• Imaging Science in Dentistry
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• 제37권1호
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• pp.27-33
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• 2007

Purpose : The research was done to investigate the effectiveness of 2D bony morphometry and microstructure of micro-computed tomography (micro-CT) on the osteoporotic bony change. We performed the bone morphometric analysis of proximal femur in ovariectomized rabbits with BMD and micro-CT examination. Materials and Methods : Twenty-one female (Newzealand, about 16 weeks old, 2.9-3.4kg) rabbits were used. Three rabbits were sacrificed on the day when experiment began (Baseline). The remaining 18 rabbits were divided into two groups. One group was ovariectomized bilaterally (OVX) and the other animals were subjected to sham operation (Sham). Bone specimens were obtained from the right and left femur of sacrificed rabbits. At intervals of 1, 2, 3, 5, 6 months respectively, BMD tests were performed on the proximal femur by using PIXlmus 2 (GE Lunar Co. USA), 2-dimensional bone morphometric analysis by custome computer program and 2D/3D bone structure analysis by micro-CT (Skyscan 1072, Antwerpen, Belgium). Statistical analysis was carried out for the correlation between bone morphometry, micro-CT and BMD Result : BV/TV, Tb.Th, Tb.N of micro-CT parameters showed higher values in sham group than OVX group. N.Nd/Ar.RI, N.NdNd, N.NdTm, N. TmTm, PmB/Ar.RI, 3-D BoxSlope of 2D morphometric parameters showed higher values in Sham group than OVX group. The micro-CT parameters of Tb.Sp, Tb.N were statistically significant correlated with BMD respectively. Several 2D morphometric parameters were statistically significant correlated with BMD respectively. Conclusion : Several parameters of 2D bony morphometry and micro-CT showed effective aspects on the osteoporotic bony change.

• 대한의용생체공학회:의공학회지
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• 제24권5호
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• pp.421-425
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• 2003

한 개 척추 운동 분절에 대한 유한요소 모델을 이용하여 수직 충격력이 가해질 경우 발생되는 척추 경막의 교합을 해석 하였다. 교합은 수직 충격력의 지속 시간 변화에 따른 골편의 이동으로 인한 척추 경막의 단면적 변화를 계산하여 계량화 하였다. 계산 결과 8∼12ms 의 충격 지속 시간에서 골편의 이동으로 인한 가장 큰 척추 경막의 단면적 변화가 나타났으며 $\Delta$t = 400 ms의 경우에서는 4%만의 척추 경막의 단면적 변화가 나타났다, 이와 같은 해석 결과는 6kN의 수직 정 하중이 가해질 경우에 발생되는 량이 유사한 값으로 이 정도의 충격 지속 시간은 준 정 하중 상태와 유사함을 보이고 있었다.

• 치과방사선
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• 제11권1호
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• pp.41-50
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• 1981

Radiographic features of maxillary sinusitis, types of mucosal thickening, types of bony wall change, and relationship between the radiographic features and symptoms of patients were observed and classified in the Waters' view of 360 patients with 441 maxillary sinuses demonstrating radiologic changes. And the classification of antral floor and pathologic change was observed in the 154 periapi- cal films. Finally, the value of orthopantomography in the diagnosis of maxillary sinusitis was evaluated in the 138 cases, The obtained results were as followings. 1. Among 441 maxillary sinuses examined by Waters' projection, mucosal thickening was seen in 56.7% and generalized opacification was seen in 36.3%. 2. Among 270 mucosal thickenings classified 8 types, overall regularly thickened type was the highest in incidence (36.3%). 3. Bony wall change was seen in 35.6% of all cases and the indistinct white line of the cortical plates was the highest in incidence (78.2%) among the 6 types. 4. Pain (41.9%) and pus discharge (21.0%) were the most frequent symptoms. And pus discharge, foul odor, and headache was more prevalent in type of generalized opacification than any other types. 5. Regular pneumatization involving all roots of premolars and molars was the highest in incidence (55.0%). The first molar presented the most frequent involvement (61.0%). 6. In orthopantomography, 46.4% showed apparent increased radiopacity and 23.9% showed suspicious increased radiopacity in comparison to Waters' projection.

• 대한치과교정학회지
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• 제8권1호
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• pp.49-58
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• 1978

This investigation was undertaken to know how the bony facial profile could be changed with age. The 5 serial lateral cephalometric roentgenograms of the fourteen boys and fourteen girls between 7 and 11 years of age were studied and the findings seems to warrant the following conclusions. 1. The manaible tended to become more prognathic in relation to the cranial base (S-N) during growth, but the maxilla showed very little change. 2. There was increase in the inclination of the lower border of mandible associated with the increase in mandibular prognathism. 3. There was a tendency to being straight in bony facial profile due to the decrease in angle ANB with age. 4. The chin portion had a tendency to forward and downward growth in relation to the cranial base but there was slight strong tendency in downward growth. 5. The vertical growth was more prominant in the maxilla than in the mandible. 6. There was uniform and gradual increase of all measurements during growth. 7. Dimension of the craniofacial complex was larger in the boys than in the girls but this difference was not statistically significant. 8. Individual variation in skeletal growth was a normal occurrence.

• Imaging Science in Dentistry
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• 제36권4호
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• pp.199-206
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• 2006

Purpose: The purpose of this study was to evaluate comparison of static MRI and pseudo-dynamic (cine) MRI in temporomandibular joint (TMJ) disorder patients. Materials and Methods: In this investigation, 33 patients with TMJ disorders were examined using both conventional static MRI and pseudo-dynamic MRI. Multiple spoiled gradient recalled acquisition in the steady state (SPGR) images were obtained when mouth opened and closed. Proton density weighted images were obtained at the closed and open mouth position in static MRI. Two oral and maxillofacial radiologists evaluated location of the articular disk, movement of condyle and bony change respectively and the posterior boundary of articular disk was obtained. Results: No statistically significant difference was found in the observation of articular disk position, mandibular condylar movement and posterior boundary of articular disk using static MRI and pseudo-dynamic MRI (P<0.05). Statistically significant difference was noted in bony changes of condyle using static MRI and pseudo-dynamic MRI (P<0.05). Conclusion: This study showed that pseudo-dynamic MRI didn't make a difference in diagnosing internal derangement of TMJ in comparison with static MRI. But it was considered as an additional method to be supplemented in observing bony change.

• Journal of Korean Neurosurgical Society
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• 제64권4호
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• pp.552-561
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• 2021

Objective : To compare the anterior cervical discectomy and fusion (ACDF) and posterior cervical fusion (PCF) with wide facetectomy in the treatment of parallel-shaped bony foraminal stenosis (FS). Methods : Thirty-six patients underwent surgery due to one-or-two levels of parallel-shaped cervical FS. ACDF was performed in 16 patients, and PCF using CPS was performed in 20 patients. All patients were followed up at 1, 3, 6, and 12 months postoperatively. Standardized outcome measures such as Numeric rating scale (NRS) score for arm/neck pain and Neck disability index (NDI) were evaluated. Cervical radiographs were used to compare the C2-7 Cobb's angle, segmental angle, and fusion rates. Results : There was an improvement in NRS scores after both approaches for radicular arm pain (mean change -6.78 vs. -8.14, p=0.012), neck pain (mean change -1.67 vs. -4.36, p=0.038), and NDI score (-19.69 vs. -18.15, p=0.794). The segmental angle improvement was greater in the ACDF group than in the posterior group (9.4°±2.7° vs. 3.3°±5.1°, p=0.004). However, there was no significant difference in C2-7 Cobb angle between groups (16.2°±7.9° vs. 14.8°±8.5°, p=0.142). As a complication, dysphagia was observed in one case of the ACDF group. Conclusion : In the treatment of parallel-shaped bony FS up to two surgical levels, segmental angle improvement was more favorable in patients who underwent ACDF. However, PCF with wide facetectomy using CPS should be considered as an alternative treatment option in cases where the anterior approach is burdensome.

• Imaging Science in Dentistry
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• 제30권1호
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• pp.23-32
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• 2000

Purpose : The purpose of this study is to compare radiographic techniques for the diagnostic accuracy in the detection of osteophytes of the mandibular condyle. Material and Methods : A series of bone chips were placed at four locations on the condylar head of a dried human skull. Eight radiographic techniques such as panoramic, transcranial, infracranial, transorbital, reverse-Towne's, submentovertex, multidirectional tomographic and computed tomographic techniques were compared. Three oral radiologists were asked to rate the lesions by four stage score. The statistical analysis was performed by ANOVA test. Results: For the detection of lateral osteophyte, transcranial, infracranial, transorbital and reverse-Towne' s views showed superiority. Also, transcranial and infracranial views showed superiority for medial osteophyte. While for the detection of superior and anterior osteophyte, panoramic, transcranial, infracranial, transorbital views showed superiority. Lateral tomograph showed superiority for the detection of superior and anterior osteophyte, but it showed inferiority for lateral and medial osteophyte. And antero-posterior tomograph showed superiority for the detection of all osteophytes. Axial computed tomograph showed superiority for the detection of all osteophytes, and coronal computed tomograph showed superiority for lateral, medial and superior osteophytes. While reconstructed sagittal computed tomograph showed relatively superiority for the detection of anterior and superior osteophytes. Conclusion : The conventional radiographs can be used for the detection of bony changes of the mandibular condyle, and tomograph or computed tomograph can be used additionally when it is difficult to detect bony changes on conventional radiographs.

• Imaging Science in Dentistry
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• 제38권1호
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• pp.29-37
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• 2008

Purpose: The aim of this study was to observe the bony change in the OVX rat longitudinally and to study the alendronate effect. Materials and Methods: Eighteen Sprague-Dewley rats, eight-week old each, were randomly assigned into three groups: one of those sham-operated (N=4), the other two were OVX: saline-treated (N=7) and alendronate-treated group (N=7). The saline-treated group was administered with saline solution (0.1mL/100g) daily, while the alendronate-treated group was given alendronate (1mg/kg, Sigma-Aldrich Corp. Korea) daily. Micro-CT scannings of the lumbar were consecutively done at baseline, at 3-week intervals during 9 weeks. Two and three dimensional bony analysis were done. Bone mineral density (BMD) was measured with Piximus (GE Lunar Co. USA). The average values of these three methods were compared with each group. Results: After 6 weeks the BMD of the OVX group showed lower tendency than that of sham group. After 6 weeks many 3D parameters of micro-CT showed higher values in the OVX-alendronate group compared with the OVXsaline group. Most 2D bony parameters were higher in the OVX-alendronate group compared with the OVX-saline group at 9 weeks. Conclusion: This study showed low BMD of the OVX group after 6 weeks and showed the effect of alendronate on the BMD and bony structures of ovariectomized rats. This study also showed usefulness of in vivo micro-CT in monitoring individual bone changes over time.

• 한국환경성돌연변이발암원학회지
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• 제25권1호
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• pp.25-31
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• 2005

The objective was to use MR imaging to provide a template of posterior fossa development during the late stages in the chick embryos. The MR findings were then correlated with histological data. Fourteen normal formalin-fixed embryonic specimens with a gestational age of 14 to 20 days were examined with 1.5 Tesla unit MRl using a conventional clinical magnet and pulse sequences. The MR findings were correlated with the whole-mount histological specimens. Resolution of the morphological features of posterior fossa development in embryos greater than 14 days gestational age was possible. Development of cerebellum, brain stem, 4th ventricle and bony posterior fossa was documented. In the 14-day-old embryos, a premordial cerebellum was visualized in the enlarged bony posterior fossa, and it covered the the roof of the primitive fourth ventricle. The bony posterior fossa grows at the same rate along the supratentorial skull. The supratentorial skull and the rostral part of the brain grows at the same rate. The cerebellum begins to grow later than the rostral part of the brain. In the 19- to 20-day-old embryos, MRl revealed the rapid development of the cerebellar hemispheres, along with an increase in volume manifested by the more typical mushroom-shaped configuration observed in the newly hatched. At this stage, the cerebellum almost completely filled the posterior fossa and covered the entire fourth ventricle. The brain stem grew steadily, but the volume change was too subtle to evaluate. Features of cerebellar histogeneis were beyond the resolution of MRl. However, there were lots of artifacts in the features of the bony posterior fossa. An MR template of normal posterior fossa development would be useful to avoid confusion of normal development with abnormal development and to identify the expected developmental features when provided the estimated gestational age of a embryo.

• 치과방사선
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• 제13권1호
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• pp.97-105
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• 1983

For the assessment of changes in the bone architecture of the maxilla and mandible in renal osteodystrophy, 31 chronic renal failure patients who were undergoing hemodialysis therapy were selected. They were evaluated through clinical oral examination, radiographic and biochemical examination. The results were as follows: 1. In 17 cases (54.8%), there were evidences of bony change in jawbone. 2. The most common dental radiographic finding was decreased bone density (14 cases, 45.2%). 3. The second most common dental radiographic finding was total or partial loss of lamina alveolar dura (11 cases, 35.5%). 4. The third most common dental radiographic finding was total or partial loss of inferior canal wall (8 cases, 25.8%). 5 cases showed evidences of bony change only in jawbone, and 5 cases only in hand, and 12 cases in both. 6. Serum creatinine, urea nitrogen and alkaline phosphatase values in hemodialysis group were much higher than in control group. 7. There were statistically significant correlation between bone density and lamina dura, and inferior alveolar canal wall.