Second and third molar calcification in relation to chronological age in Koreans

치의학과/석사[한글] 치아의 발육 및 형성은 사춘기에 접어들어 소구치와 견치의 형성이 끝나면 오직 제 3대구치만이 발육을 계속하는 시기적 특성을 갖고 있다. 제 3대구치의 경우 개체간의 형태, 크기, 출현 시기, 발육속도 등의 개인차가 크며, 다른 치아에 비하여 선천적 결손 빈도가 높은 치아이다. 그러나 제 3대구치 외에 연령추정을 위한 다른 생물학적 기준이 존재하지 않는 경우에는 제 3대구치가 중요한 연령추정의 대상으로 가치를 가지게 된다. 국내에서도 제 3대구치의 발육 정도에 대한 수종의 연구가 있었으나 치아의 발육 상태는 경년 변화, 영양 차이 등에 의하여 계속 변하므로, 시대적 변화에 따른 발육 정도의 변화를 고려하여 갱신된 자료적 기준이 설정되어야 할 필요성이 있다 하겠다. 또한 법의학적 실무에 있어서 제 2대구치와 제 3대구치의 발육이 동시에 존재하는 연령층의 연령추정을 시행하는 경우, 제 2대구치를 기준으로 하였을 때와 제 3대구치를 기준으로 하였을 때 추정연령의 차이가 발생하는 경우를 경험하게 된다. 따라서 제 2대구치, 제 3대구치간의 발육 정도를 비교, 연구하여 이들의 상관관계를 밝히고, 이를 참고로 하는 것이 필요하리라 사료된다. 이에 한국인에서 연령 증가에 따른 제 2대구치 및 제 3대구치의 석회화정도에 관한 연구를 위하여, 1999년에서 2003년 사이에 연세대학교 치과대학 치과병원에 내원하여 파노라마 방사선 사진을 촬영한, 신체의 발육 및 건강상태가 양호하며 특기할 전신질환 병력, 치아 발육에 영향을 미치는 것으로 알려진 치과질환 병력이 없는 환자 중 7세에서 22세에 이르는 각 연령에 40명씩인 남자 640명, 여자 640명씩 총 1,280명의 파노라마 방사선 사진 상에서 2명의 검사자가 각각 독립적으로 각각의 제 2대구치, 제 3대구치의 석회화정도를 Demirjian 등이 제시한 기준을 Solari와 Abramovitch가 수정한 총 11단계의 기준에 따라 조사, 기록, 분석하여 다음과 같은 결과를 얻었다. 1. 한국인에서 연령추정에 필요한 제 3대구치는 남성의 경우 98.3%, 여성의 경우 94.2%에서 적어도 하나 이상 출현하였다. 2. 치아의 석회화정도를 판단하는데 있어서 검사자 2명간의 신뢰도는 모든 치아에서 높은 일치율을 나타내어 검사자간의 주관적 차이는 발생하지 않았다 (κ>0.75). 3. 동일악 좌, 우측 동명 치아, 동측 상, 하악 동명 치아의 발육정도에 있어서, 제 2대구치의 경우 모든 경우에 있어 높은 상관도를 나타내었으며, 동일악 좌, 우측 제 3대구치간의 상관도는 높았으나, 동측 상, 하악 제 3대구치간의 상관도는 낮았다. 4. 연령추정시 제 2대구치를 적용하기에 적절한 연령대는 16세 미만이며, 제 3대구치의 경우, 16세 이상에서 22세 전후로 사료된다. 5. 특정 발육 단계에서 만 18세 이상일 확률을 구한 결과, Stage F1부터는 모든 경우에 있어서 대략 50% 이상의 확률값을 나타내었으며, 동일 발육 단계에서 하악, 여성에서의 확률값이 보다 높았다. 본 연구의 결과, 한국인에서 연령증가에 따른 제 2대구치 및 제 3대구치의 석회화정도에 따른 자료를 제시함으로써, 법의학적인 개인식별에 있어서 보다 정확한 연령추정에 기여할 수 있을 것으로 사료된다. [영문]The growth and development of tooth has a periodical characteristics that after complete development of canine and premolar at puberty, only the third molars continue development. And for the third molar, there are individual variations in morphology, size, eruption period, and rate of development, moreover, the rate of congenital missing is higher than that of the other teeth. However, in the case that other biological references for age estimation are not present, third molar would be a valuable reference. There have been a number of studies on the development of third molar in Korea. However, since the state of tooth development varies with years and nutritional differences, renewal of reference data considering the development change of third molar in accordance with the times. Additionally, variation of age estimation may be observed as to which tooth, second and third molar had been used when second and third molar develop simultaneously. Therefore, through comparison between the developmental degree of second molar and third molar, clarification of the interrelation between the two molars is required to be used as reference. Hence, for the study of second and third molar calcification in relation to chronological age in Koreans, orthopantomograms of 1,280 healthy patients who visited dental hospital, college of dentistry, Yonsei University were examined and recorded by two examiners independently, according to the reference were suggested by Demirjian et al., and modified by Solari and Abramovitch. The age of the patients ranged from 7 to 22, 40 people at each age with 640 males and females. The orthopantomograms of the patients who had the specific medical or dental histories which could affect tooth development are excluded in this study to avoid false results. The results were as follows: 1. In the case of male, 98.3% of the sample showed one or more third molars formation, and that of female was 94.2%. 2. The reliability between the two examiners showed high enough in every cases. There was no significant inter-observer effect. 3. In the case of the same teeth bilaterally within the same jaw and the same teeth unilaterally in upper and lower jaw, every cases of second molar resulted in high correlation. For the third molar, within the same jaw resulted in high correlation but same teeth unilaterally in upper and lower jaw resulted in low correlation. 4. The range of age that is appropriate for application of second molar in age estimation is below the age of 15 years, and for third molar is 16 to 18-year-old. 5. In case of third molar, the probability that the age would be higher than 18 years at specific calcification stage is calculated. In every situation, at stage higher than stage F1, the value of probability was more than about 50%. The probability of mandible was higher than that of maxilla, and the probability of female was higher than that of male. Based on the results, this study could suggest the data about second and third molar calcification in relation to chronological age in Koreans, and it will be applied more accurately in age estimation for human identification.ope

3차원 레이저 스캔을 이용하여 평가된 교근비대 치료에 대한 보툴리눔 A형 독소 주입의 효과

치의학과/박사[한글]보툴리눔 A형 독소(BTX-A)를 사람 교근에 주사하는 방법은 교근 비대의 치료로서 널리 이용되어져 왔다. 본 연구이 목적은 사람 교근에 대한 보툴리눔 A형 독소 주입이 하안면부 외형에 미치는 영향을 3차원 레이저 스캔을 이용하여 평가하고자 하였다. 15명의 자원자를 대상으로 BTX-A를 양측 교근에 각각 25 units씩 주사하였다. 주사 부위는 교근 하방 1/3의 중앙 부위로서 25units을 약 1cm 간격의 두 점에 같은 양으로 나누어 주사하였다. BTX-A의 임상적 효과는 술전과 술후 4주, 8주, 12주, 24주에 3차원 레이저 스캔을 채득하여 평가하였다. 분석 결과, 하안면부의 부피 및 최대 풍융부 높이의 차는 BTX-A 주사 전과 비교하여 4주, 8주, 12주, 24주 후 모두에서 유의한 차이를 보였다. 본 연구는 하안면부 윤곽성형술을 위한 BTX-A의 효과를 평가하는데 있어 3차원 레이저 스캔을 이용한 첫 번째의 전향적 연구라는데 의의가 있다 하겠다. BTX-A는 특히 교근비대가 원인일 경우 하안면부 윤곽성형술을 위한 비수술적 치료로서 안전하게 이용될 수 있다 하겠다. [영문]Botulinum toxin type A(BTX-A) injection into the masseter muscles have been used to treat masseteric hypertrophy. The aim of this study to evaluate changes in the external facial contour after injecting BTX-A on the human masseter muscle with three-dimensional(3D) laser scanning. 15 volunteers were enrolled in this study. A total of 25 units of BTX-A was injected into each side bilaterally at two points at the center of the lower 1/3 of the masseter muscle. The clinical effect of BTX-A was evaluated by 3D laser scans before the injection and 4, 8, 12, and 24 weeks after the injection. Mean values of the volume and the bulkiest height differed significantly between preinjection and 4, 8, 12, and 24 weeks postinjection. This is the first prospective study using 3D laser scanning to evaluate the effects of BTX-A in lower facial contouring. BTX-A can be safely used as a nonsurgical treatment for lower facial contouring, especially masseteric hypertrophy.ope

뉴럴 네트워크(Neural network)를 이용한 충청남도 쌀 농가의 경영분석

학위논문(석사)--서울대학교 대학원 :농경제학과,2002.Maste

Effect of botulinum toxin type A injection on lower facial contouring evaluated using a three-dimensional laser scan.

OBJECTIVE: To use three-dimensional (3D) laser scanning to elucidate changes in the external facial contour before and after botulinum toxin type A (BoNT-A) injections. METHODS & MATERIALS: BoNT-A was injected into 15 volunteers as a treatment for lower facial contouring. A total of 25 U of BoNT-A was injected into each side of the masseter muscle bilaterally. On each side, it was injected into two points at the center of the lower third of the masseter muscle separated by 1 cm. The clinical effects of BoNT-A were evaluated by performing 3D laser scans before and 4, 8, 12, and 24 weeks after the injection. RESULTS: The mean values of the volume and widths of the most prominent area at each time point differed significantly before and 4, 8, 12, and 24 weeks after the injection. CONCLUSIONS: The volumes and widths of the most prominent areas of the lower face (masseter muscle) were significantly lower 4, 8, 12, and 24 weeks after injecting BoNT-A than before the injection. The mean values of the volume and widths of the most prominent area were 2,176.93 mm(3) and 2.39 mm less, respectively, 24 weeks after the injection than beforeope

Efficacy of Self-manipulation Technique in the Treatment of Patients with Anterior Disc Displacement without Reduction

Trigeminal neuralgia is defined as “a sudden, usually unilateral, brief stabbing recurrent pain in the distribution of one or more branches of the fifth cranial nerve” by the International Association for the Study of Pain(IASP). Trigeminal neuralgia is classified as an idiopathic trigeminal neuralgia with no apparent cause and a symptomatic trigeminal neuralgia which is caused by a structural lesion such as brain tumor. Over 80% of the tumors are meningioma, acoustic neuroma, and epidermoid tumors. Symptomatic trigeminal neuralgia can not be excluded even if old-aged patient does not have abnormal neurologic sign and symptom, and good response to pharmacotherapy. Therefore, initial examinations such as MRI or CT are essential to exclude symptomatic trigeminal neuralgia. When compared with CT, MRI, especially gadolinium enhanced MRI, has an increased sensitivity in the detection of intracranial lesions. The most effective medical treatment of trigeminal neuralgia is carbamazepine. The most common side effects of carbamazepine include drowsiness, dizziness, unsteadiness, nausea, anorexia. Hepatotoxicity, bone marrow depression are the most feared side effect of carbamazepine therapy but occurs rarely. It require periodic complete blood cell counts as well as hepatic and renal function tests. It has been recommended that complete blood cell counts is done every 2 weeks for the first 2months and then quaterly thereafter. Oxcarbazepine can be used if neutropenia occurs.ope

뇌파의 의사결정트리 분석과 가능성기반 서포트벡터머신 분석을 통한 우울증 환자의 분류

우울증은 가장 유병율이 높은 기분 장애(mood disorder)의 일종으로, 약 20%의 인구가 일생동안 우울증 증상을 한번쯤 경험한다. 이러한 우울증은 크게 우울 장애(major depressive disorder)와 양극성 장애(bipolar disorder)로 구분된다. 환자의 질병 분류에 따라 사용되는 약과 의학적 처방이 다르기 때문에, 우울증 환자의 빠르고 정확한 진단 및 분류는 매우 중요하다. 기존의 다면성 인성검사(MMPI)와 같은 통계적인 방법이 우울증 환자의 진단을 위해 사용돼 왔으나, 장시간의 집중력을 요구하기 때문에 집중력 저하의 특징을 보이는 우울증 환자들에게 적용하는데 어려움이 있다. 이 논문에서는 이러한 문제를 해결하고자, 빠른 측정이 가능하고 측정동안 집중력을 요하지 않는 EEC 데이터의 분석을 통해 우울증 환자의 분류를 시도하였다. EEG 채널 간 정보 흐름에서의 비선형성과 근사 엔트로피(approximate entropy)의 크기를 속성(attribute)으로 사용하여 데이터 마이닝 기법 중 의사 결정 트리(decision tree)와 가능성 기반 서포트 벡터머신(possibilistic support vector machines) 통해 분석을 수행하였다. 30명의 주요 우울장애환자와 24명의 양극성 장애 환자를 통해 위의 분석을 수행한 결과 의사 결정 트리의 경우 85.19% 의 정확도를 가지며 분류해냈고, 가능성 기반 서포트 벡터머신의 경우 77.78%의 정확도를 보여줬다. 본 연구는 가능성 기반 서포트 벡터 머신 분석이 우울증 환자는 진단하고 분류하는데 유용하게 적용될 수 있는 가능성을 제시하고 있다

쥐의 휴식 상태에서 뇌 연결성 분석: fMRI와 전기 생리학을 이용한 연구

학위논문(박사) - 한국과학기술원 : 바이오및뇌공학과, 2012.8, [ xiii, 98 p. ]Collections of afferent and efferent connections and associated neuroelectric activities provide a framework for constructing brain connectivity networks. Advances in neural signal acquisition and analysis methods improved the understanding of both structural and functional aspects of the neurofunctional networks. In particular, based on the strong coupling between neural and hemodynamic activities, blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI) has long been established as a convenient means to evaluate stimulus-induced activity in the brain with excellent spatial resolution. However, the fMRI technique is limited to resolve only stimuli- or task-specific responses and to assess the functionality of responding brain regions. An alternative, a relatively new fMRI approach, resting-state fMRI (rs-fMRI) has been introduced to evaluate organization of the functional connectivity networks and changes of such in the whole brain. The rs-fMRI relies on periodic spontaneous neurohemodynamic events and related MRI signal changes due to fluctuations of the deoxygenated hemoglobin concentration in the local brain tissue. We posit that such unsolicited neural activities are particularly important and useful for understanding baseline of the functional neural networks and also for assessing neuropathological conditions such as stroke, ALS, alzheimer’s and parkinson’s dieseases. In mid 1990’s, low-frequency (~0.1 Hz) fluctuations (LFFs) have been identified in the resting-state BOLD MRI time series. Since the discovery, researchers have demonstrated the temporal synchronicity of LFFs across functionally related brain regions. Several studies have substantiated the neural basis of LFFs while correlations between fMRI time series have expanded the applicability of BOLD fMRI from a tool to assess task-elicited brain activity to one that can be used to construct global maps of neural connectivity networks. However, since the BOLD signal is an i...한국과학기술원 : 바이오및뇌공학과

Extrahippocampal Radiomics Analysis Can Potentially Identify Laterality in Patients With MRI-Negative Temporal Lobe Epilepsy

Objective: The objective of the study was to investigate whether radiomics features of extrahippocampal regions differ between patients with epilepsy and healthy controls, and whether any differences can identify patients with magnetic resonance imaging (MRI)-negative temporal lobe epilepsy (TLE). Methods: Data from 36 patients with hippocampal sclerosis (HS) and 50 healthy controls were used to construct a radiomics model. A total of 1,618 radiomics features from the affected hippocampal and extrahippocampal regions were compared with features from healthy controls and the unaffected side of patients. Using a stepwise selection method with a univariate t-test and elastic net penalization, significant predictors for identifying TLE were separately selected for the hippocampus (H+) and extrahippocampal region (H-). Each model was independently validated with an internal set of MRI-negative adult TLE patients (n = 22) and pediatric validation cohort with MRI-negative TLE (n = 20) from another tertiary center; diagnostic performance was calculated using area under the curve (AUC) of the receiver-operating-characteristic curve analysis. Results: Forty-eight significant H+ radiomic features and 99 significant H- radiomic features were selected from the affected side of patients and used to create a hippocampus model and an extrahippocampal model, respectively. Texture features were the most frequently selected feature. Training set showed slightly higher accuracy between hippocampal (AUC = 0.99) and extrahippocampal model (AUC = 0.97). In the internal validation and external validation sets, the extrahippocampal model (AUC = 0.80 and 0.92, respectively) showed higher diagnostic performance for identifying the affected side of patients than the hippocampus model (AUC = 0.67 and 0.69). Significance: Radiomics revealed extrahippocampal abnormality in the affected side of patients with TLE and could potentially help to identify MRI-negative TLE. Classification of Evidence: Class IV Criteria for Rating Diagnostic Accuracy Studies