• The Journal of Korean Academy of Prosthodontics
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• v.38 no.1
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• pp.12-25
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• 2000

To demonstrate possible influences of general bone density on the mandible, histomorphometric analysis was carried out in mandibles and iliac bones and the correlation of the two bone densities was tested. Comparison of bony density in women and men over 60 years in the mandible was carried out too. Quantitative computed tomography(QCT) was taken in cross-section of mandibles at the same site where histomorphometric analysis was peformed to evaluate the reliability of QCT. The analysis included 40 cadavers with no known diseases affecting the bones. The subjects consisted of 15 females and 25 males with a mean age of 60.3 years. Spearman correlation analysis and Wilcoxon rank sum test was performed. The results were as follows. 1. There was statistically no correlation between the mandible and iliac bone in the values of corrected cortical width(CCW), cortical porosity(POR) in cortex, and total bone volume(TBV), mean trabecular plate thickness(MTPT), mean trabecular plate density(MTPD), and mean trabecular plate separation(MTPS) in trabecular bone. 2. Comparison of women and men over 60 years, men had statistically higher bone density than women except fir POR of buccal and lingual cortex, and WTPD of alveolar trabeculae in mandible. 3. There was statistically significant correlation between TBV of trabecular bone and CT No., but not between POR and CT No. in mandible. According to the results above, there was no correlation between mandible and iliac bone density and between mandibular bony density and age. Further studies are required to support the results. A more noninvasive method to be able to measure the bone density of mandible should be developed and it is necessary to accumulate data on the normal values of bone density of mandible according to age and sex. Further study should be carried out about QCT to measure mandibular bony density using QCT.

• Imaging Science in Dentistry
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• v.45 no.1
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• pp.23-29
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• 2015

Purpose: This study aimed to assess the reliability of measurements performed on three-dimensional (3D) virtual models of maxillary defects obtained using cone-beam computed tomography (CBCT) and 3D optical scanning. Materials and Methods: Mechanical cavities simulating maxillary defects were prepared on the hard palate of nine cadavers. Images were obtained using a CBCT unit at three different fields-of-views (FOVs) and voxel sizes: 1) $60{\times}60mm$ FOV, $0.125mm^3$ ($FOV_{60}$); 2) $80{\times}80mm$ FOV, $0.160mm^3$ ($FOV_{80}$); and 3) $100{\times}100mm$ FOV, $0.250mm^3$ ($FOV_{100}$). Superimposition of the images was performed using software called VRMesh Design. Automated volume measurements were conducted, and differences between surfaces were demonstrated. Silicon impressions obtained from the defects were also scanned with a 3D optical scanner. Virtual models obtained using VRMesh Design were compared with impressions obtained by scanning silicon models. Gold standard volumes of the impression models were then compared with CBCT and 3D scanner measurements. Further, the general linear model was used, and the significance was set to p=0.05. Results: A comparison of the results obtained by the observers and methods revealed the p values to be smaller than 0.05, suggesting that the measurement variations were caused by both methods and observers along with the different cadaver specimens used. Further, the 3D scanner measurements were closer to the gold standard measurements when compared to the CBCT measurements. Conclusion: In the assessment of artificially created maxillary defects, the 3D scanner measurements were more accurate than the CBCT measurements.

• The Journal of Advanced Prosthodontics
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• v.9 no.6
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• pp.470-475
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• 2017

PURPOSE. The purpose of this study was to identify the complex course of the mandibular canal using 3D reconstruction of microCT images and to provide the diagram for clinicians to help them understand at the interforaminal region in Korean. MATERIALS AND METHODS. Twenty-six hemimandibles obtained from cadavers were examined using microCT, and the images were reconstructed. At both the midpoint of mental foramen and the tip of anterior loop, the bucco-lingual position, the height from the mandibular inferior border, the horizontal distance between two points, and position relative to tooth site on the mandibular canal were measured. The angle that the mental canal diverges from the mandibular canal was measured in posterior-superior and lateral-superior direction. RESULTS. The buccal distance from the mandibular canal was significantly much shorter than lingual distance at both the mental foramen and the tip of anterior loop. The mandibular canal at the tip of anterior loop was significantly located closer to buccal side and higher than at the mental foramen. And the mental canal most commonly diverged from the mandibular canal below the first premolar by approximately $50^{\circ}$ posterior-superior and $41^{\circ}$ lateral-superior direction, which had with a mean length of 5.19 mm in front of the mental foramen, and exited to the mental foramen below the second premolar. CONCLUSION. These results suggest that it could form a hazardous tetrahedron space at the interforaminal region, thus, the clinician need to pay attention to the width of a premolar tooth from the mental foramen during dental implant placement.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.4
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• pp.430-439
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• 2009

Posterior Cruciate Ligament (PCL) plays an important role in knee extension. Rotational instability due to injured PCL can be restored by various PCL reconstruction methods. In this study, the initial lengthening affected by fixation device and location was demonstrated, and furthermore, the slippage and the relationship between lengthening ratio and slippage ratio in the calcaneus and soft tissue fixation methods was newly suggested. Eight specimens of proximal tibia and Achilles tendon grafts were harvested from four cadavers and divided into four groups in regard to the four different types of transtibial fixation techniques. The cyclic load ranged from 50 N to 250 N applied to each graft fixed to proximal tibia in 55 degrees. The initial lengthening ratio to the total elongation has been approximately constant regardless of the fixation methods. The soft tissue fixation method with an interference screw showed about 56.4% slippage ratio to the total elongation and the same method with a double cross-pin presented about 45.4% slippage ratio. The soft tissue fixation method with an interference screw demonstrated approximately 2 mm less total elongation and about 13% more slippage than lengthening because of poor fixation compared to the same method with a double cross-pin.

• Journal of Digital Contents Society
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• v.17 no.4
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• pp.287-293
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• 2016

Some studies require sufficient amount of time, spaces, and financial condition for practical exercises and training. In particular for the Medical education, time and space limitation is very high and difficulties occurs, since the practices are done with cadavers (deceased human body). Many alternate 3D Virtual surgery training system exist currently, however the burdensome of obtaining those costly equipments is problematic. Providing the surgical environment as similar to real as possible using 3D Virtual Reality can be a solution to current problems. The effectiveness of training could be maximized with minimized costs without the general interfaces such as keyboard and mouse, but with Oculus Rift and Leap Motion. This paper will develop and practice the 3D Virtual Operation System with two devices to investigate the possibility and expand to other Simulation fields.

• The Journal of the Korean dental association
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• v.44 no.2 s.441
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• pp.115-122
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• 2006

Objective : The purpose of this study was to evaluate the dimensional errors between real tooth, 3D CT image and CARP model. Materials and Methods : Two maxilla and two mandible block bones with intact teeth were taken from two cadavers. Computed tomography was taken either in dry state and in wet state. After then, all teeth were extracted and the dimensions of the real teeth were measured using a digital caliper at mesio-distal and bucco-lingual width both in crown and cervical portion. 3D CT image was generated using the V-works $4.0^{TM}$ (Cybemed Inc., Seoul, Korea) software. Twelve teeth were randomly selected for CARP model fabrication. All the measurements of 3D Ct images and CARP models were made in the same manner of the real tooth group. Dimensional errors between real tooth, 3D CT image model and CARP model was calculated. Results : 1) Average of absolute error was 0.199 mm between real teeth and 3D CT image model, 0.169 mm between 3D CT image model and CARP model and 0.291 mm between real teeth and CARP model, respectively. 2) Average size of 3D CT image was smaller than real teeth by 0.149 mm and that of CARP model was smalier than 3D CT image model by 0.067mm. Conclusion : Within the scope of this study, CARP model with the 0.291 mm average of absolute eror can aid to enhance the success rate cf autogenous tooth transplantation due to the increased accuracy of recipient bone and donor tooth.

• The Journal of the Korea Contents Association
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• v.13 no.2
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• pp.341-347
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• 2013

There are insufficient cadaver-used practice programs for paramedic student education. To provide the basic data for the effective cadaver practice program, the study interviewed 255 students in department of EMT, who attended cadaver practicum. The results indicated that the average satisfaction level in education was 4.5 out of 5 and in relation to allotted time was 3.61 out of 5. The average understanding level of was 4.5 out of 5. In conclusion, senior students who have already taken clinical education & clinical procedure are recommended to focus on clinical anatomy practice and lower grade students are recommended to focus on understanding human body structure in cadaver-used practice program.

• Journal of Korean Neurosurgical Society
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• v.30 no.10
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• pp.1187-1192
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• 2001

Objective : The lateral extracavitary approach(LECA) to the thoracolumbar spine is known as one of procedure which allows not only direct vision of pathologic lesion, but also ventral decompression, and dorsal fixation of the spine through the same incision. However, some drawbacks of LECA, including the technically- demanding, time-consuming, unfamiliar surgical anatomy and excessive blood loss, make surgeons to hesitate to use this approach. This study is to provide the surgical anatomy of LECA using cadavers, for detailed informations when LECA is considered for the surgery. Methods : We performed the 10 cadaveric studies, 7 male and 3 female, and careful dissection was carried out on right side of thoracolumbar region, except one for thoracic region. The photographs with micro-lens were taken to depict the close-up findings and for demonstrating detailed anatomy. Results : The photographs and hand-drawings demonstrated the relationships among the musculature, segmental vessels and nerve roots seen during each dissection plane. The lateral branches of dorsal rami of spinal nerve and the transverse process were confirmed to be the most important landmark of this approach. Conclusion : We concluded that detailed anatomical findings for LECA through this step-by-step dissection would be useful during operative intervention to reduce the intraoperative complications in LECA.

• Journal of Korean Neurosurgical Society
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• v.46 no.2
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• pp.130-135
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• 2009

Objective: The purpose of this study was to determine the normal morphometric landmarks of the uniting and dividing points of the brachial plexus (BP) in the periclavicular region to provide useful guidance in surgery of BP injuries. Methods: A total of 20 brachial plexuses were obtained from 10 adult, formalin-fixed cadavers. Distances were measured on the basis of the Chassaignac tubercle (CT), and the most lateral margin of the BP (LMBP) crossing the superior and inferior edge of the clavicle. Results: LMBP was located within 25 mm medially from the midpoint in all subjects. In the supraclavicular region, the upper trunk uniting at 21$\pm$7 mm from the CT, separating into divisions at 42$\pm$5 mm from the CT, and dividing at 19$\pm$4 mm from the LMBP crossing the superior edge of the clavicle. In the infraclavicular region, the distance from the inferior edge of the clavicle to the musculocutaneous nerve (MCN) origin was 49$\pm$12 mm, to the median nerve origin 57$\pm$7 mm, and the ulnar nerve origin 48$\pm$6 mm. From the lateral margin of the pectoralis minor to the MCN origin the distance averaged 3.3$\pm$10 mm. Mean diameter of the MCN was 4.3$\pm$1.1 mm (range, 2.5-6.0) in males (n = 6), and 3.1$\pm$1.5 mm (range, 1.6-4.0) in females (n = 4). Conclusion: We hope these data will aid in understanding the anatomy of the BP and in planning surgical treatment in BP injuries.

• Journal of Korean Neurosurgical Society
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• v.50 no.1
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• pp.30-35
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• 2011

Objective : Morphometric data for the sympathetic ganglia (SG) of the upper thoracic spine was investigated to identify the exact location of the SG in order to reduce normal tissue injury in the thoracic cavity during thoracoscopic sympathectomy. Methods : In 46 specimens from 23 formalin-fixed adult cadavers, the authors measured the shortest distance from the medial margin of the T1, T2 and T3 SG to the most prominent point and medial margin of the corresponding rib heads, and to the lateral margin of the longus colli muscle. In addition, the distance between the most prominent point of the rib head and the lateral margin of longus colli muscle and the width of each SG were measured. Results : The shortest distance from the medial margin of the SG to the prominent point of corresponding rib head was on average 1.9 mm on T1, 4.2 mm, and 4.1 mm on T2, T3. The distance from the medial margin of the SG to the medial margin of the corresponding rib head was 4.2 mm on T1, 5.9 mm, and 6.3 mm on T2, T3. The mean distance from the medial margin of the SG to the lateral margin of the longus colli muscle was 6.7 mm on T1, 8.8 mm, 9.9 and mm on T2, T3. The mean distance between the prominent point of the rib head and the lateral margin of the longus colli muscle was 4.8 mm on T1, 4.6 mm, and 5.9 mm on T2, T3. The mean width of SG was 6.1 mm on T1, 4.1 mm, and 3.1 mm on T2, T3. Conclusion : We present morphometric data to assist in surgical planning and the localization of the upper thoracic SG during thoracoscopic sympathectomy.