. Results: The skeletal effects of activator treatment on Class II malocclusion patients were evident on ramal height, body length, effective body length, ANB, and overjet. Clockwise rotation of the long axis of the Atlas was found in Group 1, but there was no inclination change of the Atlas in groups 2 and 3. There was no significant correlation between anterior and posterior positions of the atlas or morphological change in all groups. - except for posterior movements of the Atlas found in group 1. Conclusion: Clockwise rotation of the atlas axis resulted from activator treatment in Cl II malocclusion patients. Change in atlas axis can be thought of as an indicator for success of activator treatment.

• The korean journal of orthodontics
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• v.46 no.6
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• pp.395-408
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• 2016

We report a case involving a young female patient with severe mandibular retrognathism accompanied by mandibular condylar deformity that was effectively treated with Le Fort I osteotomy and two genioplasty procedures. At 9 years and 9 months of age, she was diagnosed with Angle Class III malocclusion, a skeletal Class II jaw relationship, an anterior crossbite, congenital absence of some teeth, and a left-sided cleft lip and palate. Although the anterior crossbite and narrow maxillary arch were corrected by interceptive orthodontic treatment, severe mandibular hypogrowth resulted in unexpectedly severe mandibular retrognathism after growth completion. Moreover, bilateral condylar deformities were observed, and we suspected progressive condylar resorption (PCR). There was a high risk of further condylar resorption with mandibular advancement surgery; therefore, Le Fort I osteotomy with two genioplasty procedures was performed to achieve counterclockwise rotation of the mandible and avoid ingravescence of the condylar deformities. The total duration of active treatment was 42 months. The maxilla was impacted by 7.0 mm and 5.0 mm in the incisor and molar regions, respectively, while the pogonion was advanced by 18.0 mm. This significantly resolved both skeletal disharmony and malocclusion. Furthermore, the hyoid bone was advanced, the pharyngeal airway space was increased, and the morphology of the mandibular condyle was maintained. At the 30-month follow-up examination, the patient exhibited a satisfactory facial profile. The findings from our case suggest that severe mandibular retrognathism with condylar deformities can be effectively treated without surgical mandibular advancement, thus decreasing the risk of PCR.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.4
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• pp.550-555
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• 2009

Distribution of orthodontic patients in pediatric dental clinics has increased recently. So it is worth to study about the present status of orthodontic patients in pediatric dental clinics. The purpose of this study was to recognize the characteristics and orthodontic patterns of orthodontic patients in pediatric dental clinics. The material consisted of distribution and orthodontic analysis records of 792 new patients in the department of pediatric dentistry, Seoul National University Dental Hospital, from 2006 to 2008. Results were as follows 1. In age distribution, 8-year-olds group comprised 22%, 7-year-olds 19%, 9-year-olds 16%, 10-year olds 15%, 11-year-olds 11%, and other age groups comprised 18%. 2. In skeletal patterns, skeletal class I patients comprised 52%, class II 29%, and class III 19%. 3. In vertical facial types mesofacial comprised 41%, brachyfacial 35%, and dolichofacial 24%. 4. Out of 792 patients 218 patients(28%) showed anterior cross-bite, and the occurrence ratio of anterior cross-bite increased as the age decreased.

• The korean journal of orthodontics
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• v.39 no.2
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• pp.120-129
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• 2009

Objective: To estimate dental maturity using the Demirjian Index for the mandibular third molar and investigate the relationships between dental maturity and skeletal maturity among growing children. Methods: The samples were derived from panoramic, lateral cephalometric and hand-wrist radiographs of 270 female subjects registered as patients at the orthodontic department, dental hospital, Yonsei University. Dental maturity [Demirjian Index (DI)] and skeletal maturity [skeletal maturation indicators (SMIs)] and cervical vertebrae maturation indicators (CVMIs)] were estimated from these radiographs. Results: There was a significant correlation (r = 0.64) between SMIs and DI, and a similar correlation (r = 0.59) was observed between CVMIs and DI (p < 0.001). If DI was above Stage E, then the SMI was above Stage 10 and the CVMI was above Stage 5. There was a weak correlation (r = 0.26) between age at menarche and DI (p < 0.001). There was no significant difference in DI among Class I, II or III malocclusions. Conclusions: Dental maturity evaluation using the mandibular third molar will be an adjunctive tool in combination with cervical vertebrae and hand-wrist maturity evaluations.

• The korean journal of orthodontics
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• v.30 no.3 s.80
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• pp.307-315
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• 2000

This study was performed to evaluate the reproducibility of natural head position according to skeletal malocclusion types and sex using cephalometric radiographs for establishing orthodontic diagnosis and treatment planning. The sample consisted of 90 young adults (male 45, female 45) who had the skeletal malocclusion. Cephalometric radiographs were taken in natural head position, and statistical analysis was performed and method error of 6 postural variables were estimated to evaluate the reproducibility of the natural head position. The following results were obtained : 1. In the reproducibility of the natural head position, postural variables had no statistical significance In male and female (P>0.05). 2. In the reproducibility of the natural head position, postural variables had no statistical significance in Class I, II, III, and total group (P>0.05). 3. The reproducibility of natural head position using method error was excellent in all groups.