Autotransplantation with a 3-dimensionally printed replica of the donor tooth minimizes extra-alveolar time and intraoperative fitting attempts: a multicenter prospective study of 100 transplanted teeth

Purpose: Three-dimensional (3D) autotransplantation is a technique for surgical transposition of a tooth to another site within one patient, using 3D printed replicas of the donor tooth. In this study, we evaluated intraoperative experiences during 3D autotransplantation of teeth.Materials and Methods: A multicenter prospective clinical study was implemented. All procedures were performed using preoperative cone-beam computed tomography imaging and computer-assisted design with computer-assisted manufacturing resulting in a 3D replica of the donor tooth.Results: The 100 autotransplantation procedures (79 patients) included canines, premolars, molars, and 1 supernumerary tooth. In 82% of the procedures, the transplantation was performed with an extra-alveolar time of less than 1 minute and an immediate good fit of the donor tooth. In 14%, the extra-alveolar time was 1 to 3 minutes or multiple fitting attempts were necessary. In 4%, the extra-alveolar time exceeded 3 minutes. Difficulties during the procedures were caused by movement artifacts on the preoperative cone-beam computed tomography imaging, a long interval between the imaging and the procedure, or insufficient bone volume at the recipient site.Conclusions: The use of a 3D printed donor tooth replica during autotransplantation procedures minimized the extra-alveolar time and intraoperative fitting attempts of transplants. This facilitated a quick and reliable treatment and enabled more difficult procedures. (C) 2019 American Association of Oral and Maxillofacial Surgeon

Meta-analysis of Genome-Wide Association Studies for Extraversion: Findings from the Genetics of Personality Consortium

Extraversion is a relatively stable and heritable personality trait associated with numerous psychosocial, lifestyle and health outcomes. Despite its substantial heritability, no genetic variants have been detected in previous genome-wide association (GWA) studies, which may be due to relatively small sample sizes of those studies. Here, we report on a large meta-analysis of GWA studies for extraversion in 63,030 subjects in 29 cohorts. Extraversion item data from multiple personality inventories were harmonized across inventories and cohorts. No genome-wide significant associations were found at the single nucleotide polymorphism (SNP) level but there was one significant hit at the gene level for a long non-coding RNA site (LOC101928162). Genome-wide complex trait analysis in two large cohorts showed that the additive variance explained by common SNPs was not significantly different from zero, but polygenic risk scores, weighted using linkage information, significantly predicted extraversion scores in an independent cohort. These results show that extraversion is a highly polygenic personality trait, with an architecture possibly different from other complex human traits, including other personality traits. Future studies are required to further determine which genetic variants, by what modes of gene action, constitute the heritable nature of extraversion

The genetics of complex human behaviour: Cannabis use, personality, sexuality and mating

Item does not contain fulltextI investigated the genetic and environmental etiology of individual differences in a variety of complex human behaviours, broadly captured within three domains - 1) cannabis use, 2) personality, and 3) sexuality and mating. Research questions and hypotheses are addressed with large community-based, genetically informative datasets and various methodological and statistical approaches. Section I focuses on the genetics of cannabis use. By meta-analysing existing twin studies I determined more precisely the relative contributions of genes and environment on individual differences in cannabis use and abuse. For cannabis use initiation I found a heritability estimate of 48% in males and 40% in females. For problematic cannabis use the heritability estimates were 51% and 59% for males and females. I then performed a gene-based association test on a large sample to test for genetic association between ten previously reported candidate genes and lifetime frequency of cannabis use. None of the candidate genes reached even nominal significance, which may point to our limited understanding of the neurobiology of cannabis use and also to potential publication bias and false-positive findings in previous studies. To identify potential new genetic variants underlying cannabis use, I then meta-analysed results from two large genome-wide association studies for cannabis use initiation. I did not identify any genetic variant significantly contributing to cannabis use initiation. Furthermore, I estimated that only approximately 6% of variance in cannabis initiation is due to common genetic variants. This suggests that non-additive effects, and/or rare mutations may also play a role in cannabis use vulnerability. Section II focuses on personality traits, which are known to be moderately heritable. I performed the first genome-wide association study on Cloninger’s personality traits to identify genetic variants underlying personality, followed by a meta-analysis of four genome-wide association studies. I also performed gene-based association tests and investigated if genes in specific biological pathways showed elevated association with personality traits. Additionally, I performed a genetic prediction analysis to test if the aggregated effects of common variants obtained from genome-wide association results from a discovery sample could predict personality in another sample. In both studies no genetic variants or pathways were found to be significantly related to any personality trait, nor could the genetic prediction scores explain a substantial part of the variation in any personality dimension. Our findings indicate that individual common genetic variants with an effect size of more than ~0.5% do not contribute to personality variation, which has important implications regarding the genetic architecture of personality and the evolutionary mechanisms by which heritable variation is maintained. In the next study, I tested these different evolutionary mechanisms by estimating the percentage of the genetic variation underlying personality attributable to the combined effect of common variants by using a newly developed methodology utilising genome-wide single nucleotide polymorphism data; I also investigated whether inbreeding affects personality. I estimated that little variation in the personality traits is due to the combined effect of common, additive genetic variants, suggesting that most heritable variation in personality is due to rare variant effects and/or some combination of dominance and epistasis. Furthermore, higher levels of inbreeding were associated with less socially-desirable personality trait levels in three of the four personality dimensions. These findings are consistent with genetic variation in personality traits having been maintained by mutation-selection balance. Section III focuses on human sexuality and mating. By employing the classical twin design, I found that individual differences in risky sexual behaviour are influenced to the same extent by genes, shared environment and residual influences. Moreover, risky sexual behaviour is associated with adolescent misconduct in other domains, primarily because of genetic correlation between the variables. I then investigated the etiology of elevated lifetime depression rates in homosexuals and bisexuals as compared to heterosexuals in a genetically informative sample. Analyses revealed that genetic factors account for the majority of the correlation between sexual orientation and depression. In addition, childhood sexual abuse and risky family environment were also significant predictors of both sexual orientation and depression, further contributing to their correlation. The last three studies investigated the genetic and environmental influences on human mate preferences and realised choices on a wide variety of physical and behavioural traits. Mate preferences showed substantial heritability, whereas for realised mate-choice the average heritability was near-zero. I also found that mate choice is not significantly influenced by sexual imprinting, where individuals acquire mate-choice criteria by using their opposite-sex parent as the template of a desirable mate. The main detectable pattern of mate choice was assortative mating, which I showed is likely due to both phenotypic matching (choosing a partner based on their self-similarity) and social homogamy (choosing a partner from within one’s social group, which includes individuals who tend to be self-similar). Following the empirical papers, I provide a general discussion in which I summarise the findings and their implications, mention potential limitations of the research, and suggest directions for future research.School of Psychology, University of Queensland, Brisbane, Australia in collaboration with the Queensland Institute of Medical Research, 11 mei 2012Promotores : Martin, N.G., Boomsma, D.I., Medland, S.E.324 p

No evidence for genetic assortative mating beyond that due to population stratification

Contains fulltext : 155932.pdf (publisher's version ) (Open Access)1 p

Systematic review of polygenic gene-environment interaction in tobacco, alcohol, and cannabis use

Contains fulltext : 204120.pdf (publisher's version ) (Open Access)Studies testing the effect of single genetic variants on substance use have had modest success. This paper reviewed 39 studies using polygenic measures to test interaction with any type of environmental exposure (GxE) in alcohol, tobacco, and cannabis use. Studies using haplotype combinations, sum scores of candidate-gene risk alleles, and polygenic scores (PS) were included. Overall study quality was moderate, with lower ratings for the polygenic methods in the haplotype and candidate-gene score studies. Heterogeneity in investigated environmental exposures, genetic factors, and outcomes was substantial. Most studies (N = 30) reported at least one significant GxE interaction, but overall evidence was weak. The majority (N = 26) found results in line with differential susceptibility and diathesis-stress frameworks. Future studies should pay more attention to methodological and statistical rigor, and focus on replication efforts. Additional work is needed before firm conclusions can be drawn about the importance of GxE in the etiology of substance use.17 p

Behavioural genetic analyses of mate preferences and preferred traits: Testing models of mate choice and sexual selection

Item does not contain fulltextBehavior Genetics Association 42nd Annual Meeting Abstracts1 p

Testing the prediction from sexual selection of a positive genetic correlation between human mate preferences and corresponding traits

Item does not contain fulltextSexual selection can cause evolution in traits that affect mating success, and it has thus been implicated in the evolution of human physical and behavioural traits that influence attractiveness. We use a large sample of identical and nonidentical female twins to test the prediction from mate choice models that a trait under sexual selection will be positively genetically correlated with preference for that trait. Six of the eight preferences we investigated, i.e. height, hair colour, intelligence, creativity, exciting personality, and religiosity, exhibited significant positive genetic correlations with the corresponding traits, while the personality measures 'easy going' and 'kind and understanding' exhibited no phenotypic or genetic correlation between preference and trait. The positive results provide important evidence consistent with the involvement of sexual selection in the evolution of these human traits.5 p

Riflessioni sul telelavoro

Item does not contain fulltextSexual selection can cause evolution in traits that affect mating success, and it has thus been implicated in the evolution of human physical and behavioural traits that influence attractiveness. We use a large sample of identical and nonidentical female twins to test the prediction from mate choice models that a trait under sexual selection will be positively genetically correlated with preference for that trait. Six of the eight preferences we investigated, i.e. height, hair colour, intelligence, creativity, exciting personality, and religiosity, exhibited significant positive genetic correlations with the corresponding traits, while the personality measures 'easy going' and 'kind and understanding' exhibited no phenotypic or genetic correlation between preference and trait. The positive results provide important evidence consistent with the involvement of sexual selection in the evolution of these human traits.5 p