1
|
Santos BZD, Dutra RC, Santos ARSD, Casarin M, Goldfeder EM, Bosco VL, Cordeiro MMR. Immunohistochemistry of resorption and inflammation factors in the periodontal ligament of human deciduous teeth. Braz Oral Res 2022; 36:e056. [PMID: 36507743 DOI: 10.1590/1807-3107bor-2022.vol36.0056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 12/01/2021] [Indexed: 12/15/2022] Open
Abstract
The understanding of the biological mechanisms involved in root resorption in deciduous teeth is important to the future development of preventive measures and treatments of this condition. The aim of the present study was to compare the expression and immunostaining of iNOS, MMP-9, OPG and RANKL in the periodontal ligament (PDL) of deciduous teeth with physiologic root resorption (GI), inflammatory pathological root resorption (GII) and permanent teeth (GIII), the negative control. Teeth in GI (n = 10), GII (n = 10) and (GIII) (n = 10) were submitted to immunohistochemical analysis to determine the expression of iNOS, MMP-9, OPG, and RANKL. The immunostaining was analysed by optical density. Statistical analysis included one-way ANOVA, followed by Student-Newman-Keuls post hoc test (p < 0.05). The results showed that iNOS, MMP-9 and RANKL expression in the PDL was higher in GII compared to GI and GIII (p < 0.05). Moreover, RANKL expression was higher in GI compared to GIII (p < 0.001), while OPG immunolabelling was lower in GII compared to GI and GIII (p < 0.001). The PDL of deciduous teeth bearing inflammatory processed exhibited upregulation of resorption-associated factors as well as enzymes related to tissue degradation which, in turn explains the exacerbation and greater susceptibility of those teeth to root resorption process.
Collapse
Affiliation(s)
- Bianca Zimmermann Dos Santos
- Universidade Franciscana, School of Dentistry, Postgraduate Programme in Maternal and Child Health, Santa Maria, RS, Brazil
| | - Rafael Cypriano Dutra
- Universidade Federal de Santa Catarina - UFSC, Department of Health Science, Araranguá, SC, Brazil
| | | | - Maísa Casarin
- Universidade Federal de Pelotas - UFPel, Department of Semiology and Clinic, Pelotas, RS, Brazil
| | - Eliane Maria Goldfeder
- Universidade Federal de Santa Catarina - UFSC, Centre for Biological Sciences, Department of Morphological Sciences, Florianópolis, SC, Brazil
| | - Vera Lucia Bosco
- Universidade Federal de Santa Catarina - UFSC, Centre of Health Sciences, Department of Dentistry, Florianópolis, SC, Brazil
| | - Mabel Mariela Rodriguez Cordeiro
- Universidade Federal de Santa Catarina - UFSC, Postgraduate Programme in Dentistry, Department of Dentistry, Florianópolis, SC, Brazil
| |
Collapse
|
2
|
Lima TCDS, Amaro RG, Dos Santos LCM, Coste SC, Silva EFE, Barbato-Ferreira DA, Colosimo EA, Silva TAD, Bastos JV. Expression of matrix metalloproteinases 2 and 9 in replanted teeth with external root resorption: A cross-sectional study. Arch Oral Biol 2021; 129:105194. [PMID: 34147732 DOI: 10.1016/j.archoralbio.2021.105194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 06/01/2021] [Accepted: 06/02/2021] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To evaluate matrix metalloproteinase (MMP) expression in replanted permanent teeth with external root resorption (ERR). DESIGN The present cross-sectional study included 42 patients with replanted permanent teeth, presenting with progressive forms of ERR, and referred for extraction according to the rehabilitation treatment plan or due to root fractures. The control group consisted of 12 healthy premolars, from 5 patients with good periodontal health and no radiographic evidence of root resorption, referred for extraction for orthodontic reasons. Root fragments were processed soon after extraction, and the supernatant was collected to measure matrix metalloproteinase 2/tissue inhibitor of metalloproteinase 2 (MMP-2/TIMP-2) and matrix metalloproteinase 9/tissue inhibitor of metalloproteinases 2 (MMP-9/TIMP-2) complexes through a double-ligand enzyme-linked immunosorbent assay (ELISA). RESULTS Case groups with external inflammatory root resorption (EIRR) or external replacement root resorption (ERRR) showed significantly higher levels of MMP-2/TIMP-2 and MMP-9/TIMP-2 complexes than the control group. Additionally, comparisons between the case groups demonstrated that the MMP-2/TIMP-2 complex also had significantly higher levels in the ERRR group (p < 0.001). CONCLUSIONS Our results suggest that MMP-2 and MMP-9 participate in the pathobiology of both types of ERR. In addition, the higher levels of MMP-2/TIMP-2 complex in the ERRR group support common modulation mechanisms with physiological bone turnover.
Collapse
Affiliation(s)
- Thiago César da Silva Lima
- Restorative Dentistry Department, School of Dentistry, Universidade Federal de Minas Gerais, 31270-901, Belo Horizonte, Brazil
| | - Roberta Gabriela Amaro
- Restorative Dentistry Department, School of Dentistry, Universidade Federal de Minas Gerais, 31270-901, Belo Horizonte, Brazil
| | | | - Sylvia Cury Coste
- Restorative Dentistry Department, School of Dentistry, Universidade Federal de Minas Gerais, 31270-901, Belo Horizonte, Brazil
| | - Eduardo Fernandes E Silva
- Statistics Department, Institute of Exact Sciences, Universidade Federal de Minas Gerais, 31270-901, Belo Horizonte, Brazil
| | | | - Enrico Antônio Colosimo
- Statistics Department, Institute of Exact Sciences, Universidade Federal de Minas Gerais, 31270-901, Belo Horizonte, Brazil
| | - Tarcília Aparecida da Silva
- Department of Oral Pathology and Surgery, School of Dentistry, Universidade Federal de Minas Gerais, 31270-901, Belo Horizonte, Brazil
| | - Juliana Vilela Bastos
- Restorative Dentistry Department, School of Dentistry, Universidade Federal de Minas Gerais, 31270-901, Belo Horizonte, Brazil.
| |
Collapse
|
3
|
Transcriptomic profiling of feline teeth highlights the role of matrix metalloproteinase 9 (MMP9) in tooth resorption. Sci Rep 2020; 10:18958. [PMID: 33144645 PMCID: PMC7641192 DOI: 10.1038/s41598-020-75998-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 10/14/2020] [Indexed: 12/11/2022] Open
Abstract
Tooth resorption (TR) in domestic cats is a common and painful disease characterised by the loss of mineralised tissues from the tooth. Due to its progressive nature and unclear aetiology the only treatment currently available is to extract affected teeth. To gain insight into TR pathogenesis, we characterised the transcriptomic changes involved in feline TR by sequencing RNA extracted from 14 teeth (7 with and 7 without signs of resorption) collected from 11 cats. A paired comparison of teeth from the same cat with and without signs of resorption identified 1,732 differentially expressed genes, many of which were characteristic of osteoclast activity and differentiation, in particular matrix metalloproteinase 9 (MMP9). MMP9 expression was confirmed by qPCR and immunocytochemistry of odontoclasts located in TR lesions. A hydroxamate-based MMP9 inhibitor reduced both osteoclast formation and resorption activity while siRNA targeting MMP9 also inhibited osteoclast differentiation although had little effect on resorption activity. Overall, these results suggest that increased MMP9 expression is involved in the progress of TR pathogenesis and that MMP9 may be a potential therapeutic target in feline TR.
Collapse
|
4
|
Effect of Low Intensity Pulsed Ultrasound (LIPUS) on Tooth Movement and Root Resorption: A Prospective Multi-Center Randomized Controlled Trial. J Clin Med 2020; 9:jcm9030804. [PMID: 32188053 PMCID: PMC7141368 DOI: 10.3390/jcm9030804] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 03/11/2020] [Accepted: 03/12/2020] [Indexed: 11/16/2022] Open
Abstract
The aim of this study was to evaluate the possible effect of low intensity pulsed ultrasound (LIPUS) on tooth movement and root resorption in orthodontic patients. Twenty-one patients were included in a split-mouth study design (group 1). Ten additional patients were included with no LIPUS device being used and this group was used as the negative control group (group 2). Group 1 patients were given LIPUS devices that were randomly assigned to right or left side on upper or lower arches. LIPUS was applied to the assigned side that was obtained by randomization, using transducers that produce ultrasound with a pulse frequency of 1.5 MHz, a pulse repetition rate of 1 kHz, and average output intensity of 30 mW/cm2. Cone-beam computed tomography (CBCT) images were taken before and after treatment. The extraction space dimensions were measured every four weeks and root lengths of canines were measured before and after treatment. The data were analyzed using paired t-test. The study outcome showed that the mean rate of tooth movement in LIPUS side was 0.266 ± 0.092 mm/week and on the control side was 0.232 ± 0.085 mm/week and the difference was statistically significant. LIPUS increased the rate of tooth movement by an average of 29%. For orthodontic root resorption, the LIPUS side (0.0092 ± 0.022 mm/week) showed a statistically significant decrease as compared to control side (0.0223 ± 0.022 mm/week). The LIPUS application accelerated tooth movement and minimized orthodontically induced tooth root resorption at the same time.
Collapse
|
5
|
Hikida T, Yamaguchi M, Shimizu M, Kikuta J, Yoshino T, Kasai K. Comparisons of orthodontic root resorption under heavy and jiggling reciprocating forces during experimental tooth movement in a rat model. Korean J Orthod 2016; 46:228-41. [PMID: 27478800 PMCID: PMC4965594 DOI: 10.4041/kjod.2016.46.4.228] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Revised: 10/21/2015] [Accepted: 11/23/2015] [Indexed: 11/10/2022] Open
Abstract
OBJECTIVE Root mobility due to reciprocating movement of the tooth (jiggling) may exacerbate orthodontic root resorption (ORR). "Jiggling" describes mesiodistal or buccolingual movement of the roots of the teeth during orthodontic treatment. In the present study, buccolingual movement is described as "jiggling." We aimed to investigate the relationship between ORR and jiggling and to test for positive cell expression in odontoclasts in resorbed roots during experimental tooth movement (jiggling) in vivo. METHODS Male Wistar rats were divided into control, heavy force (HF), optimal force (OF), and jiggling force (JF) groups. The expression levels of cathepsin K, matrix metalloproteinase (MMP)-9 protein, interleukin (IL)-6, cytokine-induced neutrophil chemoattractant 1 (CINC-1; an IL-8-related protein in rodents), receptor activator of nuclear factor κB ligand (RANKL), and osteoprotegerin protein in the dental root were determined using immunohistochemistry. RESULTS On day 21, a greater number of root resorption lacunae, which contained multinucleated odontoclasts, were observed in the palatal roots of rats in the JF group than in rats from other groups. Furthermore, there was a significant increase in the numbers of cathepsin K-positive and MMP-9-positive odontoclasts in the JF group on day 21. Immunoreactivities for IL-6, CINC-1, and RANKL were stronger in resorbed roots exposed to jiggling than in the other groups on day 21. Negative reactivity was observed in the controls. CONCLUSIONS These results suggest that jiggling may induce ORR via inflammatory cytokine production during orthodontic tooth movement, and that jiggling may be a risk factor for ORR.
Collapse
Affiliation(s)
- Takuji Hikida
- Department of Orthodontics, Nihon University School of Dentistry at Matsudo, Japan
| | - Masaru Yamaguchi
- Department of Orthodontics, Nihon University School of Dentistry at Matsudo, Japan
| | - Mami Shimizu
- Department of Orthodontics, Nihon University School of Dentistry at Matsudo, Japan
| | - Jun Kikuta
- Department of Orthodontics, Nihon University School of Dentistry at Matsudo, Japan
| | - Tomokazu Yoshino
- Department of Orthodontics, Nihon University School of Dentistry at Matsudo, Japan
| | - Kazutaka Kasai
- Department of Orthodontics, Nihon University School of Dentistry at Matsudo, Japan
| |
Collapse
|
6
|
Wen X, Yi LZ, Liu F, Wei JH, Xue Y. The role of cathepsin K in oral and maxillofacial disorders. Oral Dis 2015; 22:109-15. [PMID: 26458004 DOI: 10.1111/odi.12378] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Accepted: 09/30/2015] [Indexed: 01/05/2023]
Abstract
Cathepsin K (CTSK) was thought to be a collagenase, specifically expressed by osteoclasts, and played an important role in bone resorption. However, more and more research found that CTSK was expressed in more extensive cells, tissues, and organs. It may not only participate in regulating human physiological activity, but also be closely related to a variety of disease. In this review, we highlight the relationship between CTSK and oral and maxillofacial disorders on the following three aspects: oral and maxillofacial abnormities in patients with pycnodysostosis caused by CTSK mutations, oral and maxillofacial abnormities in Ctsk(-/-) mice, and the role of CTSK in oral and maxillofacial diseases, including periodontitis, peri-implantitis, tooth movement, oral and maxillofacial tumor, root resorption, and periapical disease.
Collapse
Affiliation(s)
- X Wen
- State Key Laboratory of Military Stomatology, Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi, China
| | - L-z Yi
- State Key Laboratory of Military Stomatology, Department of Oral Biology, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi, China
| | - F Liu
- Department of Stomatology, Northwest Women's and Children's Hospital, Xi'an, China
| | - J-h Wei
- State Key Laboratory of Military Stomatology, Department of Oral and Maxillofacial Surgery, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Y Xue
- State Key Laboratory of Military Stomatology, Department of Oral Biology, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi, China.,Clinic of Oral Rare and Genetic Diseases, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi, China
| |
Collapse
|
7
|
Evaluation of two formulations containing mineral trioxide aggregate on delayed tooth replantation: relevance of RANKL/RANK/OPG system. Odontology 2015; 104:211-9. [DOI: 10.1007/s10266-015-0204-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Accepted: 03/10/2015] [Indexed: 11/26/2022]
|
8
|
Xue Y, Wang L, Xia D, Li Q, Gao S, Dong M, Cai T, Shi S, He L, Hu K, Mao T, Duan X. Dental Abnormalities Caused by Novel Compound Heterozygous CTSK Mutations. J Dent Res 2015; 94:674-81. [PMID: 25731711 DOI: 10.1177/0022034515573964] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Cathepsin K (CTSK) is an important protease responsible for degrading type I collagen, osteopontin, and other bone matrix proteins. The mutations in the CTSK gene can cause pycnodysostosis (OMIM 265800), a rare autosomal recessive bone dysplasia. Patients with pycnodysostosis have been reported to present specific dental abnormalities; however, whether these dental abnormalities are related to dysfunctional CTSK has never been reported. Here we investigated the histologic changes of cementum and alveolar bone in a pycnodysostosis patient, caused by novel compound heterozygous mutations in the CTSK gene (c.87 G>A p.W29X and c.848 A>G p.Y283C). The most impressive manifestations in tooth were extensive periradicular high-density clumps with unclear periodontal space by orthopantomography examination and micro-computed tomography scanning analysis. Hematoxylin/eosin and toluidine blue staining and atomic force microscopy analysis showed that the cementum became significantly thickened, softened, and full of cementocytes. The disorganized bone structure was the main character of alveolar bone. The p.W29X mutation may represent the loss-of-function allele with an earlier termination codon in the precursor CTSK polypeptide. Residue Y283 is highly conserved among papain-like cysteine proteases. Three-dimensional structure modeling analysis found that the loss of the hydroxybenzene residue in the Y283C mutation would interrupt the hydrogen network and possibly affect the self-cleavage of the CTSK enzyme. Furthermore, p.Y283C mutation did not affect the mRNA and protein levels of overexpressed CTSK in COS-7 system but did reduce CTSK enzyme activity. In conclusion, the histologic and ultrastructural changes of cementum and alveolar bone might be affected by CTSK mutation via reduction of its enzyme activity (clinical trial registration: ChiCTR-TNC-10000876).
Collapse
Affiliation(s)
- Y Xue
- State Key Laboratory of Military Stomatology, Department of Oral Biology, Clinic of Oral Rare and Genetic Diseases, School of Stomatology, Fourth Military Medical University, Xi'an, Shaanxi, P. R. China
| | - L Wang
- Department of Molecular Biology, Fourth Military Medical University, Xi'an, Shaanxi, P. R. China
| | - D Xia
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Aarhus C, Denmark
| | - Q Li
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Aarhus C, Denmark
| | - S Gao
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Aarhus C, Denmark
| | - M Dong
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Aarhus C, Denmark
| | - T Cai
- Oral Infection and Immunity Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, USA
| | - S Shi
- Center for Craniofacial Molecular Biology, University of Southern California School of Dentistry, Los Angeles, CA, USA
| | - L He
- State Key Laboratory of Military Stomatology, Department of Oral and Maxillofacial Surgery, School of Stomatology, Fourth Military Medical University, Xi'an, Shaanxi, P. R. China
| | - K Hu
- State Key Laboratory of Military Stomatology, Department of Oral and Maxillofacial Surgery, School of Stomatology, Fourth Military Medical University, Xi'an, Shaanxi, P. R. China
| | - T Mao
- State Key Laboratory of Military Stomatology, Department of Oral and Maxillofacial Surgery, School of Stomatology, Fourth Military Medical University, Xi'an, Shaanxi, P. R. China
| | - X Duan
- State Key Laboratory of Military Stomatology, Department of Oral Biology, Clinic of Oral Rare and Genetic Diseases, School of Stomatology, Fourth Military Medical University, Xi'an, Shaanxi, P. R. China
| |
Collapse
|
9
|
Effect of cytokines on osteoclast formation and bone resorption during mechanical force loading of the periodontal membrane. ScientificWorldJournal 2014; 2014:617032. [PMID: 24574904 PMCID: PMC3916098 DOI: 10.1155/2014/617032] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2013] [Accepted: 11/20/2013] [Indexed: 01/10/2023] Open
Abstract
Mechanical force loading exerts important effects on the skeleton by controlling bone mass and strength. Several in vivo experimental models evaluating the effects of mechanical loading on bone metabolism have been reported. Orthodontic tooth movement is a useful model for understanding the mechanism of bone remodeling induced by mechanical loading. In a mouse model of orthodontic tooth movement, TNF-α was expressed and osteoclasts appeared on the compressed side of the periodontal ligament. In TNF-receptor-deficient mice, there was less tooth movement and osteoclast numbers were lower than in wild-type mice. These results suggest that osteoclast formation and bone resorption caused by loading forces on the periodontal ligament depend on TNF-α. Several cytokines are expressed in the periodontal ligament during orthodontic tooth movement. Studies have found that inflammatory cytokines such as IL-12 and IFN-γ strongly inhibit osteoclast formation and tooth movement. Blocking macrophage colony-stimulating factor by using anti-c-Fms antibody also inhibited osteoclast formation and tooth movement. In this review we describe and discuss the effect of cytokines in the periodontal ligament on osteoclast formation and bone resorption during mechanical force loading.
Collapse
|
10
|
Tsuchiya S, Tsuchiya M, Nishioka T, Suzuki O, Sasano Y, Igarashi K. Physiological distal drift in rat molars contributes to acellular cementum formation. Anat Rec (Hoboken) 2013; 296:1255-63. [PMID: 23775928 DOI: 10.1002/ar.22731] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2012] [Accepted: 04/15/2013] [Indexed: 12/15/2022]
Abstract
Occlusal forces may induce the physiological teeth migration in humans, but there is little direct evidence. Rat molars are known to migrate distally during aging, possibly caused by occlusal forces. The purpose of this study was to determine if a reduction in occlusion would decrease teeth migration and affect associated periodontal structures such as cementum. To reduce occlusal forces, the right upper first molar (M1) in juvenile rats was extracted. The transition of the position of upper second molar (M2) and formation of M2 cementum was followed during aging. From the cephalometric analyses, upper M2 was located more anterior compared with the original position with aging after M1 extraction. Associated with this "slowing-down" of the physiological drift, cementum thickness on distal surface, but not on mesial surface, of M2 root was significantly increased. The accumulation of alizarin red as vital stain indicative of calcification, was observed in the distal cementum of M2 root only on the side of M1 extraction. Extraction of M1 that results in less functional loading, distinctly attenuates the physiological drift only in the upper dentition. The decreased physiological drift appears to activate acellular cementum formation only on distal surface of M2 root, perhaps due to reduced mechanical stress associated with the attenuated distal drift. In conclusion, the physiological distal drift in rat molars appears to be largely driven by the occlusal force and also affects the formation of acellular cementum. These findings provide additional direct evidence for an important role of occlusal forces in tooth migration.
Collapse
Affiliation(s)
- Shinobu Tsuchiya
- Division of Oral Dysfunction Science, Tohoku University Graduate School of Dentistry, Sendai, Japan
| | | | | | | | | | | |
Collapse
|
11
|
Wan Hassan WN, Stephenson PA, Waddington RJ, Sloan AJ. An ex vivo culture model for orthodontically induced root resorption. J Dent 2012; 40:406-15. [PMID: 22342686 DOI: 10.1016/j.jdent.2012.02.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2011] [Revised: 01/30/2012] [Accepted: 02/01/2012] [Indexed: 01/03/2023] Open
Abstract
OBJECTIVES Root resorption is a ubiquitous although undesirable sequela to orthodontic treatment. Current methods to investigate the pathophysiology have certain limitations. In pursuit to understand and develop treatment modalities for orthodontically induced root resorption, the ability to manipulate cells within their natural extracellular matrix in a three dimensional organotypic model is invaluable. The study aimed to develop a laboratory-based organotypic model to investigate the effect of orthodontic forces on the periodontium. METHODS Mandibular slices of male Wistar rats were maintained in Trowel-typed cultures at 37°C in 5% carbon dioxide in air for 7 days with test specimens subjected to compressive forces at 50 g and 100g by stainless steel springs. Tissue architecture and cell viability were maintained under culture conditions. RESULTS Osteoclast numbers increased significantly in both test groups whilst odontoclasts increased in the 50 g group. Immunohistochemistry demonstrated increased dentine sialoprotein expression in both test groups, suggesting changes in mineralization-related activity due to mechanical strain. CONCLUSION The study showed initial cellular and molecular changes of key markers that relate to root resorption in response to mechanical loading. CLINICAL SIGNIFICANCE Severe root resorption may occur when forces applied are heavy or transmitted over an extended period and could lead to mobility and tooth loss. This ex vivo model can be used to investigate cellular and molecular processes during orthodontic tooth movement which may advance the clinical management of root resorption.
Collapse
Affiliation(s)
- W N Wan Hassan
- Department of Children's Dentistry and Orthodontics, University of Malaya, Kuala Lumpur, Malaysia.
| | | | | | | |
Collapse
|
12
|
Yoshimatsu M, Kitaura H, Fujimura Y, Kohara H, Morita Y, Eguchi T, Yoshida N. Inhibitory effects of IL-12 on experimental tooth movement and root resorption in mice. Arch Oral Biol 2012; 57:36-43. [DOI: 10.1016/j.archoralbio.2011.07.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2010] [Revised: 06/15/2011] [Accepted: 07/18/2011] [Indexed: 11/26/2022]
|