• Journal of the korean academy of Pediatric Dentistry
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• v.38 no.2
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• pp.137-145
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• 2011

The purpose of this study was to obtain the data for dental caries experience and occlusal pattern to utilize these data for motivating oral health promotion and activating oral health care programme in preschool children of multicultural family. Caries prevalence on primary teeth was surveyed for 3-5 years old 190 children of multicultural families in Chonbuk province. The results were as follows : 1. Dental caries prevalence rate of primary teeth (dmf rate) was 61.7% at 3 years of age, 88.7% at 4 years of age, and 92.6% at 5 years of age (p>0.05). 2. Average score of dmft index was 2.22 at 3 years of age, 4.97 at 4 years of age, and 6.62 at 5 years of age (p>0.05). 3. Most of the caries-prevailed tooth was maxillary primary central incisor and showed 28.8% at 3 years of age, 56.7% at 5 years of age. 4. dmft index and dmfs index of children of Vietnamese, Cambodian, and Filipinos women were higher than those of Chinese and Japanese. 5. In sagittal primary molar relationship, flush terminal plane type was 82.6%, distal step type was 5.2% and mesial step type was 8.4%. This study is the first report for children of multicultural families in Korea. More attention for children of multicultural families will be needed in aspect of oral disease prevention and treatment.

• Journal of the korean academy of Pediatric Dentistry
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• v.38 no.4
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• pp.385-390
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• 2011

When many factors involved in the eruption of the teeth act as negative effects, they can cause eruption disturbance. Periodic observation, space acquirement, surgical exposure, orthodontic traction, orthodontic traction accompanied with surgical exposure, and surgical repositioning are considered as the treatment options of an impacted tooth, which is a form of eruption disturbance. In the first case, a male patient, age 9, visited Yonsei University Dental Hospital (YUDH) with a chief complaint of ectopic impaction of the upper left lateral incisor. We extracted the upper left primary lateral incisor and primary canine, and 5 months later, a window opening procedure was executed. Eight months later, the upper left lateral incisor partially erupted, and 18 months after the extraction, the axis of the tooth improved and the tooth erupted spontaneously. In the second case, a male patient, age 10, visited YUDH with a chief complaint of ectopic impaction of the upper right first premolar. We extracted the upper right first primary molar. Ten months later, the upper right first premolar erupted partially, and 19 months after the extraction, the upper right first premolar erupted spontaneously. We reported two cases in which improvement of eruption path and spontaneous eruption of an ectopic impacted tooth was achieved by extracting the deciduous tooth which interfered with the proper eruption of it.

• Journal of the korean academy of Pediatric Dentistry
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• v.23 no.3
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• pp.667-673
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• 1996

The prevalence of class III malocclusion is approximately 5$\sim$9%, and about one fourth of this malocclusion is due to underdeveloped maxilla. Maxillary protraction appliance is an orthopedic device which promote the growth of a deficient maxilla by applying extraoral force to actively growing patients. The object of using maxillary protraction appliance is to guide a normal growth of maxilla and mandible and improve the occlusal relationship and also improve the facial profile. The author treated three patients whom were diagnosed as a class III malocclusion due to deficient maxilla using maxillary protraction appliance and the followings are the conclusions : 1. In these cases, anterior crossbite was corrected by anterior movement of maxilla and downward backward rotation of mandible and simultaneously, anterior facial height was increased. 2. The amount of dental change compare to skeletal change was greater as the patients got older. 3. When 500gm of force to each side was applied, the treatment period has been decreased. 4. As a result of applying the force between maxillary first primary molar and canine, there was a small degree of changes in palatal plane. So, it can be concluded that the maxillary protraction appliance is effective in treating growing patients with a deficient maxilla.

• Journal of the korean academy of Pediatric Dentistry
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• v.50 no.4
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• pp.469-482
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• 2023

This study aimed to investigate the treatment options for the delayed eruption of mandibular premolars and identify the predictors of spontaneous eruption using panoramic radiography. The prevalence of delayed mandibular premolar eruption in this retrospective analysis, comprising 254 patients (aged 9 - 15 years), was 5.19%, with no significant difference based on gender. The mandibular second premolars were most affected (4.39%) compared to the first premolars (0.76%). No significant difference in prevalence was observed between the left and right sides. Among the treated mandibular premolars, primary molar-related lesions were identified as the leading cause (7.85%) of delayed tooth eruption. The treatment duration varied based on the Nolla stage, eruption stage, and treatment method. Teeth with Nolla stage 7 or lower had a treatment duration of 22.89 ± 11.96 months, whereas those with stage 8 or higher had a 15.02 ± 6.34 month duration. The deeper the tooth was located in the bone, the longer the treatment period became. The treatment duration varied depending on the treatment method, and statistically, there was no significant difference. The treatment durations for affected mandibular premolars increased with the depth of impaction angle of inclination. In this study, the treatment duration for delayed eruptions varied depending on the Nolla stage, eruption stage, and treatment method. Variations in the impaction depth and inclination angle across various treatment approaches, as explored in this study, might offer valuable insights into the selection of the most suitable management options for delayed tooth eruptions.

• The Journal of Korea Assosiation for Disability and Oral Health
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• v.12 no.2
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• pp.87-91
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• 2016

Pierre Robin syndrome (PRS) is characterized by the triad of congenital mandibular hypoplasia, glossoptosis and cleft palate. Infant PRS patients are frequently suffering from upper airway obstruction, gastroesophageal reflux and growth retardation caused by above mentioned problems. We report a dental caries treatment of 3-year old girl with Pierre Robin syndrome with multiple caries. The cause of multiple caries was mainly presumed as patient's eating habit caused by her general condition. She had some feeding problems and had history of gastric tube. She was still using milk bottle and took more than an hour to finish a meal. The treatment was performed under general anesthesia considering patient's condition; mild autism, poor cooperation and respiratory problem due to micrognathia. Severely affected upper incisors were treated with pulp treatment and restored with zirconia crown for esthetic purpose. Lower incisors were treated with pulp treatment and restored with composite resin. Upper right first primary molar was restored with stainless steel crown and other primary molars were treated with composite resin. There were no postoperative complications. According to her parents, the patient's compliance to oral hygiene management was greatly improved after the treatment since she was very pleased with the esthetic result and highly motivated by her looks. The treatment without sedation or general anesthesia would be possible once the airway is improved as the mandible grows.

• The Journal of Korean Academy of Prosthodontics
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• v.47 no.1
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• pp.29-38
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• 2009

Statement of problem: A casting connection technique is widely used for repair, correction and addition to base metal framework. However, a casting connection technique may increase the risk of failure in clinical situations when high stresses exist. Purpose: The purpose of this study was to investigate the mechanical retentive groove design comparatively to increase the joint strength by using the three-dimensional finite element analysis model of a 3-unit fixed partial denture. Material and methods: Ten finite element models were constructed. (Model A: One retentive groove, Model B: Two retentive grooves, Model C: Three retentive grooves, Model D: Four retentive grooves, Model E: One horizontal groove and two vertical grooves, Model F: Two horizontal grooves and one vertical groove, Model G: One groove with the enlarged dimension, Model H: Two grooves with the enlarged dimension, Model I: One groove with the increased height, Model J: One groove with the increased width of base). The vertical force was applied to the mesial and the distal fossa to the casting connection of mandibular first molar. Results: The main factors, affecting joint strength of casting connection were both the retention between the primary cast and the secondary cast and the thickness of the primary cast remaining after preparing retentive groove. The increase of retentive force, according to the numbers and the dimension of retentive groove had an effect on distributing stress. However, in some cases, the increase of retentive force resulted in the increase of stress by reducing thickness of the primary cast in the connection area. Conclusion: The design of retentive groove that limits number of retentive groove for metal thickness and increases the depth of retentive groove for retention is highly recommended.

• Progress in Medical Physics
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• v.26 no.1
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• pp.52-58
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• 2015

The automated dental cavity detection program for a new concept intra-oral dental x-ray imaging device, an auxiliary diagnosis system, which is able to assist a dentist to identify dental caries in an early stage and to make an accurate diagnosis, was to be developed. The primary theory of the automatic dental cavity detection program is divided into two algorithms; one is an image segmentation skill to discriminate between a dental cavity and a normal tooth and the other is a computational method to analyze feature of an tooth image and take an advantage of it for detection of dental cavities. In the present study, it is, first, evaluated how accurately the DRLSE (Direct Regularized Level Set Evolution) method extracts demarcation surrounding the dental cavity. In order to evaluate the ability of the developed algorithm to automatically detect dental cavities, 7 tooth phantoms from incisor to molar were fabricated which contained a various form of cavities. Then, dental cavities in the tooth phantom images were analyzed with the developed algorithm. Except for two cavities whose contours were identified partially, the contours of 12 cavities were correctly discriminated by the automated dental caries detection program, which, consequently, proved the practical feasibility of the automatic dental lesion detection algorithm. However, an efficient and enhanced algorithm is required for its application to the actual dental diagnosis since shapes or conditions of the dental caries are different between individuals and complicated. In the future, the automatic dental cavity detection system will be improved adding pattern recognition or machine learning based algorithm which can deal with information of tooth status.

• The Journal of Korea Assosiation for Disability and Oral Health
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• v.12 no.2
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• pp.82-86
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• 2016

Lowe syndrome is X-linked gene disorder, characterized by cataracts, renal dysfunction and brain abnormalities. Oral healthcare of young patients with Lowe syndrome could be easily neglected due to the uncooperative behavior or other systemic condition of the child. We are presenting a case of successful treatment under general anesthesia with uncooperative child with Lowe syndrome. A 3-year old boy with Lowe syndrome visited Seoul National University Dental Hospital for multiple caries. He had been suffering from congenital cataract, medullary nephrocalcinosis and hypotonia. Multiple caries were observed from clinical and radiographic examination. Concerning behavior management problem and possibility of aspiration due to hypotonia, dental treatment under general anesthesia was planned. Left upper primary first molar was extracted to prevent further infection. Other teeth were treated with Stainless steel crown or composite resin restoration based upon the extent and the severity of dental caries. Under general anesthesia, dental procedure was carried out successfully and safely. Considering uncooperative behavior and other medical conditions of the patient, general anesthesia could be effective. Home oral care and periodic visit to dental clinic should be emphasized to the caregiver of patient with Lowe syndrome, considering the susceptibility of dental caries and other oral manifestation.

• Journal of Korean society of Dental Hygiene
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• v.23 no.6
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• pp.431-439
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• 2023

Objectives: The aim of this study was to investigate the essential services, importance, interval of examinations, and role of dental hygienists in children's family dentistry program. Methods: A total of 124 participants completed a self-administered questionnaire. The data were analyzed using independent t-test, and ANOVA, and Pearson correlation analysis. Results: All participants stated that oral examination and panoramic radiography are required; children should be educated about brushing, use of oral products, and regular check-ups; and preventive treatments such as molar sealants and prophylaxis should be offered. They stated that light-curing resins and glass ionomer fillings should be offered in treatment services. They stated that examination intervals should be shorter for education and prevention rather than treatment. Dental hygiene students were more likely than dentists and dental hygienists to say that the program was more important. There was a correlation between oral examinations and education and treatment, and between essential services and their importance. Conclusions: Services considered essential and important should be provided first, education and prevention should be provided more frequently than treatment, and their importance should be emphasized not only to dental hygiene students but also to dental hygienists and dentists who are the main providers of services.

• The Journal of Korean Academy of Prosthodontics
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• v.37 no.5
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• pp.581-596
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• 1999

The purpose of this study was to investigate the stress distribution of the abutment and sup-porting tissues according to the slopes and types of the guiding plane of distal extension removable partial dentures. The 3-dimensional finite element method was used and the finite element models were prepared as follows. Model I : Kratochvil type guiding plane with $90^{\circ}$ to residual ridge Model II : Kratochvil type guiding plane with $95^{\circ}$ to residual ridge Model III : Kratochvil type guiding plane with $100^{\circ}$ to residual ridge Model IV : Krol type guiding plane with $90^{\circ}$ to residual ridge Distal extension partial denture which right mandibular first and second molar were lost was used and the second premolar was prepared as primary abutment with RPI type retainer. Then 150N of compressive force was applied to central fossae of the first and second molars and von Mises stress and displacement were measured. The results were as follows 1. Model I and Model IV showed a similar stress distribution pattern and the stress was concentrated on the apex of the root of the abutment. 2. The stress was increased and concentrated on mesial side of the root of the abutment in Model II. The stress was concentrated on buccal and mesiobuccal side of the root of the abutment in Model IV. 3. In Model I, the root of the abutment displaced and twisted a little in clockwise. In Model IV, the root of the abutment displaced to distolingually at apical region of the root and mesiobuccally at cervical region of the root. 4. In Model II, the root of the abutment displaced to mesiolingually at apical region of the root and more displaced and twisted in counterclockwise at cervical region of the root. In Model III, the root of the abutment displaced to mesiobucally at apical region of the root and more displaced and twisted in clockwise at cervical region of the root.