• The Korean Journal of Oral and Maxillofacial Pathology
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• 제42권6호
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• pp.183-187
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• 2018

The supernumerary tooth which is extra tooth in comparison to normal dentition is one of the developmental problems. The most common type of supernumerary tooth is mesiodens which may cause several complications like delayed eruption, crowding, spacing et al. Moral Incisor Hypomineralization (MIH) describes the clinical appearance of enamel hypomineralization of systemic origin affecting one or more permanent first molars that associated frequently with affected incisors. We report a case of a 6 - year - old boy who visited our clinic for removal of mesiodentes. The patient was diagnosed by mesiodentes and MIH by clinical examination and radiographic examination. Under local anesthesia, Mesiodentes were removed surgically. The demarcated opacities, a feature of MIH, were observed in the removed mesiodentes. After removal of mesiodentes, the maxillary central incisors erupted normally and in order to manage the teeth affected MIH, follow-up and fluoride varnish application were done every 3 months.

• The korean journal of orthodontics
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• 제29권5호
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• pp.563-573
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• 1999

The purpose of this study was to evaluate the availability of computer system for the measurement of tooth size in the model analysis through the comparison of two measurements: One was to use a computer; and the other was to use vernier calipers. Twenty sets of casts were used, which showed a moderate degree of crowding and full eruption of all teeth. The mesio-distal width of 12 teeth from the left central incisor to the left first molar at each set of the casts were measured twice with vernier calipers and a computer respectively. This measurement was repeated two weeks later. First, for the reproducibility analysis, the two computer measurements were compared then the vernier calipers measurements were compared. Second, all the teeth were sepapated into the region of mesiodistal contact points and its width was measured by a micrometer to obtain standard measurements. For the accuracy analysis, these standard measurements were compared with the measurements from the dental casts using two methods. The difference between them was defined as the measurement error. To investigate the cause of measurement error, an examination was made for the presence and degree of contact point deviation on each tooth from the upper and lower occlusograms, and the mesio-distal angulation of each tooth was measured with TARG. Following results were obtained through statistical analysis. 1. In the analysis for reproducibility; the measurements with vernier calipers showed significant differences in three out of twelve teeth while the computer measurements showed significant differences in one out of twelve teeth. 2. In the analysis for accuracy; compared with the standard measurements, the measurements with vernier calipers showed significant differences in three out of twelve teeth while the computer measurements showed significant differences in two out of twelve teeth. 3. Compared with the standard measurements, the measurements with vernier calipers were apt to be larger at the upper first molar, and smaller at the lower first molar The computer measurements, however, were apt to be larger at both upper and lower first molars. 4. The measurements with vernier calipers showed the largest error at the lower first molar and the degree of error was variable according to the tooth while the difference of error was small in the computer measurements. 5. In the analysis for the correlation of the degree of measurement errors with the contact point deviation index and the mesio-distal crown angulation of each tooth, the measurements with vernier calipers did not show significant correlation while the measurements with computer showed slight Positive correlations. The results of this study indicate that a computer system may be useful for the measurement of tooth size in the model analysis.

• Journal of the korean academy of Pediatric Dentistry
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• 제38권4호
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• pp.337-347
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• 2011

The basic structure of the primary crowns usually resemble their succeeding permanent teeth. However, maxillary second primary molars resemble ipsilateral first permanent molars. Accordingly in this study, odontometric data of the two teeth was obtained, then analyzed to verify the morphological relationship and sex difference between the two teeth. Dental study casts were examined for their mesiodistal and buccolingual width of the crowns, diameter of each cusps, and intercuspal distances. Photographs of the crowns were taken to measure the angles between each cusp tip. The results are as follows : 1. In boys, PrI, PaI, DBC angle, and MBC angle did not show any statistically significant difference between the two teeth(p>0.05), and moderate level of correlations were observed. 2. In girls, crown index, DBC angle, and MBC angle of the two teeth did not show any statistically significant difference(p>0.05), and moderate level of correlations were recognized. 3. Measurements that did not show statistically significant difference between the two teeth in both boys and girls were DBC angle and MBC angle(p>0.05). In DLC angle, however, statistically significant difference was observed(p<0.01). 4. Most of the measurements showed sex differences, except DBC angle, which did not show any sex difference in both teeth(p>0.05).

• The korean journal of orthodontics
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• 제30권1호
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• pp.43-52
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• 2000

Hemifacial microsomia ( HFM ) is the second most common craniofacial abnormalies. HFM represnted a spectrum of clinical findings such as hypoplasia of the mandibular ramus and condyle, confinement of maxilla growth, external and/or middle ear defects, involvement of some cranial suture, buccal soft tissue, facial nerve, and muscles in the affected side. HFM often showed progressive facial asymmetry and occlusal plane slanting to the affected side with growth. There were several reports about asymmetry of tooth maturation, hypodontia, delayed eruption, enamel hypoplasia in HFM. Since teeth develope in close association with size and morphology of the maxillary and the mandible, it is highly likely that dental changes will be present in HFM. So the Purpose of this study was to investigate the differences of the primary and the permanent teeth dimensions in the maxillary and the mandibular dentition between the affected and the non-affected side of HFM.. The sample of this study consisted of 34 unilateral HFM Patients (18 males and 16 females, average age : 5 year 11 months old). The authors examined the mesiodistal and the faciolingual dimensions of the primary and the permanent teeth and performed statistical study by using paired t-test. The results were as follows 1. The mesiodistal dimensions of the mandibular second primary molar and the mandibular first permanent molar in the affected side of HFM were significantly smaller than those of non-affected side. But there were no significant differences in the anterior teeth and the mandibular first primary molar. It means that a gradient of severity from anterior teeth to posterior teeth was found in the mandibular dentition. 2. Although there were no significant differences in the faciolingual dimensions of the primary and the permanent teeth in the maxillary and the mandibular dentition between the affected and non-affected side of HFM, there were general trend of compensatory increase in faciolingual dimension of the mandibular primary and the permanent teeth in the affected side Therefore these results showed that HFM might affect on the abnormality of tooth dimension, especially the most posterior teeth, in the affected side of the mandible.

• The korean journal of orthodontics
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• 제45권5호
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• pp.217-225
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• 2015

Objective: Three-dimensional (3D) printing is a recent technological development that may play a significant role in orthodontic diagnosis and treatment. It can be used to fabricate skull models or study models, as well as to make replica teeth in autotransplantation or tooth impaction cases. The aim of this study was to evaluate the accuracy of fabrication of replica teeth made by two types of 3D printing technologies. Methods: Fifty extracted molar teeth were selected as samples. They were scanned to generate high-resolution 3D surface model stereolithography files. These files were converted into physical models using two types of 3D printing technologies: Fused deposition modeling (FDM) and PolyJet technology. All replica teeth were scanned and 3D images generated. Computer software compared the replica teeth to the original teeth with linear measurements, volumetric measurements, and mean deviation measurements with best-fit alignment. Paired t-tests were used to statistically analyze the measurements. Results: Most measurements of teeth formed using FDM tended to be slightly smaller, while those of the PolyJet replicas tended to be slightly larger, than those of the extracted teeth. Mean deviation measurements with best-fit alignment of FDM and PolyJet group were 0.047 mm and 0.038 mm, respectively. Although there were statistically significant differences, they were regarded as clinically insignificant. Conclusions: This study confirms that FDM and PolyJet technologies are accurate enough to be usable in orthodontic diagnosis and treatment.

• Journal of Periodontal and Implant Science
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• 제36권1호
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• pp.139-146
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• 2006

Many factors have been implicated in the etiology of gingival recession, including faulty toothbrushing, the position of the tooth in the arch(malalignment), the presence of inflammation, frenal attachment, impingement of restoration margins, orthodontic treatment and trauma from occlusion. Among the many factors, this study was to evaluate the relationship of occlusion and gingival recession. 640 teeth without other etiologic factors of gingival recession were evaluated in 40 subjects aged 21-59 years. Only 1st, 2nd premolar and molar were included in this study. We recorded nonworking contacts, working contacts, cervical abrasion, sex, gingival recession and evaluated that relation of occlusion and gingival recession. The results of this study were as follows; 1. Teeth with nonworking contacts were significantly more gingival recession than teeth without nonworking contacts.(p<0.01) 2. Teeth with working contacts were significantly more gingival recession than teeth without working contacts.(p<0.01) 3. Teeth with cervical lesion were significantly more gingival recession than teeth without cervical lesion.(p<0.01) 4. Men's teeth were more gingival recession than women's teeth but it was not significant.(p>0.01)

• Maxillofacial Plastic and Reconstructive Surgery
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• 제20권3호
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• pp.207-213
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• 1998

Purpose : This study attempted to relate the incidence of fractures at the mandibular angle with the presence and state of eruption of lower third molars, and to find out the real risk factors for angle fractures in the states of lower third molars. Materials and Methods : Medical records and radiographs of 395 patients with mandibular fractures were retrospectively reviewed. The presence and states of third molars were assessed for each patients and related to the occurrence of angle and other mandibular fractures. Results : Of 395 patients with mandibular fractures, 142 had angle fractures. The incidence of angle fractures was found to be significantly greater when partial erupted lower third molars were present and it had a definite role for risk factors for angle fractures. But there were no clear relationship between the incidence of angle fracrtures and states of without, fully erupted lower third molars. Furthermore, the states of patial and unerupted lower third molar had an effect on bony segment displacement. Conclusions : This study provides clinical evidence to suggest that patial erupted third molar teeth weaken the mandibular angle both quantitatively and qualitatively.

• 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.

• The korean journal of orthodontics
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• 제23권1호
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• pp.123-136
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• 1993

The purpose of this report is to present the successful improvement of occlusal relationship and facial esthetics in class II division 1 malocclusion with severe labioversion of upper anterior teeth and severe overjet, and in class II malocclusion with infraversion of bilateral maxillary canines by MEAW mechanics, which enables us to get effective distal on mass movement of maxillary dentition, with upper second molar extraction. After treatment, there were natural contact points at canine and premolar regions, normal occlusal relation-ship and treatment results, satisfied the gnathologic concept, in this 2 cases. Compared with the routine treatment with premolar extraction, the treatment time and patients' discomfort were reduced. And the MEAW mechanics, which enables us to get effective distal on mass movement of maxillary dentition, resulted in reduction of the treatment time and getting the good treatment results. Consequently, the majot concerns in orthodontic treatment are appropriate diagnosis and treatment plan, so, the application of second molar extraction with appropriate case analysis and diagnosis is very helpful to orthodontic treatment.

• The Journal of Korea Assosiation for Disability and Oral Health
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• 제12권2호
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• pp.45-49
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• 2016

This study investigates the success rate of pulpotomy using electrosurgery operated on a primary molar in caries. The pulpotomy using electrosurgery was done on 253 primary molars of 111 young patients from 2 to 9 years old during the period of the first day of January 2011 to the last day of December 2015. After the amputation of pulp and hemostasis of primary molar were done using electrosurgery, MTA as pulp capping material was applied to the primary molar and the tooth was restored with the stainless steel crown. The follow up period after the treatment ranged from 4-46 months. The clinical and radiographic success rate ranged from 92.1 - 94.3%. Which is comparable to formocresol and ferric sulfate pulpotomy. Due to its non-pharmacological characteristic, electrosurgery can minimize harmful effect on the pulp tissue. Its fast bleeding control makes it easy and safe to use in pediatric and disabled patients in comparatively simple manner. Electrosurgery can be an alternative for pulp therapy considering the side effects of pharmacological ways.