• Imaging Science in Dentistry
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• v.32 no.3
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• pp.141-145
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• 2002

Purpose : The purpose of this study was to propose standard values for alveolar and basal bone in normal adult mandibles, and radiologically analyze the remodeling process of the edentulous mandible by examining molar areas and comparing them to the established normal values. Materials and Methods : Panoramic and CT scans of mandible were performed on 20 normal adults and 20 edentulous or partially edentulous adults. In both groups, arch half diameter and distance of alveolar bone were measured. Also the distance from the mandibular canal to the caudal edges, the buccal and lingual external borders of basal bone, were measured. A statistical comparison between the mean values of normal and edentulous mandibles was carried out in the selected areas. Results : There was evidence of decreasing arch half diameter and distance in the edentulous mandible, but statistically no significant change was seen between the normal and edentulous alveolar bone. There was evidence of decreasing buccal basal bone and increasing in the lingual basal bone in the edentulous mandible. A statistically significant difference between normal and edentulous mandibles was noted in the buccal basal bone. Conclusion: There was an inward and forward atrophic change of the edentulous mandibular molar area compared to the control. CT scanning required the use of sophisticated and expensive procedures to analyze the remodeling process of edentulous mandibles. Consequently, the development and application of a more simplified and objective radiographic procedure for broad and long-term study of remodeling procedures of edentulous mandible was recommended.

• The korean journal of orthodontics
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• v.11 no.1
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• pp.7-15
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• 1981

Tooth movement by orthodontic force is based upon alveolar bone resorption at compression site and bone formation at tension site of tooth. The function of cyclic AMP is to participate not only in initial action of bone cells by mechanical forces but also in the continuous cellular response leading to bone remodeling. This experiment was performed to clarify the role of cyclic AMP in bone remodeling by mechanical forces. The orthodontic forces of about 80 gm and 100 gm were applied to the right canines of maxillary and mandibular bone, respectively, in cats, treated for periods of time ranging from one hour to 28 days. Alveolar bones were obtained from compression and tension sites surrounding tipping maxillary and mandibular canines as well as from contralateral control sites. The samples were extracted, boiled and homogenized, and the supernatants were assayed for cyclic AMP by a radioimmunoassay method. The results were as follows: 1. The orthodontic movement of canines was increased to the end of experimental period and the action of orthodontic forces on tooth movement was more effective in maxillary canine. 2. The cyclic AMP levels of alveolar bones in compression and tension sites initially decreased, then increased and remained elevated to the end of experiment. The differences of the cyclic AMP levels between treated sites and non-treated sites were gradually increased. 3. The cyclic AMP levels in treated sites of mandibular alveolar bone was higher than that of maxillary alveolar bone.

• Journal of Periodontal and Implant Science
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• v.31 no.1
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• pp.57-74
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• 2001

The purpose of this study was to evaluate the adjunctive combined effect of demineralized freeze-dried bone allograft(DFDB) in guided bone regeneration on supra-alveo-lar peri-implant defect. Supra-alveolar perio-implant defects, 3mm in height, each including 4 IMZ titanium plasma-sprayed implants were surgically created in two mongrel dogs. Subsequently, the defects were treated with 1 of the following 3 modalities: Control) no membrane or graft application, Group1) DFDB application, Group2) guided bone regeneration using an expanded polytetra-fluoroethylene membrane, Group3) guided bone regeneration using membrane and DFDB. After a healing period of 12-week, the animals were sacrificed, tissue blocks were harvested and prepared for histological analysis. Histologic examination were as follows; 1. New bon formation was minimal in control and Group 1, but considerable new bone formation was observed in Group 2 and Group 3. 2. There was no osteointegration at the implant-bone interface in the high-polished area of group2 and Group 3. 3. In fluorescent microscopic examination, remodeling of new bone was most active during week 4 and week 8. There was no significant difference in remodeling rate between group 2 and group 3. 4. DFDB particles were observed, invested in a connective tissue matrix. Osteoblast activity in the area was minimal. The results suggest that guided bone regeneration shows promising results in supra-alveolar peri-implant defects during the 12 week healing period although it has a limited potential in promoting alveolar bone regeneration in the high-polished area. There seems to be no significant adjunctive effect when DFDB is combined with GBR.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.29 no.1
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• pp.43-53
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• 1999

Purpose: The aim of this study was to analyze radiologically the location and course of the mandibular canal and to observe the alveolar and basal bone changes during the remodeling procedures of atrophic mandible. Materials and Methods: CT scanning was performed on dry 30 edentulous or partially dentulous mandibles. In 48 edentulous lower halves, measuring areas were determined by three points in the length of the mandibular canal. The distance from the mandibular canal towards cranial and caudal edges, buccal and lingual external borders of the body of the mandible were measured. A statistical comparison between the mean values of different classes of mandibular body was carried out in the selected areas. Results: The distance between the mandibular canal and caudal borders of the body of the mandible and lingual borders dose not change in the atrophic process of mandible. The mandibular canal within the mandible courses downwards from mandibular foramen towards mesial and subsequently it gets to the mental foramen. The distance between the mandibular canal and buccal external border of basal bone changes similar to the change of cranial borders of alveolar bone in the atrophic process of mandible. Conclusion: CT scanning was very effective and practicable to analyze the location and course of the mandibular canal and to observe the alveolar and basal bone changes of atrophic mandible. Also more detailed investigation of basal bone changes observed during the remodeling procedures of atrophic mandibles seems reasonable to rely on the massive anthropologic collections of atrophic mandibles combined with CT scanning.

• Journal of Korean Dental Science
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• v.9 no.2
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• pp.55-62
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• 2016

Purpose: Alveolar bone develops with tooth eruption and is absorbed following tooth extraction. Various ridge preservation techniques have sought to prevent ridge atrophy, with no superior technique evident. Collagen has a long history as a biocompatible material. Its usefulness and safety have been amply verified. The related compound, atelocollagen, is also safe and displays reduced antigenicity since telopeptides are not present. Materials and Methods: The current study evaluated whether the $Rapiderm^{(R)}$ atelocollagen plug (Dalim Tissen, Seoul, Korea) improves tissue healing of extraction sockets and assessed the sequential pattern of bone regeneration using histology and microcomputed tomography in six beagle dogs. To assess the change of extraction socket, hard tissues were examined 2, 4, 6, and 8 weeks after tooth extraction. Result: The experimental groups showed better bone fill with slow remodeling process compared to the control groups although there was no statistical difference between groups. Conclusion: The atelocollagen seems to have a tendency to slow bone remodeling in the early phase of healing period and maintain remodeling capacity until late phase of remodeling. Also, use of atelocollagen increased the bone-to-tissue ratio compared to healing of untreated extraction socket.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.35 no.1
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• pp.55-59
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• 2013

In the oral and maxillofacial area, bone defects are created by various reasons and demand for bone grafts, while dental implant implantation has been increased consistently. To solve these problems, there has been development of autogenous tooth-bone graft material (AutoBT$^{(R)}$, Korea Tooth Bank Co., Korea), and we have collected ground reasons to substitute free autobone graft with this material in clinical use. This autogenous tooth-bone graft material is produced in powder type and block type. Block type is useful in esthetic reconstruction of the defect site and vertical and horizontal augmentation of alveolar bone because this type has high strength value, well maintained shape and is less absorbed. Therefore, the author of this study gained favorable result by grafting the block type autogenous tooth-bone graft material after dental implant implantation on the bone defects of the mandibular molar extraction site. Moreover, the author represents this case with literature review after confirming bone remodeling on the computed tomography image and by histological analysis.

• Imaging Science in Dentistry
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• v.53 no.1
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• pp.1-9
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• 2023

Purpose: The aim of this study was to evaluate 3-dimensional cone-beam computed tomography (CBCT) images of alveolar bone changes in patients who underwent minimally invasive periodontal surgery-namely, the pinhole surgical technique (PST). Materials and Methods: Alveolar bone height was measured and compared on CBCT images of 254 teeth from 23 consecutive patients with Miller class I, II, or III recession who had undergone PST. No patient with active periodontal disease was selected for surgery. Two different methods were used to assess the alveolar bone changes postoperatively. In both methods, the distance between the apex of the tooth and the mid-buccal alveolar crestal bone on pre- and post-surgical CBCT studies was measured. Results: An average alveolar bone gain >0.5 mm following PST was identified using CBCT(P=0.05). None of the demographic variables, including sex, age, and time since surgery, had any significant effect on bone gain during follow-up, which ranged from 8 months to 3 years. Conclusion: PST appears to be a promising treatment modality for recession that results in stable clinical outcomes and may lead to some level of resolution on the bone level. More long-term studies must be done to evaluate the impact of this novel technique on bone remodeling and to assess sustained bone levels within a larger study population.

• The korean journal of orthodontics
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• v.35 no.3 s.110
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• pp.196-206
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• 2005

This study was undertaken to investigate the effect of vitamin C deficiency on the orthodontic tooth movement and bony remodeling processes. Thirty six male guinea pigs were divided on the basis of the given amount of vitamin C (normal group: 5mg/day, deficient group: 0.2mg/day) and 75gm of force was applied to the maxillary incisors. Experimental animals were sacrificed at day 0. day 1 day 3, day 5. day 7 and day 14 after force application and the amount of tooth movement was measured and tissues were studied histologically. The results showed that the amount of collagen fiber in the periodontal ligament and alveolar bone of the deficient group was less than that of the normal group. In the stretched side. the osteoblastic activity and alveolar bone formation of the normal group increased in a time dependent manner during experimental periods, but the deficient group showed less activity and formation. The amount of tooth movement in the deficiency group was more than in the normal group at day 0. day 1, day 3, day 5, and day 7. According to the above results, a deficiency of vitamin C resulted in a defect of collagen synthesis of the periodontium and inhibition of bone formation and stimulation of bone resorption with rapid tooth movement in early periods of force application.

• The Journal of the Korean dental association
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• v.54 no.4
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• pp.284-295
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• 2016

The aim of this study was to evaluate the effect of Epigallocatechin-3-Gallate (EGCG) on the alveolar bone metabolism in a collagen-induced arthritis (CIA) model in mice to enhance the understanding of rheumatoid arthritis (RA)-associated alveolar bone loss. Following the induction of CIA in animals (mice, n=16), mandibles were retrieved for micro-computed tomography (micro-CT) and isolation of alveolar bone cells (ABCs). In vitro osteogenic potentials of ABCs were evaluated and the mRNA expression of downstream effector genes was assessed. CIA was successfully induced in all animals, and micro-CT data showed that alveolar bone loss was significantly increased in the CIA group while the treatment of EGCG prevented the alveolar bone resorption. Osteogenesis by ABCs was significantly increased in the CIA+EGCG group in vitro. The analysis of mRNA expressions showed that osteoclastogenesis-associated genes were increased in CIA group while bone protecting genes were upregulated in EGCG treated group. The results demonstrate that EGCG downregulated the alveolar bone resorption in a CIA model in mice, and upregulation of bone protecting genes appear to be involved. Further studies are warranted.

• The korean journal of orthodontics
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• v.20 no.2
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• pp.247-266
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• 1990

The alveolar bone remodeling is essential in tooth movement by orthodontic forces. The collagen and chondroitin sulfate are acting as an important roles in bone remodeling. This study was performed to measure out the quantity of the collagen and chondroitin sulfate in the alveolar bone of rats applied by experimental orthodontic forces. The 150 Sprague-Dawley male rats were divided into the $PGE_2$ treated group, indomethacin treated group and the normal group. A 80gm force rubber band was used as a orthodontic appliance between upper incisors and right upper 1st molar, and left side of experimental rats with no appliance was regarded as a control side. The samples of alveolar bones were obtained from pressure and tension sites in all three groups. respectively, and in control sides, too. The results were as follows. 1. The change in total collagen remains stable in both pressure and tension sites of all three groups, compared with control side by the time consuming. 2. The change in soluble collagen showed the most highest level in tension site, lowest level in pressure site of $PGE_2$ treated group in 5th. experimental day. 3. The change in chondroitin sulfate showed the most highest level in pressure site, lowest level in tension site of $PGE_2$ treated group in 5th. experimental day. 4. In indomethacin treated group, the change of soluble collagen and chondroitin sulfate showed small range of variance compared with $PGE_2$ treated and normal group.