• The korean journal of orthodontics
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• v.41 no.4
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• pp.255-267
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• 2011

Objective: The purpose of this study was to confirm the reliability of a cone beam computed tomography (CBCT)-generated panoramic view based on a CBCT 3D image and to find the most helpful 2D panoramic image compared with CBCT 3D image when examining the mesiodistal tooth axis. Methods: A test model was constructed according to cephalometric norms. The test model was repeatedly repositioned for CBCT and panoramic radiographic imaging. Panoramic radiographs were acquired at each of the following 3 occlusal plane positions: $-5^{\circ}$, $0^{\circ}$, and $+5^{\circ}$. Measurements of mesiodistal tooth axis in CBCT 3D image, CBCT-generated panoramic view, and panoramic radiographs were compared. Results: Compared with the CBCT-generated panoramic view, CBCT 3D image showed significant difference in the mesiodistal tooth axis in the premolars and no significant difference in the mesiodistal tooth axis in the incisors and canines. Mesiodistal tooth axis on the CBCT-generated panoramic view was significantly different from that on panoramic radiographs. Conclusions: CBCT-generated panoramic view can be a useful tool for evaluating mesiodistal tooth axis.

• Journal of Dental Rehabilitation and Applied Science
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• v.40 no.4
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• pp.225-233
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• 2024

Purpose: The aim was to conduct a three-dimensional comparison of impacted canines with their contralateral normal counterparts in patients exhibiting unilateral buccal impaction of the maxillary canine, utilizing the palatal plane as the benchmark reference. Materials and Methods: Computed tomography scans from a cohort of 31 patients diagnosed with unilateral buccal impaction of the maxillary canine were analyzed. The impacted canine was examined against the contralateral normal canine, focusing on the variables of rotation, torque, angulation, root length, and root volume. The disparities in these parameters between the left and right canines and their association with patient age were evaluated. Results: Notable differences were observed in rotation, angulation, torque, root length, and root volume when comparing the impacted canine to its contralateral normal counterpart. Furthermore, a significant positive correlation was identified between the age of the patients and the root length discrepancy of the impacted and contralateral normal canines. Conclusion: The palatal plane proves to be a viable skeletal reference for predicting the impaction of maxillary canines, with rotation, angulation, and torque serving as reliable indicators. The study further elucidates that the unilateral buccally impacted maxillary canine is characterized by a discernibly shorter root length and diminished root volume in comparison to the contralateral normal canine.

• The Transactions of the Korea Information Processing Society
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• v.13 no.10
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• pp.568-573
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• 2024

Accurate placement of prosthetics represents a critical aspect of dental implant surgery. however, it heavily depends on the dentist's decision and visual obstructions caused by various factors can lead to errors during the procedure. This paper proposes a 2D image-based real-time implant placement guiding system that predicts the implant position using 2D surgical video without the need for preoperative oral scans or 3D model generation. In the initial phase of the surgical video, two segmentation models are employed to measure prior statistics of the occlusal and incisal surfaces for each tooth. Subsequently, a single segmentation model is used to separate the occlusal and incisal surfaces, and the implant placement is predicted and guided based on the axis and length of adjacent teeth as well as the center of the prosthesis to be implanted. The system was designed and implemented using a dental phantom model, which replicates the oral structure of an actual human. The algorithm's average execution time for guiding implant placement on 10 images was measured to be 12.14 ms, demonstrating its feasibility for real-time application in surgical video.

• The Journal of the Korean dental association
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• v.56 no.12
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• pp.707-713
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• 2018

Multiple myeloma is a lymphohematopoietic disorder leading to abnormal hemostasis and significant pathologic changes of skeletal system. It induces multiple circular or oval-shaped radiolucent lesions which are characterized by 'punched-out appearance'. The surrounding trabecular bone normally shows no significant sclerotic reaction. Multiple myeloma patients may visit dental clinics, without perception of the disease themselves, due to discomfort from edema of orofacial region, oral ulcers, tooth mobility, pain or gingival bleeding. Multiple myeloma is susceptible to various complications, including delayed hemostasis and infection, which could occur during routine dental treatment such as periodontal and surgical operation. For radiographic diagnosis of multiple myeloma, common radiologic features of this tumor could be visualized by panoramic radiographs in the dental clinics, and further medical examinations and treatment can be recommended as a result.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.14 no.1
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• pp.153-161
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• 1984

Orthopantomograph는 치과진료에서 가장 일반적인 국외촬영방법으로 이용되고 있다. 저자는 1983년 서울대학교병원 치과진료부 치과방사선과에 래원한 환자중 Orthopantomogram을 촬영한 2,160명을 대상으로 골경화증의 성별, 연령별 발생빈도와 발생부위, 경화상의 크기, 모양등을 분류하고 특발성 골경화증과 condensing osteitis에 관하여 관찰하였든 바 다음과 같은 결과를 얻었다. 1. Idiopathic osteosclerosis의 발현율은 16.0%, condensing osteitis의 발현율은 9.8%였고 남녀간의 차이는 없었다. 2. 골경화증의 호발부위는 하악소구치, 대구치부위였고, 상악에서의 발생율은 적었다. 3. 골경화상의 크기는 idiopathic osteosclerosis는 10㎜이내였고, condensing osteitis는 10-20㎜의 폭경을 가지고 있었다. 4. 골경화상의 형태, 건강골과의 경계 및 발현되는 상태는 일정하지 않았다.

• Proceedings of the KOSOMBE Conference
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• v.1994 no.05
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• pp.35-36
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• 1994

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.20 no.1
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• pp.7-17
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• 1990

• Journal of the Korean Academy of Pediatric Dentistry
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• v.48 no.4
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• pp.405-413
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• 2021

The purpose of this in vivo study was to assess the clinical screening performance of a quantitative light-induced fluorescence (QLF) device in detecting proximal caries in primary molars. Fluorescence loss, red autofluorescence and a simplified QLF score for proximal caries (QS-proximal) were evaluated for their validity in detecting proximal caries in primary molars compared to bitewing radiography. Three hundred and forty-four primary molar surfaces were included in the study. Carious lesions were scored according to lesion severity assessed by visual-tactile and radiographic examinations. The QLF images were analyzed for two quantitative parameters, fluorescence loss and red autofluorescence, as well as for QS-proximal. For both quantitative parameters and QS-proximal, the sensitivity, specificity and area under receiver operating curve (AUROC) were calculated as a function of the radiographic scoring index at enamel and dentin caries levels. Both quantitative parameters showed fair AUROC values for detecting dentine level caries (△F = 0.794, △R = 0.750). QS-proximal showed higher AUROC values (0.757 - 0.769) than that of visual-tactile scores (0.653) in detecting dentine level caries. The QLF device showed fair screening performance in detecting proximal caries in primary molars compared to bitewing radiography.

• The Journal of the Korean dental association
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• v.54 no.2
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• pp.142-148
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• 2016

본 연구의 목적은 특이한 C형 치근과 근관을 가지고 있는 상악 제 1대구치의 근관치료 증례를 콘빔단층촬영을 사용하여 진단 및 치료하였음을 보고하는 것이다. 본 증례에서는 특이적인 해부학적 근관 형태가 콘빔단층촬영을 사용하여 확인되었으며 비외과적 근관치료가 시행되었다. 촬영한 영상에서 모든 치근이 C 형태로 융합되어 있으며 독립적인 4개의 근관을 포함하고 있음이 관찰되었다. C형 근관계의 복잡성을 고려할 때 콘빔단층촬영이 적절한 근관계의 확인과 의원성 손상을 예방하기 위해 유용한 보조적 방법인 것으로 보여진다.