• 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.

• Journal of Periodontal and Implant Science
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• v.34 no.3
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• pp.523-533
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• 2004

The purpose of this study was to evaluate the alveolar bone surface following root separation angle in the mandibular second molars. The fifty mandibular second molars(which were extracted) were selected, and the alveolar bone surface following root separation angle of the selected teeth were evaluated. The results were obtained as follows; 1. The root separation angle of fifty mandibular second molars were divided into three groups. The first $group(10-20^{\circ})$ was made up of ten teeth, the second $group(20-30^{\circ})$ was made up of fifteen teeth, and the third group(30-40$^{\circ}$) was made up of twenty-five teeth. 2. The mean root separation angle was $28.1^{\circ}$. The mean alveolar bone rate on the mesial surface of the mesial root was 44.27%, on the distal surface of the mesial root was 36.52%, on the mesial surface of the distal root was 33.45%, and on the distal surface of the distal root was 25.28%. 3. The mean alveolar bone rate on the distal surface of the mesial root, which composed the root separation area, was 32.95% in the first group, 36.06% in the second group, and 38.22% in the third group. The mean alveolar bone rate in the mesial surface of the distal root was 31.40% in the first group, 31.93% in the second group, and 35.18% in the third group. 4. The positive correlation was found between the root separation angle and the alveolar bone rate in the root separation area.(P<0.05) Although the mandibular second molar is a very important tooth in the oral cavity, its treatment and diagnosis is very difficult due to the variation of its root form. When periodontal disease involves the mandibular second molar, the result of this study assists in its treatment and diagnosis.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.29 no.3
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• pp.250-254
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• 2007

Dentigerous cysts are the most common type of developmental odontogenic cysts. They form as a result of a separation of the follicle from around the crown of an unerupted tooth. Usually this lesion can be asymptomatic. Such cysts are often discovered accidently on inspection of x-rays. In other advanced cases, cortical bone expansion, displacement of teeth, secondary infection can be observed. The treatment of dentigerous cyst is enucleation. And according to size, location of lesion and environmental structure marsupialization can be considered. However, Marsupialization takes long treatment time and, cystic tissues are remained so secondary surgery may be needed for total removal., Risks of oroantral fistula, damage on maxillary sinus wall and infraorbital nerve can be considered as complications of conventional surgical treatment of cysts located in maxillary sinus. We treated third molar origin dentogerous cyst located in maxillary sinus removing endoscopically both the tooth and an associated dentigerous cyst. We report our clinical experience with literature review.

• Imaging Science in Dentistry
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• v.42 no.4
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• pp.255-260
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• 2012

Dentigerous cysts are the most common developmental cysts of the jaws, most frequently associated with impacted mandibular third molar teeth. Dentigerous cysts around supernumerary teeth, however, account for 5% of all dentigerous cysts, with most developing around a mesiodens in the anterior maxilla. This report describes two cases of a dentigerous cyst associated with an impacted mesiodens. Both of the patients complained of swelling in the maxillary anterior region. Radiographic examination revealed an impacted mesiodens surrounded by a large corticated radiolucency in both cases. A provisional diagnosis of infected odontogenic cyst was made. The cysts were enucleated with the removal of the mesiodens in the two cases. Histopathological examination confirmed the diagnosis of infected dentigerous cyst associated with an impacted mesiodens in both cases. The patients remained asymptomatic, and no complications were noted.

• Journal of Periodontal and Implant Science
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• v.38 no.4
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• pp.709-716
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• 2008

Purpose: Autogenous transplantation of teeth can be defined as transplantation of teeth from one site to another in the same individual, involving transfer of impacted or erupted teeth into extraction sites or surgically prepared sockets". Successful autogenous transplantation of teeth depends upon a complex variety of factors. Such factors include damage to the periodontal ligament of the donor tooth, residual bone height of the recipient site, extra-oral time of tooth during surgery. Schwartz and Andreasen previously reported that autogenous transplantation of teeth with incomplete root formation demonstrated higher success rate than that of teeth with complete root formation. Gault and Mejare yielded similar rate of successful autogenous transplantation both in teeth with complete root formation and in teeth with incomplete root formation when appropriate cases were selected. This case report was aimed at the clinical and radiographic view in autogenous transplantation of teeth with complete root formation. Materials and Methods: Patients who presented to the department of periodontics, Chonnam National University Hospital underwent autogenous transplantation of teeth. One patient had vertical root fracture in a upper right second molar and upper left third molar was transplanted. And another patient who needed orthodontic treatment had residual root due to caries on upper right first premolar. Upper right premolar was extracted and lower right second premolar was transplanted. Six months later, orthodontic force was applied. Results: 7 months or 11/2 year later, each patient had clinically shallow pocket depth and normal tooth mobility. Root resorption and bone loss were not observed in radiograph and function was maintained successfully. Conclusion: Autogenous transplantation is considered as a predictive procedure when it is performed for the appropriate indication and when maintenance is achieved through regular radiographic taking and follow-up.

• Imaging Science in Dentistry
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• v.51 no.1
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• pp.9-16
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• 2021

Purpose: The purpose of this study was to analyze the reliability of 7 panoramic radiographic signs for predicting proximity of the root apices of mandibular third molars to the mandibular canal using cone-beam computed tomography and to correlate these findings with the Pell and Gregory and the Winter classification systems. Materials and Methods: An observational, cross-sectional, descriptive study was conducted on 74 patients with bilateral impacted mandibular third molars. Four panoramic radiographic signs were observed in the tooth root (darkening, deflection, and narrowing of the root apices, and bifid apices), and another 3 in the mandibular canal (diversion, narrowing, and interruption of the mandibular canal). Cone-beam computed tomography images were analyzed to identify disruption and diversion of the mandibular canal and root deflection. Results: Binary logistic regression showed that only 4 of the 7 panoramic radiographic signs were able to predict proximity of the root apices of the mandibular third molars to the mandibular canal: darkening of the root, deflection of the root, narrowing of the root, and interruption of the mandibular canal(P<0.05). Conclusion: Darkening, deflection, and narrowing of the root, in tandem with the interruption of the mandibular canal on panoramic radiographs, indicate that cone-beam computed tomography should be performed when planning the extraction of impacted mandibular third molars. Proximity between mandibular third molars and the mandibular canal is correlated with the Winter classification.

• Journal of Food Hygiene and Safety
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• v.12 no.2
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• pp.102-106
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• 1997

The purpose of this study was to evaluate the bioflavonoids naringin on dental caries and periondontal disease in the albinorat. Twenty-five-day-old-male rats were fed the experimental diets for 42 days in this work at the end of the 42-day experimental period. The tooth surfaces were examined under a dissecting microscope. The sulcular caries lesions were recorded : the first molars were more affected than the second and third molars. Alveolar bone loss was measured on the buccal and lingual aspects of each molar: three site measurements (mesialpoint midpoint and distalpoint) were taken on the first molars. The results showed that the bioflavonoids, naringin had beneficial effects in the prevention of periodontal disease.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.15 no.1
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• pp.21-26
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• 1985

The author observed 97 cases ameloblastoma diagnosed in Department of Oral Radiology in Seoul National University and analyzed patient's age, sex, location, relation with adjacent anatomic structures, and radiographic forms. The obtained results are as follows: 1. The average age of patients was 28.7 years. The mean age of male was 28.5 years, and female's 30.0 years. Third decades revealed highest rate. 2. The occurrence of ameloblastoma is approximately evenly distributed in both sexes, male 46 cases (47.2%), female 51 cases (52.6%). 3. Ninty-five (98.0%) cases occurred in the mandible. The mandibular molar-ramus region was the most frequent site of the tumor (74 cases, 76.3%). 4. Most of the cases affected adjacent anatomic structures. 24 cases (24.7%) were shown to be definitely associated with an impacted tooth. 5. Radiographic forms are unilocular (29 cases, 29.3%), honeycomb (17 cases, 17.5%), and multilocular (67 cases, 69.1%) radiolucencies.

• Journal of Korean Dental Science
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• v.7 no.1
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• pp.43-47
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• 2014

Few dental procedures are potentially life-threatening. Note, however, that a dental extraction can result in preventable death. Severe post-extraction bleeding can occur, which may give rise to an alarming situation if there is any delay in detecting and managing the problem. The most immediate danger for a healthy patient with severe post-extraction hemorrhage is airway compromise. Acute airway obstruction from post-extraction hematoma is relatively uncommon, but it may occur with fatal consequences if there is any reluctance to maintain the airway clearance. Therefore, dentists and oral and maxillofacial surgeons should have clear understanding of the problem and measures to control it. Active bleeding that is not controlled by local measures in a dental office should be referred to the nearest hospital emergency department as soon as possible for appropriate management.

• Imaging Science in Dentistry
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• v.52 no.1
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• pp.19-25
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• 2022

Purpose: This study evaluated the distance from the posterior root apices to the maxillary sinus floor (MSF) and the frequency of roots touching or protruding through the MSF using cone-beam computed tomography (CBCT). Materials and Methods: This study included 100 subjects divided into different vertical and anteroposterior skeletal growth patterns. On CBCT images, the distance from the posterior root apices to MSF was measured and the frequency of roots touching or protruding through the MSF was evaluated using NNT software (version 5.3.0.0; ImageWorks, Elmsford, NY, USA). Results: No statistically significant differences were found in the distance from the posterior root apices to the MSF among vertical skeletal groups (P>0.05). The palatal roots of the first molar and the palatal, mesio-buccal and disto-buccal roots of the second molars had significantly less distance from MSF in skeletal class II than in class III (P<0.05). The high-angle group had the highest frequencies of roots touching or protruding into the maxillary sinus (49.8%); the lowest proportion of these roots was found in skeletal class III (28.3%) and the highest proportion in class II (50.3%). Males had shorter distances from the posterior root apices to the MSF and higher frequencies of roots protruding through or touching the MSF than females. Conclusion: Anteroposterior skeletal growth patterns and sex affected the distances from the maxillary posterior roots to the MSF. The frequency of roots protruding into or touching the sinus was affected by both vertical and anteroposterior skeletal groups and sex. These findings have implications for dental practice.