title: Age-related changes in the tooth-bone interface area of acrodont dentition in the chameleon.
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.
authors.affiliation: 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.
authors.forename: Hana
authors.initials: H
authors.lastname: Dosedělová
authors.affiliation: Department of Chemistry, Faculty of Science, Masaryk University, Brno, Czech Republic.
authors.forename: Kateřina
authors.initials: K
authors.lastname: Štěpánková
authors.affiliation: CEITEC - Central European Institute of Technology, Brno, University of Technology, Brno , Czech Republic.
authors.forename: Tomáš
authors.initials: T
authors.lastname: Zikmund
authors.affiliation: 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.
authors.forename: Herve
authors.initials: H
authors.lastname: Lesot
authors.affiliation: CEITEC - Central European Institute of Technology, Brno, University of Technology, Brno , Czech Republic.
authors.forename: Jozef
authors.initials: J
authors.lastname: Kaiser
authors.affiliation: Department of Chemistry, Faculty of Science, Masaryk University, Brno, Czech Republic.|CEITEC - Central European Institute of Technology, Brno, University of Technology, Brno , Czech Republic.
authors.forename: Karel
authors.initials: K
authors.lastname: Novotný
authors.affiliation: 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.
authors.forename: Jan
authors.initials: J
authors.lastname: Štembírek
authors.affiliation: Clinic of Small Animals, University of Veterinary and Pharmaceutical Sciences Brno, Brno, Czech Republic.
authors.forename: Zdeněk
authors.initials: Z
authors.lastname: Knotek
authors.affiliation: Department of Teratology, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, Prague, Czech Republic.
authors.forename: Oldřich
authors.initials: O
authors.lastname: Zahradníček
authors.affiliation: 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.
authors.forename: Marcela
authors.identifier: 0000-0002-0262-6774
authors.initials: M
authors.lastname: Buchtová
mesh_terms: D000375:Aging; D000818:Animals; D003817:Dentition; D007568:Jaw / Q000033:anatomy & histology*; D008116:Lizards; D014070:Tooth / Q000033:anatomy & histology* / Q000502:physiology*; D014074:Tooth Calcification / Q000502:physiology*; D055114:X-Ray Microtomography
keywords: acrodont dentition; laser-induced breakdown spectroscopy; micro-computed tomography; reptiles