• Journal of the korean academy of Pediatric Dentistry
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• v.21 no.2
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• pp.439-455
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• 1994

The purpose of this study was to investigate the distribution of nerves in the periodontal ligament of a dog's primary teeth by each developing stage. The distribution of nerves in the periodontal ligament were investigated by means of immunohistochemistry for detection of neurofilament protein (NFP). The results were as follows: The NFP-immunoreactive nerve fibers were found to be densely distributed in the apical third of the periodontal ligament, while they were sparse in the coronal two third, in both primary and permanent teeth. In generally the density of distribution and degree of arborization of nerve fibers in periodontal ligament of primary teeth revealed a poor appearance compared with that of permanent teeth. Periodontal ligament in anterior teeth showed more abundant nerve innervation than posterior teeth, and the periodontal ligament of the bifurcation area in posterior teeth roots were not observed to have nerve fiber. The density of nerve distribution in the periodontal ligament of primary teeth was reduced according to the physiological root resorption and nerve fibers were not observed in the surrounding area on the root of the exfoliation stage in primary teeth. The distribution of nerve fibers in mucogingival tissue, was poor innervated according to the aging of the dogs. A more abundant distribution of nerve fiber was represented in the lingual mucogingival tissue than in the labial side. Most of the nerve endings in the periodontal ligament of primary teeth showed a tree-like appearance. However, the typical Ruffini-like nerve endings were not observed.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.2
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• pp.217-223
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• 2005

The term 'impaction teeth' is used to designate a tooth which remains unerupted in jaw beyond the time at which it should normally be erupted. Most cases of impacted teeth reported in the literature are permanent teeth. The impaction of primary teeth occur rarely whereas impaction of second primary molars is more numerous than all other impactions. Failure of eruption of primary teeth may cause a number of complications, such as interference with development and eruption of successive permanent teeth, malocclusion, cystic change of tooth follicle. The clinican should consider the various treatment option available (a) No treatment and observation, (b) surgical extraction (c) space regainer. Proper treatment plan should be established after thought consideration of impacted tooth and it's relation with successive permanent tooth.

• The Journal of Advanced Prosthodontics
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• v.2 no.3
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• pp.106-110
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• 2010

The severe wear of anterior teeth facilitates the loss of anterior guidance, which protects the posterior teeth from wear during excursive movement. The collapse of posterior teeth also results in the loss of normal occlusal plane and the reduction of the vertical dimension. This case report describes 77-year-old female, who had the loss of anterior guidance, the severe wear of dentition, and the reduction of the vertical dimension. Occlusal overlay splint was used after the decision of increasing vertical dimension by anatomical landmark, facial and physiologic measurement. Once the compatibility of the new vertical dimension had been confirmed, interim fixed restoration and the permanent reconstruction was initiated. This case reports that a satisfactory clinical result was achieved by restoring the vertical dimension with an improvement in esthetics and function.

• Journal of Oral Medicine and Pain
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• v.17 no.1
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• pp.31-39
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• 1992

The authors evaluated the degree of permanent tooth wear in order to make the basic date that are necessary to estimate the age. 10443 teeth of 389 individuals with known age were selected to estimate the degree of tooth wear. The obtained results were as follows : 1. The degree of tooth wear was decreased in males and females with aging. (P<0.001) 2. The degree of tooth wear in males in higher than that of females.(P<0.05) 3. The decision coefficient increased gradually from anterior teeth to posterior teeth.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.5
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• pp.39-51
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• 2014

This paper deals with design of a direct-coupled, small-scaled permanent magnet generator (PMG) for wind power application. First, this paper determines rated power and speed of the PMG from measured characteristics of wind turbines. Second, we derive analytical solutions for the open-circuit field in order to determine optimum magnet thickness and pole pitch/arc ratio. Third, on the basis of open circuit field solutions, stator magnetic circuit including slot opening, teeth width and yoke thickness is designed. And then, a diameter of stator coil which agree with a required current density is calculated, and its turns are determined from the area of slot considering winding packing factor. Finally, finite element (FE) method is employed in analyzing the details of the designed PMG and, test results such as back-emf measurements are given to confirm the design.

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.3
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• pp.506-512
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• 2007

Traumatic injury of tooth in children is commonly occurred problem. It is classified into tooth, periodontal tissue, supporting bone, soft tissue injury by it's area and extent. Among the periodontal tissue injuries, traumatically intruded teeth are common in anterior maxillary area, though the occurrence rate is rather low, the pulp and supporting tissue injury is possible by vertical impact. The treatment method of traumatically intruded teeth is various. Observation on the spontaneous reeruption for 3-4 weeks is recommended if the traumatized teeth are deciduous teeth or slightly intruded immature permanent anterior teeth. If this did not occur because the extent of intrusion is severe or the traumatized teeth are mature permanent anterior teeth, orthodontic traction is applied by fixed/removable appliances. At this time, light and continuous force is applied for the extrusive movement of the intruded teeth. When above procedures are impossible, surgical repositioning and fixation is recommended. In these cases, we performed conventional endodontic therapy for pulp necrosis and orthodontic traction with fixed appliance. We obtained satisfactory results and will report that.

• Journal of the korean academy of Pediatric Dentistry
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• v.24 no.1
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• pp.19-26
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• 1997

Odontodysplasia is a rare developmental anomaly of tooth formation in which hard tissue are affected. Odontodyplasia affects the primary and permanent dentitions in the maxilla, mandible, or both jaws. The maxilla is involved twice as often as the mandible. The condition is more common in female than in male patients and in the anterior than in the posterior regions. The clinical manifestation of odontodysplasia are hypoplasia and hypocalcification of the enamel and dentin of affected teeth. Teeth tend to be small and discolored, with short roots and widely open pulp canal. Delayed eruption of affected teeth with abscess formation is common. Radiographically teeth assume a faint radiolucent image ("ghost teeth"). enamel and dentin appear thin and are similar in radiodensity. The pulp chambers are often larger than normal, calcifications(pulp stone and denticle) are found within them. The etiology of regional odontodysplasia is unknown. However, several causes have been discussed, including somatic mutation, local circulatory disorders, local trauma, failure of migration and differentiation of neural crest cells, local infection.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.31 no.5
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• pp.440-443
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• 2009

Cleidocranial dysplasia(CCD) is a rare syndrome usually caused by an autosomal dominant gene or no apparent genetic cause. The skull is large and short with marked bossing of the frontal bone. Closure on the fontanelles and sutures is delayed. The clavicle may be unilaterally or bilaterally aplastic. Oral manifestations include multiple impacted permanent teeth, prolonged retention of primary teeth and multiple supernumerary teeth. There are many difficulties in the early diagnosis of CCD because a majority of the craniofacial abnormalities becomes obvious only during adolescence. Late diagnosis produce occlusional & psychological problem. Therefore early detection and treatment of CCD can reduce the period and the extent of orthodontic and surgical interventions. We experienced CCD patient with multiple supernumerary teeth and will report it with the literature review.

• Journal of the Korea Convergence Society
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• v.8 no.1
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• pp.89-96
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• 2017

This study is to analyze seven fluoride varnishes remineralizing effects on early carious lesions in the clinical field. While CS, MI, CW, VV, EP, FP and FN were used for permanent teeth, CS, MI, CW and FP were used for primary teeth. The specimens were demineralized for 4 days after forming a $3{\times}3mm^2$ window with nail varnish, applied with varnishes separately, then were stirred in artificial saliva for 1 week. QLF-D analysis of carious lesion size showed that permanent teeth's ${\Delta}F$ value decreased after applying CS(4,64), MI(4.86), CW(4.50), and EP(5.50), while for primary teeth, FP(3.00) and MI(3.00) displayed a remineralizing effect. Thus, MI can be used effectively for preventing caries for both adults and children in the clinical field.

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.4
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• pp.630-635
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• 1999

Transposition has been described as an interchange of position of permanent tooth and is a relatively rare dental anomaly. Transposition of teeth may occur both in the maxillary and mandibular arches. but it appears more often in the maxilla of individual teeth, the maxillary canine is the most often involved. A canine transposes most often with a first premolar and less frequently transposes with a lateral incisor. Incomplete transposition is a condition describing an interchange in the position of the crowns of two permanent teeth, while the root apices remain in their relative position. Complete transposition is a situation in which both the crowns and entire root structure are transposed. The etiologic factors of transposition are tooth buds interchange, retained deciduous canines, migration of the erupting canine, trauma to deciduous teeth etc. This report describes a case of a transposition between a maxillary left canine and a lateral incisor and impaction of a maxillary left central incisor due to trauma to deciduous dentition.