Genetic, environmental and epigenetic influences on variation in human tooth number, size and shape

Abstract

The aim of this review is to highlight some key recent developments in studies of tooth number, size and shape that are providing better insights into the roles of genetic, environmental and epigenetic factors in the process of dental development. Advances in molecular genetics are helping to clarify how epigenetic factors influence the spatial and temporal regulation of the complex processes involved in odontogenesis. At the phenotypic level, the development of sophisticated systems for image analysis is enabling new dental phenotypes to be defined. The 2D and 3D data that are generated by these imaging systems can then be analysed with mathematical approaches, such as geometric morphometric analysis. By gathering phenotypic data and DNA from twins, it is now possible to use 'genome-wide' association studies and the monozygotic co-twin design to identify important genes in odontogenesis and also to clarify how epigenetic and environmental factors can affect this process. Given that many of the common dental anomalies affecting the human dentition are interrelated, apparently reflecting pleiotropic genetic effects, the discoveries and new directions described in this paper should have important implications for clinical dental practice in the future.

Deciduous dentition and dental eruption of Hyainailouroidea (Hyaenodonta, “Creodonta,” Placentalia, Mammalia)

“…Deciduous dental morphology is heritable in mammals (Hughes et al, 2000;Townsend et al, 2012) and is a rich source of phenotypic character information. The character-taxon matrix is an expansion of hyanodonts sampled by Borths et al (2016), and Borths and Stevens (2017), building upon previous work by Polly (1996), Zack (2011), andSolé et al (2014), adding additional characters of the deciduous dentition (14 deciduous, 148 total), and expanding the OTUs (84 total).…”

Avances en La Genética De La Formación Dental: Una Revisión

“…Diversos autores afirman que alrededor de trescientos genes se encuentran implicados en el proceso de odontogénesis 5,6 ; estos juegan un papel importante en la codificación de factores de transcripción, factores de crecimiento, moléculas de la matriz extracelular y en la comunicación celular. Algunas de las vías de señalización genética involucradas en dicha comunicación incluyen el Factor de Crecimiento de Fibroblastos (FGF) y proteínas morfo genéticas (BMP).…”

“…De igual forma, sugirieron que el desarrollo de incisivos se presenta debido a los genes MSX 21 . De modo que la etapa de iniciación es crítica en determinar el número de dientes que se formarán y garantiza que los diferentes tipos de dientes, incisivos, caninos, premolares y molares se desarrollen en las regiones apropiadas dentro de la cavidad bucal 5,6 . Es así como las diversas investigaciones muestran la necesidad de una relación equilibrada y sinérgica entre el epitelio y mesénquima.…”

“…El primero con origen en el ectodermo y los dos últimos con origen en el ectomesenquima. Histológicamente en el órgano del esmalte se pueden distinguir el epitelio externo, retículo estrellado y el epitelio interno compuesto por células cilíndri-cas bajas que se diferenciarán en ameloblastos 5,13 . Algunos autores manifiestan que durante la morfogénesis, el control del tamaño y la forma de cada diente dependerá del nudo primario del esmalte.…”

Dental microevolution in Portuguese Neolithic and modern samples using an alternative morphometric analysis

“…Jernvall and colleagues reported a disparity in adult tooth morphology, related to differences in gene expression in the developing tooth bud (Jernvall and Jung, 2000;. Later on, many protein-coding genes, such as EDA, EDAR, HOXB2 or IGFBP1, have been identified as being involved in dental development and cusp formation, number and position (Kangas et al, 2004;Kassai et al, 2005;Townsend et al, 2012). This multigenic signalling works as a patterning cascade of events in the formation of the various molar cusps, relying on precise temporal and spatial control for its development (Jernvall, 2000;Jernvall and Jung, 2000;Boccone and Moggi Cecchi, 2010).…”