Genetic aspects of dental disorders

Abstract

This paper reviews past and present applications of quantitative and molecular genetics to dental disorders. Examples are given relating to craniofacial development (including malocclusion), oral supporting tissues (including periodontal diseases) and dental hard tissues (including defects of enamel and dentine as well as dental caries). Future developments and applications to clinical dentistry are discussed. Early investigations confirmed genetic bases to dental caries, periodontal diseases and malocclusion, but research findings have had little impact on clinical practice. The complex multifactorial aetiologies of these conditions, together with methodological problems, have limited progress until recently. Present studies are clarifying previously unrecognized genetic and phenotypic heterogeneities and attempting to unravel the complex interactions between genes and environment by applying new statistical modelling approaches to twin and family data. Linkage studies using highly polymorphic DNA markers are providing a means of locating candidate genes, including quantitative trait loci (QTL). In future, as knowledge increases; it should be possible to implement preventive strategies for those genetically-predisposed individuals who are identified to be at risk.

Genes and Gene Polymorphisms Associated with Periodontal Disease

“…Linkage studies have been particularly effective in identifying the genetic basis of Simple Mendelian traits (OMIM, 2000). Linkage studies of complex genetic traits have not been as successful for a variety of reasons (Townsend et al, 1998;Glazier et al, 2002). A limiting factor for the traditional application of linkage to complex diseases includes the fact that complex diseases are due to the combined effects of "multiple genes of minor effect".…”

The Western Australian Register of Childhood Multiples: Effects of Questionnaire Design and Follow-up Protocol on Response Rates and Representativeness

“…In Australia, the Australian Twin Registry (ATR), established in the late 1970s, contains information on over 30,000 twin pairs (Hopper, 2002). It is a volunteerbased register of twins of all ages across all Australian states, and has been used as a sampling frame for research into a wide range of health-related conditions, for example, asthma (Duffy et al, 1990), breast cancer (Boyd et al, 2002), bone density (Hopper et al, 1998), rheumatoid arthritis (Bellamy et al, 1992), dental disorders (Townsend et al, 1998), baldness (Ellis et al, 1998), attention-deficit/hyperactivity disorder (ADHD) (Levy et al, 1997), cardiovascular diseases (Harrap et al, 2000), and melanoma (Zhu et al, 1999). However, the voluntary nature of the register could lead to problems of non-generalizability for some studies, because the expression of many of the conditions of interest to public health research are strongly influenced by factors such as social class, which also modulate response to voluntary data collection (Heath et al, 2001).…”

Jumeaux et héritabilité des phénotypes dento-faciaux

“…La morphologie des surfaces occlusales serait fortement sous influence génétique [23,58,59], la similarité de taille et de contours, analysée par informatique et traitement statistique, montrant une nette différence dans la comparaison de jumeaux MZ avec des jumeaux DZ et des sujets non apparentés [21]. Certaines particularités anatomiques (tubercule de Carabelli, taurodontisme, talon cingulaire) ou des anomalies morphologiques (gemination, fusion, dens in dente, dent conoïde.…”

“….) ont donné lieu à des rapports de cas chez des jumeaux MZ, ce qui renforce l'idée d'une transmission géné-tique [26,44,55,58,59]. …”