Influence of genetic and environmental factors on oral diseases and function in aged twins

Abstract

This study was conducted to quantify the genetic and environmental contributions to oral disease and function in twins. Participants were middle-aged and old twins, 116 monozygotic and 16 dizygotic pairs whose mean age was 66·1 ± 10·3 (SD) years. Number of teeth, percentage of decayed, filled and missing teeth and periodontal status were recorded as indicators of oral disease. The widths of upper and lower dental arch served as indicators of morphological figures. Furthermore, stimulated salivary flow rate, occlusal force and masticatory performance were measured as indicators of oral function. Univariate genetic analysis with monozygotic and dizygotic twin pairs was conducted to detect the fittest structural equation model of each outcome. Both number of teeth and periodontal status fitted the model composed of common environmental factor and unique environmental factor. Decayed, filled and missing teeth, morphological figures and measurements of oral function fitted the model composed of additive genetic factor and unique environmental factor. The model fitting of each measurement suggested that periodontal disease was mainly affected by environmental factors, while morphological figures and oral functions were influenced by both genetic and environmental factors.

State of Dentition Among Twins Considering the Influence of Genetic and Environmental Factors: The Systematic Review of the Literature

“…Similar results were achieved by Lovelina et al [7], who in their studies of 9 pairs of identical twins and 21 pairs of fraternal twins revealed a higher correlation of occurrence of dental caries and periodontal diseases in the case of the first group of subjects. Different results were achieved by Kurushima et al [6], probably because of the relatively higher age of patients, and as a consequence, a higher influence of the environmental component, which was defined as the main component connected with the periodontium and coexisting with genetic component -in the case of dental caries.…”

“…The researched works confirmed that a genetic component has an influence on the appearance of multifactoral diseases, such as teeth caries [7,8] or periodontitis [7,9]. However, they are not excluded from environmental factors, the importance of which was proved by Ooi et al [10] and Kurushima et al [6].…”

“…Monozygotic twins share 100% of genetic material, while dizygotic twins usually share about 50% of genes originated from parents [6]. If a significantly larger level of compatibility is reached in the case of identical twins, heredity of the given feature may be concluded.…”

“…Identical twins (monozygotic) are characterized by the genetic material shared in 100%, and consequently, the variability of features among individual pairs arises from diverse influences of the environment. Fraternal twins (dizygotic) share a set of genes derived from parents only partially, but they used to have a common environment in terms of birth delivered in the same time and place [6,7]. The most significant and known research of that type, which touches upon the biggest number of dental issues, is the project conducted for over 30 years by Australian researchers from the Medical University in Adelaide [4].…”

Assessment of CASP gene polymorphisms in periodontal disease

“…A study of self-reported periodontal disease in a Virginia twin population showed the key role of genetic factors for adult-onset periodontal disease risk (Corey et al, 1993), and oral morphology and function have been observed to be influenced by genetic components (Kurushima et al, 2015). Furthermore, data from twin studies indicate that both genetic and environmental circumstances affect periodontal disease (Michalowicz, 1994).…”