• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.38 no.4
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• pp.249-254
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• 2012

Bilateral coronoid process hyperplasia is a rare condition characterized by an enlarged mandibular coronoid process. The painless progressive reduction of a mouth opening is caused by coronoid process impingement on the posterior aspect of the zygomatic bone. Hyperplasia of the bilateral coronoid process leads to the restriction of a mandibular opening consequent to the impingement of the enlarged coronoid process on the temporal surface of the zygomatic bone or with the medial surface of the zygomatic arch. The process has been diagnosed as developmental hyperplasia. Otherwise, the development of the coronoid process may be associated with growth hormone. This paper describes a case of trismus caused by coronoid hyperplasia in an idiopathic short-stature patient who received growth hormone therapy by somatropin injections.

• International Journal of CAD/CAM
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• v.6 no.1
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• pp.81-87
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• 2006

This paper describes a method for extracting surfaces from multi-material CT (Computed Tomography) data. Most contouring methods such as Marching Cubes algorithm assume that CT data are composed of only two materials. Some extended methods such as [3, 6] can extract surfaces from the multi-material (non-manifold) implicit representation. However, these methods are not directly applicable to CT data that are composed of three or more materials. There are two major problems that arise from fundamentals of CT. The first problem is that we have to use n(n-1)/2 threshold values for CT data contains n materials and select appropriately one threshold value for each boundary area. The second is that we cannot reconstruct only from CT data in which area three or more materials are adjacent each other. In this paper, we propose a method to solve the problems by using image analysis and demonstrate the effectiveness of the method with application examples construct polygon models from CT data of machine parts.

• Journal of Korean Ophthalmic Optics Society
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• v.5 no.2
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• pp.211-219
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• 2000

The fine structure on the compound eye surface of 6 species belong to 6 genera of Asilinae in Korea was morphologically studied with a scanning electron microscope and image analyser. The compound eye was divided into 3 parts(medial, middle, and lateral) according to a difference in the diameter of a facet which was various form. The fine structure of a facet in Trichomachimus scutellaris(Coquillett) was valuable in taxonomy because it was differ from each species in Asilinae.

• The Journal of Korean Society for Radiation Therapy
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• v.27 no.1
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• pp.13-22
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• 2015

Purpose : We investigated the safety of Intrabeam$^{TM}$ system, X-ray unit for Intraoperative Radiotheray (IORT) by measuring surface dose using Optically Stimulated Luminescent Dosimeter(OSLD). Materials and Methods : 30 patients were selected, who were in breast cancer patients and had an operation of breast conserving surgery (BCS). At the inner surface of tumor bed, 20 Gy were described, and 5 Gy at 1cm depth from the inner surface. Along the size of tumor bed which could be decided after resection of tumor, the size of applicator were determined. Usual treatment time were from 18 to 40 minutes. For the measurement of surface doses, OSLD were placed at superior(U1,2), inferior(D1,2), lateral(L1,2) and medial(M1,2) directions from the center of applicator. Each direction, two OSLD were placed at 0.5 cm and 1.5 cm from the center. Mean, maximum, and minimum doses were analyzed to be compared. Results : Mean values were U1 $2.23{\pm}0.80Gy$, U2 $1.54{\pm}0.53Gy$, D1 $1.73{\pm}0.63Gy$, D2 $1.25{\pm}0.45Gy$, L1 $1.95{\pm}0.82Gy$, L2 $1.38{\pm}0.42Gy$, M1 $2.03{\pm}0.70Gy$, and M2 $1.51{\pm}0.58Gy$. Maximum values were 4.34 Gy at U1, and Minimum values were 0.45 Gy at M2. 13.3 % of patient (4pts out of 30) were reported that surface dose were over 4 Gy. Conclusion : The fact that skin dose of all patients were less than 5 Gy based on OSLD measurement showed the safety of Intrabeam$^{TM}$ system. In the relatively small breast volume, the tendency that surface dose was increased had been shown, which was analyzed by the data of patients who irradiated over 4Gy at skin surface. Therefore, for appropriate indication for IORT, it is suggested that breast volume as well as the size and position of tumor should be carfully considered.

• Radiation Oncology Journal
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• v.23 no.4
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• pp.230-235
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• 2005

Purpose: To evaluate the contralateral breast dose using a virtual wedge compared with that using a Physical wedge and an open beam in a Siemens linear accelerator. Materials and Methods: The contralateral breast dose was measured using diodes placed on a humanoid phantom. Diodes were placed at 5.5 cm (position 1), 9.5 cm (position 2), and 14 cm (position 3) along the medial-lateral line from the medial edge of the treatment field. A 6-MV photon beam was used with tangential irradiation technique at 50 and 230 degrees of gantry angle. Asymmetrically collimated $17{\times}10cm$ field was used. for the first set of experiment, four treatment set-ups were used, which were an open medial beam with a 30-degree wedged lateral beam (physical and virtual wedges, respectively) and a 15-degree wedged medial beam with a 15-degree wedged lateral beam (physical and virtual wedges, respectively). The second set of experiment consists of setting with medial beam without wedge, a 15-degree wedge, and a 50-degree wedge (physical and virtual wedges, respectively). Identical monitor units were delivered. Each set of experiment was repeated for three times. Results: In the first set of experiment, the contralateral breast dose was the highest at the position 1 and decreased in order of the position 2 and 3. The contralateral breast dose was reduced with open beam on the medial side ($2.70{\pm}1.46%$) compared to medial beam with a wedge (both physical and virtual) ($3.25{\pm}1.59%$). The differences were larger with a physical wedge ($0.99{\pm}0.18%$) than a virtual wedge ($0.10{\pm}0.01%$) at all positions. The use of a virtual wedge reduced the contralateral breast dose by 0.12% to 1.20% of the proscribed dose compared to a physical wedge with same technique. In the second experiment, the contralateral breast dose decreased in order of the open beam, the virtual wedge, and the physical wedge at the position 1, and it decreased in order of a physical wedge, an open beam, and a virtual wedge at the position 2 and 3. Conclusion: The virtual wedge equipped in a Siemens linear accelerator was found to be useful in reducing dose to the contralateral breast. Our additional finding was that the surface dose distribution from the Siemens accelerator was different from a Varian accelerator.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.14 no.1
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• pp.71-80
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• 1984

The author has studied each landmark for successful interpretation in the radiograph of the head that have the complex anatomic structures, using panoramic radiograph, postero-anterior cephalometric radiograph, lateral cephalometric radiograph, Waters' radiograph of the skull. The anatomic structures of the human dry skull attached by radiopaque materials were taken radiographs and analysed comparatively. The results were as follows: 1. The overall anatomic structures of the mandible showed sharp images in the panoramic radiograph than other radiographs with relatively less distortion, superimposition, blurring of the image. 2. The anatomic structures were situated on sagital plane of the skull showed blurred images in panoramic radiograph than other radiographs. 3. The anatomic structures which were situated on the basal portion of the skull showed blurred and secondary images in the panoramic radiograph than other radiographs. 4. In the panoramic radiograph, the lower 3rd portion of the orbit appeared to be superimposed with the superior portion of the maxillary sinus and the medial and lateral surface of the nasal cavity showed extensively superimposition of the orbit and the maxillary sinus, which images showed blurring. 5. The inferior surface and posterior surface of maxillary sinus showed to be good image in the panoramic radiograph than other radiographs. 6. In the panoramic radiograph, line of maxillary bone between lateral pterygoid plate, line of maxillary bone between zygomatic bone showed distinct image with another structures.

• Korean Journal of Applied Biomechanics
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• v.30 no.1
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• pp.103-109
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• 2020

Objective: The purpose of this study is to compare the muscle activity by electrode location in the biceps brachii during the arm curl isometric exercise and to provide the basic data needed to develop the proper electrode location of the biceps brachii based on the study results comparing the muscle activity by the angle of the elbow joint. Method: 17 adult males (Age: 21.50±4.63 yrs, height: 175.29±5.97 cm, weight: 63.79±15.31 kg, upper-arm length: 30.10±1.22 cm) participated in the study. In the arm curls isometric exercise, the experiment was divided into 1st and 2nd steps to compare muscle activity according to electrode location in the biceps brachii and muscle activity according to elbow angle change. In the first experiment, the surface electrode was attached at one-third point on the line from medial acromion to cubital fossa, according to the measurement method indicated by SENIAM. The elbow angle was set to 90°. In the second experiment, according to the proposed method of this study, the electrodes were separated at one finger's width in the left and right direction at one-third point on the line from medial acromion to cubital fossa, attached at the long head and short head. From the long head electrode, in about a width of two fingers in proximal direction, a total of three electrodes were attached at the myotendinal junction of the long head. The elbow angles were set as 70°, 90°, and 110°, and the isometric exercise (100% MVC) for 5 seconds was maintained with keeping the forearm and the rope to be 90° for the first and second experiments. Results: During the arm curl isometric exercise, there was no significant difference in SH and SENIAM proposition location proposed by this researcher. LH was shown to be lower than the muscle activity of the location proposed by SENIAM and there were significant (p<.01) differences. MJ appeared lower than the muscle activity of the location proposed by SENIAM and there were significant (p<.001) differences. The muscle activity by the elbow joint angle of SH in the biceps brachii was shown in large order of 70°<90°<110°, but there was no significant difference. The muscle activity by the elbow joint angle of LH was shown in large order of 90°<70°<110°, but there was no significant difference. The muscle activity by the elbow joint angle of MJ was shown in large order of 110°<90°<70°, but there was no significant difference. Conclusion: During the arm curl isometric exercise of the biceps brachii, it is judged appropriate to attach surface electrodes to the location proposed by SENIAM.

• International Journal of CAD/CAM
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• v.7 no.1
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• pp.71-80
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• 2007

Recently, feature-based solid modeling systems have been widely used in product design. However, for engineering analysis of a product model, an ed CAD model composed of mid-surfaces is desirable for conditions in which the ed model does not affect analysis result seriously. To meet this requirement, a variety of solid ion methods such as MAT (medial axis transformation) have been proposed to provide an ed CAE model from a solid design model. The algorithm of the MAT approach can be applied to any complicated solid model. However, additional work to trim and extend some parts of the result is required to obtain a practically useful CAE model because the inscribed sphere used in the MAT method generates insufficient surfaces with branches. On the other hand, the mid-surface ion approach supports a practical method for generating a two-dimensional ed model, even though it has difficulties in creating a mid-surface from some complicated parts. In this paper, we propose a dimension reduction approach on solid models based on the midsurface abstraction approach. This approach simplifies the solid model by abbreviating or removing trivial features first such as the fillet, mounting, or protrusion. The geometry of each face is replaced with mid-patches from the simplified model, and then unnecessary topological entities are deleted to generate a clean ed model. Also, additional work, such as extending and stitching mid-patches, completes the generation of a mid-surface model from the patches.

• The Journal of Korean Physical Therapy
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• v.26 no.1
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• pp.9-14
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• 2014

Purpose: The purpose of this study was to investigate how different knee alignments (genu varum and genu valgum) affected activations of quadriceps muscles with measurements of onset-time differences between vastus medialis and vastus lateralis during isometric contractions at both 30 and 60 degree knee flexion. Methods: Fifty-two adults (20 genu varum, 12 genu valgum, and 20 control) were enrolled in this study. Subjects with over 4cm distance between knee medial epicondyles were assigned to Genu varum, while subjects with over 4cm distance between ankles medial malleolus were considered as genu valgum group. Surface EMG was used to measure onset time of both vastus medialis and vastus lateralis during isometric contraction at 30 and 60 degree knee flexion. Results: The onset time of vastus lateralis was delayed in genu varum group, and that of vastus medialis was delayed in genu valgum group at both 30 and 60 degree knee flexions. Moreover, onset time difference at $30^{\circ}$ knee flexion between muscles was larger in genu valgum group than genu varum group. Conclusion: Subjects with genu varum or valgum activated quadriceps muscles with different orders pending on flexion degrees. Therefore, when quadriceps training program were planned to prevent pain or deformities, the findings that quadriceps were activated with different orders affected by knee alignments and joint degree at which trainings were performed, must be considered. If the selective training programs of quadriceps femoris are planned to prevent pain or deformities due to poor knee alignments, these should consider the subject's knee alignment condition.

• Imaging Science in Dentistry
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• v.47 no.2
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• pp.99-107
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• 2017

Purpose: Erosions and osteophytes are radiographic characteristics that are found in different stages of temporomandibular joint (TMJ) osteoarthritis. This study assessed the effectiveness of digital subtraction radiography (DSR) in diagnosing simulated osteophytes and erosions in the TMJ. Materials and Methods: Five intact, dry human skulls were used to assess the effectiveness of DSR in detecting osteophytes. Four cortical bone chips of varying thicknesses (0.5 mm, 1.0 mm, 1.5 mm, and 2.0 mm) were placed at the medial, central, and lateral aspects of the condyle anterior surface. Two defects of varying depth (1.0 mm and 1.5 mm) were created on the lateral, central, and medial poles of the condyles of 2 skulls to simulate erosions. Panoramic images of the condyles were acquired before and after artificially creating the changes. Digital subtraction was performed with Emago dental image archiving software. Five observers familiar with the interpretation of TMJ radiographs evaluated the images. Receiver operating characteristic (ROC) analysis was used to evaluate the diagnostic accuracy of the imaging methods. Results: The area under the ROC curve (Az) value for the overall diagnostic accuracy of DSR in detecting osteophytic changes was 0.931. The Az value for the overall diagnostic accuracy of panoramic imaging was 0.695. The accuracy of DSR in detecting erosive changes was 0.854 and 0.696 for panoramic imaging. DSR was remarkably more accurate than panoramic imaging in detecting simulated osteophytic and erosive changes. Conclusion: The accuracy of panoramic imaging in detecting degenerative changes was significantly lower than the accuracy of DSR (P<.05). DSR improved the accuracy of detection using panoramic images.