• Imaging Science in Dentistry
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• 제34권4호
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• pp.185-190
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• 2004

Purpose: To compare the diagnostic accuracy for the detection of root fractures in CMOS-based digital periapical images with conventional film-based periapical images. Materials and Methods: Sixty extracted single-root human teeth with closed apices were prepared endodontically and divided into two groups; artificially induced vertical root fracture group and control group. All radiographs were obtained using the paralleling technique. The radiographs were examined by 4 observers three times within a 4 week interval. Receiver operating characteristic (ROC) analysis was carried out using data obtained from four observers. Intra- and inter-examiner agreements were computed using kappa analysis. Results: The area under the ROC curve (Az) was used as an indicator of the diagnostic accuracy of the imaging system. Az values were as follows: direct-digital images; 0.93, film-based images; 0.92, and inverted digital images; 0.91. There was no significant difference between imaging modalities (P<0.05). The kappa value of inter-observer agreement was 0.42 (range: 0.28-0.60) and intra-observer agreement was 0.57 (range: 0.44-0.75). Conclusion : There is no statistical difference in diagnostic accuracy for the detection of vertical root fractures between digital periapical images and conventional periapical images. The results indicate that the CMOS sensor is a good image detector for the evaluation of vertical root fractures.

• Restorative Dentistry and Endodontics
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• 제47권4호
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• pp.39.1-39.12
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• 2022

Objectives: This study investigated the prevalence and characteristics of external cervical resorption (ECR) regarding sex, age, tooth, stages of progression, and portal of entry, using cone-beam computed tomography (CBCT) scans. Materials and Methods: CBCT scans of 1,313 patients from a Brazilian subpopulation comprising 883 female and 430 male patients (mean age, 55.2 years), acquired using a PreXion 3D CBCT unit, were evaluated. All permanent teeth included in the scans were evaluated for the presence of ECR according to the 3-dimensional classification and the portal of entry. The association between the presence of ECR and the factors studied was assessed using the χ² test. Intra-observer agreement was analyzed with the kappa test (α = 0.05). Results: In total, 6,240 teeth were analyzed, of which 84 (1.35%) were affected by ECR. A significant association was found between the presence of ECR and sex, with a higher prevalence in male patients (p = 0.002). The most frequently affected teeth were the mandibular and maxillary central incisors. The most common height was the mid-third of the root. For the portal of entry, 44% of cases were on the proximal surfaces, 40.5% on the lingual/palatal surface and 15.5% on the buccal surface. Intra-observer agreement was excellent. Conclusions: The prevalence of ECR was 1.35%, with a higher prevalence in male patients and a wide age distribution. The mandibular and maxillary central incisors were the most commonly affected teeth, and cases of ECR most frequently showed a height into the mid-third of the root and proximal entry.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제48권2호
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• pp.122-124
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• 2022

Various techniques are well documented to obtain anatomic reduction, such as reduction forceps, manual reduction, or a combination of these methods. However, these techniques have inherent drawbacks. We propose a new intra-operative technique for anatomic reduction using screw-wire traction for open reduction and internal fixation of mandibular fractures.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제48권4호
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• pp.242-244
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• 2022

Extraction of premolars for orthodontic purposes may prove challenging when the tooth is blocked or lingualised. The standard buccal approach may prove difficult in such cases. A novel technique was used for 16 patients with healthy linguoverted mandibular premolars using maxillary extraction forceps. The ease of extraction increased and resulted in uneventful postoperative healing in all patients. The authors suggest this as a preferred technique for extracting mandibular premolars in linguoversion.

• 대한치과의사협회지
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• 제52권6호
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• pp.354-362
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• 2014

With the development of digital dentistry, various intra-oral scanners which acquire intraoral image without conventional impression taking and stone pouring steps have been introduced. Fixed dental prostheses such as inlay, onlay, crown, and bridge fabricated by CAD/CAM technique combined with digital impressions is getting popular due to the recent rapid progress of digital impression taking system. In comparison with traditional prosthetic procedure, the advantages of intraoral image acquiring and CAD/CAM technique are as follows; the omission of conventional impression materials, reduced workflow step, and increased efficiency by online communication with clinic and laboratory. This review article covers some opinions about the suitable scanning procedures for the various prosthodontic treatments and the utilization of digital intraoral scanner and CAD/CAM system.

• Nuclear Engineering and Technology
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• 제33권5호
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• pp.514-525
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• 2001

Optimum characteristics of digital X-ray sensor components were analyzed to develop intra- oral dental digital X-ray image sensor using indirect method. Parametric analysis was carried out to optimize the phosphor thickness and the fiber optic plate (FOP) coupling to charge coupled device (CCD). X-ray absorption and light diffusion in the phosphor layer were analyzed by the Monte Carlo method. Real time X-ray image was obtained with prototype X- ray image sensor using general CCD camera with 1∼10 Ip/mm resolution. It has been previously shown that large resolution degradation in X-ray images was caused by miss alignment of FOP to CCD and optical adhesive selection. In this study, we reported that X-ray image quality was greatly improved by using optimized characteristics of alignment device and phosphor thickness.

• 대한치과의사협회지
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• 제5권1호
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• pp.75-78
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• 1964

1.The author have had a case of partial andontia. 2. The first examination of mandible development and intra-oral sign was reexamined four years later. 3. The disturbance was shown on the mandible development and mastication.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제28권3호
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• pp.226-230
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• 2002

Carcinomas derived from ameloblastomas have been designated by a variety of terms, including malignant ameloblastoma, ameloblastic carcinoma, metastatic ameloblastoma, and primary intra-alveolar epidermoid carcinoma. The term of ameloblastic carcinoma is differentiated from the term of malignant amelblastoma and is defined as an ameloblastoma in which there is histologic evidence of malignancy in the primary tumor or the recurrent tumor(or metastasis), regardless of whether it has metastasized. The well-documented and adequately followed cases are currently lacking and this report described an instance of ameloblastic carcinoma with good result after treatment and review of literature.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제48권5호
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• pp.315-317
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• 2022

Osseous metaplasia is defined as the formation of lamellar bone inside soft tissue structures where bone normally does not exist. It results from the transformation of non-osseous connective tissue into mature bone. This condition is rare in the oral and maxillofacial region. We report a case of osseous metaplasia of the maxilla, a rare benign tumor in an uncommon region. A 60-year-old male patient visited our clinic complaining of foreign body sensation and asymptomatic swelling on the right palatal side. However, he did not experience pain and reported no local trauma that he could remember. Intra-oral examination revealed an exophytic lesion on the right palatal portion. On computed tomography, there was a round hard-tissue mass approximately 2 cm in diameter on the right palate area. The mass was biopsied and diagnosed as an osseous metaplasia. We review the clinical, radiographic, and histologic features and common causes of osseous metaplasia and report a rare case of osseous metaplasia of the palate.

• Journal of Dental Anesthesia and Pain Medicine
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• 제17권2호
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• pp.121-127
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• 2017

Background: There are no studies regarding 4% articaine infiltration injection into the retro-molar area for an impacted lower third molar (LITM) surgery. This study aimed to evaluate the efficacy of infiltration using 1.7 ml (single cartridge: SC) of 4% articaine versus 3.4 ml (double cartridges: DC) of 4% articaine with 1:100,000 epinephrine in LITM surgery. Method: This study involved 30 healthy patients with symmetrical LITM. The patients were assigned to receive either a DC or SC of 4% articaine with 1:100,000 epinephrine as a local anesthetic for each operation. Onset, duration, profoundness, need for additional anesthetic administration, total volume of anesthetic used, vitality of the tooth, and pain score during operation were recorded. Results: The DC of 4 % articaine had a significantly higher success rate (83.3%) than did the SC (53.3%; P<0.05). The duration of soft tissue anesthesia was longer in the DC group. The intra-operative pain was higher in the SC group with a significant (P < 0.05) requirement for a supplementary local anesthetic. Conclusion: We concluded that using DC for the infiltration injection had a higher success rate, longer duration of anesthesia, less intra-operative pain, and a lower amount of additional anesthesia than SC in the surgical removal of LITM. We recommend that a DC of 4% articaine and a 1:100,000 epinephrine infiltration in the retro-molar region can be an alternative anesthetic for LITM surgery.