• Restorative Dentistry and Endodontics
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• v.36 no.5
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• pp.431-435
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• 2011

Maxillary canines have less anatomical diversities than other teeth. They usually have a single root and root canal. This report describes an endodontic treatment of a maxillary canine with two separated root canals which have not been reported through the demonstration of radiography and computerized tomography (CT). Even though appropriated endodontic treatment has been performed, the severe pain could happen due to lack of consideration of anatomical variations of the teeth. Therefore, the clinicians should be well aware of the possibility of anatomical variations in the root canal system during endodontic treatment even if the number of root canals is obvious such as in this case.

• Imaging Science in Dentistry
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• v.41 no.4
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• pp.143-150
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• 2011

Purpose : The aim of this study was to compare the diagnostic accuracy of cone-beam computed tomography (CBCT) images and bitewing images in detection of secondary caries. Materials and Methods : One hundred and twenty proximal slots of Class II cavities were randomly prepared on human premolar and molar teeth, and restored with amalgam (n=60) and composite resin (n=60). Then, artificial secondary caries lesions were randomly created using round steel No. 4 bur. The teeth were radiographed with a conventional bitewing technique and two CBCT systems; Pax-500ECT and Promax 3D. All images were evaluated by five observers. The area under the receiver operating characteristic (ROC) curve ($A_z$) was used to evaluate the diagnostic accuracy. Significant difference was tested using the Friedman test (p value<0.05). Results : The mean $A_z$ values for bitewing, Pax-500ECT, and Promax 3D imaging systems were 0.882, 0.995, and 0.978, respectively. Significant differences were found between the two CBCT systems and film (p=0.007). For CBCT systems, the axial plane showed the greatest $A_z$ value. Conclusion : Based on the design of this study, CBCT images were better than bitewing radiographs in detection of secondary caries.

• Journal of Periodontal and Implant Science
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• v.50 no.3
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• pp.197-206
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• 2020

Purpose: The aim of this study was to determine the impact of different compressive forces on deproteinized bovine bone mineral (DBBM) particles covered by native bilayer collagen membrane (NBCM) during alveolar ridge preservation (ARP) in the molar area, and to identify any histomorphometric and clinical differences according to the compressive force applied. Methods: Sockets were filled with DBBM after tooth extraction, and different compressive forces (30 N and 5 N, respectively) were applied to the graft material in the test (30 N) and control (5 N) groups. The DBBM in both groups was covered with NBCM in a double-layered fashion. A crossed horizontal mattress suture (hidden X) was then made. A core biopsy was performed using a trephine bur without flap elevation at the implant placement site for histomorphometric evaluations after 4 months. The change of the marginal bone level was measured using radiography. Results: Twelve patients completed the study. The histomorphometric analysis demonstrated that the mean ratios of the areas of new bone, residual graft material, and soft tissue and the implant stability quotient did not differ significantly between the groups (P>0.05). However, the mean size of the residual graft material showed a significant intergroup difference (P<0.05). Conclusions: The application of 2 compressive forces (5 N, 30 N) on particulate DBBM grafts during open-healing ARP in the posterior area led to comparable new bone formation, implant feasibility and peri-implant bone level.

• Journal of Veterinary Clinics
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• v.35 no.3
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• pp.107-110
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• 2018

A 5-year-old Thoroughbred race horse was presented to Busan Korea Racing Authority equine hospital with a 3-year history of a slow-growing left rostral maxillary mass. The location and progressive growth of the mass eventually resulted in poor food prehension, quidding and mouth bit placement. The mass was solitary and hard, and covered by normal smooth oral mucosa. Radiographic examination of the maxillae showed a flocculated and mixed radiolucent lesion protruding outward and displacing the 202 and 203 teeth caudally. The 202 tooth was in normal size and the 203 tooth was hypoplastic on radiography. Under general anesthesia, a partial surgical resection of the mass was performed to minimize functional loss and facilitate prompt return to track. After surgery, there was improvement in food intake, mouth bit placement, and cosmetic appearance. Histopathological examination determined the resected maxillay mass to be an ossifying fibroma. However, there was continued growth of remnant mass in the maxilla. Equine ossifying fibroma is a rare condition and primarily affects the rostral mandible, and less commonly, the maxillae. In this case, the lesion was slow-growing, and caused cosmetic and functional impairments, including poor food intake and reduced trainability. Surgical resection was performed, but the effect of treatment was limited due to advanced size / stage of the tumor. Early dental care is suggested for horse owners to prevent belated identification and improve successful treatment of oral disorders like ossifying fibroma.

• The korean journal of orthodontics
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• v.50 no.3
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• pp.181-187
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• 2020

Objective: This study aimed to evaluate the differences in cephalometric characteristics and skeletal maturation in girls with central precocious puberty (CPP) via lateral and hand-wrist radiographs. We also aimed to identify the indicators that are most effective for determining skeletal maturity in these patients. Methods: The study included 70 Korean girls (mean age, 8.5 ± 0.5 years) diagnosed with CPP at the Department of Pediatrics, and 48 normal healthy age-matched girls who visited the Department of Orthodontics and had no history of hormone treatment or growth problems. Skeletal maturation was evaluated using lateral cephalometric and hand-wrist radiographs using cervical vertebrae maturation indicators (CVMI) and skeletal maturity indicators (SMI). Results: The mean mandibular plane angle was smaller in the CPP group than in the control group (35.8° ± 4.9° vs. 39.0° ± 6.5°), resulting in greater posterior facial height (p = 0.003). SMI was significantly greater in the CPP group (3.5 ± 1.4 vs. 2.0 ± 1.0) than in the control group (p = 0.001) and was significantly associated with CPP (r = 0.492; p = 0.001), whereas CVMI was not. Conclusions: In comparison with the control group, the CPP group exhibited a smaller mandibular plane angle, greater posterior facial height, and greater skeletal maturation. SMI may be more suitable than CVMI for determining skeletal maturation in CPP. Hand-wrist radiography is recommended in addition to lateral cephalogram for predicting growth in girls with CPP.

• Imaging Science in Dentistry
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• v.33 no.1
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• pp.35-41
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• 2003

Purpose: To aid in determining the volume of graft bone required before a maxillary sinus lift procedure and compare the alveolar bone height measurements taken by panoramic radiographs to those by CT images. Materials and Methods : Data obtained by both panoramic radiographs and CT examination of 25 patients were used in this study. Maxillary sinus volumes from the antral floor to heights of 5 mm, 10 mm, 15 mm, and 20 mm, were calculated. Alveolar bone height was measured on the panoramic images at each maxillary tooth site and corrected by magnification rate (PBH). Available bone height (ABH) and full bone height (FBH) was measured on reconstructed CT images. PBH was compared with ABH and FBH at the maxillary incisors, canines, premolars, and molars. Results: Volumes of the inferior portion of the sinuses were 0.55 ± 0041 ㎤ for 5 mm lifts, 2.11 ± 0.68 ㎤ for 10 mm, 4.26 ± 1.32 ㎤ for 15 mm, 6.95 ± 2.01 ㎤ for 20 mm. For the alveolar bone measurement, measurements by panoramic images were longer than available bone heights determined by CT images at the incisor and canine areas, and shorter than full bone heights on CT images at incisor, premolar, and molar areas (p<0.001). Conclusion: In bone grafting of the maxillary sinus floor, 0.96 ㎤ or more is required for a 5 mm-lift, 2.79 ㎤ or more for a 10 mm-lift, 5.58 ㎤ or more for a 15 mm-lift, and 8.96 ㎤ or more for a 20 mm-lift. Maxillary implant length determined using panoramic radiograph alone could result in underestimation or overestimation, according to the site involved.

• Imaging Science in Dentistry
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• v.42 no.3
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• pp.147-154
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• 2012

Purpose: This study was performed to evaluate the incidence and degree of external apical root resorption of maxillary incisors after orthodontic treatment and to evaluate particular associated factors related to external apical root resorption. Materials and Methods: The records and maxillary incisor periapical radiographs of 181 patients were investigated. Crown and root lengths were measured and compared on the pre- and post-treatment periapical radiographs. Crown length was measured from the center of the incisal edge to the midpoint of the cemento-enamel junction (CEJ). Root length was measured from the CEJ midpoint to the root apex. A correction factor for the enlargement difference was used to calculate root resorption. Results: The periapical radiographs of 564 teeth showed that the average root resorption was $1.39{\pm}1.27$ ($8.24{\pm}7.22$%) and $1.69{\pm}1.14$ mm ($10.16{\pm}6.78%$) for the maxillary central and lateral incisors, respectively. The results showed that the dilacerated or pointed roots, maxillary premolar extraction cases, and treatment duration were highly significant factors for root resorption (p<0.001). Allergic condition was a significant factor at p<0.01. Age at the start of treatment, large overjet, and history of facial trauma were also factors significantly associated with root resorption (p<0.05). There was no statistically significant difference in root resorption among the factors of gender, overbite, tongue-thrusting habit, types of malocclusion, and types of bracket. Conclusion: These results suggested that orthodontic treatment should be carefully performed in pre-treatment extraction patients who have pointed or dilacerated roots and need long treatment duration.

• Imaging Science in Dentistry
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• v.42 no.4
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• pp.225-229
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• 2012

Purpose: This study aimed to evaluate the trabecular bone changes after alveolar bone grafting in unilateral cleft lip and palate (UCLP) patients using a computer-aided diagnosis (CAD) system. Materials and Methods: The occlusal radiographs taken from 50 UCLP patients were surveyed retrospectively. The images were categorized as: 50 images in group 0 (before bone grafting), 33 images in group 1 (one month after bone grafting), 24 images in group 2 (2-4 months after bone grafting), 15 images in group 3 (5-7 months after bone grafting), and 21 images in group 4 (8 or more months after bone grafting). Each image was grouped as either "non-cleft side" or "cleft side". The CAD system was used five times for each side to calculate the pixel area based on the mathematical morphology. Significant differences were found using a Wilcoxon signed ranks test or paired samples t test. Results: The pixel area showed a significant difference between the "non-cleft side" and "cleft side" in group 0 ($404.27{\pm}103.72/117.73{\pm}92.25$; p=0.00), group 1 ($434.29{\pm}86.70/388.31{\pm}109.51$; p=0.01), and group 4 ($430.98{\pm}98.11/366.71{\pm}154.59$; p=0.02). No significant differences were found in group 2 ($423.57{\pm}98.12/383.47{\pm}135.88$; p=0.06) or group 3 ($433.02{\pm}116.07/384.16{\pm}146.55$; p=0.19). Conclusion: Based on the design of this study, alveolar bone grafting was similar to normal bone within 2-7 months postoperatively.

• Imaging Science in Dentistry
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• v.40 no.4
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• pp.159-163
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• 2010

Purpose : This retrospective study was performed to investigate the prevalence of the idiopathic osteosclerosis (IO) in Korean malocclusion patients according to age, sex, and the Angle's classification of malocclusion. Materials and Methods : This study consisted of 2,001 randomly selected patients from the Department of Orthodontics at the Gangneung-Wonju National University Dental Hospital, Korea. The prevalence of IO in Korean malocclusion patients was recorded using their panoramic radiographs, and the following parameters were surveyed; age, sex, and the Angle's classification of malocclusion. The chi-square test was analyzed to determine the statistical significance of differences in the prevalence of IO between age, sex, and the Angle's classification of malocclusion. Results : The prevalence of IO in the jaws was 6.7% in a total of 2,001 examined orthodontic patients. The majority of IO was found in the mandible (96.58%). The 30-39 age group showed the highest prevalence of IO (9.60%). There was a higher prevalence in females (6.89%) than in males (6.45%). The prevalence of IO in Angle Class I group (7.07%) was the most frequent, followed by Angle Class II group (6.72%), and Angle Class III group (6.40%). However, there was no statistical significance in sex and Angle's classification of malocclusion. Conclusion : The prevalence of IO in malocclusion patients showed the differences between various age groups and most of them were found in the mandibular posterior area. However, sex and the type of malocclusion are not to be considered as a contributing factor of IO.

• Journal of Periodontal and Implant Science
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• v.40 no.2
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• pp.69-75
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• 2010

Purpose: Implant survival rates using a bone-added osteotome sinus floor elevation (BAOSFE) procedure with simultaneous placement of a non-submerged sand blasted with large grit and acid etched (SLA) implant are well documented at sites where native bone height is less than 5 mm. This study evaluated the clinical results of non-submerged SLA Straumann implants placed at the time of the BAOSFE procedure at sites where native bone height was less than 4 mm. Changes in graft height after the BAOSFE procedure were also assessed using radiographs for 5 years after the implant procedure. Methods: The BAOSFE procedure was performed on 4 patients with atrophic posterior maxillas with simultaneous placement of 7 non-submerged SLA implants. At least 7 standardized radiographs were obtained from each patient as follows: before surgery, immediately after implant placement, 6 months after surgery, every year for the next 3 years, and after more than 5 years had passed. Clinical and radiographic examinations were performed at every visit. Radiographic changes in graft height were calculated with respect to the implant's known length and the original sinus height. Results : All implants were stable functionally, as well as clinically and radiographically, during the follow-up. Most of the radiographic reduction in the grafted bone height occurred in the first 2 years; reduction after 2 years was slight. Conclusions: The simultaneous placement of non-submerged SLA implants using the BAOSFE procedure is a feasible treatment option for patients with severe atrophic posterior maxillas. However, the grafted bone height is reduced during the healing period, and patients must be selected with care.