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Ultastructural study of the fibroblast remodeling in the radiation: impaired wound healing in the tongue of the rat.

Jin Koo LEE ; Soon Chul CHOI ; Tae Won PARK ; Dong Soo YOU

Journal of Korean Academy of Oral and Maxillofacial Radiology.1997;27(1):141-166.

Radiation-imparied wound healing in animal experiments was believed to be an another logical experimental model to understand the wound healing mechanism in patients. the purpose of this study was to reveal the block point which would result impaired healing. Twenty four rats(Sprague-Dawley stains) were divided into two gruops according to the time interval between irradiati on and wounding. Group I, observing the healing effect on the 1st day and group II are the healing effects on the 7th d ays after irradiation to the wound of the rat tongue. Experimental animals were sacrificed 3, 6, 12 and 24 hours after w ounding. The specimens were examined by the light microscope and trasmission electron microscope. The following results were obtained: 1. Fibroblasts in both goups showed degenerative changes which were dilated mitochondria and rER, reduced microorganell e, vacuoles and little cytoplasmic process. 2. Average length between bands and quantity of the newly produced collagen fibers aroud fibroblasts remained unchanged against control group. 3. The severity of degenerative change of the fibroblast and impairment of wond healing including shortening of the thi ckness of collagen fibers were more sever in the group II than in the group I.
Animal Experimentation ; Animals ; Collagen ; Cytoplasm ; Fibroblasts* ; Humans ; Logic ; Mitochondria ; Models, Theoretical ; Rats* ; Tongue* ; Vacuoles ; Wound Healing* ; Wounds and Injuries*

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An experimental study of mandibular fracture wound healing in the calcium deficient rat.

Sang Hoon LEE ; Eui Hwan HWANG ; Sang Rae LEE

Journal of Korean Academy of Oral and Maxillofacial Radiology.1997;27(1):123-140.

The purpose of this study was to investigate effects of osteoporosis on fracture wound healing in the calcium defi cient rat. To research the experiment some ten-week old Wistar strain rats with approximately 300 gms weight were selected. Then , the rats were divided into two groups: Normal diet group(rats given a normal diet before and after bone fracture) and Low calcium diet group(rats given a low calcium diet before and after bone fracture). Both groups had been provided wit h each diet for three weeks. When the rats became thirteen weeks old, the mandibular angle of rats in both groups was ar tificially fractured for test. The healing of fracture wounds was reviewed by using soft x-ray radiography and 99m Tc-MDP bone scan and also histopathologic examination. The obtained results were as follows : 1. The radiolucency of the fracture site for the Normal diet group started to decrease from the 14th day since the expe riment was made, while the Low calcium diet group began decrease in the radiolucency from the 21st day of the experiment . The radiolucency for the normal diet group disappeared at the 42nd day, but one for the Low calcium diet group disappe ared at the 56th day of the experiment. 2. The highest uptake rate of (99m)Tc-MDP stood at the 14th day of the experiment in the Normal diet group and the Low calium diet group's maximum rate was recorded at the 21st day of the experiment. These both groups were gradual ly experiencing decrease in the uptake rate as the experiment time was going on. However, the uptake rate in the Low cal ium diet group was lower than one in the Normal diet group. 3. For the Normal diet group, the newly formed trabecular, which were similar to one of the surrounding bone, were seen at the 42nd day of the experiment. On the other hand, the Low claium diet group showed at the 56th day of the experimen t that the osteoporotic findings looked weak, irregular trabecular, and also large bone marrow space were observed clear ly. As a result of the above experiment, it is said that the healing of the fracture can be completed for both groups, t he Normal diet group and the Low calium diet group. However, the amount of the newly formed bone wound in the Low calciu m diet group is rather decreased compared to one in the normal diet group and at the same time the healing of the fractu re is delayed in the Low calcium diet group. Consequently, for the successful healing of fracture in osteoporosis, it is considered that the management of the etiologic factors of osteoporosis must be preceded. the more study of calcium met abolism and functions of osteoblast and osteoclast needs to proceed on.
Animals ; Bone Marrow ; Calcium* ; Diet ; Hand ; Mandibular Fractures* ; Osteoblasts ; Osteoclasts ; Osteoporosis ; Radiography ; Rats* ; Wound Healing* ; Wounds and Injuries*

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An experimental study on the change of the radiosensitivity of several tumor cell lines and primary cultured gingi cal fibrobrast..

Sam Sun LEE ; Dong Soo YOU

Journal of Korean Academy of Oral and Maxillofacial Radiology.1997;27(1):107-122.

Radiation sensitivity data was generated for two human cancer cell lines(KB, RPMI 2650) and human primary gingival fibroblast was tested three times using a viable cell number counting with a hemocytometer, MTT(3-[4,5-dimethylthiazol 2-yl]-2,5-dipheny tetrazolium bromide) assay, and LDH(Lactate dehydrogenase) assay. Single irradiation of 2, 4, 6, 10, 15, 20 Gy were aplied to the tumor cell lines and the primary cultured gingical fibroblast. The two fractions of 4 Gy an d 10 Gy were seperated with a 4 hour time interval. The irradiation was done with 241.5 cGy/min dose rate using 137 Cs MK cell irradiator at room temperature. The obtained results were as followed: 1. There was significantly different viable cell numbers as the amount of radiation dose on the tested cells were cell number counted with a hemocytometer, In fractions, there were more viable cells remaining, 2. Phase-contrast microscopically, radiation-induced morphologic changes were pronounced on the tumor cells, however, a lmost no differences on the gingival fibroblast. 3. There was significantly different absorbance at 2 Gy on RPMI 2650, 4 Gy on KB and GF in MTT assay. In fractions, the absorbance was significantly higher on KB. 4. THe level of extracellular LDH activity in the experimental group was significantly higher in the 2-4 Gy than the co ntrol group. 5. The total level of extracellular and intracellular LDH activity was decreased as increased amounts of radiation dose was applied.
Cell Count ; Cell Line, Tumor* ; Fibroblasts ; Humans ; Radiation Tolerance*

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A comparative study of computed radiographic cephalometry and conventional cephalometry in reliability of head film measurements (landmarks identification).

Hyung Don KIM ; Kee Deog KIM ; Chang Seo PARK

Journal of Korean Academy of Oral and Maxillofacial Radiology.1997;27(1):99-106.

The purpose of this study was to compare and to find out the variability of head film measurements(landmarks ide ntification) between Fuji computed radiographic cephlometry and conventional cephalometry. 28 Korean adults were selected. Lateral cephalometric FCR film and conventional cephalometric film of each subject wa s taken. Four investigators identified 24 cephalometric landmarks on lateral cephalometric FCR film and conventional cep halometric film were statistically analysed. The results were as follows: 1. In FCR film and conventional film, coefficient of variation(C.V.) of 24 landmarks was taken horizontally and ver tically. 2. In comparison of significant differences of landmarks variability between FCR film and coventional film, horizonta l value of coefficient of variation showed significant differences in four landmarks among twenty-four landmarks, but ve rtical a value of coefficient of variation showed significant differences in sixteen landmarks among twenty-four landmar ks. FCR film showed significantly less variability than conventional film in 17 subjects among 20(4+16) subjects that sho wed significant difference.
Adult ; Cephalometry* ; Head* ; Humans ; Research Personnel

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A study on assessment of bone mass from aluminum-equivalent image by digital imaging system.

Jin Soo KIM ; Jae Duk KIM

Journal of Korean Academy of Oral and Maxillofacial Radiology.1997;27(1):87-97.

The purpose of this study was to evaluated the method for quantitative assessment of bone mass from aluminum-equiv alent value of hydroxyapatite by using digital imaging system consisted of Power Macitosh 7200/120, 15-inch color monitor, and GT-9000 scanner with transparency unit. After aluminum-equivalent image made from correlation between aluminum thickness and grey scale, the accuracy of conversion to mass from aluminum-equivalent value was evaluated. Measured bone mass was compared with converted bone mass fr om aluminum-equivalent value of hydroxyapatite block by correlation formula between aluminum-equivalent value of hydroxy apatite block and hydroxyapatite mass. The results of this study were as follows: 1. Correlation between aluminum thickness and grey level for obtaining aluminum-equivalent imge was high positively ass ociated(r2=0.99). Converted masses from aluminum-equivalent value were very similar to measured masses. There was, statistically, no significnat difference(P<0.05) between them. 2. Correlation between hydroxyapatitie aluminum-equivalent and hydroxyapatite mass was shown to linear relation(r2 =0.95). 3. Converted masses from aluminum-equivalent value of 3 dry mandible segments were similar to measured masses. the diff erence between the exposure directions was not significantly different(P<0.05).
Aluminum ; Durapatite ; Equidae ; Mandible

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An Assessment of Image Analysis of Longitudinal Bone Changes.

Young Jin KIM ; Jae Duk KIM

Journal of Korean Academy of Oral and Maxillofacial Radiology.1997;27(1):73-86.

This study was performed to assess the analyzing methods developed to detect clinically and quantitatively longitu dinal bone changes. through preliminary experiment, accuracy of Cu-Eq value conversion to the mass of HA was examined. For main experiment, 15 intraoral radiograms taken at soon, 1st, 2nd, 4th, and 6th week after implantation of mixture in extracted sites of 3 cases were user. We took the radiograms with copper step wedge as test object and HA phantom. X -ray taking was standardized by using Rinn XCP device customized directly to the individual dentition with resin bite bl ock. The images inputted by Quick scnner into computer were digitized and analyzed by NH image program, the stability of the copper equivalent trasformation and the usefulness of two analyzing methods by ROI and Reslice were examined. Obtained results as follows: 1. On the Cu equivalent images, the coefficient of variation in the measurement of Cu-Eq. value of ROI ranged from 0.05 to 0.24 and showed high reproducibility. 2. All results obtained by resliced contiguous images were coincident with those obtained from the assessment by ROI an d formation of plot profile. 3. On the stacked and resliced image at the line of interest, we could analyze directly and quantitatively the longitud inal changes at several portions by plot profile and qualitatively by surface plot. 4. Implant area showed marked resorption till 2 weeks after implantation and showed significant increase in Cu-Eq. valu e at 6th week(P<0.01) and periapical area showed increase in cu-eq. value at 6th week compared to after-operation's.
Copper ; Dentition

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The effects of various exposure times in the detectability on the tips of the endodontic files in Digora(R).

Jae Young KO ; Chang Seo PARK

Journal of Korean Academy of Oral and Maxillofacial Radiology.1997;27(1):55-71.

Digora(R)-an intraoral digital radiography system utilizing image plate(IP) - has a dynamic range of expo sure time which allows it to decrease the patient's exposure time and to increase diagnostic ability through imge proces sing, transmission and storage. The purpose of this study was to evaluate the Digora(R) system by assessing the effects of various exposure times on the detectability on the tip of the endodontic file. Examining the root canals of 45 extracted sound premolars, K-files No. 10, 15, and 20 were placed at slightly varying distances from the apex. The teeth were glued onto resin-pla ster blocks. Five exposure times varying between 0.01 seconds and 0.25 seconds were used. Four observers were asked to m easure the distance between the tip of the file and a reduction of crown portion, and obtained mean errors (subtracting true file length from the measured file length), comparing Digora(R) monitors with E-plus films, which were bot h obtained under the same geometrical positions. The results were as follows : 1. Comparing E-plus film with Digora(R) at 0.01 seconds, the mean errors in E-plus film showed -4.453mm, -4.49 7mm, and -3.857mm, while the mean errors in Digora(R) showed 0.065mm, 0.607mm, and 0.719mm according to the fil e groups. Therefore there was a significant difference between E-plus film and Digora(R)(P<0.05). 2. By comparison of mean errors according to the various exposure times in the Digora(R) system, the mean error at standard deviation was the highest at 0.01 seconds was significantly lower than that at 0.12 and 0.25 seconds in No . 10 and 20 file group(P<0.05). and the standard deviation was the highest at 0.01 seconds. 3. Comparing E-plus film at 0.25 seconds with the Digora(R) system, the mean errors showed a significant diffe rence between E-plus at 0.25 seconds and the Digora(R) system at 0.25 seconds in No. 10 and 20 file groups (P <0.05). 4. Comparing E-plus film at 0.25 seconds with other exposure times, the mean errors showed a significant difference between E-plus film at 0.25 seconds and E-plus film at 0.01 and 0.03 seconds in 10 file group(p<0.05). In the NO. 15 and 20 file groups, there was a significant difference between E-plus film at 0.25 seconds and E-plus film at 0.01 seconds(p<0.05). In conclusion, Digora(R) was better than E-plus film in detectability on the tip of the file at the exposure time of 0.01 seconds in all file groups. And we concluded that Digora(R) can shorten exposure times up to 4% of 0.25 seconds (0.01 sec), which is adequate exposure time for premolar in E-plus film using No. 15 and 20 files.
Bicuspid ; Crowns ; Dental Pulp Cavity ; Radiographic Image Enhancement ; Tooth

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A Study on the radiosensitivity and chemosensitivity of YAC-1 Cell Line in Vitro.

Eui Hwan CHOI ; Kwang Joon KOH

Journal of Korean Academy of Oral and Maxillofacial Radiology.1997;27(1):43-53.

The purpose of this study was to aid in the prediction of tumor cell tolerance to radiotherapy and/or chomotherapy . For this study, cell surviving curves were obtained for mouse lymphoma YAC-1 cell line using semiautomated MTT assay. 2, 4, 6, 8, 10Gy were irradiated at a dose rate of 210cGy/min using 60Co Irradiator ALDORADO 8. After irra diation, YAC-1 cell lines(3X10(4) cells/ml) were exposed to bleomycin or cisplatin for 1 hour. The viable cells were determined for each radiation dose and/or each concentration of drug at the 4th day. And they w ere compared to control values. The obtained results were as follows: 1. The surviving curve with gentle slope was obtained after irradiation of 2, 4, 6, 8, 10Gy on YAC-1 cell line. 2. The cytotoxicity of bleomycin or cisplatin was increased significantly at all concentration of 0.2microgram/ml, microgram/ml an d 20microgram/ml on YAC-1 cell line (P<0.01). 3. There were no significant differences of surviving fractions among 4Gy, 6Gy, and 8Gy after irradiation of each radia tion dose with 2microgram/ml of bleomycin compared with irradiation only on YAC-1 cell line(P<0.05). 5. There were significant differences of surviving fractions between the groups of irradiation only and the groups of i rradiation with 2microgram/ml of bleomycin or cisplatin at all doses of 2, 4, 6, 8 and 10Gy on YAC-1 cell line(P<0.05).
Animals ; Bleomycin ; Cell Line* ; Cisplatin ; Lymphoma ; Mice ; Radiation Tolerance* ; Radiotherapy

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A radiographic study of mandibular condyle shape and position a comparision of trascranial radiograms and individulized corrected tomograms.

Sang Rae LEE ; Eui Hwan HWANG

Journal of Korean Academy of Oral and Maxillofacial Radiology.1997;27(1):25-42.

The purpose of this study was to observe mandibular condyle shape and position in an asymptomatic population. In o rder to carry out this study, 142 temporomandibular joints in 71 adults(35 males, 36 females), who were asymptomatic for temporomandibular joint disorders and had no history of prosthodontic or orthodontic treatments, were selected, and rad iographed using the Accurd-200 head holder(Denar Co., U.S.A.) for lateral individualized corrected tomograms. Mandibular condyles were classified morphologically and evaluated in positional relationships with articular fossae and articular eminences at centric occlusiohn and 1 inch mouth opening. The obtained results were as follows : 1. In the classification of mandibular condyle shape, the convex type was more prevalent in trascranial radiograms and tomograms taken at medial, central, and lateral locations. 2. In the mandibular condyle position at centric occlusion, the mandibular condyles were palced posterior to the center of articular fossae in trascranial radiograns and anterior to the center of articular fossae in tomograns taken at medi al, central, and lateral locations. 3. In the mandibular condyle position in right and left TMJs at centric occlusion, the mandibular condyles were placed bilateral asymmetric relationships to the articular fossae in trascranial radiograms and tomograms taken at medial, cent ral, and lateral location, 4. In the mandibular condyle position at 1 inch mouth opening, the mandibular condyles were placed anterior to the arti cular eminences in trascranial radiogramas and tomograms taken at central location and posterior to the articular eminen ces in tomograms taken at medial and lateral locations.
Classification ; Head ; Humans ; Male ; Mandibular Condyle* ; Mouth ; Prosthodontics ; Temporomandibular Joint ; Temporomandibular Joint Disorders

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Comparison of digitized radiographic alveolar features with age.

Keon Il LEE

Journal of Korean Academy of Oral and Maxillofacial Radiology.1997;27(1):17-24.

The purpose of the present stydy was to use digital profile image features and digital imge analysis of fixed-dime nsion bone regions, extracted from standardized periapical radiographs of the maxilla, to determine whether differences exist in alveolar bone of younger women(mean age: 59.23+/-7.34 years) and just menopaused women(mean age: 59.23+/-7.34), Periapical films were used from two groups of 20 randomly selected women. None of the subjects had a remarkabel medical history. To simplify protocal, we chose one interproximal bone area between the maxillary right canine and lateral inci sor for study. Each film was digitized into a 1312X1024 pixelX8 bit depth matrix by means of a Nikon 35 mm film scanner(LS-3510AF, Japan) with fixed gain and internal dark current correction to maintain constant illumination. The scanner was interfaced to a Macintosh LC III computer(Apple Computer, Charlotte, N.C.). Area and profile orientation were selecte d with a NIMH Image 1.37(NIH Research Services Brach, Bethesda, Md.). Histogram features were extracted form each profil e and area. The results of this study indicate that mean pixel intensities didn't differ significantly between two group s and there was a high correlation-coefficient between digitized radiographic profile features and area features.
Female ; Humans ; Lighting ; Maxilla ; National Institute of Mental Health (U.S.)

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