Molar Intercuspal Dimensions: Genetic Input to Phenotypic Variation

@article{Townsend2003MolarID,
  title={Molar Intercuspal Dimensions: Genetic Input to Phenotypic Variation},
  author={G. C. Townsend and Lindsay C. Richards and Toby E Hughes},
  journal={Journal of Dental Research},
  year={2003},
  volume={82},
  pages={350 - 355}
}
Molecular studies indicate that epigenetic events are important in determining how the internal enamel epithelium folds during odontogenesis. Since this process of folding leads to the subsequent arrangement of cusps on molar teeth, we hypothesized that intercuspal distances of human molar teeth would display greater phenotypic variation but lower heritabilities than overall crown diameters. Intercuspal distances and maximum crown diameters were recorded from digitized images of dental casts in… Expand
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Carabelli's trait and tooth size of human maxillary first molars.
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References

SHOWING 1-10 OF 28 REFERENCES
Genetic and environmental contributions to variation in human tooth size
TLDR
There were significant levels of non-additive genetic variation in MD diameters of canines and first premolars, which is consistent with selective pressures acting on these teeth at some stage in human evolution. Expand
Intercuspal Distances of Maxillary Pre-molar Teeth in Australian Aboriginals
  • G. Townsend
  • Biology, Medicine
  • Journal of dental research
  • 1985
TLDR
It appears that the sex differences, which are observed in overall crown dimensions, are established after the cusp tips are localized, and intercuspal distances appear to have a strong genetic component of variability, although they show high phenotypic variability and fluctuating asymmetry. Expand
Genetic analysis of deciduous tooth size in Australian twins.
TLDR
This study shows that variation in deciduous crown size has a strong genetic component, similar to that observed in the permanent dentition, and a model incorporating additive genetic and unique environmental variation was found to be the most parsimonious for all tooth-size variables. Expand
Individual variation in enamel structure of human mandibular first premolars.
  • D. Stern, Z. Skobe
  • Materials Science, Medicine
  • American journal of physical anthropology
  • 1985
TLDR
It was concluded that within this tooth type, there is a large amount of individual variation not only in gross morphology but also in enamel ultrastructure, which underscores the fact that interspecific comparisons must be made with care. Expand
Genotype, phenotype, and developmental biology of molar tooth characters.
TLDR
The whole cusp pattern is a product of a dynamic developmental program manifested in the activation of the developmental modules, and this patterning cascade mode of cusp development can be used to explain the variational properties of dental characters and character states related to cusp initiation. Expand
Model for the examination of evolutionary trends in tooth development.
TLDR
Serial C-t scans were used to compare two distinct developmental stages represented by the dentine-enamel junction (DEJ) and outer enamel surface (OES), respectively, in mandibular DM2 and M1 of 31 archaeological specimens, supporting the hypothesis that differences between the two teeth increase throughout development. Expand
Reiterative signaling and patterning during mammalian tooth morphogenesis
TLDR
The advancing tooth morphogenesis is punctuated by transient signaling centers in the epithelium corresponding to the initiation of tooth buds, tooth crowns and individual cusps, which could have allowed the evolutionary divergence of tooth shapes among the four tooth types. Expand
A gene network model accounting for development and evolution of mammalian teeth
TLDR
Large morphological effects frequently can be achieved by small changes, according to this model, and similar morphologies can be produced by different changes, consistent with why predicting the morphological outcomes of molecular experiments is challenging. Expand
Morphologic Relationships Between Enamel and Dentin Surfaces of Lower First Molar Teeth
  • B. S. Kraus
  • Biology, Medicine
  • Journal of dental research
  • 1952
TLDR
In order to ascertain whether or not complete topical and metrical correspondences exist between the enamel and dentin surfaces, a study was made of 50 lower first molars, and it was assumed that the daily rate of formation of enamel proceeds uniformly throughout theEnamel crown. Expand
Three-dimensional measurement of the morphological relationship between molar occlusal surface and enamel-dentin junction
The occlusal surfaces of lower molars and their enamel-dentin junction (EDJ) were photographed by means of moire contourography. Three-dimensional measurements were obtained from these photographs to… Expand
...
1
2
3
...