No abstract available.
Tooth*

No abstract available.
Hypothyroidism* ; Thyroid Gland*

No abstract available.
Hypothyroidism* ; Thyroid Gland*

A poor prognosis of oral squamous cell carcinoma (SCC) is partly due to the invasiveness and metastasis of the tumor. A key element in tumor invasion and metastasis in the degradation of extracellular matrix is matrix metalloproteinases (MMPs). This study was performed to determine the expression of MMP-2 and MMP-9 of oral SCCs with regard to the histologic invasiveness and differentiation in 5 normal oral mucosa and 36 oral SCCs. The histologic invasiveness of oral SCCs were classified into 4 grades. The differentiation of oral SCCs was divided into 3 grades. The streptavidin-biotin immunohistochemical staining, using MMP-2 and MMP-9 monoclonal antibodies, was performed to determine the expression of MMP-2 and MMP-9. The expression of MMP-2 was positive in 6 of 17 oral SCCs with weak invasiveness and was positive in 7 of 19 oral SCCs with strong invasiveness. The MMP-2 expression did not increase significantly with respect to the invasiveness of oral SCCs (P>0.05). The expression of MMP-9 was strongly positive in 6 out of 17 SCCs with weak invasiveness and was strongly positive in 14 of 19 SCCs with strong invasiveness. The MMP-9 expression increased significantly with respect to the invasiveness of oral SCCs; the stronger the expression, the stronger the invasiveness (P<0.05). The expression of MMP-9 was in 57.9% of well differentiated SCCs, 57.1% of moderately differentiated ones, and 33.3% of poorly differentiated SCCs. The expression of MMP-2 and MMP-9 did not increase significantly with respect to the histologic differentiation. We conclude that with respect to the invasiveness, the MMP-9 expression increases significantly in oral SCCs but the MMP-2 expression does not; and that with respect to the histologic differentiation, their expressions do not increase significantly. These results suggeste that MMP-9 can be used as a tool to evaluate the invasiveness of oral SCCs.
Antibodies, Monoclonal ; Carcinoma, Squamous Cell* ; Extracellular Matrix ; Matrix Metalloproteinase 2* ; Matrix Metalloproteinases ; Mouth Mucosa ; Neoplasm Metastasis ; Prognosis

The purpose of this study was to evaluate the effects of the mandibular retractive force on the mandibular condyle of growing dog. The experimental animals were six mongrel dogs of two-month old. Their deciduous dentition were completed. Two of them was used as control group, and experimental group was composed of remaining four. Head band and chin cup were made of cotton tape, and hooks are fabricated on the chin cup and had band for closed coil. Mandibular retractive force was 100g/side and chin cap appliance was used for 14 hours/day during night. Experimental group were sacrificed at 2, 4, 6, 8 weeks from beginning of the experiment. Right TMJ was prepared for histologic study and left TMJ was examined grossly for disc, fossa, and condyle. The conclusions are: 1. Two-month old control animal showed active cartilaginous growth on the mandibular condyle, therefore showed thick proliferative and hypertrophic zones. Remodeling process in the condyle head was observed in which there were bone resorption on the anterior surface and bone apposition on the posterior surface. 2. Four-month old control animal showed marked reduction of hypertrophic zone but the condylar bone remodeling was more pronounced. 3. In experimental group, there are marked reduction of hypertrophic zone at 4 weeks from beginning of experiment, and hypertrophic zone disappeared at posterior-superior portion of condyle in 6-week experimental animal. 8 week experimental animal showed slight recovery of hypertrophic zone. 4. In experimental group, bone deposition was increased at anterior surface of condyle, and bone resorption was increased at posterior surface of condyle. 5. In control group, the glenoid fossa and surrounding bone showed mainly bone apposition. But experimental group showed bone resorption at anterior surface of articular eminence and increased bone apposition at posterior surface of postglenoid spine. 6. No marked traumatic change was seen but 4 weeks and 8 weeks experimental animal showed flattening of posterior surperior condylar surface. Bone marrow of condyle showed minute focal bleeding in 2 weeks and 4 weeks experimental animal, and congestion and depression of hematopoietic bone marrow during all experimental period.
Animals ; Bone Marrow ; Bone Remodeling ; Bone Resorption ; Chin ; Depression ; Dogs* ; Estrogens, Conjugated (USP) ; Head ; Hemorrhage ; Mandibular Condyle* ; Spine ; Temporomandibular Joint ; Tooth, Deciduous

Facial cleft is not a common anomaly of craniofacial region. But it is often accompanied with cleft lip and/or palate, so it seems important to orthodontist. Facial cleft is defined as a fissure or elongated opening of the facial region, and it's etiology is the failure of the fusion of the parts which will form the face in embryonic developmental period. Facial cleft can be classified according to the time of occurrence and the area involved during developmental period. It develops 1-2.5 weeks earlier than cleft lip and/or cleft palate. In facial cleft, the deformity is generally confined to the facial region, but sometimes deformity of other body region can accompany. The interaction of the facial cleft and the genetic anomaly is not confirmed, but genetic anomaly is known to be able to occur in the patient with other anomaly of body. As an orthodontist we should know the general considerations of facial cleft and it's treatment procedures other than orthodontic treatment.
Body Regions ; Cleft Lip ; Cleft Palate ; Congenital Abnormalities ; Embryonic Development ; Female ; Humans ; Palate ; Pregnancy

This study was undertaken to investigate the cytotoxicity of orthodontic wires after doing various treatments to the wires. 018x025 inch Stainless steel(A) and Co-Cr(B) wires were used and each of them were divided into 4 groups. A-1 and B-1 groups were as received state, and A-2 and B-2 groups were heat treated. A-3 and B-3 groups were electropolished after heat treatment, and A-4 and B-4 groups were soldered with Ag-solder. Each group had 3 wires and these were sterilized with Ethylene Oxide gas. We used human gingival fibroblast cell culture and agar overlay technique to investigate the cytotoxicity of each group of wires. The cytotoxicity of wire was assessed using reaction index (zone index / lysis index). The findings of this study were as follows: 1. Both of the stainless steel wire and Co-Cr wire showed no cytotoxicity in as received state. 2. Heat treatment or electropolishing of the wires had no effect on the cytotoxicity of the wires. 3. Soldered stainless steel wires showed a little wider zone of discoloration than soldered Co-Cr wires, but the zone index and cytotoxicitytreaction index) was not different. 4. Soldered wires showed moderate cytotoxicity in both of the wires.
Agar ; Cell Culture Techniques ; Ethylene Oxide ; Fibroblasts ; Hot Temperature ; Humans ; Orthodontic Wires* ; Stainless Steel

This study was undertaken to investigate the three dimensional vascular changes of periodontal ligament following orthodontic tooth movement. Experimental tooth movement was carried out in 96 Sprague-Dawley rats with the weight of 250g. They were divided into four experimental groups (each 24 rats). The left maxillary first molar was moved mesially with 25g force in group I, and with 75g force in group II. Each three animals were sacrificed after 1, 6, 12, 24 hours, and 3, 7, 14, 21 days. In group III, 25g mesial force was applied for 3 days, and in group IV, 75g mesial force was applied for 3 days. Then the appliances were removed, and each three animals were sacrificed after 1, 6, 12, 24 hours, and 3, 7, 14, 21 days from removal of appliance. The contralateral molars were used for control group. Casting media was injected via left ventricle and polymerized in warm water. After corrosion of surrounding soft tissue, three dimensional vascular changes were examined using scanning electron microscopy. The findings of this study were as follows: 1. Pressure side of group I and II showed degenerative vascular changes such as vascular compression, reduction of vasculature, leakage of casting media. But, regenerative changes were dominant after 7 days of tooth movement. Although the degenerative vascular changes were more severe in group II, which was exposed to heavy force, the timing of these changes was not different between two groups. 2. Periodontal vasculature was reestablished by the growth of new capillaries and their differentiation and union from the remaining periodontal vessels and vessels of alveolar bone marrow. Although vascular regeneration was more rapid in group I, which was exposed to light force, the vasculature was not fully normalized in both groups even after 21 days. 3. There was no remarkable changes in tension side of group I and II, but looping of capillary, new capillary growth, dilation of vessels, redirection of vessels in the direction of tensile force were occurred. 4. In pressure side of group III and IV, in which appliance was removed after 3 days of orthodontic force, bone resorption was continued even after removal of appliance. Regeneration of vasculature was initiated after 1-6 hours, and it was more rapid in group III than group IV. In both groups, the vasculature was not fully normalized even after 21 days. 5. After removal of appliance, tension side of group III and IV showed vascular compression and loss of vasculature.
Animals ; Bone Marrow ; Bone Resorption ; Capillaries ; Corrosion Casting* ; Corrosion* ; Heart Ventricles ; Microscopy, Electron, Scanning ; Molar* ; Periodontal Ligament* ; Polymers ; Rats* ; Rats, Sprague-Dawley ; Regeneration ; Tooth Movement* ; Tooth* ; Water

In order to investigate various physical and biological properties of dental magnetic attachments studies on retentive characteristics, corrosion properties, cytotoxicity of different magnetic systems for dental applications were done. For the study of retentive characteristics changes of retentive force by increasing air gap, wear properties of various attachment systems and loss of magnetic force by heat treatment were measured. For the study of corrosion property of magnet covering metal electrochemical corrosion was done in artificial saliva and 0.9% NaCl solution between -1,000 mVSCE and +1,000 mVSCE. Anodic polarization curves are obtained about 6 types of samples and 2 types of solution. Corroded surfaces were examined with metallurgical microscope, scanning electron microscope and surface profilometer. For the study of cytotoxicity of magnetic attachment and its field cell growth and agar overlay test were done. The results of this study were as follows. 1.In Magnetic attachments using closed circuit retentive force at zero air gap was greater than magnets using open circuit, but decrease of retentive force by increasing air gap was also greater than open systems. 2.After 40,000 cycles of wear test all mechanical attachment resulted in varing degree of retention loss but in magnetic attachments no loss of retentive force was observed. 3.The magnetic attachment using Neodymium magnet showed early loss of retentive force about 200degrees C but attachment using Samarium magnet showed some resistance to heat treatment and complete retention loss was observed about 500degrees C. The keeper was not influenced by heat treatment in retention. 4.In electrochemical corrosion test Dyna magnetic attachment covering metal showed the highiest corrosion resistance and Shiner magnet covering metal showed the least corrosion resistance and examination of corroded surface with metallurgical microscope, scanning electron microscope and surface profilometer also showed same results with anodic polarization curves. 5.The result of cell culture tests on the magnet covered with metal showed least recognizable cytotoxicity.
Agar ; Cell Culture Techniques ; Corrosion ; Cyprinidae ; Hot Temperature ; Neodymium ; Population Characteristics* ; Saliva, Artificial ; Samarium

PURPOSE: A composite of aluminum and vanadium (Ti-6Al-4V) is one of the most common compositions of titanium-based alloys. Unfortunately, vanadium has been found to cause adverse reactions. We evaluated the effects of vanadium containing titanium alloy (Ti-6Al-4V) on an osteoblast-like cell line (SaOS-2). MATERIALS AND METHODS: We studied the biologic and morphologic responses of SaOS-2 cell to Ti alloy with grit blasting and Ti coated Ti alloy with grit blasting. We performed energy-dispersive x-ray spectroscopy (EDS) and scanning electron microscopy (SEM) investigations and performed a cell proliferation assay, ALP activity, and cell migration assay of SaOS-2 cells. RESULTS: The morphologic assessment of cells through SEM showed that the two surfaces were covered with similar amounts of small slender osteoblast like cells. The amount of proliferation, ALP activity and the migration extent of SaOS-2 cells on the surfaces of each group were not statistically different. CONCLUSION: We used a grit-blasted Ti-coated Ti alloy, coated using electron beam deposition, and a grit-blasted Ti alloy to evaluate the toxicity of Ti-6Al-4V on SaOS-2 cell. Compared with pure titanium, the vanadium-containing Ti-alloy did not show an adverse effect on SaOS-2 cells.
Alloys ; Aluminum ; Cell Line ; Cell Migration Assays ; Cell Proliferation ; Electrons ; Microscopy, Electron, Scanning ; Osteoblasts ; Spectrum Analysis ; Titanium ; Vanadium