Tooth attachment, replacement, and growth in the butterfly fish, Chaetodon miliaris (Chaetodontidae, Perciformes)

1984 ◽  
Vol 62 (2) ◽  
pp. 183-189 ◽  
Author(s):  
Philip Jay Motta
Keyword(s):  
Tooth Development ◽  
Annular Ligament ◽  
Tooth Replacement ◽  
Tooth Structure ◽  
Pulp Cavity ◽  
Tooth Growth

Despite much work on tooth development and attachment in fishes there has been little published on this subject in advanced actinopterygians. This paper describes tooth structure, arrangement, attachment, growth, and replacement in the butterflyfish, Chaetodon miliaris. Each tooth is composed of a cap, shaft, and pulp cavity, and is articulated to attachment bone pedestals by an annular ligament. Tooth growth occurs initially by cap formation followed by elongation of the tooth shaft. These growing replacement teeth remain unattached to the bone, forming in troughs in the premaxilla and dentaries. Jaw tooth replacement appears to occur either laterally or lingually to functional teeth; addition of teeth lateral to functional rows may provide increase in tooth numbers during growth. The dentition and jaw morphology of this species appears to represent a compromise between planktivory and benthic feeding and may indicate a recent entry into the planktivorous guild.

scholarly journals Thecodont tooth attachment and replacement in bolosaurid parareptiles

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9168 ◽  
Author(s):  
Adam J. Snyder ◽  
Aaron R.H. LeBlanc ◽  
Chen Jun ◽  
Joseph J. Bevitt ◽  
Robert R. Reisz
Keyword(s):  
Alveolar Bone ◽  
Tooth Development ◽  
Tooth Replacement ◽  
Deep Roots ◽  
Pulp Cavity ◽  
Functional Tooth ◽  
Tomographic Data ◽  
Ct Data ◽  
Density Boundary ◽  
Tooth Buds

Permian bolosaurid parareptiles are well-known for having complex tooth crowns and complete tooth rows in the jaws, in contrast to the comparatively simple teeth and frequent replacement gaps in all other Paleozoic amniotes. Analysis of the specialized dentition of the bolosaurid parareptiles Bolosaurus from North America and Belebey from Russia, utilizing a combination of histological and tomographic data, reveals unusual patterns of tooth development and replacement. The data confirm that bolosaurid teeth have thecodont implantation with deep roots, the oldest known such example among amniotes, and independently evolved among much younger archosauromorphs (including dinosaurs and crocodilians) and among synapsids (including mammals). High-resolution CT scans were able to detect the density boundary between the alveolar bone and the jawbone, as confirmed by histology, and revealed the location and size of developing replacement teeth in the pulp cavity of functional teeth. Evidence provided by the paratype dentary of Belebey chengi indicates that replacement teeth are present along the whole tooth row at slightly different stages of development, with the ontogenetically more developed teeth anteriorly, suggesting that tooth replacement was highly synchronized. CT data also show tooth replacement is directly related to the presence of lingual pits in the jaw, and that migration of tooth buds occurs initially close to these resorption pits to a position immediately below the functional tooth within its pulp cavity. The size and complex shape of the replacement teeth in the holotype of Bolosaurus grandis indicate that the replacement teeth can develop within the pulp cavity to an advanced stage while the previous generation remains functional for an extended time, reminiscent of the condition seen in other amniotes with occluding dentitions, including mammals.

scholarly journals Histological characterization of denticulate palatal plates in an Early Permian dissorophoid

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3727 ◽  
Author(s):  
Bryan M. Gee ◽  
Yara Haridy ◽  
Robert R. Reisz
Keyword(s):  
Soft Tissue ◽  
Histological Analysis ◽  
External Morphology ◽  
Tooth Replacement ◽  
Simple Description ◽  
Pulp Cavity ◽  
Histological Data ◽  
Tissue Implantation ◽  
Soft Tissue Covering

Denticles are small, tooth-like protrusions that are commonly found on the palate of early tetrapods. Despite their widespread taxonomic occurrence and similar external morphology to marginal teeth, it has not been rigorously tested whether denticles are structurally homologous to true teeth with features such as a pulp cavity, dentine, and enamel, or if they are bony, tooth-like protrusions. Additionally, the denticles are known to occur not only on the palatal bones but also on a mosaic of small palatal plates that is thought to have covered the interpterygoid vacuities of temnospondyls through implantation in a soft tissue covering; however, these plates have never been examined beyond a simple description of their position and external morphology. Accordingly, we performed a histological analysis of these denticulate palatal plates in a dissorophoid temnospondyl in order to characterize their microanatomy and histology. The dentition on these palatal plates has been found to be homologous with true teeth on the basis of both external morphology and histological data through the identification of features such as enamel and a pulp cavity surrounded by dentine. In addition, patterns of tooth replacement and ankylosis support the hypothesis of structural homology between these tiny teeth on the palatal plates and the much larger marginal dentition. We also provide the first histological characterization of the palatal plates, including documentation of abundant Sharpey’s fibres that provide a direct line of evidence to support the hypothesis of soft tissue implantation. Finally, we conducted a survey of the literature to determine the taxonomic distribution of these plates within Temnospondyli, providing a broader context for the presence of palatal plates and illustrating the importance of maintaining consistency in nomenclature.

scholarly journals Evaluation of secondary dentin formation for forensic age assessment by means of semi-automatic segmented ultrahigh field 9.4 T UTE MRI datasets

2020 ◽  
Vol 134 (6) ◽  
pp. 2283-2288
Author(s):  
Maximilian Timme ◽  
Jens Borkert ◽  
Nina Nagelmann ◽  
Andreas Schmeling
Keyword(s):  
Dental Pulp ◽  
Automatic Segmentation ◽  
Tooth Pulp ◽  
Human Teeth ◽  
Age Assessment ◽  
Ultrahigh Field ◽  
Tooth Structure ◽  
Pulp Cavity ◽  
Magnetic Resonance Imaging Mri ◽  
Dentin Formation

Abstract Dental methods are an important element of forensic age assessment of living persons. After the development of all the teeth, including third molars, is completed, degenerative characteristics can be used to assess age. The radiologically detectable reduction of the dental pulp cavity has been described as such a feature. We investigated the suitability of ultrahigh field 9.4 T ultrashort time echo (UTE) magnetic resonance imaging (MRI) for the evaluation of pulp cavity volume in relation to the total tooth volume in 4 extracted human teeth. The volume calculations were performed after semi-automatic segmentation by software AMIRA using the different intensities of the structures in the MRI dataset. The automatically selected intensity range was adjusted manually to the structures. The visual distinction of pulp and tooth structure was possible in all cases with in-plane resolution < 70 μm. Ratios of tooth/pulp volume were calculated, which could be suitable for age estimation procedures. Intensity shifts within the pulp were not always correctly assigned by the software in the course of segmentation. 9.4 T UTE-MRI technology is a forward-looking, radiation-free procedure that allows the volume of the dental pulp to be determined at high spatial resolution and is thus potentially a valuable instrument for the age assessment of living persons.

scholarly journals The Effects of Premature Tooth Extraction and Damage on Replacement Timing in the Green Iguana

2020 ◽  
Vol 60 (3) ◽  
pp. 581-593
Author(s):  
Kirstin S Brink ◽  
Ping Wu ◽  
Cheng-Ming Chuong ◽  
Joy M Richman
Keyword(s):  
Tooth Extraction ◽  
Tooth Development ◽  
Tooth Wear ◽  
X Rays ◽  
Tooth Replacement ◽  
Green Iguana ◽  
Dental Tissues ◽  
Functional Tooth ◽  
Green Iguanas ◽  
Replacement Cycle

Synopsis Reptiles with continuous tooth replacement, or polyphyodonty, replace their teeth in predictable, well-timed waves in alternating tooth positions around the mouth. This process is thought to occur irrespective of tooth wear or breakage. In this study, we aimed to determine if damage to teeth and premature tooth extraction affects tooth replacement timing long-term in juvenile green iguanas (Iguana iguana). First, we examined normal tooth development histologically using a BrdU pulse-chase analysis to detect label-retaining cells in replacement teeth and dental tissues. Next, we performed tooth extraction experiments for characterization of dental tissues after functional tooth (FT) extraction, including proliferation and β-Catenin expression, for up to 12 weeks. We then compared these results to a newly analyzed historical dataset of X-rays collected up to 7 months after FT damage and extraction in the green iguana. Results show that proliferation in the dental and successional lamina (SL) does not change after extraction of the FT, and proliferation occurs in the SL only when a tooth differentiates. Damage to an FT crown does not affect the timing of the tooth replacement cycle, however, complete extraction shifts the replacement cycle ahead by 4 weeks by removing the need for resorption of the FT. These results suggest that traumatic FT loss affects the timing of the replacement cycle at that one position, which may have implications for tooth replacement patterning around the entire mouth.

scholarly journals Anatomical and histological structure of the cavy’s teeth as a basis for diagnosis of dental diseases

2021 ◽  
Vol 77 (01) ◽  
pp. 6500-2021
Author(s):  
JUSTYNA DZIECH ◽  
TOMASZ PIASECKI
Keyword(s):  
Histological Structure ◽  
Dental Cementum ◽  
Pulp Cavity ◽  
Apical Bud ◽  
Dental Diseases ◽  
Acellular Cementum ◽  
And Cartilage ◽  
Tooth Growth ◽  
Periodontal Ligaments

The cavy’s dentition can be shortly described as diphyodont, heterodont, and hypselodont. Histologically, each tooth consists of enamel formed of 4 layers of cells, which together form an apical bud, dentin formed by odontoblasts, and dental cementum. The facies lingualis of incisors is covered with classical acellular cementum, whereas a few circular islands of cementum pearls occur on facies labialis. There are 3 types of cementum in cheek teeth: acellular cementum, cementum pearls, and cartilage-like cementum. Constant tooth growth is ensured by an open pulp cavity within the apex. Periodontal ligaments that are part of the desmodontium are responsible for anchoring teeth in the alveolus.

scholarly journals Wnt Signalling in Regenerative Dentistry

2021 ◽  
Vol 2 ◽  
Author(s):  
Anahid A. Birjandi ◽  
Paul Sharpe
Keyword(s):  
Tooth Development ◽  
Cell Types ◽  
Biological Properties ◽  
Wnt Signalling ◽  
Pulp Tissue ◽  
Tooth Structure ◽  
Regenerative Dentistry ◽  
Injury And Repair ◽  
Tooth Repair ◽  
Treatment Procedures

Teeth are complex structures where a soft dental pulp tissue is enriched with nerves, vasculature and connective tissue and encased by the cushioning effect of dentin and the protection of a hard enamel in the crown and cementum in the root. Injuries such as trauma or caries can jeopardise these layers of protection and result in pulp exposure, inflammation and infection. Provision of most suitable materials for tooth repair upon injury has been the motivation of dentistry for many decades. Wnt signalling, an evolutionarily conserved pathway, plays key roles during pre- and post-natal development of many organs including the tooth. Mutations in the components of this pathway gives rise to various types of developmental tooth anomalies. Wnt signalling is also fundamental in the response of odontoblasts to injury and repair processes. The complexity of tooth structure has resulted in diverse studies looking at specific compartments or cell types of this organ. This review looks at the current advances in the field of tooth development and regeneration. The objective of the present review is to provide an updated vision on dental biomaterials research, focusing on their biological properties and interactions to act as evidence for their potential use in vital pulp treatment procedures. We discuss the outstanding questions and future directions to make this knowledge more translatable to the clinics.

scholarly journals Early development of rostrum saw-teeth in a fossil ray tests classical theories of the evolution of vertebrate dentitions

2015 ◽  
Vol 282 (1816) ◽  
pp. 20151628 ◽  
Author(s):  
Moya Meredith Smith ◽  
Alex Riley ◽  
Gareth J. Fraser ◽  
Charlie Underwood ◽  
Monique Welten ◽  
...  
Keyword(s):  
Oral Cavity ◽  
Early Development ◽  
Developmental Plasticity ◽  
Tooth Development ◽  
Ct Scanning ◽  
Tooth Size ◽  
Micro Ct ◽  
Tooth Replacement ◽  
Self Renewal ◽  
Dental Lamina

In classical theory, teeth of vertebrate dentitions evolved from co-option of external skin denticles into the oral cavity. This hypothesis predicts that ordered tooth arrangement and regulated replacement in the oral dentition were also derived from skin denticles. The fossil batoid ray Schizorhiza stromeri (Chondrichthyes; Cretaceous) provides a test of this theory. Schizorhiza preserves an extended cartilaginous rostrum with closely spaced, alternating saw-teeth, different from sawfish and sawsharks today. Multiple replacement teeth reveal unique new data from micro-CT scanning, showing how the ‘cone-in-cone’ series of ordered saw-teeth sets arrange themselves developmentally, to become enclosed by the roots of pre-existing saw-teeth. At the rostrum tip, newly developing saw-teeth are present, as mineralized crown tips within a vascular, cartilaginous furrow; these reorient via two 90° rotations then relocate laterally between previously formed roots. Saw-tooth replacement slows mid-rostrum where fewer saw-teeth are regenerated. These exceptional developmental data reveal regulated order for serial self-renewal, maintaining the saw edge with ever-increasing saw-tooth size. This mimics tooth replacement in chondrichthyans, but differs in the crown reorientation and their enclosure directly between roots of predecessor saw-teeth. Schizorhiza saw-tooth development is decoupled from the jaw teeth and their replacement, dependent on a dental lamina. This highly specialized rostral saw, derived from diversification of skin denticles, is distinct from the dentition and demonstrates the potential developmental plasticity of skin denticles.

scholarly journals Zebrafish sp7 mutants show tooth cycling independent of attachment, eruption and poor differentiation of teeth

2018 ◽  
Author(s):  
E Kague ◽  
P.E Witten ◽  
M Soenens ◽  
CL Campos ◽  
T Lubiana ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Thin Layer ◽  
Root Formation ◽  
Tooth Development ◽  
Tooth Replacement ◽  
Stages Of Development ◽  
Odontoblast Differentiation ◽  
Osteoclast Activity ◽  
Poor Differentiation

SummaryThe capacity to fully replace teeth continuously makes zebrafish an attractive model to explore regeneration and tooth development. The requirement of attachment bone for the appearance of replacement teeth has been hypothesized but not yet investigated. The transcription factor sp7 (osterix) is known in mammals to play an important role during odontoblast differentiation and root formation. Here we study tooth replacement in the absence of attachment bone using sp7 zebrafish mutants. We analysed the pattern of tooth replacement at different stages of development and demonstrated that in zebrafish lacking sp7, attachment bone is never present, independent of the stage of tooth development or fish age, yet replacement is not interrupted. Without bone of attachment we observed abnormal orientation of teeth, and abnormal connection of pulp cavities of predecessor and replacement teeth. Mutants lacking sp7 show arrested dentinogenesis, with non-polarization of odontoblasts and only a thin layer of dentin deposited. Osteoclast activity was observed in sp7 mutants; due to the lack of bone of attachment, remodelling was diminished but nevertheless present along the pharyngeal bone. We conclude that tooth replacement is ongoing in the sp7 mutant despite poor differentiation and defective attachment. Without bone of attachment tooth orientation and pulp organization are compromised.

scholarly journals Bioengineered Tooth Buds Exhibit Features of Natural Tooth Buds

2018 ◽  
Vol 97 (10) ◽  
pp. 1144-1151 ◽  
Author(s):  
E.E. Smith ◽  
S. Angstadt ◽  
N. Monteiro ◽  
W. Zhang ◽  
A. Khademhosseini ◽  
...  
Keyword(s):  
Replacement Therapy ◽  
Tooth Development ◽  
Tooth Replacement ◽  
Dental Tissue ◽  
Bioengineered Tooth ◽  
Natural Teeth ◽  
Cell Niche ◽  
Tooth Buds ◽  
Improved Methods ◽  
Natural Tooth

Tooth loss is a significant health issue currently affecting millions of people worldwide. Artificial dental implants, the current gold standard tooth replacement therapy, do not exhibit many properties of natural teeth and can be associated with complications leading to implant failure. Here we propose bioengineered tooth buds as a superior alternative tooth replacement therapy. We describe improved methods to create highly cellularized bioengineered tooth bud constructs that formed hallmark features that resemble natural tooth buds such as the dental epithelial stem cell niche, enamel knot signaling centers, transient amplifying cells, and mineralized dental tissue formation. These constructs were composed of postnatal dental cells encapsulated within a hydrogel material that were implanted subcutaneously into immunocompromised rats. To our knowledge, this is the first report describing the use of postnatal dental cells to create bioengineered tooth buds that exhibit evidence of these features of natural tooth development. We propose future bioengineered tooth buds as a promising, clinically relevant tooth replacement therapy.

The ontogeny of tooth succession in Lacerta vivipara Jacquin (1787)

1971 ◽  
Vol 179 (1056) ◽  
pp. 261-289 ◽  
Keyword(s):  
Tooth Development ◽  
Biological Significance ◽  
Tooth Replacement ◽  
Similar Sequence ◽  
Dental Lamina ◽  
Oral Ectoderm ◽  
Three Stages ◽  
Lacerta Vivipara ◽  
Tooth Germs ◽  
Almost All

Edmund (1960) has shown that in the dentitions of almost all non-mammalian vertebrates, teeth are replaced in waves which regularly sweep through alternate tooth positions. He explained the ontogeny of these patterns of tooth replacement in terms of biological units called Zahnreihen whose existence has been accepted by nearly all workers studying tooth replacement. In the present paper it is argued that there is no unequivocal evidence, either during development or in adult animals, that Zahnreihen have any biological significance. Reconstructions were made from serial sections of the developing dentitions in the lower jaws of 15 embryos of Lacerta vivipara . It was evident that Zahnreihen have no significance in this animal. Rudimentary teeth were produced with varying frequency in positions 3, 5, 6, 8, 10 and 13. Contrary to the predictions of all previous theories explaining the ontogeny of tooth development in reptiles it was in these apparently random positions that the first teeth were produced. Furthermore, apart from during the first few days of embryonic dental development, it was clear that the development of a row of alternating teeth was initiated in sequence from the back to the front of the jaw to be followed by a similar sequence of development of the intervening teeth. On the basis of this evidence a new model to explain the sequence of tooth initiation in reptiles is proposed. The following assumptions have been made. (A) Ectomesenchymal cells migrate anteriorly through the developing jaws initiating a reaction from the oral ectoderm. (B) The oral ectoderm develops competence to react to the ectomesenchyme in three stages. First it generates abortive clumps of ectodermal cells; second it becomes capable of inducing the adjacent ectomesenchymal cells to form dentine and third it becomes capable of laying down enamel. (C) At all times the dental lamina has the potential of taking part in tooth development according to the regional competence achieved. (D) Developing tooth germs produce a condition which inhibits tooth development around them. Using these assumptions it is possible to explain all stages in the development of the wave replacement of alternate teeth in L . vivipara . It is also possible to explain previous observations on the ontogeny of reptilian dentitions. The sphere of inhibition which surrounds developing teeth is particularly important because it ensures that developing teeth are evenly spaced through the jaw. It is argued that the wave replacement of alternate teeth is an automatic sequel to this and is of only secondary functional significance.

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