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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY
Journal Basic Information
Journal DOI :
Korean Academy of Pediatric Dentistry
Editor in Chief :
Volume & Issues
Volume 30, Issue 4 - Nov 2003
Volume 30, Issue 3 - Aug 2003
Volume 30, Issue 2 - May 2003
Volume 30, Issue 1 - Feb 2003
Selecting the target year
DEVELOPMENT OF FILTERING SYSTEM OF LASER FLUORESCENCE FOR IMPROVEMENT OF THE DIAGNOSTIC SENSITIVITY FOR DENTAL CARIES
Lee, Sang-Ho ; Park, Jong-Whi ; Kook, Jung-Ki ; Lee, Nan-Young ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 30, issue 2, 2003, Pages 189~195
The objective of this study is to improve the optical sensitivity of laser fluorescence for detection of incipient enamel caries. An incipient carious lesion was formed in various stages by placing an enamel specimen of a bovine tooth in STPP demineralization solution. After measuring the optical density of the lesion surface by laser fluorescence induced by argon laser and various alter of yellow(500-520nm), amber(520-540nm), orange(540-560nm), and red(560-580nm), the specimen was cut vertically to measure the depth of the lesion using a polarizing microscope. SAS statistical program was used to analyze the relationship between the optical density of the lesion suface and the depth of the lesion. The results were as follows: 1. The optical density of early carious lesion, measured by laser fluorescence with amber and orange filter, and lesion depth observed by polarizing microscope, were increased as demineralization time increased. 2. The correlation coefficient between optical density of the lesion surface and the histological depth of the lesion was the highest in orange filter(r=0.49), followed by amber(r=0.32), yellow(r=0.13) and red(0.01). 3. Regression analysis showed that the most linear relationship between the optical density and the lesion depth was existed in orange filter group. In regard above results, laser fluorescence could be considered to be reliable for optical diagnosis of dental caries.
THE EFFECTS OF DRYING AGENTS AND BONDING AGENTS ON THE SHEAR BOND STRENGTH OF SEALANTS TO ENAMEL
Lim, Hyun-Hwa ; Jang, Ki-Taek ; Kim, Chong-Chul ; Hahn, Se-Hyun ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 30, issue 2, 2003, Pages 196~203
The application of sealants is a highly technique-sensitive procedure, requiring an extremely dry field prior to placement. Moisture contamination of the etched enamel surface before sealant placement is cited as the main reason for sealant failure. The purpose of this study was to evaluate the effects of different methods of sealant application on the shear bond strength of sealants to enamel. In groups 1, 2, 3, 4 Teethmate(unfilled sealant) was used, while Ultraseal XTplus(filled sealant) was used in groups 5, 6, 7, 8. Groups 1 and 5(control) were acid etched for 15 seconds using 35% phosphoric acid, washed and then dried. In groups 2, 6 drying agents were applied, and in groups 3, 7 bonding agents were applied and light cured. In groups 4 and 8 both drying agent and bonding agent were applied. Then sealant was cured to the specimen using molds 3mm in diameter and 2mm in height. Thermocycling was performed and shear bond strength was finally measured. The following results were obtained : 1. Groups using filled sealant(groups 5, 6, 7, 8) showed higher shear bond strengths compared to groups using unfilled sealant(groups 1, 2, 3, 4). 2. Among groups using unfilled sealant(groups 1, 2, 3, 4), groups 2, 3, 4 showed significantly higher shear bond strength compared to group 1(p<0.05). There were no significant differences among groups 2, 3 and 4. 3. There were no significant differences(p>0.05) among groups using filled sealant(groups 5, 6, 7, 8). 4. When modes of fracture were examined, cohesive failure was observed in groups 2, 3 and 4.
ORAL REHABILITATION OF UNSTABLE OCCLUSION DUE TO SEVERELY DESTRUCTED FIRST PERMANENT MOLARS
Baik, Byeong-Ju ; Lee, Sun-Young ; Kim, Jae-Gon ; Jeon, So-Hee ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 30, issue 2, 2003, Pages 204~209
A 9-year old boy visited Department of Pediatric dentistry, Chonbuk National University Hospital due to unstable occlusion. He had permanent 1st molars destructed severely by dental caries and lost vertical stop. He could not occlude in the same position on closing of the jaw since he could not find his centric occlusion. The treatment plan was made, which was oral rehabilitation with crown restorations on permanent 1st molars based on clinical and radiographic examinations and centric relation of the jaw. Treatment plan consisted of endodontic treatment, crown lengthening and restoration of the occlusal vertical dimension (OVD) with gold crown by 3mm-increase of OVD. After endodontic and periodontal treatments, temporary crowns made of acrylic resin were set for assessment of tolerance to an increased OVD. After a month for tolerance, final prosthetics were made and set temporarily. In a month, gold crowns were set finally. Immediately after setting, the patient showed anterior open bite, but at the appointment after 4 months, he showed normal overjet, overbite and stable occlusion.
THE PREVALENCE OF DOUBLE TEETH AND CONGENITAL MISSING TEETH IN PRESCHOOL CHILDREN OF IKSAN CITY
Ju, Jin-Hyung ; Lee, Kwang-Hee ; Kim, Dae-Eop ; Jeong, Young-Nam ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 30, issue 2, 2003, Pages 210~216
The double teeth include gemination and fusion. The congenital missing tooth is the absence of the tooth. The purpose of this study was to investigate the prevalence of double teeth and congenital missing teeth in preschool children of Iksan city. The study population consisted of 1,031 children, 569 boys and 462 girls, aged from 17 to 84 months. The double teeth possess a variety of diagnostic and treatment problems. Gemination is the partial splitting of a single bud into two distinct entities that remain joined in a Siamese twin fashion. Fusion is the joining of two buds. Both may be normal, or one may be a supernumerary tooth. Congenital missing is the absence of one or a few teeth. Twenty three(11 boys and 12 girls) of the 1,031 children had double teeth and 17(8 boys and 9 girls) exhibited congenital missing of teeth. The prevalence of double primary teeth was 2.2%. The prevalence of congenital missing teeth was 1.6%. One subject had double teeth and congenital missing tooth at the same time. Of the 17 cases of congenital missing teeth, one girl showed it in the maxilla and aye boys and six girls had them in the unilateral side of the mandible. There were no significant differences in the prevalence of double teeth and congenital missing teeth between the boys and the girls.
THE EFFECT OF BONE MORPHOGENETIC PROTEIN 2(BMP2) ON THE GROWTH OF CRANIAL BONE AND EARLY MORPHOGENESIS OF THE CRANIAL SUTURE
Jung, Hae-Kyung ; Park, Mi-Hyun ; Ryoo, Hyun-Mo ; Nam, Soon-Hyeun ; Kim, Young-Jin ; Kim, Hyun-Jung ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 30, issue 2, 2003, Pages 217~228
Co-ordinate growth of the brain and skull is achieved through a series of tissue interactions between the developing brain, the growing bones of the skull and the sutures that unite the bones. Craniosynostosis, the premature fusion of cranial sutures, presumably involves disturbance of these interactions. Bmp2, one of bone morphogenetic proteins (Bmps), is involved in the regulation of the shapes of individual bones and the relative proportions of the skeleton. Mutations in the homeobox gene Msx2, known as a downstream gene of Bmp, cause Boston-type human craniosynostosis. The phenotype of Dlx5 homozygote mutant mouse presents craniofacial abnormalities including a delayed ossification of calvarial bone. These facts suggest important roles of Bmp2, Msx2 and Dlx5 genes in the cranial bone growth and suture morphogenesis. To elucidate the function of these molecules in the early morphogenesis of mouse cranial sutures, we first analyzed by in situ hybridization the expression of Bmp2(E15-18), Msx2 and Dlx5 genes in the developing sagittal suture of calvaria during the embryonic stage. Bmp2 mRNA was intensely expressed in the osteogenic fronts and also at the low level in the periosteum of parietal bones during embryonic stage, Msx2 mRNA was intensely expressed in the sutural mesenchyme and mildly expressed in the dura mater during the embryonic stage. Dlx5 mRNA was intensely expressed osteogenic fronts and parietal bones. To further examine the role of Bmp signaling in cranial suture, we did in vitro experiments in E15.5 mouse calvarial explants. Interestingly, implantation of Bmp2-soaked beads onto the osteogenic fronts after 48 hours organ culture resulted in the increase of the tissue thickness and cell number around Bmp2 beads, compared to BSA control beads. In addition Bmp2 induced etopic expressions of Msx2 and Dlx5 genes. On the other hand, overexpression of FGF2 did not induce the expression of Msx2 and Dlx5. Taken together, these data indicate that Bmp2 signaling molecule has a important role in regulating the cranial bone growth and early morphogenesis of cranial suture. We also suggest that Bmp signaling is involved in all the stages of osteogenesis of cranial bones and the maintenance of cranial suture by regulating Msx2 and Dlx5 genes, and that Msx2 and Dlx5 genes are specific transcription factors of Bmp signaling pathway.
A STUDY ON THE MODE OF POLYMERIZATION OF LIGHT-CURED RESTORATIVE MATERIALS CURED WITH THREE DIFFERENT LIGHT SOURCES
Kwon, Min-Seok ; Jung, Tae-Sung ; Kim, Shin ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 30, issue 2, 2003, Pages 229~237
The purpose of this study was to compare the effect of exposure time on the polymerization of surface and 2 mm below the surface of light-cured restorative materials cured with three different light sources; conventional halogen light curing unit(XL 3000, 3M, U.S.A.), plasma arc light curing unit(Flipo, LOKKI, France) and light emitting diode(LED) light curing unit(Elipar Free light, 3M, U.S.A.) and compare the uniformity of polymerization from the center to the periphery of resin surfaces according to polymerization diameter cure with three different light sources. From the experiment, the following results were obtained. 1. In Z-100, Plasma arc light exposure time of 6 to 9 seconds and LED light exposure time of 40 to 60 seconds produced microhardness values similar to those produced with 40 second exposure to a conventional halogen light(p>0.05). 2. In Tetric Flow, Plasma arc light exposure time of 9 seconds and LED light exposure time of 40 to 60 seconds produced microhardness values similar to those produced with 40 second exposure to a conventional halogen light(p>0.05). 3. In Dyract AP, Plasma arc light exposure time of 6 to 9 seconds and LED light exposure time of 20 to 40 seconds produced microhardness values similar to those produced with 40second exposure to a conventional halogen light(p>0.05). 4. In Fuji II LC, Plasma arc light exposure time of 9 seconds and LED light exposure time of 20 to 60 seconds produced microhardness values similar to those produced with 40second exposure to a conventional halogen light(p>0.05). 5. Except Fuji II LC, microhardness was decreased from the center to the periphery in all light sources(p<0.05).
A STUDY ON THE MICROLEAKAGE OF PIT AND FISSURE SEALANTS WITH DIFFERENT FILLING AMOUNT
Park, Soo-Jin ; Jung, Tae-Sung ; Kim, Shin ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 30, issue 2, 2003, Pages 238~244
With the purpose of evaluating the effect of ailing amount of pit and assure sealants on the microleakage, 6 groups of specimens with different filling amount, filling materials and surface pretreatment were investigated. Sixty permanent third molars were divided into three groups. The occlusal surface of each tooth was divided into two parts; the filing width of one part was below 1mm (group1, 3, 5), and in the other part more than 2mm (group 2, 4, 6) Group 1 and 2: Helioseal F was applied directly to etched enamel; Group 3 and 4: Helioseal F was applied to etched and scotchbond Multi-purpose plus pre-treated enamel; Group 5 and 6: Tetric Flow was applied. After 500 times thermocycling and dye infiltration, we evaulated the microleakage. The results were as follows; 1. The mean microleakage score at each width were increased in the following order;group 5<3<1, and group 6<4<2. 2. In comparing the groups with same material and surface pretreatment but with different filling width (group 1 versus 2, 3 versus 4, 5 versus 6), the microleakage scores were significantly different. 3 The microleage was affected by filling amount of pit and assure sealants than Oiling materials and dentin bonding agent pretreatment.
THE COMPARISON OF LIGHT-CURED COMPOSITE RESIN POLYMERIZATION BY FTIR
Lee, Ju-Hyun ; Park, Ho-Won ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 30, issue 2, 2003, Pages 245~253
The degree of conversion of cross-linked polymer has great importance in determining the physical and mechanical properties, and biocompatibility. Therefore, this study examined the comparison of light-cured composite resin polymerization of various light-curing systems composed of plasma arc, halogen, LED curing units and pluse-delay curing with FTIR. From this experiment, The following results were obtained : 1. From FTIR, the degree of conversion(DC) of composite resin was 34.52-49.31%, DC of composite resin used in Flipo was
, VIP(mode 4)
, Elipar Freelight
in pulse-delay curing. 2. The degree of conversion of composite resin in each light-curing unit was highest DC of the LUXOMAX system, lowest DC of the pulse-delay curing. 3. Compared with other curing system, Flipo, LUXOMAX, and pulse-delay curing were significant difference(p<0.05). 4. In same curing method group, the differences of each light-curing unit were no significace in halogen(conventional) curing method(p>0.05), but significance in plasma arc curing and LED curing method(p<0.05).
RELATIONSHIP BETWEEN DENTOCULT-SM TEST, MICROBIAL ANALYSIS AND DENTAL CARIES IN THE PRE-SCHOOL CHILDREN
Shin, Doo-Kyo ; Kim, Ji-Young ; Song, Keun-Bae ; Nam, Soon-Heyun ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 30, issue 2, 2003, Pages 254~262
Dental caries has a multifactorial aetiology in which there is an interplay of three principal factors: the host(saliva and teeth), the microflora(dental plaque) and the substrate(diet), and a fourth factor time. There is no single test that takes into consideration all these factors and can accurately predict an individual's susceptibility to dental caries. The risk of dental caries can be evaluated by analysing and integrating several causative factors. The objective of the study was to clarify the relationship between caries activity and the status of caries of primary teeth and the relationship between the quantity of S. mutans in the dental plaque and the status of dental caries. Forty nine children ages 5 were examined with caries indices, Dentocult-SM and quantity of S. mutans. The results were as follows: All the survey results were similar with national means of 5-6 years Korean preschool children. The deft index of subjects was 5.46 and defs index was 9.81. There was 8.6% of negative, 10.9% of mild, 28.1% of moderate and 52.3% of active results at screening strip test. 8.6% was negative, 17.2% was mild, 33.6% was moderate and 40.6% was active in site strip test. The Spearman correlation coefficient was 0.775, and overall kappa index was 0.496 between screening strip test and site strip test. There also was a high correlation between caries incidence, Dentocult-SM test, and quantity of S. mutans. Dentocult-SM test as a caries activity test is a reliable method for measuring the status of dental caries in primary teeth.
A STUDY ON THE FORMATION OF SHEAR BONDING STRENGTH AND HYBRID LAYER ACCORDING TO THE APPLICATION TIME AND FREQUENCY OF AN ALL-IN-ONE SYSTEM IN PRIMARY TEETH.
Hong, Sang-Jin ; Park, Jong-Whi ; Park, Heon-Dong ; Lee, Sang-Ho ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 30, issue 2, 2003, Pages 263~271
The purpose of the present study was to evaluate the patterns of hybrid layer according to the application time and the frequency and its effects on the shear bonding strength of All-In-One system in primary teeth. A single bonding agent(Scotchbond Multi-Purpose Plus, 3M) and an All-In-One system(Prompt L-pop, 3M ESPE) were applied on the dentin varying the application time and the frequency in primary teeth. Shear bond strength was measured and the patterns of hybrid layers were observed by SEM. The following results were obtained ; 1. The shear bonding strength of single bonding agent was significantly higher than that of All-In-One system(P<0.05). 2. The shear bonding strength of All-In-One system applied twice or 3 times were higher than that of applied once (P<0.05). And thickness of the hybrid layer was increased when applied twice or 3 times compared to once. 3. The shear bonding strength of All-In-One system when applied for 15 second and 30 second were higher than that of 7 second (P<0.05). And the hybrid layer thickness of 15 second and 30 second's application time were higher than that of 7 second. 4. Thickness of hybrid layer applied with single bonding agent was
and that of All-In-One system was
CUTTING EFFICACY OF Er:YAG LASER AND CONVENTIONAL BUR IN DECIDUOUS AND PERMANENT TEETH
Park, In-Cheon ; Lee, Chang-Seop ; Lee, Nan-Young ; Lee, Sang-Ho ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 30, issue 2, 2003, Pages 272~285
This study was conducted to observe the microscopic structures of cavities formed after ablation of primary teeth, permanent teeth, enamel and dentin in using a bur and cavities formed after ablation using laser and the following results were obtained after comparing the effects of ablation. Using a #330 bur and Er:YAG laser irradiated at 150 mJ, 200 mJ, 250 mJ and 300 mJ all at the frequency of 5 Hz, 1 mm enamel and dentin samples were ablated and the ablation time was measured. In order to measure the surfaces ablated, 5 each of primary teeth and permanent teeth were ablated using a #330 bur and Er:YAG laser at 150 mJ, 200 mJ, 250 mJ and 300 mJ for 1 sec and the cross section and vertical section were observed. The following results were obtained : 1. Cutting time of Er:YAG laser was longer than that of conventinal high-speed bur regardless of teeth type. 2. Cutting on enamel, Cutting time of conventional high-speed bur in deciduous teeth was longer than in permanent teeth(P<0.05). But Er:YAG laser was not showed any difference between the deciduous and permanent teeth(P>0.05). 3. Cutting on dentin, Cutting time of conventional high-speed bur in permanent teeth was longer than deciduous teeth. Er:YAG laser of 150 mJ, 5 Hz in permanent teeth was longer than in deciduous teeth(p<0.05). But laser of other power did not showed mean difference. 4. The cavity surface treated with the convetional high-speed bur revealed a relatively flat appearance, almost covered with a debris-like smear layer. Cavity wall showed striped appearance because of blade of bur. 5. The cavity surface treated by the Er:YAG laser system was irregular or rough surface with the absence charring, carbonization, or cracking of the dentin. In addition, there was an absence of a smear layer. Cavity floor was round and relatively smooth. According to these results, cutting time of Er:YAG laser was almostly same in permanent and deciduous teeth, but more effective in dentin than enamel. Cutting the sample, Er:YAG laser was needed more time than conventional bur. But SEM findings suggested that laser device produced favorable surface characteristic(i.e, no smear layer, irregular surface, cracking).
FIBROMA ON THE PALATE : A CASE REPORT
Kim, Young-Jae ; Jang, Ki-Taeg ; Hahn, Se-Hyun ; Kim, Chong-Chul ; Lee, Sang-Hoon ; Kim, Jung-Wook ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 30, issue 2, 2003, Pages 286~290
The fibroma is the most common benign soft-tissue tumor found in the oral cavity and most commonly occurrs in sites predisposed to irritation or trauma. Treatment is conservative surgical excision. Seldom does the lesion recur. A 14-year old girl was referred to the Department of Pediatric Dentistry for evaluation and management of a mass on the palate. The patient's parents reported the slow growth of this soft tissue lesion over a 6-month period. A history of trauma or irritable habits was denied. Clinical examination revealed an asymptomatic, soft, pedunculated elevation of mucosa, measuring 3cm in diameter. Excisional biopsy of the lesion supported a diagnosis of fibroma. There have been no signs of recurrence during follow up of 4 years after surgical intervention. The clinical picture, pathology and management of the case are described, and the differential diagnosis and treatment are discussed.
THE ANTERIOR-POSTERIOR AND VERTICAL RELATIONSHIP OF THE GROWING CHILDREN WITH CLASS III MALOCCLUSION BY LATERAL CEPHALOMETRIC MEASUREMENT
Yang, Ku-Ho ; Choi, Nam-Ki ; Kim, Seong-Nam ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 30, issue 2, 2003, Pages 291~297
While making diagnosis and the treatment plan for the growing children who visited at Chonnam National University Hospital for orthodontic treatment, authors obtained 8 lateral cephalometric measurements in antero-posterior and vertical relationship such as APDI, WITS, ANB, SN-MP, ODI, PFH/AFH, Y-axis, SUM for children aged 7 to 9 with class III malocclusion and compared them with these of 73 children of elementary school aged 7 to 9 with proper profile and normal occlusion in Gwangju. The results were as follows: 1. Between normal occlusion and class III malocclusion, ANB, SN-MP, ODI, SUM, except PFH/AFH and Y-axis showed statistically significant differences(p<0.05). 2. Between mesurements to describe skeletal disorder of antero-posterior relationship such as APDI, WITS, ANB and skeletal disorder of vertical relationship such as SN-MP, ODI, PFH/AFH, Y-axis, SUM, all of them in both normal occlusion and Class III malocclusion showed significant correlation, except Y-axis, SUM correlation(p<0.01). 3. Wald' statistics of WITS, ANB and APDI expressing skeletal disorder of antero-posterior relationship showed 7.118, 5.148, 0.741, respectively and Wald' statistics of ODI, Y-axis, PFH/AFH, SN-MP, SUM were presented 28.348, 2.238, 1.376, 0.090, 0.089, respectively. Therefore, WITS and ODI could be considered as useful diagnotic measurements for class III malocclusion.
THE LATERAL CEPHALOMETRIC STUDY OF THE GROWING CHILDREN WITH CLASS III MALOCCLUSION BY KIM'S ANALYSIS
Yang, Ku-Ho ; Choi, Nam-Ki ; Jeong, Jin-Gug ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 30, issue 2, 2003, Pages 298~307
The purpose of this study was to investigate the distribution and differences of the cephalometric measurements between normal occlusion and the class III malocclusion. Kim's analysis was achieved and compared on both the 141 elementary school students with proper profile and normal occlusion and the class III malocclusion group at the age of 7 to 9, in Gwang-ju area and the results were as follows; 1. The ODI, APDI, IIA, UL showed statistically significant differences between normal occlusion and class III malocclusion(p<0.01). But, no significant difference existed in both CF and EI. 2. The mean value of ODI was 72.62, APDI 80.47 IIA 121.37 in normal occlusion. 3. The mean value of ODI was 64.45, APDI 87.31 IIA 129.89 in class III malocclusion. 4. ODI decreased as APDI increased, and the correlation coefficient was -0.576 in both normal occlusion and class III malocclusion. 5. The correlation coefficient related to EI was CF 0.777, LL -0.670, UL -0.588, IIA 0.485. It means that UL and LL were very sensitively reflected on EI.
THE EFFECT OF ALTERED FUNCTIONAL FORCE ON THE EXPRESSION OF SPECIFIC MRNAS IN THE DEVELOPING MOUSE MANDIBLE
Kim, Hyung-Tae ; Park, Joo-Cheol ; Lee, Chang-Seop ; Park, Heon-Dong ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 30, issue 2, 2003, Pages 308~319
Mechanical forces are known to have an effect on bone formation, maintenance and remodeling, and there is evidence that the development of the mandibular condyle in the rat or mouse is influenced by altered functional force. However, studies are lacking in molecular-biologic mechanism such as the identification of differentiation factor induced from functional force. Here a mouse model was used to investigate the functional stress-responsive gene or factors which is related to the altered force by comparing the expression genes of functional state and hypo-functional state of the mouse mandible. ICR mice were provisioned with either a soft, mushy diet (soft-diet group) or hard rat pellets (hard-diet group) beginning at weaning for the alteration of functional force and subsequently sacrificed at 89 days of age. Incisor of mice in group 1 were trimmed twice a week to reduce occlusal forces. After killing the animals, mandibular bone including condyle were collected for RNA extraction, subtractive hybridization, northern blot analysis and mRNA in-situ hybridization. The results as follows; 1. A total of 39 clones were sequenced, and 11 individual sequence types were subsequently identified by subtractive hybridization, as 28 clones were represented twice in the analyzed sets. 2. Consequently four candidate clones, FS-s (functional stress-specific)2, -5, -18, and -22 were identified and characterized by homolgy search and northern analysis. Four of these clones, FS-s2, -5, -18, and -22, were shown to be expressed differentially in the hard-diet group. 3. Histologic sections showed that osteoblastic activity along the bone trabeculae and active bone remodeling were significantly lower in soft than in hard diet animals. A soft diet seems to enable a longer period of endochondral ossification in the mandibular condyle. 4. Although the mRNAs of FS-s2, -5, -18, and -22 were expressed rarely by cells of the soft-diet group, highest expression was detected in the cells of the hard-diet group. Together with the above results, it is suggested that FS-s2, -5, -18, and -22 could act as an important factors controlling the tissue changes in response to functional stress. The exact functional significance of these findings remains to be established.
EFFECT OF CARBON DIOXIDE LASER ON INHIBITION OF DEMINERALIZATION AND REHARDENING OF PRIMARY TEETH
Lee, Kwang-Hee ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 30, issue 2, 2003, Pages 320~325
The purpose of study was to investigate the effect of carbon dioxide laser on demineralization inhibition and rehardening of primary tooth enamel according to its power and irradiation time. 2mm diameter circle on the primary enamel surface was irradiated by defocused
superpulse carbon dioxide laser at 6 Watt 2 seconds or at 3 Watt 8 seconds, before or after demineralization by Coca-Cola for 24 hours. Enamel surface change was measured by the Diagnodent. The results were analyzed with the former study results of 3 Watt 4 seconds and 6 Watt and 4 seconds. Diagnodent scores increased significantly after demineralization of irradiated enamel at 6W 2s or 3W 8s (P<0.05). Among the four groups, only 6W 4s group showed obvious demineralization inhibition effect. Diagnodent scores reduced significantly after 6W 2s or 3W 8s irradiation of demineralized enamel(P<0.05). Among the four groups, 6W 4s showed nearly complete rehardening effect, and the other groups showed partial effect. Tooth discoloration only occurred at 6W 4s. It seemed that caries inhibition and tooth discoloration depend on laser power more than total irradiation energy.
AUTOTRANSPLANTATION OF IMPACTED MAXILLARY CANINES
Kim, Tae-Wan ; Kim, Hyun-Jung ; Kim, Young-Jin ; Nam, Soon-Hyeun ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 30, issue 2, 2003, Pages 326~333
The appropriate treatment for eruption guide of impacted teeth necessitates the formulation of a comprehensive treatment plan, which is dependent upon a number of factors such as the condition of the deciduous teeth, dental and skeletal relationship, dental age of the patient, willingness of the patient to undergo extensive dental treatment and financial considerations. If the etiology of the eruption disturbance has been identified, the elimination of the causes and various procedures can be used for eruption guide. Particularly the transplantation is a valuable alternative to extraction of impacted teeth, where surgical exposure and subsequent orthodontic realignment are difficult or impossible. This report present three cases of autotransplantation of impacted maxillary canine. As the result in these cases, atraumatic removal of donor tooth during operation is prerequisite to an optimal clinical result. Due to a high possibility of pulp necrosis, endodontic treatment of fully developed transplanted teeth should be undertaken. In complex case, autotransplantation can save time and less expensive than orthodontic forced eruption. Recipient socket should be prepared to a size that is slightly larger than the root of the donor tooth, and can be prepared with open or close procedure depends on root size of donor tooth and buccolingual width at transplantion site.