• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제32권6호
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• pp.575-579
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• 2006

Purpose : The purpose of this study was to evaluate peri-implant bone loss and implant success on anterior maxillary alveolar ridges and Compare Class III and Class IV ridges in the aspect of peri-implant bone loss. Material and Methods : 14 patients (aged 21 to 68, 6males and 8females), who lacked maxillary anterior teeth and were installed from January 2000 to April 2003 at Samsung Medical Center, were selected. The type of implant used included 30 $Br\ddot{a}nemark$ implant. They were taken with digital tomographic and conventional intraoral radiographic examinmation, and were treated with implant installaion without bone augmentation. The peri-implant bone resorption was measured at the mesial and distal aspect of implant on the conventional intraoral radiographs. Results : The study classified the anterior maxillary alveolar ridge and measured peri-implant bone resorption from the period of implant installation to the 2nd year after functional loading radiographically. The study revealed no statistically significant difference between two groups, which was classified by its morphology. The average bone resorption on healing period before loading was 0.18mm and 0.18mm, the 1st year of loading period, 0.77 mm and 0.84mm, and on the 2nd year of loading period, 0.07mm and 0.06mm, respectively on both Class III and class IV. Conclusion : In the knife edge form of anterior maxillary residual ridges(Class IV), implant placement without ridge augmentation does not have significant difference with that of Class III alveolar ridge in the concern of Implant success after 2 year functional loading period in the aspect of peri-implant bone resorption radiographically.

• Imaging Science in Dentistry
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• 제44권4호
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• pp.287-292
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• 2014

Purpose: To describe the features of impacted upper canines and their relationship with adjacent structures through three-dimensional cone-beam computed tomography (CBCT) images. Materials and Methods: Using the CBCT scans of 79 upper impacted canines, we evaluated the following parameters: gender, unilateral/bilateral occurrence, location, presence and degree of root resorption of adjacent teeth (mild, moderate, or severe), root dilaceration, dental follicle width, and presence of other associated local conditions. Results: Most of the impacted canines were observed in females (56 cases), unilaterally (51 cases), and at a palatine location (53 cases). Root resorption in adjacent teeth and root dilaceration were observed in 55 and 47 impacted canines, respectively. In most of the cases, the width of the dental follicle of the canine was normal; it was abnormally wide in 20 cases. A statistically significant association was observed for all variables, except for root dilaceration (p=0.115) and the side of impaction (p=0.260). Conclusion: Root resorption of adjacent teeth was present in most cases of canine impaction, mostly affecting adjacent lateral incisors to a mild degree. A wide dental follicle of impacted canines was not associated with a higher incidence of external root resorption of adjacent teeth.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제21권1호
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• pp.13-22
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• 1999

The purpose of this investigation was to evaluate the acceptability of the collagen-based xenograft ($Laddec^{(R)}$). Full thickness bone defects were prepared in the calvaria of the rats. In the experimental groups the bone defects were filled with a kind of collagen based xenograft. And bone defects, which left without filling, were used as control groups. Sequential sacrifice was performed at the 1st, 2nd, 4th, 8th, and 16th weeks of experiment. 1. At the 1st week of experiment, infiltration of chronic inflammatory cell was observed in all groups. In the experimental group, resorption of the xenograft was initiated. 2. At the 2nd week of experiment, infiltration of chronic inflammatory cells was decreased in all groups. In the experimental group, active resorption of xenograft and new bone formation from the periphery of the xenograft was observed. 3. At the 4th and 8th weeks of experiment, more resorption of the xenograft and new bone formation with calcification was observed in the experimental group. 4. At the 16th week of experiment, small bone trabecula was formed partially in the control group but that couldn't fill the whole bone defect. In the experimental group, more advanced resorption of xenograft and more new bone formation was observed. However mid portion of the xenograft was still remained without resorption. 5. From this experiment, we concluded that the collagen-based xenograft had some osteoconductive but no osteoinductive property. So the xenograft would be used for the bone defect filling material where rapid bone remodeling is not required.

• Journal of Acupuncture Research
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• 제22권2호
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• pp.55-70
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• 2005

Objective: Ulmus davidiana Planch (Ulmaceae) has long been known to have anti-inflammnatory in the traditional Korean medicine. UD has been reported as a good enhancer for bone healing. Methods : In this experiment, we investigate the Inhibitory effects of UD on bone resorption using the bone cells culture. Different concentrations of crude extract of UD were added to mouse bone cells culture. The mitochondria activity of the bone cells after exposure was determined by colorimetric MIT assay. It was demonstrated that UD has potential effects on bone cells culture without any cytotoxicity. The most effective concentration of UD on bone cells were $100\;{\mu}g/ml$. Cathepsin K (Cat K) is the major cysteine protease expressed in osteoclasts and is thought to play a key role in matrix degradation during bone resorption. Results : When mouse long bone cells including osteoclasts and osteoblast were treated with the PI3-Kinase inhibitor, wortmannin (WT), WT prevented the osteoclast-mediated intracellular processing of Cat K. Similarly, treatment of osteoclasts-containing long bone cells with UD extracts prevented the intracellular maturation of Cat K, suggesting that UD may disrupt the intracellular trafficking of pro Cat K. This is similar to that of WT. Since secreted proenzymes have the potential to reenter the cell via mannose-6-phosphate (M6P) receptor, to prevent this possibility, we tested WT and UD in the absence or presence of M6P. Inhibition of Cat K processing by WT or UD was observed in a dose-dependent manner. Furthermore, the addition of M6P resulted in enhanced potency of WT and UD. Conclusion : UD dose-dependently inhibited in vitro bone resorption with a potency similar to that observed for inhibition of Cat K processing.

• Journal of Nutrition and Health
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• 제39권2호
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• pp.109-114
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• 2006

The effects of the erect bipedal stance exercise on bone mass and the biomarkers of bone formation and resorption were investigated in rats. Five-week old rats were assigned into control and exercise groups. The rats of exercise group were weight-bearing-trained for 13 weeks in the cage designed to adjust progressively the height from 26.5 cm to 31.5 cm to force the rats rising an erect bipedal stance for feeding and drinking. There was no significant difference in food intakes between two groups. But body weight gain was significantly increased in control group. The lengths of femur, tibia, humerus and radius were significantly longer in control group than exercise group, but the femur and tibia weights per body weight were significantly higher in exercise group than control group. Also the breaking force of femur and tibia in exercise group were higher than control group significantly. The calcium contents of femur and tibia were significantly increased in exercise group than control group. The activity of bone specific alkaline phosphatase (B-ALP) and the osteocalcin contents of serum (the biomarkers of bone formation) in exercise group were higher than control group, but the carboxyterminal propeptide of type I procollagen (P1CP) contents of serum did not show any difference between two groups. However the urinary deoxypridinolin (DPD) excretion, biomarker of bone resorption, was significantly lower in exercise group than control group. From these results, it has been indicated that the erect bipedal stance exercise enhanced the density and the strength of femur and tibia by increasing biomarkers of bone formation and suppressing a biomarker of bone resorption in rats.

• 대한치과교정학회지
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• 제51권5호
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• pp.329-336
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• 2021

Objective: To compare the magnitude of external apical root resorption (EARR) 6 months after starting orthodontic treatment using orthodontic aligners (OAs) and fixed appliances (FAs). Methods: This parallel randomized clinical trial included 40 patients randomized into two groups: OA group (n = 20, 160 incisors) and FA group (n = 20, 160 incisors). For evaluation of the tooth length, periapical radiographs and standardized linear measurements of the maxillary and mandibular incisors were acquired before (T0) and 6 months after treatment initiation (T1). EARR was calculated through the difference in length between the two time points (T1-T0). Statistical comparisons were performed by means of using t-tests, chi-squared test and covariance analysis (a = 5%). Results: Rounding of the root apex was observed in both groups; the resorption involved 2.88% of the root length, so 97.12% of the tooth length remained intact. Intragroup comparisons between the two time points revealed a significant difference, with (T1-T0) ranging from -0.52 to -0.88 mm in the FA group and from -0.52 to -0.85 mm in the OA group. In the intergroup comparisons, only tooth #21 presented a statistically significant difference (OA: -0.52 ± 0.57 mm, FA: -0.86 ± 0.60 mm); however, the overall differences between groups were not clinically relevant, ranging from 0.03 to 0.35 mm. Conclusions: OA and FA treatment resulted in a similar degree of EARR in the maxillary and mandibular incisors at 6 months after treatment initiation. However, the amount of resorption was small and does not impair tooth longevity.

• 대한치과교정학회지
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• 제51권2호
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• pp.86-94
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• 2021

Objective: This study aimed to investigate the effect of micro-osteoperforations (MOPs) on external apical root resorption (EARR) during the initial orthodontic alignment phase of maxillary anterior crowding. Methods: Thirty patients (25 females, 5 males; mean age, 22.66 ± 3.27 years) who presented with moderate crowding of the upper labial segment and underwent extraction-based fixed appliance treatment were recruited. They were randomly allocated to receive adjunctive therapy with MOPs (n = 15) or treatment with fixed appliances only (control group; n = 15). EARR was measured from long-cone periapical radiographs taken at the start and the sixth month of treatment. A correction factor for the enlargement difference was used to calculate EARR. Data were analyzed with descriptive statistics and repeated-measures analysis of variance. Results: The mean root lengths of 168 teeth were measured and showed no statistically significant difference (p > 0.05) after six months of fixed appliance treatment in the MOP (mean difference [MD] = 0.13 mm; 95% confidence interval [CI] = -0.10-0.35) and control group (MD = 0.14 mm; 95% CI = -0.10-0.37). Most of the roots in the MOP and control groups (42.86% and 52.38%, respectively) showed only mild resorption. Less than 8% of the roots in both groups (7.14% in the MOP group and 4.76% in the control group) showed moderate resorption. Conclusions: Acceleration of orthodontic tooth movement with adjunctive MOPs therapy during the alignment phase does not exacerbate EARR in patients with moderate crowding of the upper labial segment in comparison with controls.

• The Journal of Advanced Prosthodontics
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• 제13권1호
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• pp.55-64
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• 2021

PURPOSE. To investigate the biomechanical effect of marginal bone resorption (MBR) on the mandibular mini implant (MI)-retained overdenture (MI-OD) on the edentulous model. MATERIALS AND METHODS. The experimental mandibular edentulous model was modified from a commercial model with 2 mm thick artificial soft tissue under denture base. Two MIs (Φ2.6 mm × 10 mm) were bilaterally placed between the lateral incisor and the canine area and attached with magnetic attachments. Three groups were set up as follows: 1) alveolar bone around the MI without MBR (normal group), 2) with MBR to 1/2 the length of the implant (resorption group), and 3) complete denture (CD) without MI (CD group). Strain around the MI, pressure near the first molar area, and displacement of denture were simultaneously measured, loading up to 50 N under bilateral/unilateral loading. Statistical analysis was performed using independent-samples t test and one-way ANOVA (α=.05). RESULTS. The strain around the MI with MBR was approximately 1.5 times higher than that without MBR. The pressure in CD was higher than in MI-ODs (P<.05), while there was no statistical difference between the normal and resorption group (P>.05). Similarly, the CD demonstrated a greater displacement of the denture base than did the MI-ODs during bilateral and unilateral loadings (P<.05). CONCLUSION. The strain around the MI with MBR was approximately 1.5 times higher than that without MBR. The pressure on posterior alveolar ridge and denture displacement of MI-ODs significantly decreased compared to CDs, even when MBR occurs. Bilateral balanced occlusion was recommended for MI-ODs, especially when MBR occurred.

• Imaging Science in Dentistry
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• 제53권2호
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• pp.145-151
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• 2023

Purpose: Prior to cone-beam computed tomography (CBCT), orthodontic competence included radiological interpretation. Nevertheless, maxillary impacted canines (MICs), because of their position and adjacent complex anatomy, have been challenging to interpret, particularly with regard to root resorption. Although CBCT cross-sectional reconstructions of MICs yielded clearer insights into its diagnosis and treatment planning, the value of simultaneously using 2 different cross-sectional or multiplanar reconstructions of the CBCT datasets - orthogonal and curved/panoramic multiplanar reconstructions - has hitherto not been considered. Materials and Methods: Both orthogonal and curved/panoramic multiplanar reconstruction series of 5 screenshots were each reconstructed from the 5 cm×5 cm CBCT datasets of 15 separate MICs. Fifteen credentialled and experienced orthodontist volunteers reviewed 2 separate PowerPoints of 15 randomized series each, 1 week apart. Their review considered 6 factors that could affect treatment: the position and level of the MIC, the presence or absence of root resorption, ankylosis, cysts, and dilaceration. Results: All 15 orthodontists were statistically similar regarding overall years of experience and of CBCT use. Although either reconstruction alone allowed the orthodontists to determine whether ankylosis and, to a lesser extent, most of the other features were present or absent in the MIC, reviewing both reconstructions together was necessary to determine whether root resorption was present or absent in the adjacent tooth. Conclusion: Reviewing both orthogonal and curved/panoramic multiplanar reconstructions was necessary to evaluate the presence or absence of root resorption in the teeth adjacent to MICs and that of many other features.

• Restorative Dentistry and Endodontics
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• 제48권3호
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• pp.24.1-24.16
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• 2023

This review aimed to answer the following question "Does photobiomodulation treatment of the root surface decrease the occurrence of root resorption in reimplanted teeth?" Electronic searches were performed in the MEDLINE/PubMed, Cochrane Library, Scopus, Web of Science, Embase, and Grey Literature Report databases. Risk of bias was evaluated using SYRCLE Risk of Bias tool. The Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) tool was used to assess the certainty of evidence. In total, 6 studies were included. Five studies reported a reduced occurrence of root resorption in teeth that received photobiomodulation treatment of the root surface prior to replantation. Only 1 study reported contradictory results. The photobiomodulation parameters varied widely among studies. GRADE assessment showed a low certainty of evidence. It can be inferred that photobiomodulation treatment of the root surface prior to replantation of teeth can reduce the occurrence of root resorption. Nonetheless, further clinical studies are needed.