구강내 개화성 유두종증을 가진 악성 흑색극세포증의 증례보고

정재광,신홍인,민보경,Jung, Jae-Kwang,Shin, Hong-Ihn,Min, Bo-Kyung 대한안면통증구강내과학회 2010 Journal of Oral Medicine and Pain Vol.35 No.4

흑색극세포증은 대개 피부가 접히는 부위에서 짙은 색의 반점과 함께 벨벳양상을 가진 두꺼워진 피부 그리고 혀, 치은, 점막, 구개를 포함하는 구강내 및 입술부위의 유두종증의 특징을 가진다. 그중에서도 악성 흑색극세포증은 기저 암종과 연관되어 발생되며 특징적으로 입술과 눈꺼풀의 개화성 유두종증, 손바닥 및 발바닥의 저명한 과각화증, 레제르-트렐라 증후와 같은 세가지 특징이 나타난다. 본 증례의 환자에서 악성 흑색극세포증의 전형적인 임상적 그리고 조직학적 특징과 함께 악성 위장 선암종의 병력을 가지고 있었다.

보 하류부 하상보호공 길이산정을 위한 실험연구

정재광 한국습지학회 2011 한국습지학회지 Vol.13 No.3

본 연구에서는 하천의 이동상 실험분석을 통하여 보 하류부의 하상보호공 길이 산정을 위한 공식을 제안하였으며, 실제 하천과 유사한 모형수로와 하천을 횡단하는 보 구조물을 설치하여 수리모형실험을 수행하였다. 실험을 통하여 하천 횡단 구조물인 보가 설치되었을 경우 수리학적 특성인 수위, 유속의 변화와 하상변동 등을 분석하였으며, 수리모형실험 수행 이후 실험 결과에 대한 분석을 통하여 보 설치에 따른 수리실험을 실시하여 하상 보호공 공식을 고정보 및 가동보에 대하여 제시하였고, 제시된 공식과 기존의 하상보호공 길이 산정공식을 비교해 본 결과 본 연구에서 제안된 공식에 의하여 산정된 바닥보호공 길이가 실험결과와 일치하는 것으로 나타났다. 또한, 본 실험을 통하여 보 설치에 따른 하상 퇴적 길이 및 하상변화를 산정하였으며, 산정결과 유량의 증가에 따라 보 직하류부부터 시작되는 세굴심과 최대세굴거리가 증가함을 확인하였다.

The Relationship between Temporomandibular joint Pain and the Relative Signal Intensity of Retrodiscal Tissue on T1-, and T2-Weighted MRI Images

정재광,허윤경,최재갑,Jung, Jae-Kwang,Hur, Yun-Kyung,Choi, Jae-Kap Korean Academy of Orofacial Pain and Oral Medicine 2011 Journal of Oral Medicine and Pain Vol.36 No.3

Aims: The purpose of this study was to evaluate the relationship between temporomandibular joint pain and the relative signal intensity (RSI) of retrodiscal tissue on T1-, and T2-weighted MRI images. Materials and Methods: This study was based on 122 TMJs of 61 patients who complain of TMJ pain in only one side but were revealed to have disc displacement in both TMJs according to MRI findings. The signal intensities of regions of interest (ROIs) in retrodiscal tissues were measured using T1-, and T2-weighted MRI images. The RSIs of retrodiscal tissues were referenced to the signal intensities of the ROIs of brain gray matter. The relationships between the RSI of retrodiscal tissue and joint pain, joint effusion, condylar degenerative change, and degree of disc displacement were examined. In addition, the relationships between joint pain and joint effusion, condylar degenerative change, and degree of disc displacement were examined. Results: On T1-weighted MR images, the painful TMJs showed significantly higher retrodiscal tissue RSI than non-painful TMJs. In addition, there is an association between joint pain and the degree of disc displacement. However, on T2-weighted MR images, the RSIs of retrodiscal tissues didn't show any significant differences with regard to joint pain, joint effusion, condylar degenerative change, and degree of disc displacement. Conclusions: The signal intensity of retrodiscal tissue can be used as a diagnostic marker for painful TMJ. However, the overall results suggest the signal intensity of retrodiscal tissue has a limited diagnostic significance in determining the pathologic status of TMJ.

The Effect of Mandibular Protrusion on Dynamic Changes in Oropharyngeal Caliber

정재광,최재갑,허윤경 대한안면통증∙구강내과학회 2010 Journal of Oral Medicine and Pain Vol.35 No.3

The purpose of this study was to determine the sites of narrowing/obstruction and to measure the regional severity of narrowing through the evaluation of dynamic changes in upper-airway of healthy subjects. The selected 9 subjects were proved not to have any sleep-related disorder such as snoring or obstructive sleep apnea through clinical examination, radiological examination, sleep study with a portable recording system. Afterward, the Electron Beam Tomography was performed during the waking and sleeping state of subjects, with their mandible in resting and protruded position. Intravenous injection of DormicumⓇ was used for the induction of sleep. The maximum and minimum cross-sectional areas at each airway level during tidal ventilation were measured and the Collapsibility Index for each level of cross-section was also computed. In a comparison with results under variable conditions, the result was showed that the significant difference between each airway level divided with upper, middle, lower region of upper airway is not observed in the average minimum cross-sectional areas and Collapsibility Index. The significant difference only between in wake and sleep state was observed in the average minimum cross-sectional area at the lower region. Also, in wake state, the significant difference between resting and protrusive position of mandible for the average minimum was also observed in cross-sectional area at middle region. In sleep state, no significant difference between resting and protrusive position of mandible was observed in cross-sectional area and the Collapsibility Index.

Acute Occlusal Change Following Acute Anterior Disc Displacement without Reduction: A Case Report

정재광,허윤경,최재갑,Jung, Jae-Kwang,Hur, Yun-Kyung,Choi, Jae-Kap The Korean Academy of Orofacial Pain and Oral Medi 2012 Journal of Oral Medicine and Pain Vol.37 No.4

35세 여자환자가 갑작스런 개구장애와 함께 발생한 급성 교합변화를 주소로 내원하였다. 환자는 이전 수년 동안의 관절잡음의 병력을 가지고 있었으며 관절잡음의 소실과 동시에 개구제한이 발생하였음을 보고하였다. 환자는 개구제한과 함께 개구시 우측 악관절의 통증을 호소하였으며 구강내 교합 검사 시 전치부의 개교합과 함께 하악이 우측으로 전위된 양상이 관찰되었다. 또한 좌측으로의 측방운동량 또한 감소된 것으로 관찰되었다. 자기공명영상에서 우측 악관절에서 비정복성 관절 원판 전방 변위가 관찰되었으며 후방 관절강의 협착이 관찰되었다. 이 환자는 우측 악관절의 비정복성 관절원판 전방변위로 진단되었으며, 급성 교합변화는 변위된 관절원판에 의해 야기된 과두위치의 변화로 초래된 것으로 추정하였다. 처음 3개월간의 물리치료와 약물치료와 병행된 안정교합장치요법에서는 만족할 만한 치료결과를 얻지 못하였으나, 그 다음 약 8개월간 사용된 악간견인장치 치료를 통해서 통증 및 교합변화가 해소되었으며 정상적인 개구량으로 회복되었다. 술후 촬영된 자기공명영상에서 우측 과두가 재형성된 양상을 관찰할 수 있었다. A 35 year-old female presented with the complaint of sudden occurrence of bite change and concurrent opening limitation, as well as pain in the right temporomandibular joint (TMJ) during mouth opening. From her history it was revealed that she had simple clicking of right TMJ for several years before onset of these symptoms, and that the clicking sound subsided recently after development of opening limitation. On clinical examination, anterior open bite, midline shift of the mandible to right, and premature contacts on left posterior teeth were observed. Maximum mouth opening and lateral movement to left were also restricted. On magnetic resonance images, the right TMJ showed anterior disc displacement without reduction and the posterior joint space is greatly collapsed by retrusion of the condyle. It was thought that the sudden occurrence of occlusal change would be resulted from abrupt displacement of the mandible associated with development of the anterior disc displacement without reduction. The stabilization appliance traction therapy was performed initially for first 3 months along with physical and pharmacologic therapy. However, the anterior open bite and opening limitation didn't resolve and the position of mandible still remained altered. So the stabilization appliance was changed to intermaxillary traction device. Then the mandible returned progressively to normal position and the occlusion became more stable and comfortable. After 5 months of intermaxillary traction therapy, the anterior open bite was dissolved completely and the occlusion became stabilized satisfactorily along with recovery of normal mouth opening range. On post-treatment magnetic resonance image, remodeling of condylar head was observed.

Analysis of the characteristics of mouthguards that affect isokinetic muscular ability and anaerobic power

정재광,채원식,이규복 대한치과보철학회 2013 The Journal of Advanced Prosthodontics Vol.5 No.4

PURPOSE. The purpose of this study was to estimate the effects of occlusal stability to identify action mechanisms of mouthguards, known to have a modulatory effect on limb muscle function. MATERIALS AND METHODS. This study included 20 male subjects to perform the isokinetic muscle tests and the Wingate anaerobic power test on both knee joints under five closed-mouth conditions: without or with 4 types of mouthguards with thickness of 2 mm based on premolar area: (1) full-coverage, (2) anterior partial-coverage, (3) right posterior partial-coverage, and (4) left posterior partial-coverage. The obtained results were subjected to One-way ANOVA with repeated measures, followed by post hoc test of the contrast method (α=.05). RESULTS. There was no significant difference between the closed position with and without a full-coverage mouthguard in all variables. However, significant differences were observed between with and without a partial-coverage mouthguard in muscular endurance during extension of the left knee, muscular power and endurance during flexion of the right knee. Additionally, significant differences were found between occlusal states with full-and partial-coverage mouthguards in muscular power and endurance during extension of the left knee. CONCLUSION. These findings indicate the elevation of vertical dimension by 2 mm or the inducement of occlusal stability had little effect on isokinetic muscle strength and anaerobic performance, while uneven distribution of occlusal force might have some positive effects.

Basic Understanding of Transcutaneous Electrical Nerve Stimulation

정재광,변진석,최재갑 대한안면통증∙구강내과학회 2016 Journal of Oral Medicine and Pain Vol.41 No.4

Transcutaneous electrical nerve stimulation (TENS) is one of the representative physiotherapicalmodalities used for the treatment of various musculoskeletal disorders by the applicationof electrical stimuli. In dental practice, it has long been used in the treatment of acute andchronic orofacial pain conditions including temporomandibular disorders. TENS is the deliveryof therapeutic electrical stimuli with a variety of electrical intensity, frequency and durationto stimulate peripheral nerve through surface electrodes with various form and placement. While controversy still remains over the clinical effectiveness and application of TENS, basicunderstanding of its electrical properties and the expected biological reactions is important toincrease the therapeutic effect and decrease the risk of possible side effects. This review, therefore,focuses on basic understanding of TENS including its underlying mechanisms and stimulationparameters.

KOSPI 200 구성종목 변경 전후의 기업 공시행태 변화에 대한 연구

정재광,변정윤,문두철,최병철 한국공인회계사회 2021 회계·세무와 감사 연구 Vol.63 No.1

This paper examines the effect of changes in KOSPI 200 index on corporate disclosure using Difference in Differences(DID) method. By using DID method, this study controls the endogeneity issue arising from KOSPI 200 index inclusion criteria, which mainly is market capitalization. Also, DID method controls the effect of changes in disclosure rules and regulations. This paper’s empirical results are summarized as follows. First, any evidence that firms’ disclosure frequency increased after KOSPI 200 index inclusion was not found. This result suggests that index inclusion does not lead market oversight to demand more information from firms. Instead, firms’ disclosure frequency significantly increased a year before inclusion due to the increase in firm size. Second, disclosure frequency significantly decreased after index exclusion. With the univariate result which shows no significant change in firm size, this suggests that exclusion event itself triggered firms to decrease disclosure frequency. In summary, contrary to the hypothesis that KOSPI 200 index inclusion will lead to increased market oversight demanding more disclosures from firms, newly included firms’ disclosure frequency did not change. However, as for exclusion case, firms decreased disclosures. These findings contribute to prior literatures by providing a new aspect of corporate behavior around KOSPI 200 index change. While prior studies mainly examined stock price response and firms’ accounting policies, this paper expands these understandings to firms’ disclosure behavior. In addition, DID method used in this paper provides a valuable implication on the methodology of prior studies. 본 연구는 KOSPI 200 구성종목 변경 전후로 기업의 공시유인 변화와 이에 따른 공시행태 변화를 이중차분법(Difference in Differences)을 사용하여 분석하였다. 분석을 위해 2003년부터 2016년까지 KOSPI 200 신규 편입・편출기업과 1:1 대응표본을 대상으로 편입 및 편출사건 전후 표본을 구성하였으며, 편입은 1,139개, 편출은 1,171개의 기업-연도(firm-year) 표본을 사용하였다. 또한, Schoenfeld(2017)이 제시한 이중차분법을 사용하여 지수편입 기준인 시가총액이 야기할 수 있는 내생성(Endogeneity) 문제와 공시규정 변경에 의한 연도별 공시빈도 차이를 통제하였다. 분석 결과, 신규 편입 전후 자율공시와 공정공시 모두 통계적으로 유의한 변화는 나타나지 않았지만, 신규 편입 직전 연도에는 매출액, 수익성, 자산규모, 시가총액의 유의한 증가에 공시빈도도 유의하게 증가하였다. 편출의 경우, 편출사건을 기점으로 자율공시와 공정공시 모두 유의하게 감소하였다. 동일 분석 기간에 편출기업의 수익성과, 시가총액, 자산규모가 유의하게 변하지 않았다는 분석 결과를 고려하면, 해당 결과는 편출 전후 자산규모나 수익성, 시가총액 등의 기업특성 변화에 의한 것이 아닌 편출로 인한 정보수요와 공시유인의 감소로 공시감소행태가 나타난 것으로 해석된다. 본 연구는 정보비대칭 감소와 시장효율성, 투자자보호 측면에서 더욱 그 중요성이 강조되는 기업의 자율공시 및 공정공시 행태가 지수편입 및 편출에 의해 영향을 받는지를 연구하여 투자자의 정보환경이 지수편입 편출사건에 의해 영향을 받을 수 있음을 제시하며 지수편입 및 편출효과에 대한 연구를 공시행태 연구로 확대하였다. 또한, 본 연구는 이중차분법을 사용하여 지수편입 및 편출효과를 고려하여 선행연구가 잠재적으로 가질 수 있는 방법론을 보완하였다는데 그 의의가 있다.

Clinical Consideration of Trigger Point Injection/Dry Needling Therapy: A Narrative Review

정재광,변진석,최재갑 대한안면통증∙구강내과학회 2017 Journal of Oral Medicine and Pain Vol.42 No.3

Myogenous temporomandibular disorder is a collective term for pathologic conditions of the masticatory muscles, mainly characterized by pain and dysfunction associated with various pathophysiological processes. Among the subtypes of myogenous temporomandibular disorder, myofascial pain is one of the most common muscle disorders, characterized by the presence of trigger points (TrPs). Various modalities, such as ultrasound, manipulative therapy, spray and stretch technique, transcutaneous electrical nerve stimulation, injection/dry needling, and low-level laser therapy are used to inactivate TrPs. Needling/injection on the TrPs is one of the most common treatments for myofascial pain. Despite the evidence, there is continued controversy over defining the biological and clinical characteristics of TrPs and the efficacy of injection/dry needling. This review discusses the current concept of injection/needling to relieve TrPs.

미만성 큰 B-세포 림프종에 의해 발생한 안면 통증을 동반한 Numb Chin Syndrome 증례

정재광,허윤경,최재갑,Jung, Jae-Kwang,Hur, Yun-Kyung,Choi, Jae-Kap 대한안면통증구강내과학회 2011 Journal of Oral Medicine and Pain Vol.36 No.4

Numb chin syndrome, is a rare neuropathy, characterized by facial and oral numbness restricted to the distribution of the mental nerve. Even though this neuropathy is uncommon, but this still has an important clinical meaning because it can be related with a malignancy. Because orofacial symptoms can even present the first clinical feature of a malignancy, dentists should pay careful attention to their meaning and importance to detect the malignant tumor early. Moreover, patients who present with a sudden numbness on chin should be investigated for the undiagnosed malignancy. In this report, we described a patient with stabbing orofacial pain and numbness of chin who was diagnosed with diffuse large B-cell lymphoma and placed the importance on the diagnosis of NCS.