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Dosedělová H, Štěpánková K, Zikmund T, Lesot H, Kaiser J, Novotný K, Štembírek J, Knotek Z, Zahradníček O, Buchtová M. Age-related changes in the tooth-bone interface area of acrodont dentition in the chameleon. J Anat 2016; 229:356-68. [PMID: 27173578 DOI: 10.1111/joa.12490] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/06/2016] [Indexed: 11/29/2022] Open
Abstract
Chameleon teeth develop as individual structures at a distance from the developing jaw bone during the pre-hatching period and also partially during the post-hatching period. However, in the adult, all teeth are fused together and tightly attached to the jaw bone by mineralized attachment tissue to form one functional unit. Tooth to bone as well as tooth to tooth attachments are so firm that if injury to the oral cavity occurs, several neighbouring teeth and pieces of jaw can be broken off. We analysed age-related changes in chameleon acrodont dentition, where ankylosis represents a physiological condition, whereas in mammals, ankylosis only occurs in a pathological context. The changes in hard-tissue morphology and mineral composition leading to this fusion were analysed. For this purpose, the lower jaws of chameleons were investigated using X-ray micro-computed tomography, laser-induced breakdown spectroscopy and microprobe analysis. For a long time, the dental pulp cavity remained connected with neighbouring teeth and also to the underlying bone marrow cavity. Then, a progressive filling of the dental pulp cavity by a mineralized matrix occurred, and a complex network of non-mineralized channels remained. The size of these unmineralized channels progressively decreased until they completely disappeared, and the dental pulp cavity was filled by a mineralized matrix over time. Moreover, the distribution of calcium, phosphorus and magnesium showed distinct patterns in the different regions of the tooth-bone interface, with a significant progression of mineralization in dentin as well as in the supporting bone. In conclusion, tooth-bone fusion in chameleons results from an enhanced production of mineralized tissue during post-hatching development. Uncovering the developmental processes underlying these outcomes and performing comparative studies is necessary to better understand physiological ankylosis; for that purpose, the chameleon can serve as a useful model species.
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Affiliation(s)
- Hana Dosedělová
- Department of Anatomy, Histology and Embryology, University of Veterinary and Pharmaceutical Sciences Brno, Brno, Czech Republic.,Institute of Animal Physiology and Genetics, v.v.i., Academy of Sciences of the Czech Republic, Brno, Czech Republic
| | - Kateřina Štěpánková
- Department of Chemistry, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Tomáš Zikmund
- CEITEC - Central European Institute of Technology, Brno, University of Technology, Brno , Czech Republic
| | - Herve Lesot
- INSERM (French National Institute of Health and Medical Research), 'Osteoarticular and Dental Regenerative NanoMedicine' Laboratory, Faculté de Médicine, Université de Strasbourg, UMR 1109, Strasbourg, France.,Faculté de Chirurgie Dentaire, Université de Strasbourg, Strasbourg, France
| | - Jozef Kaiser
- CEITEC - Central European Institute of Technology, Brno, University of Technology, Brno , Czech Republic
| | - Karel Novotný
- Department of Chemistry, Faculty of Science, Masaryk University, Brno, Czech Republic.,CEITEC - Central European Institute of Technology, Brno, University of Technology, Brno , Czech Republic
| | - Jan Štembírek
- Institute of Animal Physiology and Genetics, v.v.i., Academy of Sciences of the Czech Republic, Brno, Czech Republic.,Department of Oral and Maxillofacial Surgery, University Hospital Ostrava, Ostrava, Czech Republic
| | - Zdeněk Knotek
- Clinic of Small Animals, University of Veterinary and Pharmaceutical Sciences Brno, Brno, Czech Republic
| | - Oldřich Zahradníček
- Department of Teratology, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Marcela Buchtová
- Institute of Animal Physiology and Genetics, v.v.i., Academy of Sciences of the Czech Republic, Brno, Czech Republic.,Department of Experimental Biology, Masaryk University, Brno, Czech Republic
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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: 13] [Impact Index Per Article: 1.1] [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.
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Affiliation(s)
- Shinobu Tsuchiya
- Division of Oral Dysfunction Science, Tohoku University Graduate School of Dentistry, Sendai, Japan
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Andou K, Nakamura M, Ina Y, Sasaki K, Sasano Y. Root and periodontal tissue development after allogenic tooth transplantation between rat littermates. Oral Dis 2010; 17:379-86. [PMID: 21029265 DOI: 10.1111/j.1601-0825.2010.01761.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVE The study was designed to investigate the development of roots and periodontal tissues after allogenic tooth transplantation between rat littermates by micro-computed tomography (micro-CT) and histology. MATERIALS AND METHODS The upper right second molars in 2-week-old rats were extracted and immediately transplanted into the upper right first molar socket of rat littermates under anesthesia. The upper left second molars in 2-week-old recipient rats were used as a control. The rats were fixed and tissues analyzed at 0, 4, 8, or 12 weeks after transplantation. Root development of seven rats in each group was analyzed quantitatively using micro-CT. Periodontal tissue formation was examined qualitatively by histologic methods. RESULTS Roots developed after allogenic transplantation, but they were significantly shorter than control roots. The number of roots varied from one to four in transplanted teeth, while it was consistently four in control teeth. Periodontal tissue formation in transplanted teeth was equivalent to that of the control teeth. CONCLUSION Allogenic transplantation between rat littermates permits root development and periodontal tissue formation.
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Affiliation(s)
- K Andou
- Division of Advanced Prosthetic Dentistry, Tohoku University Graduate School of Dentistry, Sendai, Japan
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Nakajima D, Kamakura S, Nakamura M, Suzuki O, Echigo S, Sasano Y. Analysis of appositional bone formation using a novel rat experimental model. Oral Dis 2008; 14:308-13. [PMID: 18410575 DOI: 10.1111/j.1601-0825.2007.01377.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIM To analyze the process of appositional bone formation using our original rat experimental model. MATERIALS AND METHODS Rats were anesthetized and a ring made of polytetrafluorethylene was placed on the parietal bone surface in the surgical procedure. The time course of appositional bone formation was analyzed with histomorphometry and in situ hybridization for type I collagen and bone sialoprotein. RESULTS The rat experimental model allowed new bone to be formed on the pre-existing bone surface and persist for 12 weeks. We demonstrated that bone is apposed actively for the first 4 weeks and less actively thereafter. CONCLUSIONS The experimental model may contribute to biological analysis for appositional bone formation expected to occur in clinical procedures such as alveolar bone augmentation and sinus lifting.
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Affiliation(s)
- D Nakajima
- Divisions of Oral Surgery, and Craniofacial Development and Regeneration, Tohoku University Graduate School of Dentistry, Sendai, Japan
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