• The korean journal of orthodontics
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• v.51 no.4
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• pp.241-249
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• 2021

Objective: This study aimed to evaluate the volume, amount, and localization of root resorption in the maxillary first premolars using micro-computed tomography (micro-CT) after expansion with four different rapid maxillary expansion (RME) appliances. Methods: In total, 20 patients who required RME and extraction of the maxillary first premolars were recruited for this study. The patients were divided into four groups according to the appliance used: mini-implant-supported hybrid RME appliance, hyrax RME appliance, acrylic-bonded RME appliance, and full-coverage RME appliance. The same activation protocol (one activation daily) was implemented in all groups. For each group, the left and right maxillary first premolars were scanned using micro-CT, and each root were divided into six regions. Resorption craters in the six regions were analyzed using special CTAn software for direct volumetric measurements. Data were statistically analyzed using Kruskal-Wallis one-way analysis of variance and Mann-Whitney U test with Bonferroni adjustment. Results: The hybrid expansion appliance resulted in the lowest volume of root resorption and the smallest number of craters (p < 0.001). In terms of overall root resorption, no significant difference was found among the other groups (p > 0.05). Resorption was greater on the buccal surface than on the lingual surface in all groups except the hybrid appliance group (p < 0.05). Conclusions: The findings of this study suggest that all expansion appliances cause root resorption, with resorption craters generally concentrated on the buccal surface. However, the mini-implant-supported hybrid RME appliance causes lesser root resorption than do other conventional appliances.

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.4
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• pp.524-534
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• 2000

Deciduous teeth can be extracted for two reasons, one due to the physiologic resorption and the other by the inflammation at the apex after traumatic injury. Physiologic resorption may be different from pathologic resorption in timing and mechanism. Therefore we resumed the different features of physiologic and pathologic resorption root surfaces. Many previous studies showed micromorphology of resorbed surface of roots of deciduous teeth. But, few studies compared physiological and pathological root resorption surfaces. In this study, we carefully observed microscopic morphologies of those two different root surfaces by scanning electron microscope and histologic features by light microscope. The resultant differences between physiologic and pathologic resorption surfaces of deciduous teeth were as follows: 1. The morphology of pathologic resorption lacunae due to inflammation varied in size and shape with irregular boundaries compared with the physiologic areas from scanning electron microscope observations. 2. From light microscope observations, several large resorption fossae containing numerous resorption lacunae were found, whereas the resorption lacunae were irregular in shape with pathologic resorption surface. 3. Numerous multinucleated giant cells were closely attached to the physiologic resorption lacunae, whereas several kinds of mesenchymal cells with numerous inflammatory cells were found in the areas adjacent to the pathologic resorption surface. 4. Light microscope findings showed that compensating cementum formation took place along some of the areas of inflammatory dentinal resorption. In conclusion, several morphological differences were present between physiologic and pathologic root resorption surfaces of human deciduous teeth. The future studies should include cytochemistry to clarify the cellular roles in resorption process observations of pulpal surfaces of coronal and radicular dentin to and the changes that occur in each phase of human deciduous tooth resorption.

• Proceedings of the KACD Conference
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• 2001.05a
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• pp.243-244
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• 2001

Root resorption is conventionally divided into internal and external varieties. Internal resorption occurs where there is loss of the internal wall of the root canal. and is usually associated with a localized area of necrotic pulp(Trope '||'&'||' Chivian 1984). External resorption occurs where there is loss of the external surface of the root and the resorption may be either transient or progressive(Tronstad 1988). External inflammatory resorption usually occurs following damage to the periodontal ligament or where there is communication between the periodontal ligament and a necrotic pulp. via open dentinal tubules or accessory canals. This type of resorption is usually progressive until root canal treatment is instituted (Barclay 1993).

• The korean journal of orthodontics
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• v.34 no.6 s.107
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• pp.526-536
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• 2004

This study was undertaken to determine the effect of a 2.2mg/Kg/day intraoral administration of NaF on the amount of root resorption and osteoclastic activity during or after a rapid maxillary expansion procedure. Ten puerile female dogs were divided into two groups: a control group and a NaF-treated group. A fixed type maxillary expansion device was delivered to all dogs. The appliance was activated twice daily throughout a 20-day period, causing a 5-mm expansion of maxillary bone. After the expansion procedure, the animals were sacrificed at days 0, 15, 30, 45, and 60 of the retention period. The buccal surface of the root of each maxillary canine was examined by means of a surface electron microscope (SEM). Using SEM, web-like resorption lacunae were observed on the bone or the tooth surface at the site of osteoclastic activity; these observations were verified by histological methods. No peculiar resorption lacunae were found in the apical tip of the roots of either the control group or the NaF-treated group animals. The NaF-treated retention group was found to have less resorption lacunae formation on day 45 and day 60. The preventative effect of NaF on resorption lacunae formation on the surface of the bone covering the anchor tooth was confirmed. Larger areas of resorption lacunae were found on the surface of the bone covering the canines in the control group animals, as compared to those of the NaF-treated group, especially on day 30 and day 60. Using SEM, the present study revealed a difference between the control group and the NaF-treated group in the prevalence and the size of the resorption lacunae formation on the cemental root surface. The preventative effect of NaF on bone resorption was confirmed. Further studies concerned with the optimum concentration of NaF that has an effect in vivo are necessary.

• Proceedings of the KACD Conference
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• 2003.05a
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• pp.291-291
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• 2003

손상에 의한 치근 흡수는 표면 흡수(surface resorption), 염증성 흡수(inflammatory resorption) 및 대치성 치근 흡수(replacement resorption)가 있는데 치근 흡수의 정도는 탈구와 재식 사이의 시간, 치주 인대의 손상 정도, 탈구된 치아의 보관 조건 및 치아 발육 정도 등에 영향을 받는다.(중략)

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.25 no.2
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• pp.375-387
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• 1995

The purpose of this study was to quantitatively evaluated experimental tooth root resorption for digital radiography. For this study, experimentally three root sites were used, and radiograms were taken with standardized apparatus. Digital imaging system were consisted of NEC PC-980l(computer), TRINITRON(monitor), SONY XC-711 CCD camera. The display monitor had a resolution of 512X512 pixels. The obtained results were as follows: 1. In the difference of the four X-ray film of the contrast correction, the contrast difference was one gray scale variation at mean value. 2. Viewing of the view box of the periapical radiographs, experimental tooth root resorption of the periapical area of the first premolar, middle of mesial surface of the first molar mesial root, middle of lingual surface of the first molar distal root were recognized by increased diameter. 3. On the analysis by histogram, the periapical area of the first premolar, the middle of mesial surface of the first molar mesial root were each recognized tooth root resorption of the 5,6,7 pixel, 2,4,5 pixel by increased diameter. 4. On the analysis by histogram, the middle of lingual surface of the first molar distal root was each recognized tooth root resorption of the none, 3,6 pixel by increased diameter.

• Journal of the korean academy of Pediatric Dentistry
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• v.44 no.3
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• pp.289-297
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• 2017

Local and general factors have been attributed to root resorption occurred by injuries such as trauma and dental caries that affect periodontal ligament or dental pulp tissue. Pathologic root resorption is different from physiologic root resorption in terms of resorption pattern such as micromorphology of resorption fossae and types of observed cells. Microscopic morphologies and histologic features of physiologic and pathologic root resorption surface of maxillary primary central incisors resulting from trauma and periapical inflammation were observed by scanning electron microscope and light microscope. The morphology of physiologic resorption lacunae was small and oval or circular shape with regularities. The morphology of pathologic resorption lacunae was large and polygonal shape with irregularities compared with the physiologic resorption lacunae. Multinucleated giant cells and mononuclear cells were closely attached to the physiologic and pathologic resorption lacunae, whereas several kinds of mesenchymal cells with numerous inflammatory cells were found in the areas adjacent to the pathologic resorption surface. Compensating cementum formation took place along some of the areas of physiologic and pathologic resorption area resulting from trauma, but could not be observed on pathologic resorption area resulting from periapical inflammation.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.10 no.1
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• pp.29-33
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• 1980

An ameloblastoma produces more extensive resorption of the teeth on which it encroaches than do most of the other lesions. In this study, intraoral and extraoral radiographs of 78 cases of ameloblastoma were observed and the root resorption associated with ameloblastoma was classified into four types of resorption. With these, the following conclusions were obtained. 1. The root resorption was observed in 72 cases of ameloblastoma. (92.3%) 2. In the aspect of resorptive changes of 424 roots observed, 342 roots showed smooth resorption. (80.6%) 3. The 424 roots associated with ameloblastoma revealed the following radiographic features. a) Root apex resorption in contact with the lesion appeared in 189 roots. (44.5%) b) The resorption of roots projected into the lesion appeared in 147 roots. (34.6%) c) Slight resorption of root surface in contact with the lesion was observed in 56 roots. (13.2%) d) Loss of lamina dura and periodontal space without root resorption were observed in 32 roots. (7.7%)

• The Journal of Korean Academy of Prosthodontics
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• v.59 no.4
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• pp.405-414
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• 2021

Purpose. This study was conducted to evaluate clinical usefulness by evaluating the marginal bone resorption and survival rate of an implant with a taper straight type SLA surface domestically available on the market recently. Materials and methods. 40 implants satisfying the including criteria were observed for one year of 125 implants of 83 adult men and women who had KISPLANT^® implanted from August 2016 to December 2019 at the Department of Periodontology, Chonnam National University Dental Hospital. The marginal bone level was measured on periapical radiographs taken initially and 1 year later and we analyzed implant survival and success rates. A t-test was used for the analysis of the association between the marginal bone resorption and the severity of periodontitis, supportive periodontal therapy, the inserted site, the cause of extraction, immediate placement, and systemic disease. Results. After 1 year of loading, the mesial bone resorption was 0.74 ± 1.07 mm, and the distal bone resorption was 0.53 ± 1.04 mm. The marginal bone resorption of 2 mm or more occurred at 3 implants out of 40 implants after 1 year, so the success rate of implant was 92.5% and survival rate was 100%. There was a significant difference in mesial marginal bone resorption according to the inserted site and no significant differences were found between marginal bone resorption and the other factors. Conclusion. As a result of marginal bone resorption, success rate, and survival rate in this study, we found little marginal bone resorption and high survival and success rate. It can be concluded that they represent excellent clinical results.

• Restorative Dentistry and Endodontics
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• v.38 no.4
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• pp.194-203
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• 2013

Objectives: To investigate the effect of enamel matrix derivative (EMD) on periodontal healing of replanted teeth in animal models. Materials and Methods: The authors searched MEDLINE, PubMed, EMBASE, Cochrane Library, Web of Knowledge and Scopus for articles published up to Oct 2012. Animal studies in which EMD was applied in transplanted or replanted teeth with adequate controls and histological data were considered. Normal periodontal healing or root resorption determined by histology after EMD was applied in replanted teeth with adequate controls was used as outcome measures. The following search strategy was used: ('Emdogain' OR 'enamel matrix proteins' OR 'enamel matrix derivative') AND ('avulsion' OR 'transplantion' OR 'autotransplantation' OR 'replantation'). Results: Six animal studies were included in the final review. There was great heterogeneity in study design among included studies. Two studies with similar study designs were identified and analyzed by a meta-analysis. The pooled estimates showed a significantly higher normal healing and surface resorption and significantly less inflammatory and replacement resorption in EMD-treated groups compared with non-EMD-treated groups. Conclusions: With the limitations of this systematic review, the use of EMD led to greater normal periodontal healing and surface root resorption and less inflammatory and replacement root resorption in the presence of periodontal ligaments. However, no definite conclusion could be drawn with regard to the effect of EMD on periodontal healing and root resorption when no periodontal ligaments exist.