• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.2
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• pp.300-309
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• 2001

The purpose of this study was to investigate the caries prevalence and caries pattern of preschool children in a small city. Six hundred twenty four kindergarten children in Milyang city were examined for their caries experience of individual teeth and surfaces by dmf index. The obtained results were as follows. 1. The rate of children with caries experience(dmft rate) in primary teeth was 74.0% in 3-year-olds, 83.8% in 4-year-olds, and 90.6% in 5-year-olds. The mean number of decayed, missed, and filled primary teeth(dmft index) was 3.47 in 3-year-olds, 5.41 in 4-year-olds, and 6.01 in 5-year-olds. 2. The caries prevalence of children in this study was higher than those of other researches in past and in other cities. 3. The caries-experienced teeth in order in 5-year-olds were as follows : mandibular 2nd primary molar, mandibular 1st primary molar, maxillary 2nd primary molar, maxillary primary central incisor and maxillary 1st primary molar. 4. The pattern of dental caries development was different between the incisors and molars. The prevalent surface of caries was proximal surface in primary incisors, but occlusal surface in primary molars.

• The Journal of Korean Academy of Prosthodontics
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• v.34 no.3
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• pp.415-430
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• 1996

The purpose of this study was to evaluate the stress distributions in the surrounding tissues of the teeth seated by indirect retainers in three different teeth of unilateral distal extension partial denture when the dislodging forces were applied on denture bases. Three dimensional photoelastic models were made. The teeth on which indirect retainers were seated were mandibular left lateral incisor (Model I), canine (Model II), and first premolar (Model III). The dislodging force with 860mg at $45^{\circ}$ angulation to occlusal plane was applied to each model. Three dimensional photoelastic stress analysis was done, and the records were diagramed and analysed. The results were as follows : The compressive stresses were shown the most on neck portions of buccal, mesial, and distal sides in all three models. Slight tensile stresses were shown on neck portions of lingual sides in all three models. The compressive stresses on buccal side were shown in strength in such order as model I, model II, and model III. The compressive stresses were shown on neck portion of mesial and distal sides of model I and mode II, with model I more than Model II. The compressive stresses were shown only on neck portion of mesial side on Model III. The general overall magnitude of compressive stresses were shown in strength in such order as Model I, Model II, and Model III.

• Journal of Korean Dental Science
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• v.3 no.1
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• pp.17-24
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• 2010

Objective : To investigate the prevalence of dental anomalies and to determine the associations between dental anomalies in permanent teeth Materials and methods : The samples were 1,240 patients (760 females and 480 males, mean age=15.1 years) who visited the Samsung Medical Center. Dental anomalies were diagnosed using pre-treatment dental casts, radiographs, clinical examinations, and medical/dental histories. Prevalence and association were investigated according to gender and sidedness. The Chi-square test was performed for statistical analysis. Results : The most common missing tooth was the lower lateral incisor, followed by the lower and upper second premolars. This particular dental anomaly is characteristic of the East Asian population (prevalence of congenital missing tooth=12.3%). The upper anterior area was the most frequently affected area (prevalence of supernumerary tooth was 1.5%). The presence of a supernumerary tooth was more prevalent in males than in females (p<.05, odds ratio=3.2). The most frequently affected tooth was the upper canine (prevalence of impacted tooth=4.3%). Unilateral impaction of the upper canine occurred significantly more often compared to bilateral impaction (p<.001). The prevalence of peg lateralis was 2.7%. The presence of congenital missing tooth was closely associated with peg lateralis (p<.01). If children aged 7~8 years have peg lateralis, the rest of the teeth should be checked for congenital absences. Conclusion : The early detection of dental anomalies and understanding of their associations help clinicians determine the appropriate treatment timing and methods of dealing with these anomalies.

• Restorative Dentistry and Endodontics
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• v.44 no.4
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• pp.39.1-39.8
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• 2019

The present report presents a case of dens invaginatus (DI) in a patient with 4 maxillary incisors. A 24-year-old female complained of swelling of the maxillary left anterior region and discoloration of the maxillary left anterior tooth. The maxillary left lateral incisor (tooth #22) showed pulp necrosis and a chronic apical abscess, and a periapical X-ray demonstrated DI on bilateral maxillary central and lateral incisors. All teeth responded to a vitality test, except tooth #22. The anatomic form of tooth #22 was similar to that of tooth #12, and both teeth had lingual pits. In addition, panoramic and periapical X-rays demonstrated root canal calcification, such as pulp stones, in the maxillary canines, first and second premolars, and the mandibular incisors, canines, and first premolars bilaterally. The patient underwent root canal treatment of tooth #22 and non-vital tooth bleaching. After a temporary filling material was removed, the invaginated mass was removed using ultrasonic tips under an operating microscope. The working length was established, and the root canal was enlarged up to #50 apical size and obturated with gutta-percha and AH 26 sealer using the continuous wave of condensation technique. Finally, non-vital bleaching was performed, and the access cavity was filled with composite resin.

• The Journal of Korea Assosiation for Disability and Oral Health
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• v.10 no.1
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• pp.43-46
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• 2014

Cerebral Palsy is a genetic term referring to abnormalities of motor control caused by damage to a child's brain early in the course of development. Due to the impairment of balanced perioral muscle development, the prevalence of malocclusions in patients with cerebral palsy such as maxillary protrusion is high. But most clinicians may feel uncomfortable to treatment of these problems. Here a case report about mitigation of maxillary anterior teeth protruded in patient with cerebral palsy. 8y 4m old boy who have cerebral palsy visited our dental hospital. He showed severely protrusive maxillary anterior teeth with mouth breathing and could not close his mouth. He and his mother wanted to improve dental and facial esthetic problem. Specially designed or modified intraoral fixed appliance and rubber elastic chain was used in the therapy. Treatment carried out for 8 months and we could observe maxillary incisor angle was improved and mouth breathing habit was stopped. In conclusion, modified fixed appliance therapy for the patients with cerebral palsy might be useful. Continuous rehabilitation training of lips should be followed after treatment to correct imbalance of muscle tone.

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.1
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• pp.157-161
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• 1999

Odontomas, hamartomas of odontogenic origin, are composed of all the structures that make up teeth. The WHO distinguishes odontoma into two types. The complex odontoma is defined as "a malformation in which all the dental tissues are represented, individual tissues being mainly well-formed but occurring in a more or less disorderly pattern." The compound odontoma is defined as "a malformation in which all the dental tissues are represented in a more orderly pattern than in the complex odontoma, so that the lesion consists of many toothlike structures. Most of these structures do not resemble morphologically the teeth of normal dentition, but in each one enamel, dentine, cementum, and pulp are arranged as in the normal tooth." Almost all odontomas are located intraosseously, but they have occasionally been reported in extrabony location. Peripheral or soft tissue odontomas, those arising outside of the alveolar bone, are very rare. Peripheral or soft tissue odontoma are defined as tumors that demonstrate the histologic characteristics of their intraosseous counterparts but occur solely in the soft tissue covering the tooth-bearing portion of the mandible and maxilla. When they mature, they appear as a radiopaque mass without the peripheral halo. The final diagnosis should be confirmed by biopsy. The origin of peripheral odontoma is probably related to remnants of the dental lamina in the gingiva. The treatment of choice is complete surgical excision, similarly to intraosseous odontoma and it does not tend to recur. This report presents a case of 5-year-old boy with swelling on labial gingiva of primary central incisor. And it was diagnosed as peripheral odontoma by excisional biopsy.

• Journal of the korean academy of Pediatric Dentistry
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• v.42 no.1
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• pp.87-101
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• 2015

The premature loss of the mandibular primary canine is relatively frequent and a sign of the upcoming space problems in the transitional period. This situation is caused by the permanent lateral incisor resorbing the root of the primary canine during its eruption. Bilateral loss of primary canines in a crowded arch leads to the lingual tipping of the permanent incisors, with the consequent reduction in the arch perimeter and increase in overbite. When the loss of a primary canine is unilateral, tipping of the adjacent incisors occurs toward the space, resulting in midline deviation. In these situations, treatment possibilities, such as extraction of the antimeric tooth or placement of a passive lingual arch, can be applied; although there are some controversies concerning this. Most space problems with less than 4 mm can be resolved through preservation of the leeway space using sequential disking of the primary teeth and a passive lingual arch, regaining space or limited arch expansion in the late mixed dentition. In cases with 4~6 mm of space problems, arch expansion (A-P or transverse) can be applied. Space problems with more than 6 mm should be treated through diagnosis and treatment planning. Most of these cases will require extraction of permanent teeth including serial extraction (guidance of eruption).

• BMB Reports
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• v.45 no.6
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• pp.337-341
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• 2012

Different from humans, who have a continuous dentition of teeth, mice have only three molars and one incisor separated by a toothless region called the diastema in the hemi mandibular arch. Although tooth buds form in the embryonic diastema, they regress and do not develop into teeth. In this study, we evaluated the proteins that modulate the diastema formation through comparative analysis with molar-forming tissue by liquid chromatography-tandem mass spectroscopy (LC-MS/MS) proteome analysis. From the comparative and semi-quantitative proteome analysis, we identified 147 up- and 173 down-regulated proteins in the diastema compared to the molar forming proteins. Based on this proteome analysis, we selected and evaluated two candidate proteins, EMERIN and RAB7A, as diastema tissue specific markers. This study provides the first list of proteins that were detected in the mouse embryonic diastema region, which will be useful to understand the mechanisms of tooth development.

• The korean journal of orthodontics
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• v.42 no.1
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• pp.39-46
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• 2012

Objective: We evaluated the detachment force, amount of deformation, fracture mode, and pull-out force of 3 different wires used for bonded lingual retainer fabrication. Methods: We tested 0.0215-inch five-stranded wire (PentaOne, Masel; group I), $0.016{\times}0.022$-inch dead-soft eight-braided wire (Bond-A-Braid, Reliance; group II), and 0.0195-inch dead-soft coaxial wire (Respond, Ormco; group III). To test detachment force, deformation, and fracture mode, we embedded 94 lower incisor teeth in acrylic blocks in pairs. Retainer wires were bonded to the teeth and vertically directed force was applied to the wire. To test pull-out force, wires were embedded in composite that was placed in a hole at the center of an acrylic block. Tensile force was applied along the long axis of the wire. Results: Detachment force and mode of fracture were not different between groups. Deformation was significantly higher in groups II and III than in group I (p < 0.001). Mean pull-out force was significantly higher for group I compared to groups II and III (p < 0.001). Conclusions: Detachment force and fracture mode were similar for all wires, but greater deformations were seen in dead-soft wires. Wire pull-out force was significantly higher for five-stranded coaxial wire than for the other wires tested. Five-stranded coaxial wires are suggested for use in bonded lingual retainers.

• The Journal of Korean Academy of Prosthodontics
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• v.30 no.2
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• pp.273-285
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• 1992

The purpose of this study was to evaluate facial form, arch form and tooth form in young adults to determine if a correlation exists. 115 subjects who had healthy natural maxillary incisors and good occlusion consisted of 71 males and 44 females ranging from 20-30 years of age. Facial photographs and, intraoral photographs of upper anterior teeth and dental casts of upper jaws were taken to demonstrate facial form, dental arch form and tooth form. Form analysis is determined by comparing the ratio of the widths of the faces, dental archs and the teeth. The Chi-square test of independence between facial form, arch form and tooth form, was executed and the significance level determined. The results were as follows : 1. The distribution of facial forms was 66.1% square-tapering, 27.0% square, 5.2% ovoid, 2% tapering-square. 2. The distribution of tooth forms was 65.2% ovoid, 20.0% square-tapering, 11.3 % tapering-square, 3.5 % square. 3. The distribution of arch forms was 50.4 % square-tapering, 48.7 % tapering, 0.9 % reverse tapering-square. 4. There was no large differences in the distribution of facial forms, dental arch forms and tooth-forms between male and female. 5. No relationship existed between the tooth form and the facial form. 6. No relationship existed between the facial form and the dental arch form. 7. No relationship existed between the tooth form and the dental arch form. 8. This gave the impression that dental arch form and facial form could not be used as a true index in tooth selection.