• The Journal of Korean Academy of Prosthodontics
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• 제42권5호
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• pp.524-534
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• 2004

Statement of problem: The meaning of the beauty has a little different nature according to a time, culture, and nation. Purpose : This study was undertaken to estimate the geometric esthetic criteria for Korean woman by analysis of facial photograph in a smiling. Material and methods: The facial photographs of 678 Korean beautiful woman were collected from Miss Korea candidates(from 1971 to 2003 year). The dento-facial composition was measured and analyzed geometrically on computer monitor using $Adobe^{(R)}$ $Photoshop^{(R)}$ 7.0. The statistical significance of the differences among the 4 decade groups was estimated by a $x^2$ test. Result : The Korean beautiful woman skewed the geometric characteristics such as the 'coincidence' (83.0%) between facial midline and dental midline, the 'normal' (96.9%) alignment and arrangement of upper anterior teeth. the 'average' (79.1%) position and 'upward' (53.4%) curvature of upper lip, the 'parallel' (85.7%) relationship between the lower lip and upper anterior incisal curvature, the 'touching' (49.9%) and 'not-touching' (44.8%) relationship between upper anterior incisor and towel lip, the 'first premolar' (54.1%) and 'second premolar' (38.9%) displayed in a smile, and the 'symmetry' (89.4%) of smile. There was statistical significance among the 4 decades in the respect of the upper lip curvature, the relationship between upper anterior incisor and lower lip, and the most posterior teeth displayed in a smile (p<0.05). Conclusion : The Korean beautiful woman showed similar results to the western esthetic criteria in the some respects and the tendency that the Korean woman had more active smiling recently.

• Imaging Science in Dentistry
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• 제50권4호
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• pp.281-290
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• 2020

Purpose: The objective of the present study was to evaluate the prevalence of dental implants positioning errors and their associations with adjacent structures and anatomical variations by means of cone-beam computed tomography (CBCT). Materials and Methods: CBCT images of 207 patients (584 dental implants) were evaluated by 2 oral radiologists. The distance between the implant and the adjacent teeth/implants was measured and classified as adequate (≥1.5 mm and ≥3 mm, respectively) or inadequate. The presence of thread exposure, cortical perforation, implant dehiscence, implant penetration into adjacent structures, and anatomical variations was also recorded. The incisor canal diameter and the depth of the concavity of the submandibular fossa were measured in order to evaluate their correlations with the frequency of implant penetration in these structures. Descriptive analyses, the Fisher exact test, and Spearman correlation analysis were performed (α=0.05). Results: The overall prevalence of positioning errors was 82.9%. The most common error was the inadequate distance between the implant and the adjacent teeth/implants. The presence of anatomical variations did not significantly influence the overall prevalence of errors (P>0.05). There was a positive correlation between the diameter of the incisor canal and the frequency of implant penetration in this structure (r=0.232, P<0.05). Conclusion: There was a high prevalence of dental implant positioning errors, and positioning errors were not associated with the presence of anatomical variations. Professionals should be aware of the space available for implant placement during the preoperative planning stage.

• Journal of the korean academy of Pediatric Dentistry
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• 제28권1호
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• pp.175-179
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• 2001

Regional odontodysplasia is a relatively rare condition in which both enamel and dentin are hypoplastic and hypocalcified. The result is localized arrest in tooth development. The etiology of regional odontodysplasia is uncertain, but, disturbance in vascular supply, somatic mutation, latent virus infection, trauma, hyperpyrexia, irradiation, nutrition, metabolic disorders and hereditary transmission are supported to be etiologic factors. Females are more often affected than males. (1.4 : 1). The maxillary arch is more often affected than the mandibular arch with the maxillary left quadrant being the most commonly involved. Affected teeth are hypoplastic, typically discolored yellow or yellowish brown, smaller in size and display a variety of surface marking including pitting and grooving. Radiographically, the teeth affected have been described to have a "ghost like" appearance or "fuzzy" appearance. Pulp calcification and denticles may be present within the pulp chambers of the affected teeth. In it's case, a 2 years old male visited for a treatment of uneruption of lower right teeth. Partial eruption of lower right deciduous central incisor and unerupted deciduous lateral incisor, deciduous canine and deciduous first molar showed severly delayed eruption state. On radiographic appearance, "Ghost like appearance", shortened root and opened apexes on lower right region were observed. It was suspected regional odontodysplasia with clinical and radiographic condition.

• The Journal of Korean Academy of Prosthodontics
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• 제38권4호
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• pp.552-560
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• 2000

Purpose : The purpose of this study was to determine proper position and angulation of an implant for immediate implantation. Materials and Method : From the years 1997 to 2000. 52 Denta $scan^R$ views, 22 upper and 32 lower jaw with an average age of 43 and 40 respectively, were investigated, which comprise intact upper and lower 6 anterior teeth and premolars. On the Denta $scan^R$, the optimal placement for the immediated implantation was simulated. The measuring methods included 1) Angulation difference between tooth long axis and alveolar bone process. 2) Angulation difference of long axis between tooth and installing fixture 3) Distance between center of tooth at cervical area and center of fixture. 4) Distance from root apex to the bone limit of vital structure. One sample t-test was used for statistical analysis. Result : The results were as follows. 1) At the maxillary central incisor and lateral incisor, angulation difference of long axis between tooth and installing fixture was respectively 0.5 and 3.2 degrees with the fixture center's palatally positioned 2mm apart from tooth center. 2) At the lower anterior 6 teeth, that was about $-2.8^{\circ}\;to\;-4.6^{\circ}$ with the fixture center's lingually positioned 1mm apart from tooth center. 3) At the maxillary canine and premolar, that was respectively $11.8^{\circ}\;and \;7.2^{\circ}$ with the fixture center palatally positioned $2\sim2.4mm$ apart from tooth center. 4) At the lower premolar area, that was about $0^{\circ}\;to\;2^{\circ}$ with the fixture center's lingually positioned $0.5{\sim}1mm$ apart from tooth center. 5) Distance from root apex to the bone limit of vital structure, at the maxillary anterior and premolars. was the range of 10 to 12mm, and at the mandibular anterior teeth and the 1st premolar, that was the range of 18 to 20mm. Conclusion : The proper implant position of maxillary anterior and premolar teeth is as paralleled as or more buccally angulated than long axis of tooth with the fixture center's palatally positioned. In mandiblular anterior region, long axis of implants is lingully angulated compared with long axis of tooth and in premolar, almost parelleled with long axis of tooth and alveolar process.

• The korean journal of orthodontics
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• 제31권2호통권85호
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• pp.209-223
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• 2001

At intrusion of upper anterior teeth in patient with periodontal defect, the use of three-piece base arch appliance for pure intrusion is required. To investigate the change of the center of resistance and of the distal traction force according to alveolar bone height at intrusion of upper anterior teeth using this appliance, three-dimensional finite element models of upper six anterior teeth, periodontal ligament and alveolar bone were constructed. At intrusion of upper anterior teeth by three-piece base arch appliance, the following conclusions were drawn to the locations of the center of resistance according to the number of teeth, the change of distal traction force for pure intrusion and the correlation to the change of vertical, horizontal location of the center of resistance according to alveolar bone loss. 1. When the axial inclination and alveolar bone height were normal, the anteroposterior locations of center of resistance of upper anterior teeth according to the number of teeth contained were as follows : 1) In 2 anterior teeth group, the center of located in the mesial 1/3 area of lateral incisor bracket. 2) In 4 anterior teeth group. the center of resistance was located in the distal 2/3 of the distance between the bracket of lateral incisor and canine. 3) In 6 anterior teeth group, the center of resistance was located in the central area of first premolar bracket .4) As the number of teeth contained in anterior teeth group increased, the center of resistance shifted to the distal side. 2. When the alveolar bone height was normal, the anteroposterior position of the point of application of the intrusive force was the same position or a bit forward position of the center of resistance at application of distal traction force for pure intrusion. 3. When intrusion force and the point of application of the intrusive force were fixed, the changes of distal traction force for pure intrusion according to alveolar bon loss were as follows :1) Regardless of the alveolar bone loss, the distal traction force of 2, 4 anterior teeth groups were lower than that of 6 anterior teeth group. 2) As the alveolar bone loss increased, the distal traction forces of each teeth group were increased. 4. The correlations of the vertical, horizontal locations of the center of resistance according to maxillary anterior teeth groups and the alveolar bone height were as follows : 1) In 2 anterior teeth group, the horizontal position displacement to the vortical position displacement of the center of resistance according to the alveolar bone loss was the largest. As the number of teeth increased, the horizontal position displacement to the vertical position displacement of the center of resistance according to the alveolar bone loss showed a tendency to decrease. 2) As the alveolar bone loss increased, the horizontal position displacement to the vertical position displacement of the center of resistance regardless of the number of teeth was increased.

• The Journal of Korean Academy of Prosthodontics
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• 제54권3호
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• pp.291-297
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• 2016

Patients with $Sj{\ddot{o}}gren^{\prime}s$ syndrome usually suffer from teeth discoloration and attrition due to xerostomia. If the anterior teeth are badly worn, problems such as loss of anterior guidance, occlusal disharmony, and limited space for restoration may occur. However, ideal occlusion is obtained in both centric and eccentric relation by regaining the disocclusion of the posterior teeth through the anterior and lateral guidance using twin-stage method. In this case, rehabilitation was performed for a $Sj{\ddot{o}}gren^{\prime}s$ syndrome patient with maxillary and mandibular incisor's severe attrition and teeth discoloration by using twin-stage method.

• Journal of the korean academy of Pediatric Dentistry
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• 제51권2호
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• pp.176-184
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• 2024

This study aimed to compare color matching between single-shade composite resin-restored teeth with various pulp capping materials and the dentin surrounding the restoration through instrumental analysis and visual evaluation of the color difference. Fifty maxillary right central incisor acrylic resin teeth were prepared with standardized Class III cavities on the proximal surfaces. These teeth were divided into five groups: restored with single-shade composite resin only; Ultra-Blend^TM plus followed by single-shade composite resin; TheraCal PT^TM followed by single-shade composite resin; Endocem^® MTA premixed followed by single-shade composite resin; and Well-root PT^TM followed by single-shade composite resin. The color difference (ΔE_ab^*) between the restored area and the center of the resin teeth was measured using a spectrophotometer. No significant color difference was observed in groups restored with only single-shade composite resin, Ultra-Blend^TM plus, and TheraCal PT^TM. The visual evaluation revealed that Ultra-Blend^TM plus exhibited the best color matching score, whereas the Endocem^® MTA premixed and Well-root PT^TM groups showed significantly lower color matching scores than the single-shade composite resin-only group. When opting for single-shade composite resin usage for anterior tooth restorations with the aim of reducing chair time, pulp capping materials Ultra-Blend^TM plus and TheraCal PT^TM provide esthetically pleasing results.

• Journal of the korean academy of Pediatric Dentistry
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• 제35권2호
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• pp.333-338
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• 2008

Supernumerary teeth are characterized by an excess number of teeth, which can be responsible for a variety of irregularities in the primary and transitional dentition. Supernumerary teeth, especially in the maxillary anterior region, may prevent the eruption of adjacent permanent teeth and cause their ectopic eruption, diastema, root resorption, or formation of dentigerous cyst. Therefore, early diagnosis of supernumerary teeth is important for prevention of such complications, and adequate treatment should be given according to their location, number, and morphologic features. In this case, four supernumerary teeth in the maxillary anterior region were disturbing the eruption of adjacent permanent incisors. Two of them were located in proximity to the central incisor tooth germs that their immediate removal may injure the permanent tooth germs. In order to minimize such complications, surgical extraction of the four supernumerary teeth was performed in two stages. At first, only two inverted conical supernumerary teeth were extracted. The other two tuberculous supernumerary teeth, close to the permanent tooth germs, were extracted later after their natural dislocation. In that way, we could minimize affects on the neighboring permanent tooth germs and also the amount of alveolar bone removed during surgery.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• 제3권1호
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• pp.7-18
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• 1973

The authors have taken the x-ray films of carpal bone and orthopantomographs in Korean children to research the degree of ossification of carpal bone, that of calcification of tooth in jaw bone, the eruption rate of tooth, and the completion rate of apical foramen, and have compared the bone age and tooth age. We have gained a series of intersting conclusions to dare to report. 1. The ossification of carpal bone and the growth of tooth had processed proportionally to each other. 2. Both the bone age and tooth age were earlier in the female than in the male. 3. The completion of tooth crown formation and that of tooth root formation had processed proportionally to each other, and the general tendency of process was the earliest in the mandibular first molar and the latest in the second molar. 4. The eruption of tooth was the earliest in the mandibular first molar. The other teeth had erupted in the following orders: the central incisor, the lateral incisor, the first premolar, the second premolar, the canine and the second molar.

• Journal of the korean academy of Pediatric Dentistry
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• 제21권2호
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• pp.510-517
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• 1994

It is a relatively common clinical experience to see a impacted maxillary central incisor. This is apparent at the dental age of about eight years and over, when the patient is in the early mixed dentition stage. The adjacent teeth may tilt toward the site of the missing tooth with resulting space closure and midline deviation. Most often, the central incisor is impacted labially. The labial impaction has been indicated as the most difficult to manage. Each of the current articles describing labial impactions shows at least one case with mucogingival recession or a minimal zone of attached gingiva. This report described the surgical uncovering and orthodontic-physiologic positioning methods with labially impacted maxillary central incisors. Through surgical exposure and direct bonding of lingual botton, the central incisors were brought into proper eruption path with elastic traction. The case 1 and 2 were treated with the physiologic erupting forces. The case 3 was applied with continuous orthodontic force. The case 1 and 2 resulted in good positioning, good esthetics and adequate width of keratinised gingiva. The case 3 resulted in local inflammation and inadequate width of keratinised gingiva.