• Journal of Korean Dental Science
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• v.14 no.2
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• pp.61-68
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• 2021

Purpose: The aim of this study was to investigate the outcomes of endodontic treatment of mandibular second molar with C-shaped canal in elderly patients and related factors affecting the survival of the tooth. Materials and Methods: From 2010 to 2015, the survival rate following endodontic treatment was evaluated in elderly patients over 60 years who visited the Veterans Health Service Medical Center for endodontic treatment. The presence of C-shaped canals was confirmed using clinical records and radiographic features. Patient's age, sex, systemic diseases, tooth location, vitality, signs and symptoms, fractures, caries, apical radiolucency, canal shaping methods, sealer leakage, filling voids, and restoration of prosthesis were included in the analyses as confounding variables. The survival rate of teeth was analyzed using Kaplan-Meire analysis and the relationship between the survival rate and variables was analyzed using Simple and Multiple Cox regression analysis. Result: In total, 107 teeth in elderly patients had C-shaped canal. The survival rate of teeth that received endodontic treatment was 63.70%. None of the factors investigated significantly influenced the survival rate (P>0.05). Conclusion: In elderly patients with C-shaped canal, the survival rate after root canal treatment was not significantly different from that of other mandibular molars.

• Journal of Periodontal and Implant Science
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• v.51 no.6
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• pp.433-443
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• 2021

Purpose: This study aimed to evaluate the effectiveness of the partial split-flap technique with a K-incision on vertical guided bone regeneration (vGBR) and to retrospectively analyze the clinical and radiographic outcomes of dental implantation using this approach. Methods: In total, 78 patients who received 104 dental implants with vGBR, categorized as (1) pre-GBR and post-implantation and (2) simultaneous GBR and implantation, were enrolled. Data analysis was based on periapical radiographs, clinical photos, and dental records. The 2-sample t-test was used to compare the 2 surgical procedures. Results: The baseline vertical bone level, augmented bone height (ABH), and treatment duration were significantly higher in the pre-GBR procedure group. The survival rates of the implants were 96.1% and 94.8% in implant- and patient-based analyses, respectively. In Cox regression analysis, high rates of implant failure were found in the presence of ABH of ≥4 mm, smoking, and diabetes. Conclusions: Within the limitations of this retrospective study, the partial split-flap technique using a K-incision for vGBR showed stable clinical outcomes and favorable dental implant survival.

• Journal of the korean academy of Pediatric Dentistry
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• v.50 no.4
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• pp.421-433
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• 2023

This study was to examine the developmental dental abnormalities in childhood cancer survivors. Risk factors were assessed for 125 children with radiographic data through a retrospective analysis of medical records and panoramic images. 68.0% of childhood cancer survivors exhibited at least one dental abnormality. The types of abnormalities varied depending on the age at cancer diagnosis and treatment intensity, ranging from microdontia (43.2%), to abnormal root development (39.2%) and tooth agenesis (33.6%). Logistic regression analysis demonstrated that a young age at diagnosis (under 3 years), the use of heavy metal agents, a history of hematopoietic stem cell transplantation (HSCT), and combination treatment of chemotherapy, radiation therapy, and HSCT were associated with a significantly higher risk for overall dental abnormalities. The increased risk ratios were 6.00, 3.06, 3.22, and 7.87, respectively (p < 0.05). The results of this study will predict dental abnormality in permanent dentition according to the diagnosis age and treatment method of childhood cancer.

• Imaging Science in Dentistry
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• v.36 no.1
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• pp.25-32
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• 2006

Purpose : To investigate the validity of digital image processing on panoramic radiographs in estimating bone quality before endosseous dental implant installation by correlating bone quality in radiographic images with clinical bone quality classification. Materials and Methods : An experienced surgeon assessed and classified bone quality for implant sites with tactile sensation at the time of implant placement. Including fractal dimension eighteen morphologic features of trabecular pattern were examined In each anatomical sites on panoramic radiographs. Finally bone quality of 67 implant sites were evaluated in 42 patients. Results : Pearson correlation analysis showed that three morphologic parameters had weak linear negative correlation with clinical bone quality classification showing correlation coefficients of -0.276, -0.280, and - 0.289, respectively (p<0.05). And other three morphologic parameters had obvious linear negative correlation with clinical bone quality classification showing correlation coefficients of -0.346, -0.488, and -0.343 respectively (p<0.05). Fractal dimension also had a linear correlation with clinical bone quality classification with correlation coefficients -0.506 significantly (p<0.05). Conclusion : This study suggests that fractal and morphometric analysis using digital panoramic radiographs can be used to evaluate bone quality for implant recipient sites.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.22 no.2
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• pp.217-232
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• 2000

The author studied on the 128 cases of benign odontogenic tumors which had been diagnosed with biopsy during the period of Jan. 1989 to Dec. 1998 at the Kyungpook National University Hospital, Yeungnam University Medical Center, Keimyung University Dongsan Medical Center, and Taegu Catholic Medical Center. This study contained the clinicostatistical analysis of the frequency in relation to sex, age, locations, chief complaints, duration, radiographic findings, recurrence, teeth, and treatment methods. The results were as follow : 1. Of a total of 128 benign odontogenic tumors, ameloblastomas(57 cases; 44.5%) and odontomas (44 cases ; 34.4%) mostly occupied. The other types of lesions were 8 calcifying odontogenic cysts, 7 benign cementoblastomas, 4 myxomas, 3 adenomatoid odontogenic tumors, 2 calcifying epithelial odontogenic tumors, 2 ameloblastic fibro-odontomas, and 1 odontogenic fibroma. 2. In age and sex distribution, benign odontogenic tumors occured slightly more often in males(53.9%) than females(46.1%) and the majority of cases(79.7%) were found during 2nd, 3rd, and 4th decade. 3. There was a predilection for mandibular lesions(mandible-maxilla ratio, 2.6 : 1). 4. The most common chief complaint was swelling(29.7%) and in respect to duration, the cases less than 1 year(50.0%) mainly appeared. 5. There were 7 cases(13.0%) of recurrence on ameloblastoma and there was no recurrence in the others. 6. In Ameloblastoma It commonly occured during 3rd and 4th decade(59.6%) and mean age was 30.2 years. The majority of cases were occurred in mandible(96.5%) , especially mandibular molar and angle area(71.9%). The most common chief complaint was swelling(47.4%) and in respect to duration, the cases less than 1 year(52.6%) mainly appeared. In relation to teeth, there were resorption of root(52.6%), displacement of teeth(31.6%), and in relation to impacted teeth(43.9%). There was higher recurrence rate in the cases by conservative treatment(14.7%) than radical treatment(10.0%). As regards radiographic findings, conservative treatments were prevalent in the cases of unilocular type(85.7%) as compared with multilocular type(48.5%). and there was higherrecurrence rate in the cases of multilocular type(18.2%) than unilocular type(4.8%). As regards the type of treatment in relation to age, conservative treatments were prevalent in patients younger than 20 years of age. 7. In Odontomas It commonly occured during 2nd decade(50.0%) and in maxillary anterior teeth(40.9%). The most common chief complaint was delayed retention and permanent impaction of teeth(72.7%), and most frequently associated with impacted teeth(79.5%).

• Journal of the Korean Arthroscopy Society
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• v.7 no.2
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• pp.215-219
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• 2003

Purpose : To report the 'condylar cut-off sign', a new radiographic sign in knees with discoid lateral meniscus and to report the sensitivity, specificity, positive predictive value and negative predictive value of the sign to elucidate the diagnostic significance of the sign for discoid meniscus. Materials and Methods : Fifty knees with complete discoid lateral meniscus and fifty normal knees formed the basis of this study. All of them were arthroscopically confirmed fer the discoid or normal lateral meniscus. The authors developed a method to measure the length of the medial and lateral condylar were compare and analyzed. Results : Tile average ratio was 0.716 in the discoid meniscus group, and 0.902 in the normal group. The stastistical analysis by the T-test revealed the t-value -11.13(p<0.0001). Stastistical analysis by chi-square test using cut point 0.8, also showed significant difference between the two groups, with $76\%$ sensitivity, $100\%$ specificity, $100\%$ positive predictive predictive value and $81\%$ negative predictive value. The 'condylar cut-off sign' was readily detectable in all cases of discoid lateral meniscus, suggesting that the cut off sign could serve as a simple and reliable radiographic sign fur the diagnosis of discoid meniscus. Conclusion : The condylar cut-off sign on the Tunnel view of simple radiography of the knee can serve as a good sign for the diagnosis of discoid lateral meniscus, with $100\%$ positive predictive value.

• Archives of Reconstructive Microsurgery
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• v.13 no.2
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• pp.93-100
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• 2004

This study was designed to investigate the optimal period of pedicles implantation in the prefabricated periosteofascial flap with a vascular tissue transfer. The flap prefabrication was prepared with a transposition of left occipital pedicles on the calvarial fascia of male Sprague-Dawley rats. Thirty flaps were divided into five groups of six flaps, including control group (group I) of the conventional periosteofascial flap based on the lateral border of the rat calvarium. The prefabricated flap was elevated as an $1{\times}1cm$ sized island flap based on the implanted pedicle at 1, 2, 3, and 4 weeks after the pedicles transfer in groups II, III, IV, and V, respectively. After the completion of creating a critical-sized calvarial defect and implanting with hydroxyapatite granules, the flap was sutured back for covering the defect and kept isolated from surrounding tissues. Six weeks after flap repositioning, the osseous changes of the defect were examined with simple radiographic findings, radiodensitometric analysis, and histological studies. By simple radiographic findings, specimens of the control, groups IV and V showed homogeneous radioopacity within the defect. But in groups II and III, focal radiolucency was observed in the defect. In the radiodensitometric analysis, the control group and the group V showed significant increased radiodensites statistically. Histologically, the implanted hydroxyapatite was absorbed partly in the defect in groups II, III, and IV. In the defects of the control group and the group V, the implanted hydroxyapatite was kept in its volume and the deposition of the bone cells was observed sparsely. In conclusion, the prefabricated periosteofascial flap can be created with a vascular tissue transfer and the pedicles should be implanted at least for 4 weeks to bring out positive osseous changes in the calvarial defect.

• Journal of the Korean Society of Physical Medicine
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• v.9 no.2
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• pp.151-159
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• 2014

PURPOSE: The purpose of this study was to evaluate whether light-emitting diodes (LED) irradiation could be effective in a noninvasive, therapeutic device for the treatment of osteoarthritis(OA). METHODS: Twenty-four male Sprague-Dawley rats were divided into four groups: Vehicle control (saline); monosodium iodoacetate-injection (MIA); LED irradiation after MIA injection (MIA-LED); indomethacin-treatment after MIA injection (MIA-IMT). OA was induced by intra-articular injection of 3 mg MIA through the patellar ligament of the right knee. Vehicle control rats were injected with an equivalent volume of saline. The LED was irradiated for 15 min/day for a week after 7 days of MIA treatment. To compare with the effect of LED irradiation, the indomethacin was administrated 20 mg/kg twice a week orally after 7 days of MIA treatment. Knee joints were removed and fixed overnight in 10% neutral buffered formalin and decalcified by EDTA for 2 week before being embedded in paraffin. The assessment of OA induction were monitored by knee movement and radiographic finding. Histologic analysis were performed following staining with hematoxylin and eosin, safranin O-fast green, or toluidine blue, picrosirius red, and histologic changes were scored according to a modified Mankin system. Apoptotic cell in tissue sections was detected using TUNEL method. RESULTS: Radiographic examination could not show the differences between the MIA-treated and the MIA-LED-treated rats. In the histologic analysis, however, LED irradiation prevented cartilage damage and subchondral bone destruction, and significantly reduced mononuclear inflammatory cell infiltration and pannus formation. LED irradiation also reduced apoptosis of cartilage cells, but it prevented apoptosis of infiltrated inflammatory cells in synovium. In addition, LED irradiation showed an increase of collagen production in the meniscus. CONCLUSION: These results suggest that the 840 nm LED irradiation would be a suitable non-thermal phototherapy for the treatment of OA, as a cartilage protection and anti-inflammatory modality.

• The Journal of Korean Academy of Prosthodontics
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• v.59 no.3
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• pp.281-290
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• 2021

Purpose. The aim of this study is to evaluate bone change around the implant in patients who underwent alveolar ridge preservation for implantation in the posterior teeth using radiographic data measuring changes of mesial, distal crestal bone level according to post-implantation, post-final prosthesis delivery and follow-up periods. Materials and methods. In total, 36 implants were placed in 32 patients. The mesial and distal crestal bone level of all the areas where alveolar ridge preservation was performed uses panoramic images taken post-implantation, post-final prosthesis delivery, and follow-up period each was measured and evaluated as a vertical value. The following factors were analyzed: associations between changes of crestal bone level and factors (e.g., age, sex, systemic diseases, dentist, implant location, tooth, bone type, membrane). The statistical analysis was performed using the mean, standard deviation and independent t-test, paired t-test (P < .05). Results. Analysis of crestal bone level differences between periods shows statistically significant differences (P < .05). There was no statistically significant difference when the changes of crestal bone level between post-implantation, post-final prosthesis delivery and follow-up periods were correlated with each factors. Conclusion. After alveolar ridge preservation, bone around the implant remained stable during the maintenance period without being affected by the patient and surgical factors, and alveolar ridge preservation is considered a clinically usable procedure.

• Imaging Science in Dentistry
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• v.50 no.2
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• pp.117-124
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• 2020

Purpose: The purpose of this study was to evaluate possible differences in the location of the inferior alveolar canal in male and female Egyptians. Materials and Methods: This cross-sectional retrospective study involved the evaluation of 210 CBCT scans of Egyptian individuals (18-70 years old). The inferior alveolar canal was localized by measuring 8 linear dimensions: 2 for the vertical localization of the mental foramen (superior and inferior to the mental foramen), 4 at the first molar bifurcation for the vertical and horizontal localization of the inferior alveolar canal (superior, inferior, buccal, and lingual to the inferior alveolar canal), and 2 for the horizontal localization of the mandibular foramen (anterior and posterior to the mandibular foramen). The measurements were statistically analyzed via comparative analysis, stepwise logistic regression, and receiver operating characteristic (ROC) curve analysis. Results: Six of the 8 measured distances differed to a statistically significant extent between the sexes. Regression analysis suggested a logistic function with a concordance index of 84%. The diagnostic accuracy capabilities of the linear measurements as sex predictors were calculated using ROC analysis, and the 6 best predictors for sex determination were selected and ranked from highest to lowest predictive power. Moreover, combining these 6 predictors increased the predictive power to 84%. Conclusion: The location of the inferior alveolar canal in the Egyptian population varies significantly by sex; accordingly, this anatomic landmark could be used as a reliable indicator of sexual dimorphism.