• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.3
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• pp.362-371
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• 2004

It is essential to have adequate knowledge of the timing of root resorption of deciduous teeth for diagnosis and treatment planning in pediatric and orthodontic dentistry. Dental development is also influenced by hereditary characteristics, environmental factors, race, sex, endocrine reaction, nutrition, socioeconomic condition and secular factor. The aims of the present study were to determine the mean age of root resorption of deciduous teeth in contemporary Korean children and to compare the mean age of root resorption time of deciduous teeth between early 1990s and early 2000s. The study population was made up of Korean children attending the pediatric dentistry ward of Kyungpook National University Hospital. One thousand thirty seven children's panoramic radiograph (girls: 528 persons, boys: 509 persons) in $1990{\sim}1992$ and one thousand sixty five children's panoramic radiograph (girls: 394 persons, boys: 671 persons) in $2001{\sim}2003$ were examined. This study utilized a cross-sectional design. Due to the problems of imaging in the maxillary region and the mandibular incisor region, the mandibular deciduous canine, the mandibular deciduous first molar and the mandibular deciduous second molar were chosen for examination. The results were as follows. 1. There is a tendency for the teeth to resort earlier in the early 2000s group than the in early 1990s group. At the Res c stage, the difference of the mean age was 0.4 years. 2. At the Res c stage, the order of difference of the mean age from smaller to larger for the girls was the mandibular deciduous canine, the mandibular first deciduous molar, and the mandibular second deciduous molar. On the other hand, for the boys, the order was the mandibular second deciduous molar, the mandibular first deciduous molar, and the mandibular deciduous canine. The difference was larger with aging in girls and smaller with aging in boys. 3. There is a tendency for the teeth to resort earlier in girls in both the early 1990s group and the early 2000s group. The difference of the mean age between girls and boys was 0.3 year. 4. The commencement of root resorption of the mandibular deciduous canine was slower than that of the mandibular first deciduous molar. However, the completion of root resorption of the mandibular deciduous canine is faster than that of the mandibular first deciduous molar. The total elapsed time of root resorption from commencement to completion was shortest in the mandibular deciduous canine. 5. For each of the teeth in the early 1990s and the early 2000s groups, the speed of root resorption was in the later stage faster than in the earlier stage. In order to know about the exact timing of root resorption of deciduous teeth, periodic and longitudinal studies preferably covering the entire period of growth, is required.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.4
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• pp.625-630
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• 2009

Root resorption of primary teeth usually occurs as the succeeding permanent teeth erupt, which induces differentiation of the hemopoietic cells into osteoclasts. Their root resorption pattern reflects the eruption path of the succeeding permanent teeth, and eventually the primary teeth shed as their succeeding permanent teeth erupt. Even when a permanent tooth germ is congenitally missing, root resorption of the corresponding primary tooth may still occur due to various factors, such as inflammation, traumatic occlusal force, and weakness of periodontium etc. Such congenital missing of permanent teeth is a commonly observed phenomenon in human be ing, and it often accompanies delayed retention of primary teeth. The etiologic factors for congenital missing in elude not only systemic diseases, but also local factors and human evolution process. In the radiographs of the cases in this report, the primary teeth without succeeding permanent teeth show pathologic root resorption. Root resorption progressed about 1/2~3/4 of the roots, and the surfaces of the resorption area were irregular. Considering high susceptibility of the periodontal ligament of primary teeth to root resorption, pathologic root resorption of primary teeth with delayed retention can be explained by the increased masticatory muscle force and abnormal occlusion developed during the mixed dentition. When the primary teeth without succeeding permanent teeth are lost, decision for space maintenance is required and long-term treatment plan for further prosthetic or orthodontic treatment should be establsihed.

• Journal of Korean Dental Science
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• v.2 no.2
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• pp.31-34
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• 2009

The survival rate of the OSSTEM GS II Implant 1 year after serving the prosthetic function in 2 domestic and foreign medical institutes was 97.57%; the success rate was 95.7%, and the average alveolar bone resorption was 0.24mm(n=389). In particular, the alveolar bone resorption occurred differently according to the placement location as well as whether or not the patient underwent bone grafting operation, but the implant s length and diameter did not have significant impact on alveolar bone resorption.

• Journal of Food Hygiene and Safety
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• v.14 no.1
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• pp.22-26
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• 1999

The purpose of this experiment was to examine the antimicrobial effect of the natural flavonoid hesperidin on dental caries and alveolar bone resorption in the albinorats. Twenty five day old male rats were fed with the experimental diets for 42 days. At the end of the 42 day experimental period, the molar tooth occlusal surface was examined by a dissecting microscope. The sulcular caries lesions were recorded: the first molar caries incidence was higher than that of the second molar and the third molar. Alvelolar bone resorption was measured on the buccal and lingual aspects of each molars. Three measurements were taken on the first molar (mesialpoint, midpoint, distalpoint). The results of this experiments, showed that hesperidin is effective in reducing dental caries and alveolar bone resorption.

• The Korean Journal of Zoology
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• v.37 no.2
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• pp.255-261
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• 1994

Recombinant human pBrathyriod hormone related peptide (1-341 (rhPTHrP) has been known to stimulate bone resorption in intact bone tissue culture system. Osteoclast has been known as a primary responsible cell for bone resorption. To examine the effect of rhPTHrP on this cell, we employed disaggregated rat osteodast culture. As a result, we found that rhPTHrP sisnificBntly elevates both the number and total area of resorbed pits in this culture. On the other hand, the conflicting results between disagsregated rat osteoc13st culture and Ca2+-deficient hen osteoclast culture system have been a big obstacle for the progress of bone research. To verify the differences between rat 3nd chick osteoclast system, we performed the same experiment using chick embryonic osteoclast. Since the similar results were obtained from the disaggregated chick osteoclast culture, the discrepancy between chick and rat osteoclast culture study seemed to be due to the difference in culture method, rather due to the species-difference.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.133.1-133.1
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• 2003

Cathepsin K (CK) is a cysteine protease that plays a major and essential role in osteoclast-mediated degradation of collagen matrix of bone. Its tissue-limited distribution and pivotal contribution to bone resorption meet the requirements as the potential therapeutic target of the disease with excessive bone loss such as osteoporosis. In a search for potent CK inhibitors. we found OST-5440 that effectively inhibited bone resorption in vivo as well as in vitro. (omitted)

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.140.2-140.2
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• 2003

Isoflavone found in Leguminosae is one of natural phytoestrogens and its effect on bone remodeling is one of key investigational interests in terms of estrogen replacement therapy (ERT). As commonly known, osteoporosis is one of hormonal deficiency diseases, especially in menopausal women. When estrogen is blocked, local factors such as 1L-1$\beta$ and IL-6 that are related in bone resorption are increased and enhance osteoclastogenesis, which is responsible for bone resorption. In the present study, we investigated the effect of isoflavones (Isocal) extracted from Sophorae Fructus on bone resorption in vitro. (omitted)

• The Journal of Dong Guk Oriental Medicine
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• v.9
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• pp.179-191
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• 2000

Anti-bone resorption properties of the Korean herbal medicine, CEDR, which is comprised 5 herbs of [Drynariae Rhizoma, Loranthi Ramus, Cibotii Rhizoma, Amydae carapax, Psoraleae semen], were investigated. Mouse calvarial osteoblast cells were isolated and cultured. Mouse osteoblasts, which were stimulated by PTH, $1,25(OH)_2D_3$, $TNF-\alpha$ and IL-1 as bone resorption agents, showed increased collagenolysis by producing the active gelatinase. IL-1 in stimulating bone resorption was examined using fetal mouse long bone organ culture. IL-1 stimulated bone resorption and produced marked resorption when present simultaneously. The results of in vitro cytotoxicities showed that CEDR extracts have no any cytotoxicities in concentrations of $1-60{\mu}g/ml$ and furthermore there is no any cytotoxicity even in concentration of $120{\mu}g/ml$ on mouse calvarial bone cells. CEDR extracts had protective activity against PTH (5 units/ml, or $IL-1{\alpha}$ (1 ng/ml) or $TNF-\alpha$ or $1,25(OH)_2D_3$ (20 ng/ml), $IL-1{\alpha}$ and $IL-1{\beta}-induced$ collagenolysis in the mouse calvarial cells. Pretreatment of the CEDR extracts for 1 h, which by itself had little effect on cell survival, did not enhance the collagenolysis, nor significantly reduced the collagenolysis by pretreatment. Furthermore, the medicinal extracts were shown to have the protective effects against collagenolysis induced by $IL-1{\alpha}$ and $IL-1{\beta}$. Pretreatment of the extracts for 1 h significantly reduced the collagenolysis. Interestingly, the CEDR extracts were shown to have the inhibiting effects against gelatinase enzyme and processing activity induced by the bone resorption agents of PTH, $1,25(OH)_2D_3$, $TNF-\alpha$, $IL-1{\beta}$ and $IL-1{\alpha}$ with strong protective effect in pretreatment with the extracts. CEDR extracts were shown to have the inhibiting effects against $IL-1{\alpha}-$ and $IL-1{\beta}-stimulated$ bone resorption and the effect of the pretreatment with a various concentrations of the medicinal extracts were significant. These results indicated that the CEDR extracts are highly stable and applicable to clinical uses in osteoporosis.

• The korean journal of orthodontics
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• v.26 no.4
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• pp.441-447
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• 1996

This study was carried out in order to find out the pattern of the root resorption following maxillary incisor retraction after maxillary 1st bicuspid extration in maxillary protrusion patients. For this study, thirty two patient who received orthodontic treatment were chosen. The results were as follows; 1. Of the total 192 teeth, 61 teeth(31.77%) showed no apical root loss, 64 teeth(33.33%) fell into the class "slight", 46 teeth(23.96%) fell into the class "moderate". Only 21 teeth(10.94%) were classified as "excessive". 2. No correlation was noted between the amount of apical root loss and the types of tooth movement of the maxillary central incisors. 3. The patients who were treated with standard brackets had more changes in tooth axis and less movement of root apexes, but the patients with straight brackets had less changes in tooth axis and more movement of root apexes. 4. Comparing the degree of root resorption between bracket types, patients who had used standard brackets showed more apical root loss than patients who had used straight brackets. 5. The most frequent degree of root resorption observed in standard bracket patients was second degree, followed by first degree and third degree. The most frequent degree of root resorption observed in straight bracket patients was zero degree, followed by first, second degree and third degree.

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.1
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• pp.96-102
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• 1999

Tooth avusion implies total displacement of teeth out of its socket. Its frequency range from 0.5 to 16% of traumatic injuries. Replantation procedure is used for the treatment of avulsed tooth. However, its major complications are pulp necrosis, inflammatory root resorption and replacement root resorption. This paper describes 10 years and 2 months old male patient whose both maxillary central incisors were avulsed due to fall-down with slightly underdeveloped root apices. Teeth were replanted 2 hours after accident. Right central incisor's pulp tissues were extirpated and filled with $Vitapex^{(R)}$(calcium hydroxide) at 3-4 weeks after replantation, but left central incisor was filled at 8-9 weeks. Right central incisor showed little inflammatory resorption in apical portion, whereas left central incisor showed severe root resorption. During 18 months' follow-up period, left central incisor showed slightly ankylosis while right central incisor did not. Based upon the above-mentioned results, the following conclusions can be drawn: 1. Inflammatory resorption could be suppressed by endodontic treatment with calcium hydroxide. 2. When apex formation is doubted in replanted tooth due to avulsion, early endodontic treatment with calcium hydroxide seems to act positively for better prognosis.