• Imaging Science in Dentistry
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• 제42권4호
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• pp.213-217
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• 2012

Purpose: This study was performed to evaluate the uniqueness and reliability of the frontal sinuses by comparing various patterns of frontal sinus as observed on Waters' radiographs for individual identification. Materials and Methods: Three Waters' radiographs of 100 individuals, taken on day one, after 6-8 months, and one radiograph with a slight variation in angulation, to mimic conditions out in the field or during autopsy. Three observers were randomly given radiographs from all there packets for comparisons and identification, by the method of superimposition and individual uniqueness. Results: The comparative identification by superimposition of the frontal sinus was 100% positive. The size, shape, unilateral or bilateral presence, absence, and septa were observed to be unique in each case; neither had the measurements changed over a period of time. Conclusion: The need to establish a reliable, low-cost, and easily reproducible method for human identification prompted the elaboration of technical, precise, and accessible parameters, such as the evaluation of the area, asymmetry, and shape of the frontal sinus. Comparison among each of the frontal sinuses of the 100 people in the sample revealed that no two sinuses are the same, that is, the sinus is unique to each individual.

• Journal of Oral Medicine and Pain
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• 제38권2호
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• pp.137-142
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• 2013

구강내과는 측두하악관절장애 및 신경병성통증 등과 같은 구강안면 통증, 연조직 질환, 구취, 레이저 치료, 코골이와 수면 무호흡증, 법치의학적인 감정 분야 등을 포함하고 있다. 이상의 질환은 비교적 흔하게 발생되며 환자에게 큰 불편과 고통을 안겨주며 때로는 건강에 치명적인 위협을 초래하기도 한다. 구강내과학적인 측면에서 볼 때, 현대 사회로 갈수록 생활 패턴의 변화와 스트레스 증가 등의 원인으로 턱관절 장애를 포함한 구강 안면 통증 환자가 늘어나고 있으며 또한 연조직 질환, 코골이와 수면 무호흡증, 법치의학적인 감정 등과 같은 구강내과적인 전문성을 요구하는 분야의 수요가 가파르게 증가되고 있다. 따라서 치과학 중에서 구강내과의 역할과 전문성에 대한 요구가 갈수록 증가되고 있다. 연간 구강내과에 내원한 신환의 질병명에 따른 분포도와 증상의 이환 기간, 내원 경로 등을 분석하는 것은 향후 구강내과의 역할과 비중에 대한 정보를 제공해주며 환자를 위한 원활한 진단과 치료를 가능하게 한다. 따라서 본 연구에서 1년간 치과대학병원 구강내과에 내원한 신환을 분석하여 향후 구강내과의 역할과 전문성에 대하여 고찰해 보았을 때 다음과 같은 결과를 얻었다. 1. 구강내과에 내원하는 신환은 주로 측두하악장애, 연조직 질환, 신경병성 통증 환자로 나타났다. 2. 측두하악장애 환자는 신환중 가장 높은 비율을 보였으며 세부 진단순은 복합 장애 환자, 근육통 환 자, 관절원판 내장증 환자 순이었다. 3. 연조직 질환 환자 중 구강건조증 환자가 가장 높은 비율을 보였으며 그다음 편평태선 환자, 재발성 아프타성 궤양 순이었다. 4. 신경병성 통증 환자에서 구강 작열감 증후군이 가장 높은 비율을 보였다.

• 대한치과교정학회지
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• 제53권3호
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• pp.194-204
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• 2023

Objective: To investigate sex-specific correlations between the dimensions of permanent canines and the anterior Bolton ratio and to construct a statistical model capable of identifying the sex of an unknown subject. Methods: Odontometric data were collected from 121 plaster study models derived from Caucasian orthodontic patients aged 12-17 years at the pretreatment stage by measuring the dimensions of the permanent canines and Bolton's anterior ratio. Sixteen variables were collected for each subject: 12 dimensions of the permanent canines, sex, age, anterior Bolton ratio, and Angle's classification. Data were analyzed using inferential statistics, principal component analysis, and artificial neural network modeling. Results: Sex-specific differences were identified in all odontometric variables, and an artificial neural network model was prepared that used odontometric variables for predicting the sex of the participants with an accuracy of > 80%. This model can be applied for forensic purposes, and its accuracy can be further improved by adding data collected from new subjects or adding new variables for existing subjects. The improvement in the accuracy of the model was demonstrated by an increase in the percentage of accurate predictions from 72.0-78.1% to 77.8-85.7% after the anterior Bolton ratio and age were added. Conclusions: The described artificial neural network model combines forensic dentistry and orthodontics to improve subject recognition by expanding the initial space of odontometric variables and adding orthodontic parameters.

• Imaging Science in Dentistry
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• 제50권2호
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• pp.153-159
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• 2020

Purpose: This study was conducted evaluate the influence of reconstruction parameters of micro-computed tomography (micro-CT) images on bone mineral density (BMD) analyses. Materials and Methods: The sample consisted of micro-CT images of the maxillae of 5 Wistar rats, acquired using a SkyScan 1174 unit (Bruker, Kontich, Belgium). Each acquisition was reconstructed following the manufacturer's recommendations(standard protocol; SP) for the application of artifact correction tools(beam hardening correction [BHC], 45%; smoothing filter, degree 2; and ring artifact correction [RAC], level 5). Additionally, images were reconstructed with 36 protocols combining different settings of artifact correction tools (P0 to P35). BMD analysis was performed for each reconstructed image. The BMD values obtained for each protocol were compared to those obtained using the SP through repeated-measures analysis of variance with the Dunnett post hoc test(α=0.05). Results: The BMD values obtained from all protocols that used a BHC of 45% did not significantly differ from those obtained using the SP (P>0.05). The other protocols all yielded significantly different BMD values from the SP(P<0.05). The smoothing and RAC tools did not affect BMD values. Conclusion: BMD values measured on micro-CT images were influenced by the BHC level. Higher levels of BHC induced higher values of BMD.

• Imaging Science in Dentistry
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• 제46권3호
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• pp.159-165
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• 2016

Purpose: The purpose of this study was to detect the anterior loop of the mental nerve and the mandibular incisive canal in panoramic radiographs (PAN) and cone-beam computed tomography (CBCT) images, as well as to determine the anterior/mesial extension of these structures in panoramic and cross-sectional reconstructions using PAN and CBCT images. Materials and Methods: Images (both PAN and CBCT) from 90 patients were evaluated by 2 independent observers. Detection of the anterior loop and the incisive canal were compared between PAN and CBCT. The anterior/mesial extension of these structures was compared between PAN and both cross-sectional and panoramic CBCT reconstructions. Results: In CBCT, the anterior loop and the incisive canal were observed in 7.7% and 24.4% of the hemimandibles, respectively. In PAN, the anterior loop and the incisive canal were detected in 15% and 5.5% of cases, respectively. PAN presented more difficulties in the visualization of structures. The anterior/mesial extensions ranged from 0.0 mm to 19.0 mm on CBCT. PAN underestimated the measurements by approximately 2.0 mm. Conclusion: CBCT appears to be a more reliable imaging modality than PAN for preoperative workups of the anterior mandible. Individual variations in the anterior/mesial extensions of the anterior loop of the mental nerve and the mandibular incisive canal mean that is not prudent to rely on a general safe zone for implant placement or bone surgery in the interforaminal region.

• Journal of Oral Medicine and Pain
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• 제25권2호
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• pp.253-263
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• 2000

We collected age determination cases which were done at Yonsei university dental hospital, department of oral medicine from 1976 to 1999 to analyze it's tendency among Koreans. We analyzed 435 clients cases which were stored by age estimation program from January 1993 to December 1999. The results are as follows: 1. There were no significant difference in the sexual distribution (male : 52.0%, female : 48.0%) and more than half percent (51%) were 20's and 30's. 2. Among the age determination clients, those who wanted to decrease their age (50.3%) and those who wanted to increase their age (49.7%) shows similar in number. And the former case were predominant in the female clients, but the latter case in the male clients. Also the clients below six years of age were predominant in the former case, but the clients more than sixty were predominant in the latter case. 3. The purposes of age correction showed different distribution for ages: job or employment for 20's and 30's, marriage for 20's, registration for school for below six, welfare and other social services for 50 and older. 4. Age was estimated by Nolla's growth stage for 12 and under, calcification of the second and third molar for 12~20, and for 20 and over, Takei's tooth abrasion model was used. 5. The alleged age was in accordance with the documents and other information given by clients, but in the 20.6% of the estimation cases, the alleged age was discarded. In the results of the analysis of age determination cases in Koreans, many of the cases resulted from our historical turbulence and social distinctiveness, causing an increase in the necessity for age correction in each age group. For more accurate determination for each age group, further studies with Koreans must be done continuously.

• Imaging Science in Dentistry
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• 제51권2호
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• pp.167-174
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• 2021

Purpose: Sex determination can be done by morphological analysis of different parts of the body. The mastoid region, with its anatomical location at the skull base, is ideal for sex identification. Statistical shape analysis provides a simultaneous comparison of geometric information on different shapes in terms of size and shape features. This study aimed to investigate the geometric morphometry of the inter-mastoid triangle as a tool for sex determination in the Iranian population. Materials and Methods: The coordinates of 5 landmarks on the mastoid process on the 80 cone-beam computed tomographic images(from individuals aged 17-70 years, 52.5% female) were registered and digitalized. The Cartesian x-y coordinates were acquired for all landmarks, and the shape information was extracted from the principal component scores of generalized Procrustes fit. The t-test was used to compare centroid size. Cross-validated discriminant analysis was used for sex determination. The significance level for all tests was set at 0.05. Results: There was a significant difference in the mastoid size and shape between males and females(P<0.05). The first 2 components of the Procrustes shape coordinates explained 91.3% of the shape variation between the sexes. The accuracy of the discriminant model for sex determination was 88.8%. Conclusion: The application of morphometric geometric techniques will significantly impact forensic studies by providing a comprehensive analysis of differences in biological forms. The results demonstrated that statistical shape analysis can be used as a powerful tool for sex determination based on a morphometric analysis of the inter-mastoid triangle.

• 대한치과교정학회지
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• 제54권1호
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• pp.26-47
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• 2024

Objective: This systematic review aimed to evaluate the correlation between vitamin D levels and the rate of tooth movement, external apical root resorption, bone biomarker expression, and bone remodeling. Methods: Three databases (PubMed, Scopus, and Web of Science) were systematically searched from inception until 14th March 2023 to identify studies investigating the correlation between orthodontic tooth movement and vitamin D in animals and humans. The quality assessment was made in accordance with the Joanna Briggs Institute Critical Appraisal Checklist. Results: Overall, 519 records were identified, and 19 were selected for the qualitative synthesis. Eleven studies investigated the effect of local administration (injections in the periodontal ligament, to the gingiva distal to the teeth, or submucosae palatal area) and systemic administration (oral supplementation) of vitamin D on tooth movement, external apical root movement, pro-inflammatory cytokines, and bone remodeling factors. The remaining eight studies investigated the correlation between serum vitamin D levels and salivary vitamin D levels on bone turnover markers and tooth movement. Conclusions: The findings of this systematic review support that vitamin D3 local injections might increase the rate of tooth movement via the receptor activator of the nuclear factor-kB/osteoprotegerin axis. However, the non-uniform study designs and the different protocols and outcome methods make it challenging to draw reliable conclusions.

• Imaging Science in Dentistry
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• 제36권1호
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• pp.49-54
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• 2006

Purpose : To evaluate accuracy and reliability of program to measure facial soft tissue thickness using 3D computed tomographic images by comparing with direct measurement. Materials and Methods : One cadaver was scanned with a Helical CT with 3 mm slice thickness and 3 mm/sec table speed. The acquired data was reconstructed with 1.5 mm reconstruction interval and the images were transferred to a personal computer. The facial soft tissue thickness were measured using a program developed newly in 3D image. For direct measurement, the cadaver was cut with a bone cutter and then a ruler was placed above the cut side. The procedure was followed by taking pictures of the facial soft tissues with a high-resolution digital camera. Then the measurements were done in the photographic images and repeated for ten times. A repeated measure analysis of variance was adopted to compare and analyze the measurements resulting from the two different methods. Comparison according to the areas was analyzed by Mann-Whitney test. Results : There were no statistically significant differences between the direct measurements and those using the 3D images (p>0.05). There were statistical differences in the measurements on 17 points but all the points except 2 points showed a mean difference of 0.5 mm or less. Conclusion : The developed software program to measure the facial soft tissue thickness using 3D images was so accurate that it allows to measure facial soft tissues thickness more easily in forensic science and anthropology.

• Journal of Oral Medicine and Pain
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• 제26권4호
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• pp.377-393
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• 2001

In order to study the closure stage of cranial sutures and its correlations with age, the ectocranial closure stage of coronal suture, sagittal suture, and lambdoidal suture of 67 skulls was measured. Among the skulls kept at the department of anatomy, college of medicine, Yonsei University, the ones with ages identified were used for this study. These measurements of suture closure were conducted by 4 examiners independently. The sutures were further divided by Frederic's method into 16 suture parts. The closure stages were classified by five stages of Broca-Ribbe. The following results were obtained: 1. The inter-observer reliability among 4 examiners showed high intraclass correlation coefficient of over 0.75(mean : 0.856) in all suture parts. Therefore, the determination of closure stage wasn't influenced by the subjective view of each examiner. 2. In all suture parts, the closure stage increased proportionally with age.(p<0.01) In terms of each suture part, the S2 part of sagittal suture showed the highest correlation(68.1%) while the L1-R part of lambdoidal suture showed the lowest correlation(51.3%). In addition, in terms of suture types, the correlation with age decreased in the order of sagittal suture(60.0%), coronal suture(57.7%), and lambdoidal suture (55.7%). In general, the average value of suture closure stages had 57.8% correlation with age(p<0.01). 3. The most frequent suture closure stage according to age group was '0' for ages below 30, '0' and '1' for ages within the 30's, '1' and '2' for ages within the 40's, and '2' for ages within the 50's. With older age groups, the frequency of '3' and '4' increased, and the suture closure stage increased proportionally with age. 4. The mean age by closure stage of each suture were within the 40's for the closure stage of '1', within the 50's for the closure stage of '2', and from 50's through 60's for the closure stage of '3'. The standard deviation was over 10 for all closure stages. In addition, at the same suture closure stage, the mean age according to the coronal suture was higher than the ages according to the sagittal suture or lambdoidal suture. Especially, C1-R, C1-L, C2-R, and C2-L parts showed the highest age when at the same suture closure stage. 5. The values appropriate for age estimations using suture closure stages of 16 suture parts were calculated, and a calculator for age estimation ($R^2=0.6944$, p<0.01) by ectocranial suture closure stage for Koreans is presented. From the above results, the method of using the closure stage of sutures of the skull to estimate age can be useful in individual identification of forensic science. Further extensive and accurate research using larger samples would be worthy of study.