Origin and Evolution of Cementum as Tooth Attachment Complex

Kozawa, Yukishige; Chisaka, Hideki; Iwasa, Yuka; Yokota, Rumi; Suzuki, Kunihiro; Yamamoto, H.

doi:10.2330/joralbiosci.47.25

Cited by 10 publications

(12 citation statements)

References 3 publications

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“…MicroXCT™ illustrated various enamel pits and cementum protrusions throughout the specimen thickness (Figure 2). This observation is similar to scallop-like cementum-enamel integration found on occlusal surfaces of herbivorous mammalian teeth [16, 15, 17, 18]. …”

Section: Discussionsupporting

confidence: 81%

Structure, chemical composition and mechanical properties of coronal cementum in human deciduous molars

Ho¹,

Senkyrikova²,

Marshall³

et al. 2009

Dental Materials

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Objectives-It was hypothesized that the coronal cementum containing collagen forms a weak junction with enamel unlike the well integrated DEJ and CDJ.Methods-The hypothesis was investigated in two parts: 1) Evaluate the structure, chemical composition and mechanical properties of coronal cementum and its junction with enamel using scanning electron microscopy, micro-X-ray computed tomography, and atomic force microscopy. The chemical composition and mechanical properties were determined by evaluating the spatial variations of inorganic ( ν 1 mode at 960 cm −1 ) and organic (C-H deformation at 1452 cm −1 ; C-H stretch at 2940 cm −1 ) contents using Raman microspectroscopy and elastic modulus and hardness values using nanoindentation. 2). Estimate the strength and evaluate the microstructure of coronal cementum interface with enamel using SEM and MicroXCT™.Results & Conclusions-Coronal cementum is heterogeneous because it is a combination of laminar acellular afibrillar cementum and acellular extrinsic fiber cementum with relatively higher organic content. It integrates micromechanically via a scallop-like weak interface with enamel unlike the biomechanically efficient DEJ and CDJ and is continuous with primary root cementum. A single tooth could exhibit all three types of cementum enamel junctions; an overlap, butt and a gap depending on the sectioning plane. The elastic modulus of coronal cementum (11.0 ± 5.8 GPa) is significantly lower (p < 0.05; Student's t-test with 95% confidence interval) than primary cementum (15.8 ± 5.3 GPa).

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Section: Discussionsupporting

confidence: 81%

Structure, chemical composition and mechanical properties of coronal cementum in human deciduous molars

Ho¹,

Senkyrikova²,

Marshall³

et al. 2009

Dental Materials

View full text Add to dashboard Cite

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“…These changes have occurred throughout ichthyosaur evolutionary history, and are not solely concentrated at the origin of the Parvipelvia, nor at the TriassicJurassic boundary. This within-group diversity is not unexpected: in some mammalian clades, for instance, a range of variation is seen in many tooth histology parameters (Davit-Béal 2009;Kozawa et al 2005;Peyer 1968). However, with the exception of mammals, discussion on within-group variation in amniote tooth tissues remains in its infancy.…”

Section: Discussionmentioning

confidence: 93%

“…Although it is similar in gross morphology to bone, cellular cementum is not secondarily remodeled (Bosshardt 2005;Kozawa et al 2005), but may be vascularized (Bosshardt 2005;Caldwell et al 2003). In these cases, the cellular cementum has a trabecular architecture, and cementeons are present (Caldwell et al 2003).…”

Section: Cementummentioning

confidence: 95%

“…Cementum shares similar organic components with bone and dentine, and is present in both cellular and acellular morphs in many amniotes (Sire et al 2009). A layer of acellular cementum separating the dentine from the cellular cementum is well known in mammals (Bosshardt 2005;Kozawa et al 2005), crocodilians (Luan et al 2009;Shimada et al 1992), mosasaurs (Caldwell et al 2003;Luan et al 2009), Iguana (Luan et al 2009), and the ichthyosaur Platypterygius (Maxwell et al 2011). It is likely also present in the basal amniote Captorhinus aguti [described as atubular dentine overlying the globular zone (de Ricqlès and Bolt 1983)].…”

Section: Cementummentioning

confidence: 98%

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Tooth histology, attachment, and replacement in the Ichthyopterygia reviewed in an evolutionary context

Maxwell

Lamoureux

2011

Paläontol. Z.

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Ichthyosaurs, an extinct group of Mesozoic marine diapsids, show a relatively small range of tooth crown morphologies. With few exceptions, members of the group bear a large number of conical teeth and show only minor heterodonty within a jaw. This uniformity in gross morphology masks a high degree of variation in both the quantity and arrangement of the mineralized tooth tissues. Here, we describe tooth tissue structure and distribution in derived ichthyosaurs. We synthesize these new observations with the historical literature, to map changes in the quantity and arrangement of tooth tissues. These changes affected tooth attachment, tooth replacement, plicidentine morphology, and the amount and distribution of cellular cementum. The amount of variation detected in features relating to ichthyosaurian dentition is not surprising given the geological longevity and morphological disparity of the group, but does emphasize the importance of extensive taxon sampling in studies of tooth histology and evolution. This study is important in that it incorporates morphological and histological information in a phylogenetic and developmental context, something that is rarely done for marine reptile dentitions.

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“…Figure , representing undecalcified sections of jaw block specimens of Carcharinus obscurus , shows the attachment apparatus of the dusky shark. The attachment is fibrous in nature with a ‘bone‐like pedicle’ (Figure ), as defined by Kozawa et al, embedded into the jaws just above a well‐defined conveyor belt (Figure B). The ‘conveyor belt is a complex fibrous system’ (Figure ) moulding over the cartilaginous mass of the jaw and responsible for the continuous mesial drift and movement of the teeth up to the apex of the jaws…”

Section: Fibrous Attachment Of Sharks: Chondrichthyans or Elasmobranchsmentioning

confidence: 99%

Developmental pathways of periodontal tissue regeneration

Ripamonti

2018

J of Periodontal Research

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Nothing is known on the impact of developmental divergence on periodontal tissue regeneration in vertebrate animals. Molecularly, the induction of tooth morphogenesis is highly conserved deploying across animal phyla a constant and reproducible set of gene pathways, which result in morphogenesis of multiple odontode forms and shapes. Genetic mutations positively affect animal speciation via evolving biting and masticatory forces as well as dietary habits selectively imprinted in animal phyla during evolutionary speciation. The geometry of the attachment apparatus of a tooth is important for the interpretation of the induction of cementogenesis with de novo Sharpey's fibres as in thecodonty, ie, a tripartite attachment of alveolar bone, periodontal ligament and cementum. This review addresses the tooth implantation in different animal clades from the fibrous attachment of the Elasmobranch Carcharinus obscurus dusky shark, reviewing the evolution and functional significance of cementum with functionally inserted Sharpey's fibres. In sharks there is a continuous tooth replacement mechanistically supported by the continuously erupting dental lamina. We show that the arching of the continuously erupting dental lamina, a critical step for the selachians' tooth differentiation, is prominently characterized by transforming growth factor-β (TGF-β ) expression not only within the dental lamina but also in cellular condensations in the mesenchymal tissues of the erupting tooth. Such findings indicate the pleiotropic multifaceted activity of a highly conserved mammalian gene across genera, masterminding tooth morphogenesis in both selachians and mammals as well as periodontal tissue induction in the non-human primate Papio ursinus. In P. ursinus, the induction of cementogenesis entails the expression of TGF-β and osteocalcin with fine-tuning and regulation of bone morphogenetic proteins BMP-2 and BMP-7, and upregulation of TGF-β . TGF-β autoinduction and upregulation during the induction of cementogenesis and osteogenesis in P. ursinus provide novel insights into the induction of cementogenesis. It is hypothesized that the evolutionary expression and upregulation of the TGF-β gene may provide the mechanistic insights into the induction of extensive cementogenesis as seen in stem mammals and the induction of trabecular-like cementum formation in mosasaurs' tooth attachment. Aspidin, the precursor of cementum, was reported to appear 310-330 million years ago (Ma) in Odontostraci armoured fish. Studies showed that the differentiation of cementum with inserted Sharpey's fibres is also present in lower amniotes such as Diatectomorpha or Diadectidae, the first herbivorous tetrapods, 323 Ma. In mosasaurs, 168-165 Ma, there is the induction of extensive trabeculation of cementum though nothing is known on the phylogenetic temporo-spatial evolution of cementum before Diadectidae and stem mammals. The large trabeculations of cementum as seen in the attachment of extinct mosasaurs invocates a pleiotropic capacity of cemental growth pre...

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Origin and Evolution of Cementum as Tooth Attachment Complex

Cited by 10 publications

References 3 publications

Structure, chemical composition and mechanical properties of coronal cementum in human deciduous molars

Structure, chemical composition and mechanical properties of coronal cementum in human deciduous molars

Tooth histology, attachment, and replacement in the Ichthyopterygia reviewed in an evolutionary context

Developmental pathways of periodontal tissue regeneration

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