• Journal of Periodontal and Implant Science
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• v.38 no.3
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• pp.521-528
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• 2008

Purpose: Tunneling is a periodontal surgical procedure that creates access for patient cleansing and maintenance within the furcal area of a molar tooth with severe furcation involvement. Up to date, there are few studies about a long term clinical and radiographic stability of tunneling. The purpose of this retrospective study is to evaluate the long term prognosis after tunnel preparation of molars with through and through furcation. Material and Methods: 25 teeth of 23 patients aged 36 to 70 (mean age 51.7) were treated surgically with tunnel preparation. These cases were followed for 2 to 13 years (mean 6.5years) after surgery. Patients were recalled for an evaluation which was based on a questionnaire, a clinical examination, and radiographic analysis. Clinical assessment included plaque index, caries registration, probing pocket depth, bleeding on probing, tooth mobility. Baseline and over 2-year follow-up radiographs were collected and evaluated for this study. Result: 3 teeth(12%) had been extracted and 1 tooth(4%) hemisected. Root caries was detected in 3 teeth(12%). Thus 72% of the teeth were still caries tree and in function. Clinical parameters including PI, PD, BOP, mobility showed somewhat favourable results. Radiographic furcal bone loss showed no statistically significant difference compared to interproximal crestal bone loss ($3.59{\pm}1.69%$ vs $3.42{\pm}2.95%$) when root length was used as reference. There was no correlation between root trunk length and furcal bone loss. Conclusion: Over 2 years after tunneling procedure, teeth showed a clinically and radiographically stable condition, despite of slight root caries and alveolar bone loss within clinically acceptable range. The tunnel procedure may be considered as a viable periodontal treatment option for molar teeth with severe furcation involvement in individuals following a regular maintenance program.

• Knee surgery & related research
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• v.30 no.4
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• pp.319-325
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• 2018

Purpose: Body mass index (BMI) is often used to predict surgical difficulty in patients receiving total knee arthroplasty (TKA); however, BMI neglects variation in the central versus peripheral distribution of adipose tissue. We sought to examine whether anthropometric factors, rather than BMI alone, may serve as a more effective indication of surgical difficulty in TKA. Materials and Methods: We prospectively enrolled 67 patients undergoing primary TKA. Correlation coefficients were used to evaluate the associations of tourniquet time, a surrogate of surgical difficulty, with BMI, pre- and intraoperative anthropometric measurements, and radiographic knee alignment. Similarly, Knee Injury and Osteoarthritis Outcome Score (KOOS) was compared to BMI. Results: Tourniquet time was significantly associated with preoperative inferior knee circumference (p=0.025) and ankle circumference (p=0.003) as well as the intraoperative depth of incision at the quadriceps (p=0.014). BMI was not significantly associated with tourniquet time or any of the radiographic parameters or KOOS scores. Conclusions: Inferior knee circumference, ankle circumference, and depth of incision at the quadriceps (measures of peripheral obesity) are likely better predictors of surgical difficulty than BMI. Further study of alternative surgical indicators should investigate patients that may be deterred from TKA for high BMI, despite relatively low peripheral obesity.

• The korean journal of orthodontics
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• v.52 no.2
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• pp.102-111
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• 2022

Objective: To develop and explore the usefulness of an artificial intelligence system for the prediction of the need for dental extractions during orthodontic treatments based on gender, model variables, and cephalometric records. Methods: The gender, model variables, and radiographic records of 214 patients were obtained from an anonymized data bank containing 314 cases treated by two experienced orthodontists. The data were processed using an automated machine learning software (Auto-WEKA) and used to predict the need for extractions. Results: By generating and comparing several prediction models, an accuracy of 93.9% was achieved for determining whether extraction is required or not based on the model and radiographic data. When only model variables were used, an accuracy of 87.4% was attained, whereas a 72.7% accuracy was achieved if only cephalometric information was used. Conclusions: The use of an automated machine learning system allows the generation of orthodontic extraction prediction models. The accuracy of the optimal extraction prediction models increases with the combination of model and cephalometric data for the analytical process.

• Korean Journal of Applied Biomechanics
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• v.19 no.2
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• pp.187-196
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• 2009

The foot type is classified into normal, high or low arch according to either foot print or medial longitudinal arch (MLA) height. Plantar fasciitis, heel pain, Achilles tendinitis, stress fracture, metatarsalgia, knee pain, shin splint pain, and etc are common foot disorders and associate to the foot type. The purpose of this study was to evaluate several suggested bony inclination used to classified the abnormal foot and if the arch index (AI) was correlated with foot morphology. Lateral view and dorso-plantar view of radiographic images and flatbed scanner measurements obtained from 57 college students were analyzed. Results showed that AI measured in this study was higher than Caucasian Americans and European, but similar with African. The ethnic origin could influent the AI distribution. The AI provided a simple quantitative means of assessing the structure of lateral and medial longitudinal arches. The correlation coefficients of true bone height with AI could be further improved by normalized foot width rather than foot length. AI also demonstrated as a good indicator of inclination between calcaneus-fifth metatarsal (CalM5) and calcaneus-first metatarsal (CalX), it is a good means to classify the foot type.

• The korean journal of orthodontics
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• v.36 no.3 s.116
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• pp.218-227
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• 2006

Although the submentovertex radiograph and surface EMG are not often used due to the difficulty of interpretation, they are accepted as useful diagnostic and analytic aids for skeletal asymmetry. There have been reports which state that they were also useful for the evaluation of vertical skeletal relations. The purpose of this study was to evaluate the correlations between EMG data, measurements from submentovertex radiographs, facial types and facial asymmetry following examination of 60 asymmetric patients. The radiographic corpus length were greater in the nonaffected sides (p<0.001), gonion to interspinosum axis were greater in the affected sides and the mandibular condyle and gonion were located more anteriorly in the non-affected sides than in the affected sides but not significant (p=0.07). The activity of the anterior temporal muscle in rest position was higher in the affected sides than in the non-affected sides (p<0.01). The activity of the masseter muscle at maximum clenching was found to be nonsignificant but it was higher in the affected sides than in the non-affected sides (p=0.09). There was positive correlation between facial index and the intercondylar axes angle (p<0.01). There was positive correlation between masseter muscle activity in maximum occlusion and facial index in the affected and non-affected sides (p<0.05). The results demonstrate that the submentovertex radiograph and EMG can provide useful information for the evaluation of horizontal and vertical skeletal relations.

• The korean journal of orthodontics
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• v.46 no.4
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• pp.199-211
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• 2016

Objective: Given the considerable disagreement between the Peer Assessment Rating (PAR) index and the American Board of Orthodontics Cast-Radiograph Evaluation, we aimed to develop a novel assessment system-the Improvement and Completion of Outcome (ICO) index-to evaluate the outcome of orthodontic treatment. Methods: Sixteen criteria from 4 major categories were established to represent the pretreatment malocclusion status, as well as the degree of improvement and level of completion of outcome during/after treatment: dental relationship (arch length discrepancy, irregularity, U1-SN, and IMPA); anteroposterior relationship (overjet, right and left molar position, ANB); vertical relationship (anterior overbite, anterior open-bite, lateral open-bite, SN-MP); and transverse relationship (dental midline discrepancy, chin point deviation, posterior cross-bite, occlusal plane cant). The score for each criterion was defined from 0 or -1 (worst) to 5 (ideal value or normal occlusion) in gradations of 1. The sum of the scores in each category indicates the area and extent of the problems. Improvement and completion percentages were estimated based on the pre- and post-treatment total scores and the maximum total score. If the completion percentage exceeded 80%, treatment outcome was considered successful. Results: Two cases, Class I malocclusion and skeletal Class III malocclusion, are presented to represent the assessment procedure using the ICO index. The difference in the level of improvement and completion of treatment outcome can be clearly explained by using 2 percentage values. Conclusions: Thus, the ICO index enables the evaluation of the quality of orthodontic treatment objectively and consecutively throughout the entire treatment process.

• Imaging Science in Dentistry
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• v.34 no.2
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• pp.75-79
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• 2004

Purpose: To compare the proliferation potential of the epithelial cells between unicystic ameloblastoma (UA), dentigerous cyst (DC), and odontogenic keratocyst (OKC) and to correlate this proliferation potential with the radiographic features of these three pathoses. Materials and Methods: Immunohistochemical expression of PCNA, Ki-67, and cytokeratin as a proliferation marker were assessed for 15 cases of UA, 15 cases of DC, and 15 cases of OKC. The degree of immunochemical expression of three proliferation markers were correlated with the radiographic features, especially cortical expansion (negative and positive) and shape of border (scalloped and round). Results: Using PCNA and Ki-67, OKC showed the highest proliferation potential and UA the lowest. Statistically significant differences were found between the OKC and the UA (p < 0.05). However, no statistically significant difference was present according to the radiographic features in all pathoses. Using cytokeratin, there was no significant differences of proliferation potential among three pathoses. Conclusions : OKC epithelium has the most intense proliferation potential, followed by the dentigeous cyst and then unicystic ameloblastoma. There is no significant relation between the radiographic features and the proliferation potential of epithelium of these three pathoses.

• Journal of the Korean Society of Radiology
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• v.13 no.5
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• pp.749-755
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• 2019

In this study, we investigated the effects of tube voltage (kVp) and tube current (mAs) on an exposure index (EI) applied to a digital radiography. There used an inverter type digital X-ray generator and an image receptor (IR) utilized a portable wireless detector without a grid. Radiographic images were acquired using a cone pyramid phantom produced using a 3D printer. The X-ray tube voltage was increased from 40 kVp to 120 kVp with 10 kVp increment, and the tube current was increased from 1 mAs to 128 mAs with the twice increment. As a result, kVp had logarithmic relationship with the EI as high $R^2$ value, and mAs had a very high linear relationship too. Also, there was a high correlation between the area dose and the EI of the IR, with the $R^2$ value being 0.76 or more. In conclusion, it had showed that mAs affected the EI linearly, and that it could be advantageous to adjust the easy-to-predict mAs to maintain proper image qualities.

• The Journal of Korean Academy of Prosthodontics
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• v.39 no.6
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• pp.698-708
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• 2001

This study was to evaluate the clinical evidence for the success and the predictability of the osseointegrated dental implants in the partially edentulous Korean patients. 201 patients have received total of 502 Branemark implants, which were restored with either single or multiunit fixed superstructures at the Implants Clinic, Yonsei University Dental Hospital. The clinical and radiographic evaluations carried out on the patients for maximum 8 years were assessed annually for peri-implant inflammation, implant mobility (PTV), Plaque Index (PI), Gingival Index (GI), Bleeding on Probing (BOP), Keratinized Mucosa width and any changes in the surrounding bone level. The radiographs were taken at completion of the restoration, and annually thereafter. On the last recall appointments the patients filled a questionnaire consist of 29 questions in four categories. The cumulative non-failure rate of success was 93.9%. The first year mean bone loss was 0.3mm and less than 0.2mm annually thereafter. The periodontal parameters, keratinized tissue width and periotest values stabilized after initial changes in the first few years. The questionnaire has shown general satisfactory responses in all four aspect of dental implants treatment, including chewing efficacy, comfort, aesthetics and speech. The results support the predictability and success of the long-term rehabilitation of implant supported prostheses in partially edentulous Korean patients.

• Korean Journal of Digital Imaging in Medicine
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• v.13 no.3
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• pp.139-144
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• 2011

The purpose of this report is recommending a standard indicator which reflects the radiation exposure that is incident on a detector after every exposure event and that reflects the noise levels present in the image data. The experiment was performed with mobile digital X-ray unit and used a acrylic phantom for exposure index measurement. Exposure modality was kVp, mAs, SID. After every exposure, make a data sheet for characteristic curve of detector response. The equipment performed Mobile digital X-ray unit provide the user with values ralated to the incident exposure(air kerma)to the digital detector. They are showed as a logarithmic function shaped. As a result, DEI means a relative measure of exposure to the detector, as compared to the expected exposure for a particular anatomical view. Radiographic technique is the combination of factors used to exposure an anatomical part to produce a high quality radiography and technique charts used most commonly by radiographers to produce consistently exposure level which patient dose can be kept acceptably low.