• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.4
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• pp.637-642
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• 2003

Morphology of primary root divergency and curvature determines the pattern of root resorption and periapical lesion, and affects successful root canal treatment. With the purpose of analysing the morphology of primary mandibular second molar roots and canals, the frequency, angle, radius, and start of curvature of the canal were measured. Fifty clinical radiographs were taken from $3{\sim}6$ years old children, followed by digitizing after scanning and analyzing by Scion image Beta 4.02TM(Scion Co. USA). The angle of curvature was determined by Schneider's method and the radius of curvature was determined by Schaefer's method. The results were as follows: 1. The angle of curvatures were $17.3^{\circ}{\pm}5.0$ (mesial), and $27.9^{\circ}{\pm}6.0$ (distal). Distal curvature was significantly larger than mesial.(p<0.05) 2. The radius of curvatures were $8.7mm{\pm}2.5$ (mesial), and $5.8\;mm{\pm}1.5$ (distal). Mesial curvature was significantly larger than distal.(p<0.05) 3. The start of curvatures were $4.1mm{\pm}0.6$ (mesial), and $4.2mm{\pm}0.6$ (distal). There were no difference between two groups. (P<0.05)

• Restorative Dentistry and Endodontics
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• v.36 no.1
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• pp.19-25
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• 2011

Objectives: The purpose of this retrospective study was to evaluate the success rate of intentionally replanted mandibular second molar with C-shaped canal configurations and to access the impact of preoperative periapical lesion on the success of intentional replantation procedure. Materials and Methods: This retrospective chart review study evaluated 52 intentionally replanted mandibular second molar teeth treated at Seoul National University Dental Hospital Department of Conservative Dentistry from January 2005 to December 2007. Seventeen teeth were lost for the follow-up, and another 6 teeth did not meet inclusion criteria of C-shaped root canal configurations. Healing outcome such as success, uncertain healing, and failure after follow-up was evaluated by clinical criteria and radiographs. Results: The overall success rate was 72.4% for the 29 intentionally replanted C-shaped mandibular second molars. The success rate of replanted teeth with preoperative periapical lesions was similar to that of replanted teeth which have no periapical lesions. Conclusions: Therefore, root canal treatment failure on C-shaped mandibular second molar can be predictably treated by intentional replantation regardless of the presence of periapical lesion.

• The Journal of the Korean dental association
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• v.47 no.10
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• pp.628-636
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• 2009

낭은 상피세포로 싸여있는 병적인 공간으로 내부가 액체나 반액체로 채워져 있다. 악골에서 낭은 다른 골 부위에서보다 더 흔하게 발생하는데 이는 대부분의 낭이 치아 형성 후에 악골에 남아있는 치성잔류물로부터 발생하는 경우가 많기 때문이다. 구강악안면부에서 발생하는 낭은 연조직에서 발생할 수도 있지만 대부분 골내에서 발생하고, 법랑질 상피나 치배와 관련해 악골내에 발생하는 치낭성이다. 치낭성은 WHO분류에서 발생근원에 따라 크게 염증성과 발육성 기원의 두 가지 군으로 분류되고, 발육성 낭은 치성과 비치성으로 세분할 수 있다. 악골에 발생하는 낭은 대부분이 치낭성이며 가장 흔한 악골 낭종은 치근단낭으로 염증성이고, 발육성인 함치성낭과 치성각화낭도 다음으로 발생률이 높은 편이다. 소아환자에서 함치성낭과 치성각화낭의 발병률이 성인보다 더 높았다. 비치성낭 중에서 비구개관낭이 가장 많이 발생하며, 연조직에서 발생하는 낭과 상피세포 경계가 없는 낭성 병소인 가성낭(pseudocyst)은 드물게 관찰된다. WHO에서 치성각화낭과 서회화치성낭은 파괴적 성장을 하고 재발 경향이 높으므로 양성 낭성 종양으로 재분류하고 있다.

• Journal of Veterinary Clinics
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• v.23 no.4
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• pp.476-479
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• 2006

A 9-year-old, female Yorkshire terrier and a 10-year-old, female Maltese were referred to the Veterinary Medical Teaching Hospital of Konkuk University. The dogs were presented with severe swelling and cutaneous sinus tract on the left suborbital lesion. Under general anesthesia, we performed physical, intraoral examinations and survey radiography, and diagnosed as periapical abscess in a left fourth premolar tooth. They were treated with tooth extraction, and the sinus tracts were drained with 0.05% chlorhexidine solution. After teeth extractions, medication applied by the result of antibiotic sensitivity test. During follow-up 10 months later, the left suborbital swelling had completely resolved.

• Restorative Dentistry and Endodontics
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• v.22 no.2
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• pp.637-647
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• 1997

The purpose of this study was to evaluate the effect of concentration and pH of lactic acid on the formation of artificial root caries lesions formation in bovine teeth. The characterictics of artificially produced early root lesions were observed with polarized light microscope and the depth of lesions were mearsured with measuring microscope The results were as follows: 1. In the group of low pH and high concentration of lactic acid, the progress of lesion formation was faster than that of high pH and low concentration lactic acid group. 2. In the same group, initial lesion progress faster, but progression rate was reduced as time goes by. 3. In the development of initial root caries, cementum was act as a barrier to protect dentin from lesion progression.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.4
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• pp.630-635
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• 2004

The etiology of mesiodens is unknown but the most widely accepted theory is the hyperactivity of the dental lamina. Complications of mesiodens are delayed or prevented eruption of maxillary central incisors, displacement or rotation of permanent teeth, crowding of affected region, abnormal diastema or permanent space closure, dilaceration or abnormal root development of permanent teeth, primordial or follicular cyst formation, root resorption of adjacent teeth, eruption into nasal cavity. If mesiodens rotate the maxillary central incisors, space deficiency is not common and relapse is very common. So overcorrection is needed. To prevent the rotational relapse, early treatment, overcorrection, long retention period, properly formed proximal surface, use of coupled force, and surgical techniques have been suggested. The authors present two cases, whose chief complain were severely rotated maxillary incisors by mesiodens, treated by orthodontic and surgical technique and showed good results.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.2
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• pp.268-277
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• 2008

Authors evaluated 1171 patients at the department of Pediatric Dentistry in Kyoungpook National University Hospital through clinical records and radiographs. And the following features were studied ; age, sex distribution, number of mesiodens per patients, cause of discovery of mesiodens, location, status of eruption, shape and orientation of crown, complication, dental age of adjacent upper incisor tooth at the time of surgical extraction of mesiodens and the relationship between the resolution rate of complication after extraction of mesiodens and the dental age of adjacent upper incisor tooth, length of diastema, the eruption status of lateral incisor and the crowding status of premaxilla. The followings are the results : 1. The cause of discovery of mesiodens were as follows ; delayed eruption of the permanent incisors in 13.8%, midline diastema in 11.6%, radiographs taken for other reasons in 23.4% and for caries treatment in 15.1%. 2. Complication due to the presence of mesiodens did not occur in 36.8%, delayed eruption of adjacent teeth was observed in 16.1%, midline diastema in 34.4%, rotation in 8.8%, displacement in 2.4%, and crowding in 1.0% of all evaluated patients. 3. As for the dental age of adjacent upper incisor tooth at the time of surgical extraction of mesiodens, below 1/3 of total root length were observed in 3.5%, $1/3{\sim}1/2$ of total root length in 19.9%, $1/2{\sim}2/3$ of total root length in 54.7% and over 2/3 in 21.9% of all evaluated patients. 4. Resolution rate of delayed eruption after the extraction of mesiodens was significant higher in the group with the root length below 1/2. Resolution rate of midline diastema was significant higher in the group with diastema width below 3mm and with non-crowding of adjacent upper incisor teeth.

• Journal of dental hygiene science
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• v.16 no.5
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• pp.349-354
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• 2016

The purpose of this study was to evaluate the efficacy of the newly-developed $Qraypen^{TM}$ (All In One Bio, Korea) system for the diagnosis of early proximal caries by comparing it with the conventional methods of visual inspection and periapical radiography. This study was carried out from July 2015 to April 2016 targeting 32 children aged 7~12 years who visited Y-Dental Clinic for school oral health examinations. Two investigators selected and examined a total of 153 primary molars that had not undergone restorative treatment. Comparisons were carried out between visual inspections, readings of posterior periapical radiography images, and readings of $Qraypen^{TM}$ images. This study revealed that the percentage of interproximal surfaces of primary molar teeth without caries incidence was 83.7% using $Qraypen^{TM}$ imaging and 84.9% using visual inspection and periapical radiography. The differences between the two methods were not statistically significant. Thus, $Qraypen^{TM}$ is expected to be a useful and convenient auxiliary diagnostic device that can facilitate the detection of hidden proximal caries in primary molars.

• Journal of Dental Rehabilitation and Applied Science
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• v.39 no.1
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• pp.1-8
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• 2023

Purpose: The purpose of this study is to analyze the prognostic factors related to tooth loss after 5 years of periodontal surgery in periodontal disease patients. Materials and Methods: From January to December 2017, 22 patients and 124 teeth who underwent periodontal treatment through periodontal surgery were targeted. At the time of treatment, the measured values were evaluated after recording the maximum probing depth, average periodontal probing depth, number of root, furcation involvement, pulp vitality, and prosthesis state on the day of periodontal surgery. Based on the initial records at the time of visit, patient-related factors were gender, age, smoking, tooth loss due to periodontal disease at the time of first visit, diabetes, and maintenance period. The influence of each factor on tooth loss was evaluated. Results: As a result of examining the influence of tooth-related factors on tooth loss, the maximum probing depth depth (P: 0.000), bone loss (P: 0.021) was found to have a significant effect on tooth loss. Conclusion: As a result of examining the influence of patient-related factors on tooth loss, any variables had no significant effect. Bone loss, maximum probing depth acted as statistically significant prognostic factors for tooth loss in patients who underwent periodontal surgery.

• The Journal of Korean Academy of Prosthodontics
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• v.53 no.4
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• pp.352-358
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• 2015

The retention of complete dentures in patients with Parkinson's disease is often poor due to their constant dislodgement by involuntary movements of the tongue and lips. Furthermore, insertion of the overdenture is expected to be difficult due to their limited voluntary movements. This case is about the bimaxillary overdenture restoration where its retention and stability are improved, using magnetic attachment of remained roots of maxilla and two implant $Locator^{(R)}$ attachments of mandible in patients with Parkinson's disease. This report describes the fabrication of this functionally improved prosthesis.