• The korean journal of orthodontics
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• v.31 no.2 s.85
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• pp.199-207
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• 2001

The segmented TMA T-loop spring, used for reciprocal space closure and described by Burstone, was used to achievebodily movement of canine. Photoelastic analysis is a technique for the transformation of internal stress into visible light patterns. The two-dimensional photoelastic stress analysis was performed, and stress distribution was recorded by photography. The purpose of this study was to visualize photoelastically the distribution of forces transmitted to the alveolus and surrounding structures using new segmented TMA T-loop spring for canine retraction. The results were as follows: 1. Decreased activation produced decreased stress of upper 1st. premolar extraction site and increased intrusive stress of upper 1st. molar, regardless of T-loop position. 2. At 5mm activation, More posterior positioning of T-loop Produced an increased stress in upper 1st. premolar extraction site. 3. At 3mm activation, More posterior positioning of T-loop produced an increased stress in upper 1st. premolar extraction site and mesial lower half of upper 1st. molar mesio-buccal root. 4. At 1mm activation, More anterior positioning of T-loop produced an increased stress in upper mesial and blew apex area of upper canine root. 5. 0.25 B/L ratio and 3mm activation produced bodily movement of canine. To summarize, desired tooth movement and anchorage requirement is possible by altering the activation and mesio-distal position of the T-loop spring.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.3
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• pp.348-353
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• 2003

Early detection and prudent management of mesiodens or supernumerary tooth should be considered essential in reducing disturbance in the eruption and position of the adjacent permanent incisor. While it is true that the presence of diastema may be regarded as normal at the early mixed dentition stage, the early detection and removal of the mesiodens is a prerequisite to facilitate spontaneous alignment or subsequent approximation of the permanent central incisors. In many cases, diastema due to mesiodens can be physiologically corrected spontaneously after the extraction of mesiodens. The best choice of treatment of diastema may be observation. Orthodontic intervention is required only spontaneous closing of diastema does not occur within observation period. In orthodontic intervention, careful treatment plan should be established. Clinician gives considerations to angulation of central and lateral incisor, proximity of lateral incisor, developmental stage and position of canine, pattern and extent of anterior crowding. Orthodontic movement should be done slowly with light force. In addition, periodic radiographic observation are needed to monitor the root development and root resorption. Case 1, 2 and 3 showed physiologic closures after the extraction of mesiodens. In these cases, acceptable alignment of central and lateral incisors was obtained. In case 4, orthodontic correction for diastema was performed successfully after the extraction of mesiodens. After the orthodontic closure of the diastema, it was decided that a retainer was not needed, because the dentition was under a dynamic stage in exchanging teeth and also developing arches.

• The korean journal of orthodontics
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• v.28 no.1 s.66
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• pp.135-142
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• 1998

The purpose of the present study was to evaluate the effect of incisor protrusion on the mucogingival parameters including the width of attached gingiva. Thirty-seven young adults with lower anterior crowding were selected for this study. From the study model, the degrees of relative and absolute protrusions were measured for each lower incisor. Clinical non height, the width of keratinized gingiva, probing depth and the width of attached gingiva were measured with digital vernier calipers and Florida Probe System. Through comparing the difference of the above measurements between protruded and non-protruded incisors, and correlation analysis between each measurement, following results were obtained: 1. The protruded incisor showed narrow width of keratinized and attached gingiva comparing to non-protruded incisor. 2. The protruded incisor showed greater clinical crown height comparing to non-protruded side while there was no difference in the probing depth between protruded and non-protruded side. 3. The difference in the width of attached gingiva between protruded and non-protruded incisors showed higher significance in the lateral incisor than in the central incisor. 4. The degree of relative protrusion showed higher correlation with the width of attached gingiva than the degree of absolute protrusion. 5. Clinical crown height showed higher correlation with the width of attached gingiva than the degree of protrusion.

• The korean journal of orthodontics
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• v.27 no.6 s.65
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• pp.871-880
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• 1997

Multiple features of occlusion have been combined by epidemiologists in attempts to objectively to determine malocclusion severity and treatment priority. Jenny et al were developed DAI(Dental Aesthetic Index), which is an orthodontic index based on socially defined aesthetic standards. This study aimed to evaluate association between 10 occlusal components of DAI and individual measures of skeletal morphology by use of univariate and multivariate analysis. In addition the relationship between a Dental Aesthetic Index score and skeletal morphology was evaluated. The data for this study were obtained from cephalometric radiographs and dental casts of 182 Korean patients(79 men, 103 women) with permanent dentition who had been accepted for the orthodontic treatment at Department of Orthodontics, Chonbuk National University. The results are as follows: 1. Several occlusal components of DAI(missing, crowding and spacing in the incisal segment, diastema, largest anterior irregularity on upper and lower arch) were not associated with individual measures of craniofacial morphology. 2. Sagittal occlusal components of DAI were associated with anteroposterior skeletal measures. 3. The relation between vertical occlusal components of DAI and vertical skeletal measures was low magnitude. 4. A Dental Aesthetic Index, which is based on several aspects of occlusion, did not identify craniofacial morphology. We can conclude that combination of certain occlusal components of the DAI may be related with specific skeletal morphology; but, this concept could not be accepted generally.

• The Journal of the Korean dental association
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• v.48 no.5
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• pp.391-406
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• 2010

Orthodontic treatment for middle-aged patients has become more commonplace with various reasons including improved socioeconomic status. Understanding of oral status and treatment modalities of middle-aged patients is mandatory for accurate diagnosis and proper treatment planning. This study investigated 100 consecutive patients aged 40s and 50s and 100 aged 20s who had been examined and diagnosed at the Department of Orthodontics, Chonnam National University Dental Hospital. The results were obtained as follows; 1. Gender distribution showed female outnumbered male patients in young-aged adult patients, but middle-aged patients showed similar male and female distribution. 2. The major concern seeking orthodontic treatment was esthetics not only in young-aged but also in middle-aged adult patients, and a number of middle-aged patients were concerned about oral health as well. 3. Considerable number of middle-aged patients were referred by other dental specialties while young-aged adult patients were more self-motivated for orthodontic treatment. 4. Middle-aged adult patients had more missing teeth and periodontal disease than young-aged adults. 5. The most frequently-observed problem was dental spacing in middle-aged patients while dental crowding in young-aged adult patients. Middle-aged patients showed higher prevalence of deep overbite and overjet while most of young-aged adults presented opposite direction of problem in overbite and overjet. 6. Limited orthodontic treatment was required rather than comprehensive treatment in middle-aged patients, and the most common tooth moving area was anterior part of dentition in case of limited treatment. Need of interdisciplinary therapy with other dental specialties was more common in middle-aged patients. 7. Intervention of specific technique such as invisible TP, passive bracketing, passive wire bonding, and lingual orthodontics was more required in middle-aged patients. Considering that middle-aged patients have different characteristics than young-aged adults, the results of the present study suggest that different treatment modalities are required in middle-aged orthodontic patients in order to manage them properly and efficiently.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.4
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• pp.619-624
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• 2009

Pyknodysostosis(PKND) is a rare sclerosing bone disorder that has an autosomal recessive trait, also known as Toulouse-Lautrec syndrome. Deficiency of the cathepsin enzyme K in the osteoclasts of PKND patients results in continuous endosteal bone deposits without osteoclastic resorption or remodeling. This causes a generalized increase in sclerosis and fragility of bones. Osteomyelitis in the mandible and recurrent fracture of the long bones are characteristic complicatons of PKND. The patients present typical features of PKND, such as short stature under 150 cm, open cranial suture and fontanelle, club-shaped phalanges, and underdevelopment of midface. This is a case of a 7-year-old girl with PKND, who visited our clinic with the chief complaint of anterior Open-bite and generalized crowding. The patient had been diagnosed as PKND by an orthopedist and manifested characteristic clinical and radiographic features, such as open cranial suture and fontanelle, obtuse madibular gonial angle, frontal and occipital bossing, grooved palate, club-shaped phalanges, and short stature. Orthodontic treatment was not considered because patients with PKND show abnormal bone resorption and remodeling. Instead, removal of deciduous teeth near exfoliation and TFA were performed, and periodic check-up is planned to maintain good oral hygiene.

• Journal of the korean academy of Pediatric Dentistry
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• v.40 no.4
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• pp.296-305
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• 2013

For the purpose of evaluating the prevalence of malocclusion and self-esteem in adolescents, 1,380 middle-school students in the Yangsan area were surveyed by oral examination and questionnaires and the obtained results were as follows: The distribution of 1st molar occlusion by Angle's classification was 69.0, 19.4, 10.6% for Class I, II and III respectively. In the horizontal relationship, the prevalence of normal overjet and crossbite was 86.9% and 5.6% respectively whereas larger and extremely larger overjet was found in 6.6% and 0.8%. In the vertical relationship of anterior teeth, normal, deep overbite and openbite was shown in 94.1%, 4.7%, and 1.2%. For the midline discrepancy, the distribution of groups with 0~1 mm, 2~4 mm and over 5 mm was 98.2%, 1.4%, and 0.4%. Crowding only in the maxilla was found in 9.6%, while that only in the mandible and in both arches was 14.1% and 24.1% respectively. Spacing only in the maxilla was seen in 3.0%, while that only in the mandible and in both arches was 2.4% and 1.7% respectively. Significant difference in self-esteem was revealed in female and malocclusion groups of crossbite and openbite(p < 0.05).

• The korean journal of orthodontics
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• v.39 no.6
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• pp.372-382
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• 2009

Objective: This study was to change of pulp blood flow among maxillary and mandibular anterior tooth with mild crowding and adjacent teeth using Ultrasound Doppler graphy. Methods: The change of pulp blood flow was measured three times using Ultrasound Doppler graphy; before the attachment of brackets, after 3 week, and after 6 week. The sample consists of 15 year old eighteen patients. Results: Before the attachment of brackets, after 3 weeks, and after 6 weeks, there were no significant differences in the change of pulp blood flow in each part (maxilla and mandible) and each tooth according to period. In addition, to compare internal dangerousness of loss of the pulp vitality, when pulp blood flow is compared in each tooth before orthodontic treatment, there were no statistically significant differences in maxillary lateral incisor and mandibular canine but it showed low values in all measurement items (p > 0.05). Conclusions: Results of this study can be not only methodological preliminary data in further study such as tooth movement type of Ultrasound Doppler graphy and particular study considered the patient age, but also reference materials for the loss of pulp vitality in orthodontic treatment.

• The korean journal of orthodontics
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• v.27 no.4 s.63
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• pp.523-538
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• 1997

In order to investigate TMD prevalence in malocclusion patients and to study its relationship with occlusal factors, 205 malocclusion patients (M67, F138, 6Y1M-46Y8M) were examined. The following examinations were carried out, Questionnaire personal history, TMD symptoms, and the associated factors Clinical examination : TMJ sound and maximum mouth opening Orthopantomogram : condyle abnormalities, length of Co'-Inc' and Co'-Go', ratio Co'- Inc'/ Co'-Go', and depth of antegonial notch Transcranial view limitation of anterior movement of condyle Model Angle classification, overjet, overbite, midline discrepancy, missing of posterior teeth, posterior crossbite, attrition of palatal cusp of maxillary molars, crowding/spacing The results could be summarized as follows, 1. The prevalence of TMD showed that Helkimo Anamestic Inder(Ai) 0 was $46.8\%$, Ai I was $22.0\%$, Ai II was $31.2\%$ and subjective symptoms increased with aging (p<0.001) and were frequent in females (p<0.05). 2. Flattening ($4.4\%$) was the most frequent condyle abnormality on Orthopantomogram, and $8.3\%$ of subjects showed some abnormalities on Orthopantomogram. 3. The cases with neck and shoulder pain (p<0.001), clenching, lip biting (p<0.01), and headache (p<0.05) showed higher scores of Ai. 4. Angle class II showed high frequency of condylar abnormalities on Orthopantomogram, and subjects whose palatal cusp of maxillary molars had been attrided had the tendency to show high hi scores (p<0.05). The other occlusal factors had nothing to do with the symptoms of TMD. 5. In the cases that 1)the value of Co'-Inc', Co'-Go' or Co'-Inc'/Co'-Go' were low or 2)the differences of Co'-Go' or Co'-Inc'/Co'-Go' between the right and the left were large, condylar abnormalities were frequently obserbed on Orthopantomogram.

• The korean journal of orthodontics
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• v.29 no.4 s.75
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• pp.483-490
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• 1999

Interdental enamel stripping is an usual method for correction of abnormal tooth shape and tooth size discrepancy which is one of the etiologic factors of malocclusion. Clinically it Is useful to correct the minor crowding in anterior teeth and posterior occlusion during finishing stage of orthodontic treatment. But this procedure has risks such as irreversible tooth reduction and remaining roughness of enamel surface can accumulate plaque which can evoke periodontal problem. Even if various methods were introduced to minimize the enamel surface roughness, their evaluation was limited in morphologic differences by scanning electronic microscope(SEM). The purpose of this study was to compare the various interdental enamel stripping method by SEM and to quantify the difference of surface roughness by use of Surfcorder SEF-30D(Kosaka Lab. Ltd.) which can measure the roughness of surface. The stripping methods were divided into mechanical and mechanical-chemical method. Air-rotor stripping and separating strip were used for mechanical stripping and $37\%$ phosphoric acid was used for chemical stripping. The enamel surface roughness after mechanical or mechanical-chemical stripping of interproximal surfaces of premolars which were extracted for orthodontic purpose were measured and compared by means of SEM and $Surfcorder^{\circledR}$, the results were as follows. 1. Enamel surface of primary treated by coarse diamond bur and separating strip groups showed highest value of roughness. 2. To compare the primary treated groups between mechanical and mechanical-chemical method, the latter group showed lower value of roughness remarkably. 3. Mechanical stripping groups which were treated both coarse and fine instrument showed lower value of roughness as much as non treated group. 4. The use of Pumice for final polishing did not show significantly smoothening the stripped enamel surface any more.