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 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.

Genome-Wide Association Study of Erosive Tooth Wear in a Finnish Cohort

2018 ◽  
Vol 53 (1) ◽  
pp. 49-59 ◽  
Author(s):  
Viivi Karoliina Alaraudanjoki ◽  
Salla Koivisto ◽  
Paula Pesonen ◽  
Minna Männikkö ◽  
Jukka Leinonen ◽  
...  
Keyword(s):  
Association Study ◽  
Genome Wide Association Study ◽  
Tooth Development ◽  
Experimental Studies ◽  
Tooth Wear ◽  
Genome Wide Association ◽  
Erosive Tooth Wear ◽  
Dental Tissues ◽  
Genome Wide ◽  
A Genome

Erosive tooth wear is defined as irreversible loss of dental tissues due to intrinsic or extrinsic acids, exacerbated by mechanical forces. Recent studies have suggested a higher prevalence of erosive tooth wear in males, as well as a genetic contribution to susceptibility to erosive tooth wear. Our aim was to examine erosive tooth wear by performing a genome-wide association study (GWAS) in a sample of the Northern Finland Birth Cohort 1966 (n = 1,962). Erosive tooth wear was assessed clinically using the basic erosive wear examination. A GWAS was performed for the whole sample as well as separately for males and females. We identified one genome-wide significant signal (rs11681214) in the GWAS of the whole sample near the genes PXDN and MYT1L. When the sample was stratified by sex, the strongest genome-wide significant signals were observed in or near the genes FGFR1, C8orf86, CDH4, SCD5, F2R, and ING1. Additionally, multiple suggestive association signals were detected in all GWASs performed. Many of the signals were in or near the genes putatively related to oral environment or tooth development, and some were near the regions considered to be associated with dental caries, such as 2p24, 4q21, and 13q33. Replications of these associations in other samples, as well as experimental studies to determine the biological functions of associated genetic variants, are needed.

scholarly journals Dental ontogeny and replacement in Pliosauridae

2015 ◽  
Vol 2 (11) ◽  
pp. 150384 ◽  
Author(s):  
Judyth Sassoon ◽  
Davide Foffa ◽  
Ryan Marek
Keyword(s):  
Tooth Development ◽  
Medial Axis ◽  
Tooth Eruption ◽  
Dental Morphology ◽  
Tooth Replacement ◽  
Posterior Teeth ◽  
Anterior Teeth ◽  
Dental Ontogeny ◽  
Replacement Cycle

Dental morphology and patterns of tooth replacement in representatives of the clade Pliosauridae (Reptilia, Sauropterygia) are evaluated in detail. The jaws of one basal ( Thalassiodracon hawkinsii ) and two derived species ( Pliosaurus carpenteri , Pliosaurus kevani ) were visualized by μCT scans, and the ontogenetic patterns, or ‘movement paths’, of replacement teeth could be mapped. Other specimens ( Peloneustes philarchus and Pliosaurus westbuyensis ) with well-preserved jaws containing functional and replacement teeth in situ were also examined directly, and waves of tooth replacement could be inferred from the degree of in situ tooth development and the fusion between functional and replacement alveoli. The analysis revealed symmetrical tooth eruption over the medial axis throughout the length of the jaw in the basal pliosaurid Thalassiodracon . By contrast, symmetrical tooth eruption patterns occur only along the anterior sections of the jaws of derived pliosaurids. In Pliosaurus , replacement schedules differ in the anterior and posterior portions of the jaws and appear to correlate with differences in tooth morphology and symmetrical replacement. The anterior teeth exhibit longer replacement cycle periods and symmetrical replacement, while shorter cycle periods and asymmetry are seen posteriorly. A longer period suggests slower replacement and is characteristic of large, specialized caniniform teeth in the longer snouted Late Jurassic taxa. Smaller posterior teeth have a shorter period and therefore a faster replacement cycle. The transition from long to short replacement period over the length of the jaw is thought to account for the loss of symmetry. This differentiation could relate to differential tooth function and a type of heterodonty. We therefore propose a new model of pliosaurid tooth replacement patterns and present it in a phylogenetic context.

Influence of Radiopacity of Dental Composites on the Diagnosis of Secondary Caries: The Correlation Between Objective and Subjective Analyses

2014 ◽  
Vol 39 (1) ◽  
pp. 90-97 ◽  
Author(s):  
AD Cruz ◽  
RG Esteves ◽  
IAVP Poiate ◽  
PP Portero ◽  
SM Almeida
Keyword(s):  
Rating Scale ◽  
Pearson Correlation ◽  
Internal Standard ◽  
Dental Composites ◽  
Internal Diameter ◽  
X Rays ◽  
Human Teeth ◽  
Secondary Caries ◽  
Pixel Intensity ◽  
Dental Tissues

SUMMARY This study aimed to objectively evaluate the radiopacity of different dental composites and their subjective influence on diagnosing secondary caries–like lesions and how these results correlate. For objective analysis, three resin specimens (1 mm thick, with a 4-mm internal diameter) were made with four composites: 1) Charisma; 2) Filtek Z250; 3) Prisma AP.H; and 4) Glacier. Three human teeth were selected and then mesio-distally sectioned (1 mm thick) to make the dental specimens. An aluminum (Al) wedge (12 steps, 1 mm thick, 99.8% purity) was used as an internal standard to calculate the radiopacity. For subjective analysis, 20 human teeth were selected and then prepared with a mesio-occluso-distal (MOD) inlay cavity, with half the teeth receiving a round cavity to simulate the carious lesion. The MOD was restored using the composites at four different times. Standardized radiographs were acquired and then digitized (300 dpi and eight-bit TIFF) for both analyses. A histogram objectively measured the pixel intensity values of the images, which were converted into millimeters of Al using linear regressions. Eight observers subjectively evaluated the images using a five-point rating scale to diagnose the caries. The data were statistically analyzed using the Student t-test, the Kappa test, diagnostic testing, and the Pearson correlation coefficient (α=0.05). All materials showed radiopacity values compatible with dental tissues (p>0.05); Glacier was similar to dentin and Prisma AP.H was similar to enamel, while the remaining materials showed a middle radiopacity. Prisma AP.H and Glacier differed (p<0.05) in relation to their accuracy to caries diagnosis, with Glacier having greater accuracy. There was a correlation between objective and subjective analyses with negative linear dependence. An increase in the material's radiopacity could have a subjectively negative influence on the diagnosis of secondary caries; thus, an ideal radiopacity for a dental composite is closer to the dentin image and produces similar attenuation to X-rays than does dentin.

Phosphohydrolase Activities in Developing and Mature Dental Tissues

1990 ◽  
Vol 45 (3-4) ◽  
pp. 280-292
Author(s):  
Edda Warth ◽  
Reinhard Jeck
Keyword(s):  
Alkaline Phosphatase ◽  
Root Formation ◽  
Specific Activity ◽  
Tooth Development ◽  
Inorganic Pyrophosphatase ◽  
Dental Tissues ◽  
Dental Hard Tissues ◽  
Hard Tissues ◽  
Enamel Epithelium ◽  
Enamel Mineralization

Abstract In the course of the odontogenesis of bovine incisors several clearly distinguishable phosphohydrolase activities are observed in the pulp and in dental hard tissues. Using various substrates and inhibitors, unspecific alkaline phosphatase, two isoenzymes of acid phosphatase, Ca2+-activated ATPase and inorganic pyrophosphatase are characterized. The enzymatic activity of alkaline phosphatase in pulp and hard tissues is significantly high at the beginning of dentine and enamel mineralization. The specific activity of this enzyme decreases quite fast with the beginning of root formation, then more slowly, until it reaches a constant final value. Histochemical studies show that during mineralization the maximum of alkaline phosphatase activity is in the subodontoblasts. Lower enzyme concentrations are found in the stratum intermedium and in the outer enamel epithelium during that process. The specific activities of ATPase, acid phosphatases and pyrophosphatase show little temporal variation during tooth development, but they also appear in a characteristic spatial pattern in the dental tissues.

scholarly journals Middle/late Miocene hoplocetine sperm whale remains (Odontoceti: Physeteridae) of North Germany with an emended classification of the Hoplocetinae

Fossil Record ◽  
2006 ◽  
Vol 9 (1) ◽  
pp. 61-86 ◽  
Author(s):  
O. Hampe
Keyword(s):  
Late Miocene ◽  
Killer Whale ◽  
Sperm Whale ◽  
Tooth Wear ◽  
Orcinus Orca ◽  
Killer Whales ◽  
Functional Tooth ◽  
North Germany ◽  
Middle Pliocene

Abstract. Hoplocetus ritzi n. sp. is a new hoplocetine physeterid from the Bolboforma fragori /subfragoris Zone of the middle/late Miocene mica-clay of Groß Pampau in Schleswig-Holstein, North Germany. The Hoplocetinae are known from the early Miocene to the Pliocene. Comparative studies of cranial characters and tooth morphology allow an emended diagnosis of the Hoplocetinae Cabrera, 1926. Four genera, Diaphorocetus, Idiorophus, Scaldicetus, and Hoplocetus are included in this subfamily. The pattern of functional tooth wear deduced from the described Hoplocetus ritzi n. sp. remains is reminescent of that known from Orcinus orca. The hoplocetine physeterids possibly occupied the killer whale niche before the killer whales appeared during the middle Pliocene. Mit Hoplocetusritzi n. sp. wird ein neuer hoplocetiner Physeteride beschrieben. Der Fund stammt aus der Bolboformafragori /subfragoris Zone des mittel-/obermiozänen Glimmertons von Groß Pampau in Schleswig-Holstein, Norddeutschland. Die Hoplocetinae sind vom unteren Miozän bis ins Pliozän nachgewiesen. Anhand vergleichender Untersuchungen an wenigen Schädelmerkmalen und der Zahnmorphologie gelingt eine Neudiagnose der Hoplocetinae Cabrera, 1926 und eine vorläufige Abgrenzung zwischen den als valid angesehenen Gattungen dieser Unterfamilie, Diaphorocetus, Idiorophus, Scaldicetus und Hoplocetus. Das Abkauungsmuster der Zähne von Hoplocetusritzi n. sp. erinnert an das des heutigen Orcinusorca. Möglicherweise sind die hoplocetinen Pottwale habituell den Schwertwalen, die erdgeschichtlich erstmals im mittleren Pliozän auftreten, vergleichbar. doi:10.1002/mmng.200600002

scholarly journals New Perspectives on Tooth Wear

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Peter W. Lucas ◽  
Ridwaan Omar
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Particle Shape ◽  
Tooth Wear ◽  
Research Strategy ◽  
Tooth Surface ◽  
Wear Particles ◽  
Dental Tissues ◽  
Worn Surface ◽  
Tooth Tissue

Some of the efforts that have been made to document tooth wear are reviewed here with an emphasis on nonhuman mammals, literature with which dentists may not be very familiar. We project a change in research strategy from the description of wear at various scales of measurement towards investigation of the mechanical mechanisms that actually create the texture of a worn surface. These studies should reveal exactly how tooth tissue is lost and what aspects of the structure of dental tissues affect this. The most important aspects of the interaction between the tooth surface and wear particles would appear to be particle size, particle shape, their mechanical properties with respect to those of tooth tissues, and the influence of saliva.

scholarly journals Differential expression of multiple cell-surface heparan sulfate proteoglycans during embryonic tooth development.

1994 ◽  
Vol 42 (8) ◽  
pp. 1043-1054 ◽  
Author(s):  
X M Bai ◽  
B Van der Schueren ◽  
J J Cassiman ◽  
H Van den Berghe ◽  
G David
Keyword(s):  
Cell Surface ◽  
Heparan Sulfate ◽  
Differential Expression ◽  
Tooth Development ◽  
Multiple Forms ◽  
Dental Tissues ◽  
Cell Matrix ◽  
Heparin Sulfate ◽  
Multiple Cell

Heparan sulfate accumulates on cell surfaces and at cell-matrix interfaces, and functionally modulates several of the effector molecules that support the interactions, growth, and differentiation of developing tissues. Using heparin sulfate-specific monoclonal antibodies MAb, we obtained evidence that extracts from rodent embryos contain multiple forms of cell surface-associated heparan sulfate proteoglycan (PG). Taking tooth development in the mouse embryo as a model to further investigate the relevance of this PG redundancy and using MAb against heparan sulfate, antibodies specific for syndecan (syndecan-1) and fibroglycan (syndecan-2) (two distinct members of a larger family of cell-surface heparan sulfate PGs), and specific cDNA probes for these two cell-surface PGs, we obtained in situ evidence for regulated and differential expression of multiple cell-surface heparan sulfate PGs. The unique, distinctive, and coordinated changes in the expressions of these PGs during morphogenesis and differentiation of dental tissues suggest that the various cell-surface PGs are not truly redundant but play important, specific, and potentially complementary roles during embryonic development.

scholarly journals Tooth wear development in the Australian Aboriginal dentition from Yuendumu: A longitudinal study

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0254151
Author(s):  
Jinyoung Lee ◽  
Sarah Fung ◽  
Robin Yong ◽  
Sarbin Ranjitkar ◽  
John Kaidonis ◽  
...  
Keyword(s):  
Mechanical Load ◽  
Tooth Wear ◽  
Human Populations ◽  
Childhood And Adolescence ◽  
Occlusal Contact ◽  
Australian Aboriginal ◽  
Masticatory Efficiency ◽  
Functional Tooth ◽  
Functional Context ◽  
Diet And Lifestyle

The analysis of dental wear, at both the microscopic and macroscopic scale, is one of the most widely used tools in archeology and anthropology to reconstruct the diet and lifestyle of past human populations. Biomechanical studies have indicated that tooth wear helps to dissipate the mechanical load over the crown surface, thus reducing the risk of tooth fracture. To date, there are only a few studies that have examined functional tooth wear variation in modern humans. Here we propose to study masticatory efficiency through the use of the Occlusal Fingerprint Analysis method, a well-developed digital approach that allows the reconstruction of the occlusal dynamics occurring during mastication. The aim of this study is to provide the first longitudinal quantitative data of molar and premolar macrowear patterns within a functional context. We examined the mixed and permanent dentition of one Australian Aboriginal child (from ages 8 to 17) from Yuendumu, using high-resolution surface scans of dental casts including both upper and lower arches. Our results suggest that the occlusal macrowear patterns of this individual did not significantly change through time. Occlusal contact parameters such as functional area, inclination and direction remain relatively unaltered throughout childhood and adolescence, indicating little change in the masticatory function of this individual. The functional tooth wear pattern in this individual did not change longitudinally indicating the degree of masticatory efficiency has most probably remained unaltered.

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