Enamel thickness in 47, XYY males' permanent teeth

Abstract

Enamel thickness of the maxillary permanent central incisors and canines in 14 47,XYY males, their male and female relatives and population-control males and females were determined from radiographs. The results indicated, although not fully unambiguously, that the thickness of enamel and that of 'dentin' (distance between mesial and distal dentino-enamel junctions) are increased in the teeth of 47,XYY males compared with normal controls. Earlier results have indicated a direct growth-promoting effect of the Y chromosome on tooth growth by influencing both enamel formation and, possibly through cell proliferations, growth of dentin. The present results can be considered additional evidence for the presence of the factors within the Y chromosome controlling different growth processes. Tooth size measurements in two males with deletions of the parts of the y chromosome suggested that there may be a specific growth-promoting gene(s) in the non-fluorescent part of the long arm. It is suggested that the way of influence of the Y chromosome on the amelogenesis is regulatory, and that the difference in tooth size between males and females is explained by a differential growth-promoting effect of the Y chromosome compared to the X chromosome.

Altering Biomineralization by Protein Design

“…With such extensive degradation of the organic matrix inextricably linked with biomineralization, a relationship with the lysosomal compartment of the ameloblast as exemplified by CD63 is likely to accompany these events. Moreover, the cell signals that are initiated through such membrane-anchored receptor-ligand events may also be important to monitor synthesis of the matrix because enamel thickness is recognized as a regulated event determined by species as well as by gender (61,62). For the mice in this study with either of the two engineered replacement amelogenin proteins, the change to such signals appears to result in reduced enamel thickness (supplemental Fig.…”

Estimation of remaining dentine thickness below deep lesions of caries

“…This method has been used in other studies for measuring tooth dimensions, for example enamel. 22 It may be argued that this may magnify the measurements but this will be the case for all measurements. This basic method of measurement was chosen as it can be replicated easily in an unmodified practice setting.…”

“…1d) was measured directly on the tooth using a clear plastic ruler. 22 Measurements were taken from the thinnest point of remaining dentine on the floor of the lesion to the pulp dentine border 8 to the nearest 0.5 mm.…”

Integrating the genotype and phenotype in hominid paleontology

“…Disruptions in these genes result in enamel mineralization pathologies such as amelogenesis imperfecta (AI) (110). Abnormalities in actual enamel thickness are associated with variations in the number of sex chromosomes (111)(112)(113)(114)(115). However, many versions of AI show inheritance patterns consistent with the localization of major loci on autosomes (116)(117)(118)(119)(120) and nonpathological primate enamel thickness variation is not sexually dimorphic (44,115,121).…”