• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.49 no.2
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• pp.86-90
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• 2023

Objectives: An ectopic tooth is a rare eruption of a tooth out of the normal dental apparatus and occurs commonly with the third molar. Thus, in this study, we reported a case series of ectopic teeth in rare jaw locations and highlight the associated pathology and our experience in the surgical management. Patients and Methods: All cases of ectopic tooth managed at the Department of Oral and Maxillofacial Surgery, University of Maiduguri Teaching Hospital from January 2011 to December 2020 were reviewed. The information retrieved includes biodata, location of the ectopic tooth, signs, symptoms, type of tooth and associated pathology, surgical approach and complications. Results: Ten cases of ectopic teeth were identified over the study period. This comprised 80.0% males with a mean age was 23.3 years. The antrum and lower border of the mandible accounted for 50.0% and 40.0% of the ectopic locations, respectively. Dentigerous cyst was the most associated pathology (70%) and usually presented with pain and swelling. Surgical intervention predominantly via the intraoral route was performed if indicated. Conclusion: Ectopic teeth are rare and not always associated with pathology. A high index of suspicion and radiological investigation are necessary for diagnosis. A more extensive multi-center study is however recommended to determine the prevalence of ectopic teeth other than the third molar.

• Restorative Dentistry and Endodontics
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• v.48 no.4
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• pp.38.1-38.10
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• 2023

Objectives: The aim of this study was to examine the use of hand or rotary files by pre-graduation (fourth- and fifth-year) and postgraduate students in endodontic treatments and to determine the incidence of file fracture and the management of cases with broken instruments. Materials and Methods: A total of 2,168 teeth undergoing primary endodontic treatment were included in this study. It was determined that 79 of these teeth resulted in broken tools. In the case of broken tools, the education level of the treating clinician, the tooth that was being treated, the canal and fracture level, the curvature of the tooth and the management of the broken instrument were recorded. Periapical radiographs of the patients were used to calculate curvature following the Schneider method. Results: There was no significant difference in the incidence of broken tools according to education level (p > 0.05). The incidence of file fracture in molar teeth (73.4%) was higher than in other teeth (p < 0.05). More files were broken in the mandibular molar MB canal (20.25%) and in the apical third of the canals (72.1%). The risk of instrument fracture was high in teeth with moderate (44.3%) and severe (38%) curvature canals. The management of apically broken (80%) files mostly involved lefting (p < 0.05). Conclusions: There was no statistically significant difference between fourth-year students, fifth-year students and postgraduate students in terms of instrument fracture.

• The Journal of the Korean dental association
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• v.13 no.6
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• pp.563-567
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• 1975

This present investigation was concerned with the content of collagen and minerals of incisor and molar dentin in rats of differednt ages. The results obtained were summarized as follows. 1. There was no remarked change in the content of collagen-hydroxyproline of incisor and molar dentin according to days after delivery. 2. The Ca content in incisor dentin rose from approximately 15.4% of the dry weight in 7 days after delivery to 21.1% in 22 days while that in molar dentin from 17.6% in 7 days to 19.7% in 22 days. 3. The P content in molar dentin rose from 8.5% in 7 days after delivery to 11.65% in 22 days. while in incisor rose from 8.05% in 7 days to 11.85 in 22 day after delivery.

• The Journal of the Korean dental association
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• v.57 no.8
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• pp.474-479
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• 2019

The purpose of the pulp treatment is to make the function of the primary molar in the oral cavity possible for as long as possible until the exfoliation of the tooth or the development of the occlusion is as long as possible. The pulpectomy is a relatively common procedure for the pediatric dentist in the clinic with dental care of the children nowadays. Primary molar is morphologically more susceptible to dental caries than permanent tooth, and the dental pulp treatment is frequently performed. Furthermore, unlike permanent teeth, the root canal has a large degree of curvature and morphological diversity and complexity, careful consideration is needed. Therefore, it is very important to comprehensively understand the morphological characteristics and diversity of the root and root canals for the successful pulp treatment of the primary molars.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.1
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• pp.119-125
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• 2005

In the primary dentitions, the majority of dental injuries involve the anterior teeth, especially the maxillary primary central incisors. When injuries affecting primary and permanent teeth are compared, it appears that trauma to the primary dentition is usually confined to the supporting structures, i.e. luxation and exarticulation, while the largest proportion of injuries affecting the permanent dentition is represented by crown fractures. But, cases reporting trauma affecting primary molars are unusual in the literature and several reports describe fractures of posterior teeth. The main goal of this report is to describe the repositioning treatment using removable appliances to an uncommon case of lingual displacement of primary molar that happened to a 4 year 5 month-old female child.

• The Korean Journal of Health Service Management
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• v.4 no.2
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• pp.63-72
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• 2010

The present study purposed to prevent oral diseases and to improve oral health in children. For this purpose, we selected 70 cases who are 5~7 years old preschoolers at the kindergarten affiliated to G College in Gyeongsangbukdo, and analyzed the general patterns of oral care and the relation of the patterns with dental plaque and deciduous dental caries in the children. Specifically, we conducted oral examination and applied pit and fissure sealant according to the eruption of deciduous molar and first molar. In addition, we executed the 1st and 2nd tooth brushing instruction (TBI), and surveyed S-OHI and PHP twice. Excluding 14 preschoolers who did not appear in the 2nd survey, we performed the study with 56 preschoolers and drew conclusions as follows. 1. The number of decayed or missed or filled teeth among deciduous teeth was 3 or more in 42.9% of female children, and 46.4% of male children, so male children showed a slightly higher rate. 2. The degree of dental plaque formation was $1.64{\pm}1.22$ among the surveyed children. 3. The oral health index was lower after TBI than before in all the children (P<.001). 4. Change in the oral health index was particularly larger in 7 year old female children (p<.005). 5. The patient hygiene performance index was lower after TBI than before in both the buccal surface and lingual surface of the children (p<.005). 6. The patient hygiene performance index was lower after TBI than before in all of male children's teeth except the right maxillary first deciduous molar (p<.001).

• The korean journal of orthodontics
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• v.46 no.5
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• pp.280-289
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• 2016

Objective: The aim of this study was to analyze tooth movement and arch width changes in maxillary dentition following nonextraction treatment with orthodontic mini-implant (OMI) anchorage in Class II division 1 malocclusions. Methods: Seventeen adult patients diagnosed with Angle's Class II division 1 malocclusion were treated by nonextraction with OMIs as anchorage for distalization of whole maxillary dentition. Three-dimensional virtual maxillary models were superimposed with the best-fit method at the pretreatment and post-treatment stages. Linear, angular, and arch width variables were measured using Rapidform 2006 software, and analyzed by the paired t -test. Results: All maxillary teeth showed statistically significant movement posteriorly (p < 0.05). There were no significant changes in the vertical position of the maxillary teeth, except that the second molars were extruded (0.86 mm, p < 0.01). The maxillary first and second molars were rotated distal-in ($4.5^{\circ}$, p < 0.001; $3.0^{\circ}$, p < 0.05, respectively). The intersecond molar width increased slightly (0.1 mm, p > 0.05) and the intercanine, interfirst premolar, intersecond premolar, and interfirst molar widths increased significantly (2.2 mm, p < 0.01; 2.2 mm, p < 0.05; 1.9 mm, p < 0.01; 2.0 mm, p < 0.01; respectively). Conclusions: Nonextraction treatment with OMI anchorage for Class II division 1 malocclusions could retract the whole maxillary dentition to achieve a Class I canine and molar relationship without a change in the vertical position of the teeth; however, the second molars were significantly extruded. Simultaneously, the maxillary arch was shown to be expanded with distal-in rotation of the molars.

• Journal of Dental Rehabilitation and Applied Science
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• v.22 no.2
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• pp.173-180
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• 2006

Objectives The aim of this study is to compare the quality of root canal preparation completed using MFile-$System^{(R)}$ instrument ( Komet, Gebr.Brsaseler, Germany) and conventional stainless steel file in the canals of Maxillary molar teeth that had a canal curvature between $25^{\circ}$ or more Materials & Methods Buccal canals of 24 first and second maxillary molar teeth, extracted for periodontal and prosthetic reasons were used. Tissue fragments and calcified debris were removed from teeth by scaling and the teeth were stored in 10% formalin solution for 24 hour. Then, teeth were stored in saline until used. To be included the roots had to have completed formed apices and angle of curvature ranging between $25^{\circ}$ or more according to the criteria described by Schneider(1971). Palatal and Second mesiobuccal canals were not included. Teeth were embedded into transparent acrylic. The teeth were randomly divided into two experimental groups. All teeth were scanned by Dental CT (PSR9000N, Asahi, Japan) to determine the root canal shape before instrumentation. Image slices were prepared from the apical end point to the pulp chamber. The first two sections were 2 mm from the apical end of root and 2 mm below the orifice. Further section was recorded, dividing the distance between the sections of apical and coronal levels into two equal lengths. 12 teeth were instrumented using stainless steel fileand another 12 teeth were instrumented using MFile-$System^{(R)}$. Following the completion of the instrumentation, the teeth were again scanned and compared with the cross sectional images taken prior to canal preparation. Amount of transportation and centering ability was assessed. Student's t-test was used for statistical analysis. Result Less transportation occurred with MFile-$System^{(R)}$ rotary instrumentation than stainless steel instrument. MFile-$System^{(R)}$ had better centering ability than stainless steel instrument. Conclusion MFile-$System^{(R)}$ rotary instrumentation transported canals less and had good centering ability.

• The Journal of the Korean dental association
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• v.10 no.11
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• pp.731-733
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• 1972

Occurence of different forms of Carabelli's cusp on the maxillary first permanent molar was studied in 282 Korean children. The results were as follows; 1. The Carabelli's cusp was absent in 36.2% of the teeth studied. 2. The percentages of various form appeared Carabelli's tubercle were as follows; a. Pronounced tubercle............9.9% b. Slight tubercle............24.5% c. Groove............25.5% d. Pit............3.9%

• The Journal of the Korean dental association
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• v.13 no.4
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• pp.329-334
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• 1975

In 190 dental casts of Korean adults, 78 males and 112 females, the author measured cuspal distances beween the lingual cusps of the samed named teeth. And following conclusions were obtained : 1. In maxillary dental arch, the smallest measurement was revealed in the interpremolar distance in both sexes. 2. In mandibular dental arch, the intercanine distance was the smallest, and then measurements were increased in molar region. 3. In both sexes the intermolar distance was smaller than the central incisor to first molar distance.