• Imaging Science in Dentistry
• /
• v.47 no.4
• /
• pp.247-254
• /
• 2017

Purpose: Dual-energy X-ray imaging is widely used today in various areas of medicine and in other applications. However, no similar technique exists for dental applications. In this study, we propose a dual-energy technique for dental diagnoses based on voltage-switching. Materials and Methods: The method presented in this study allowed different groups of materials to be classified based on atomic number, thereby enabling two-dimensional images to be colorized. Computer simulations showed the feasibility of this approach. Using a number of different samples with typical biologic and synthetic dental materials, the technique was applied to radiographs acquired with a commercially available dental X-ray unit. Results: This technique provided a novel visual representation of the intraoral environment in three colors, and is of diagnostic value when compared to state-of-the-art grayscale images, since the oral cavity often contains multiple permanent foreign materials. Conclusion: This work developed a technique for two-dimensional dual-energy imaging in the context of dental applications and showed its feasibility with a commercial dental X-ray unit in simulation and experimental studies.

• Journal of Korean Foot and Ankle Society
• /
• v.6 no.1
• /
• pp.73-79
• /
• 2002

Purpose: To evaluate the effectiveness of callotasis using the external fixator for the treatment of brachymetatarsia. Materials and Methods: Eleven patients(15 cases) who underwent callotasis were available. Follow-up averaged 23 months(15-38 months). Both the patients' postoperative satisfaction and the postoperative radiographic results were retrospectively evaluated. Results: The duration from applying the external fixator to remove averaged 15 weeks (8-21 weeks). We did osteotomy again in two cases because of early consolidation at the osteotomy site during distraction period. All cases were evaluated mild claw toe deformity and motional pain in metatarsophalangeal joint, but all patients satisfied the postoperative results except one complained motional pain and stiffness in metatarsophalangeal joint. The metatarsal shortening averaged 13mm(9-18mm) before operation. The amount of distraction for shortened metatarsals averaged 15mm(5-22mm). We found the 6 cases of narrowing of the metatarsophalangeal joint, 2 cases of subluxation of the metatarsophalangeal joint. Conclusion: We think that callotasis with external fixator is good operative method for the brachymetatarsia.

• The Journal of Korean Academy of Prosthodontics
• /
• v.36 no.6
• /
• pp.806-815
• /
• 1998

Regular radiographic examination has been considered as an essential diagnostic method for the osseointegrated dental implantation. This study investigated the marginal bone loss through the measurement on the periapical radiograph around 46 endosseous dental implants. Marginal bone loss have been observed for 5 years after delivery of prostheses. The results were as follows : 1. According to the experimental periods, average marginal bone loss in total implant was 1.821mm in the first year, 1.833mm in the second, 1.892mm at third, 1.910mm at forth and 1.957mm at fifth after delivery of prostheses(P<0.05). 2. The average bone loss was 1.832mm in the maxillae and 1.819mm in the mandible in three years but there was no significant difference between the upper and lower jaw(P>0.05). 3. The average bone loss was 1.824mm in males and 1.818mm in females in five years but there was no significant difference according to the sex(P>0.05). These results indicate that the most of the alveolar bone loss occur within the first year after delivery of dental prostheses resulting in the exposure of polished neck positions, and the bone level stabilizes at first thread portion of the implant fixtures.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
• /
• v.18 no.1
• /
• pp.67-73
• /
• 1988

This study was performed to clarify the mechanism of clicking sound and locking on temporomandibular joint and to determine the radiographic findings of them by using computed tomogram. Through the preliminary study with cadavers, the proper scanning condition and the correlatonship between the anatomy of cadaver and computed tomogram had been determined. The subjects were consisted of 10 controls and 16 patients having clicking sound or locking on temporomandibular joint. By using Hitachi-W500 as computed tomographic device, direct axial views and sagittal views reformed according to the changes in window setting and using the non-linear fraction were taken and analyzed by visual method and measuring the attenuation numbers. The obtained results were as follows: 1. The density of the anterior band of meniscus showed isodense to the surrounding muscles in normal. 2. In patient group, affected side showed increased radiopaque area anterior to condyle and underneath articular eminence as the feature of anteriorly displaced meniscus on axial and sagittal views. 3. In patient group, the condyle was rotated postero-laterally in affected side. 4. Non-linear fraction highlightened the feature of anteriorly displaced meniscus.

• Proceedings of the Korean Society of Medical Physics Conference
• /
• 2002.09a
• /
• pp.282-284
• /
• 2002

We have developed and used BISS as a radiation detector to verify patient dose and determine the physical characteristics of beams used in Stereotatic Radio Surgery(SRS) and Intensity Modulated Radiation Therapy(IMRT). In order to confirm the function and accuracy of our BISS, we simulate our measurements by BISS under the radiation of 6MV photons from a Varian Clinac 21EX equipped with a 60 leaf pairs MLC. For the simulation based on the Monte Carlo algorithm, which remains the most comprehensive and accurate theoretical method to verify beam profiles, we use the BEAM code. Compared with the measurements by BISS, our simulation of variously shaped phantom measurements show good agreements. Our simulation results can be used as a theoretical standard to compare and confirm measurements by BISS and other dosimeters such as ultramicro cylindrical ionization chamber(UCIC) and radiographic film.

• Journal of Veterinary Clinics
• /
• v.29 no.4
• /
• pp.319-322
• /
• 2012

This case presents application of bioadhesive for inguinal hernia repair of Jeju native pigs. An inguinal hernia was diagnosed in Jeju native pigs, respectively, 3 days of age and 30 days of age, by physical and radiographic examination. Inguinal herniorrhaphy was performed under sedation with azaperone. After excision of scrotal sac, gently separated testis and intestinal loops. Herniated testis was isolated from scrotal sac and intestinal loops were replaced in the abdominal cavity. The external inguinal ring surface and skin closed using the technique of tissue adhesive. The patients were recovered without post-operative complications. This result considered that bioadhesive application could be a simple method to reduction of scrotal hernia without post-treatment like removal of sutures.

• Archives of Plastic Surgery
• /
• v.32 no.1
• /
• pp.24-28
• /
• 2005

Skull or facial bone defect causes cosmetic and functional problems. On going efforts were taken to reconstruct the craniofacial bone defect with autogenous bone or alloplastic materials. Between 2001 and 2003, we reconstructed 15 cases with small to large craniofacial bone defect using Hydroxyapatite paste($BoneSource^{(R)}$, Leibinger Corp., Dallas, TX, U.S.A) and calvarial bone graft. All patients were followed up by clinical examination and periodic radiographic studies for an average of 1.6 years (range, 6 months to 2 years and 6 months). One complication case was noted with $BoneSource^{(R)}$ exposure. Otherwise, there was no evidence of adverse healing, wound infection, foreign body reaction and seroma collection in other patients. Adequate 3-dimensional aesthetic restoration of calvarial contour was noted in each case. In conclusion, $Bonesource^{(R)}$ is relatively safe and rigid material for craniofacial bone defect and reasonable method for the reconstruction of craniofacial bone defects.

• Journal of Veterinary Clinics
• /
• v.34 no.3
• /
• pp.200-203
• /
• 2017

The objective of this study was to evaluate the effectiveness of the minimally invasive plate osteosynthesis (MIPO) method for treatment of tibial shaft fractures in dogs by comparing MIPO radiographic and fracture healing time results with those from the popular open reduction and internal fixation (ORIF) technique. In this clinical study at the Royal Animal Medical Center, five consecutive dogs with diagnoses of comminuted tibial shaft fractures were treated with the MIPO surgical approach. For comparison, an additional five breed-, age-, and weight-matched dogs with comminuted tibial shaft fractures were treated with the ORIF technique. Mean healing time was $75.6{\pm}12.5$ days in the MIPO group and $131.8{\pm}18.6$ days in the ORIF group (p < 0.01). The mean surgery time in the MIPO group ($36.4{\pm}3.5$ minutes) was significantly shorter (p < 0.01) than that for the ORIF group ($47.0{\pm}2.2$ minutes). Based on the short surgical and healing times, the MIPO approach is clinically superior to the ORIF approach and should be the preferred approach in tibial fracture cases.

• The Korean Journal of Nuclear Medicine
• /
• v.20 no.1
• /
• pp.45-52
• /
• 1986

In osteoarthritis of knee, sensitive and reproducible methods of evaluation are of particular importance in unicompartmental surgery, in which choice of technique and prognosis depend on accurate preoperative knowledge of distribution and extent of disease. The various diagnostic modalities for evaluation of osteoarthritic knee are present but it is known that $^{99m}Tc-MDP$ scintigraphy is the most sensitive and noninvasive method. The authors made a comparative study of scintigraphic findings and radiographic findings of 54 cases of osteoarthritic knees at Kyung Hee University Hospital from May' 83 to August' 85. The results were as follow: 1) $^{99m}Tc-MDP$ scintigraphy appeared more sensitive not only in detection of abnormal compartment but also in evaluation of severity of the diseased compartment compared to radiography. 2) We suggest that bone scintigraphy is most sensitive for preoperative information of extent and severity of the disease related to surgical technique and prognosis.

• Imaging Science in Dentistry
• /
• v.36 no.2
• /
• pp.69-72
• /
• 2006

Purpose : We evaluated the fractal dimension changes on bovine rib radiographs according to the decalcification degree and the exposure time in the bovine rib. Materials and Methods : Twenty 5 mm thick cross-sectional blocks from bovine rib bone were progressively decalcified in 30 mL 0.1 N hydrochloric acid for 5, 30, and 90 minutes. They were radiographed at three exposure time settings (0.22, 0.36, 0.43 mAs) before and after each decalcification stage. We selected $100{\times}100$ pixel-sized regions of interests (ROIs) on trabecular bone and calculated fractal dimensions by box-counting method. Results : Repeated measures ANOVA showed that fractal dimensions gradually decreased after acid-induced demineralization and with more exposure (P<0.001). Conclusion : The fact that fractal dimensions decrease after decalcification might support the hypothesis that patients with osteoporosis have decreased radiographic fractal dimension in trabecular bone in comparison to normal subjects.