• Imaging Science in Dentistry
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• v.44 no.4
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• pp.279-285
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• 2014

Purpose: To assess the influence of anatomic location on the relationship between computed tomography (CT) number and X-ray attenuation in limited and medium field-of-view (FOV) scans. Materials and Methods: Tubes containing solutions with different concentrations of $K_2HPO_4$ were placed in the tooth sockets of a human head phantom. Cone-beam computed tomography (CBCT) scans were acquired, and CT numbers of the $K_2HPO_4$ solutions were measured. The relationship between CT number and $K_2HPO_4$ concentration was examined by linear regression analyses. Then, the variation in CT number according to anatomic location was examined. Results: The relationship between $K_2HPO_4$ concentration and CT number was strongly linear. The slopes of the linear regressions for the limited FOVs were almost 2-fold lower than those for the medium FOVs. The absolute CT number differed between imaging protocols and anatomic locations. Conclusion: There is a strong linear relationship between X-ray attenuation and CT number. The specific imaging protocol and anatomic location of the object strongly influence this relationship.

• The Korean Journal of Cytopathology
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• v.10 no.1
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• pp.55-60
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• 1999

Schwannoma is a benign encapsulated nerve sheath tumor and is histologically characterized by a mixture of Antoni type A and B tissue. A preoperative diagnosis of schwannoma by fine needle aspiration cytology or by any other means is important a preserve clinically important nerves. Therefore, it is necessary to make a specific cytological diagnosis of nerve sheath tumor. However, there are a few reports regarding cytological features of schwannoma in Korea. We experienced seven cases of solitary schwannoma and here we report their characteristic cytological features with a review of literatures. The characteristic features of schwannoma on cytology were the presence of both Antonl type A and B tissue. The cytologic findings common to all cases of schwannoma generally corresponded to the histologic findings of Antoni type A tissue, consisting of fragments of tightly cohesive fascicles with variable cellularity. Dense fibrillary substances were found, along with palisading nuclei and Verocay bodies. Individual tumor cells consisted of cohesive cells haying spindle or oval nuclei, with pointed ends and Indistinct cell borders. Variation in nuclear size and shape was also present. The Antoni type B consisted of scattered wavy or short spindle cells and some histiocytes and lymphocytes in the abundant myxoid background with formation of microcysts. Immunohistochemistry for S-100 protein revealed a uniformly strong positive reaction and was helpful to make more accurate diagnosis of schwannoma.

• The Korean Journal of Pain
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• v.27 no.3
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• pp.253-259
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• 2014

Background: Caudal block is a common technique in children for reducing postoperative pain, and there have been several reports on the variations of the sacral canal in children. However, previous studies have mainly focused on the needle trajectory for caudal block, and there is limited information on the structural variations of the sacrum in children. The purpose of this study was to analyze the anatomic variations of sacral canals in children. Methods: Three-dimensional computed tomographic images were analyzed. The data from the images included (1) fusion of the sacral vertebral laminae and the sacral intervertebral space (2) existence of the sacral cornua and (3) the types of sacral hiatus. The types of sacral hiatus were classified into 3 groups: group I (fusion of S3 or S4 vertebral laminae), group II (unfused vertebral arch with the distance of the S3 and S4 vertebral laminae < 50% of the distance between the cornua), and group III (unfused vertebral arch with the distance of the S3 or S4 vertebral laminae ${\geq}50%$ of the distance between the cornua). Results: A total of 143 children were included in this study. All of the sacral vertebral arches were not fused in 22 children (15.4%). Cornua were not identified bilaterally in 5 (3.5%) and unilaterally in 6 (4.2%) children. In the sacral hiatus, group II and group III were identified in 22 (15.4%) and 31 (21.7%) children, respectively. Conclusions: The sacral canal has various anatomical variations in children. Careful attention must be paid to identify the correct anatomic landmark.

• Archives of Reconstructive Microsurgery
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• v.7 no.1
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• pp.28-34
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• 1998

The traditionally useful coverage methods of the wrist and hand soft tissue defect are the chinese forearm flap, the ulnar forearm flap. But, this flaps are inevitably sacrifice major vessel to the hand. Advantages of the posterior interosseous artery island flap(PIA Flap) is no need to sacrifice blood supply to the hand and supply relatively large thin, good quality flap and more cosmetic than other forearm flaps. But, it is difficult to dissect and raise because of deep seat, close relation with the posterior interosseous nerve and anatomic variation. Authors evaluated 8 cases of 7 patients in the department of orthopaedic surgery, college of medicine, Hallym University from January, 1993 to December, 1995. The results are as follows: 1. The satisfactory coverage was achieved 7 cases and 1 case failed because of anatomic variation. 2 The pedicle length is average 9cm and the flap size is variable from 3cm by 4cm to 5cm by 8cm. 3. The donor site defect was repaired by direct closure in 5 cases, remained 3 cases combined with skin graft. From our experience we conclude that the PIA flap is one of the useful coverage methods of the wrist and hand soft tissue defect.

• Imaging Science in Dentistry
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• v.45 no.1
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• pp.61-65
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• 2015

The mental foramen is a bilateral opening in the vestibular portion of the mandible through which nerve endings, such as the mental nerve, emerge. In general, the mental foramen is located between the lower premolars. This region is a common area for the placement of dental implants. It is very important to identify anatomical variations in presurgical imaging exams since damage to neurovascular bundles may have a direct influence on treatment success. In the hemimandible, the mental foramen normally appears as a single structure, but there are some rare reports on the presence and number of anatomical variations; these variations may include accessory foramina. The present report describes the presence of accessory mental foramina in the right mandible, as detected by cone-beam computed tomography before dental implant placement.

• Journal of Chest Surgery
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• v.50 no.1
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• pp.44-46
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• 2017

We report the case of a newborn with a rare anatomic variation: a right aortic arch with a retroesophageal left subclavian artery and an anomalous origin of the pulmonary artery from the aorta. This variation was diagnosed using echocardiography and computed tomography, and we treated the condition surgically.

• Imaging Science in Dentistry
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• v.43 no.4
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• pp.309-312
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• 2013

A retromolar canal is an anatomical variation in the mandible. As it includes the neurovascular bundle, local anesthetic insufficiency can occur, and an injury of the retromolar canal during dental surgery in the mandible may result in excessive bleeding, paresthesia, and traumatic neuroma. Using imaging analysis software, we evaluated the cone-beam computed tomography (CT) images of two Korean patients who presented with retromolar canals. Retromolar canals were detectable on the sagittal and cross-sectional images of cone-beam CT, but not on the panoramic radiographs of the patients. Therefore, the clinician should pay particular attention to the identification of retromolar canals by preoperative radiographic examination, and additional cone beam CT scanning would be recommended.

• Archives of Reconstructive Microsurgery
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• v.19 no.2
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• pp.112-119
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• 2010

The anterolateral thigh flap is a reliable and versatile flap. It has been extensively used for soft tissue reconstruction because minimal donor site morbidity is attractive feature of this flap. It can be harvested as a cutaneous, fasciocutaneous, muscluocutaneous flap. We can be used to form as desired shape and thickness. But variation of vascular anatomy make difficult for many surgeons. We review of vascular anatomy of the anterolateral thigh to be easier access to surgery. With understanding anatomic variation, it allows you to take advantage of this surgery using little more variable form.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.35 no.6
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• pp.368-375
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• 2013

Purpose: This study is to evaluate the location of descending palatine artery, the anatomy of pterygomaxillary junction, and the association between the obtained anatomic values and several variables. Methods: We studied 40 patients who were treated for dentofacial deformites from January 2010 to December 2012 in Ulsan University Hospital, Ulsan, Korea. Cone beam computed tomogram (CBCT) was done for all patients. The reference point was approximately 5 to 7 mm above anterior nasal spine on axial image. We evaluated the location of the greater palatine canal (line a: on the coronal view, the shortest line between the center of greater palatine canal and pterygoid fossa; distance a: the distance of line a). We also measured the thickness (line b: on the coronal view, the shortest line between maxillary posterior sinus wall and pterygoid fossa; distance b: distance of line b), width (line c: on the coronal view, the line perpendicular to the line b and the nearest line from the most concave point of lateral pterygoid plate to the medial pterygoid plate; distance c: distance of line c) and height (line d: on sagittal view, the vertically longest line of pterygoid junction; distance d: the distance of line d) in pterygomaxillary junctions. We evaluated the association between the obtained anatomic values and several variables (sex, age, height and weight). Results: The mean distance a was 4.78 mm, mean distance b was 5.53 mm, mean distance c was 8.01 mm and mean distance d was 13.22 mm. The differences between age and mean distance c and weight and mean distance d in pterygomaxillary junctions are statistically significant. Conclusion: There apparently is anatomic variation of pterygomaxillary junctions by various values, particularly weight and age in a Korean clinical population.

• Archives of Reconstructive Microsurgery
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• v.22 no.2
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• pp.48-51
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• 2013

Purpose: The lessor saphenous vein is an anatomical index in various surgical methods involving an approach to the popliteal fossa. However, occasionally, there have been some cases where the surgical process was difficult because the lessor saphenous vein was not found in the popliteal fossa during the operation process. The aim of this study is to determine the frequency of the anatomical variation of lessor saphenous vein not found in the popliteal fossa with a review of the literature. Materials and Methods: This study was conducted on 83 cases of selective neurectomy for hypertrophic calf performed in our clinic from March 1997 to June 2013. There were 42 patients, with a mean age of 32.8 years old. We confirmed the existence of the lessor saphenous vein in the popliteal fossa during the operation process. Results: Among 83 cases during this study period, the lesser saphenous vein was not found in four cases. In one patient, no lesser saphenous vein was found on either side of the popliteal fossa, and in two patients, no lesser saphenous vein was found on the left side of the popliteal fossa. As a result, the frequency of variation was found to be 4.8%. Conclusion: Due to the anatomical variation of the lessor saphenous vein, it may not be found in the midline of the popliteal fossa. Based on the literature review, several possibilities for failure to observe the lesser saphenous vein could be suggested. If surgeons are well aware of these possibilities, the steadier operation could be performed.