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We report a genome-wide association study for facial features in > 6,000 Latin Americans. We placed 106 landmarks on 2D frontal photographs using the cloud service platform Face++. After Procrustes superposition, genome-wide association testing was performed for 301 inter-landmark distances. We detected nominally significant association (P-value − 8) for 42 genome regions. Of these, 9 regions have been previously reported in GWAS of facial features. In follow-up analyses, we replicated 26 of the 33 novel regions (in East Asians or Europeans). The replicated regions include 1q32.3, 3q21.1, 8p11.21, 10p11.1, and 22q12.1, all comprising strong candidate genes involved in craniofacial development. Furthermore, the 1q32.3 region shows evidence of introgression from archaic humans. These results provide novel biological insights into facial variation and establish that automatic landmarking of standard 2D photographs is a simple and informative approach for the genetic analysis of facial variation, suitable for the rapid analysis of large population samples.

Facial morphology, the most conspicuous feature of human appearance, is highly heritable. Previous studies on the genetic basis of facial morphology were mainly performed in European populations. Applying a proven data-driven phenotyping and multivariate genome-wide scanning protocol to the largest collection of 3D facial images of an East Asian population to date, we identified 244 leading variants associated with normal-range facial variation, of which 130 are novel. A newly proposed polygenic shape analysis indicates that the effects of the variants on East Asian facial shape can be generalized into the European population. Based on this analysis, we further identified 13 variants mainly related to differences between European and East Asian facial shape. Natural selection analyses suggest that the difference in European and East Asian nose shape is caused by a directional selection, mainly due to a local adaptation in Europeans. Our results expand the knowledge of human facial genetics and illustrates for the first time the underlying genetic basis for facial differences across populations.

Background Silver diamine fluoride (SDF) and sodium fluoride (NaF) are widely used for caries management. The objectives of this study are (i) to compare the caries-arresting and caries-preventive effects of SDF and NaF in young children, (ii) to determine children’s and parents’ acceptance of these fluoride therapies and (iii) to investigate the short-term (1 day) and long-term (1 year) adverse effects of these fluoride therapies. Methods/design This is a randomised, double-blind, active-controlled clinical trial to be conducted in Hong Kong kindergartens. The study has received approval from the local institutional review board. Written consent will be obtained from the parents/guardians before the study. The study will recruit at least 688 healthy 3-year-old children. This sample size is sufficient for an appropriate statistical analysis. Stratified randomisation will be performed for intervention allocation. The two intervention groups are 38% SDF and 5% NaF varnish applied on six primary upper anterior teeth. At baseline, one trained examiner will perform clinical examinations of the children in the kindergartens. The caries experience and oral hygiene status of each child will be recorded using the decayed, missing (due to caries) and filled primary tooth index and visual plaque index, respectively. Then, an independent operator will apply the assigned fluoride after the dental examinations. The examiner, the children and their parents will be blinded to the intervention allocation. In addition, a research assistant will evaluate the child’s acceptance using interval rating scales for children’s uncooperative behaviour. The examiner will then visit the children the next day to study the short-term potential adverse effects of the fluoride therapies. The same examiner will perform a follow-up examination after 1 year to evaluate the children’s caries experiences, their oral hygiene statuses and the adverse effects of the fluoride. Parental questionnaires will be used to assess parental satisfaction and concerns about the fluoride therapies. Discussion This study provides essential information about using SDF in an outreach kindergarten service for caries management from different aspects, which include the caries-arresting and caries-preventive effects, the adverse effects and children’s and parents’ acceptance. The success of the service can help to increase the adoption of SDF to reduce the global burden of early childhood caries. Trial registration ClinicalTrials.gov NCT04399369. Registered on May 2020

Background Lisu is an ethnic minority group living in Yunnan, a province in Southwest China. This study investigated the oral health status among 12-year-old Lisu children in Yunnan. Method: A multistage sampling method was adopted to recruit 12-year-old Lisu children from primary schools. A self-administrated questionnaire was distributed to the children to collect their sociodemographic background information and oral health-related behaviours. Two calibrated dentists performed the oral examinations in the primary schools. They examined dental caries, gingivitis and dental fluorosis using the diagnosis criteria recommended by the World Health Organization. A Chi-square test, the Mann-Whitney U test, zero-inflated negative binomial (ZINB) regression and multivariate logistic regression were used for statistical analysis. Results A total of 512 Lisu children were invited, and 482 children (48% boys) participated in the study (response rate: 94%). The caries prevalence was 35% and caries experience in mean (SD) DMFT scores was 0.63 (0.10). The mean (SD) DT score was 0.60 (1.10), consisting 95% of the mean DMFT scores. Gingivitis was found on 426 children (88%), while no dental fluorosis was observed. Results of ZINB model indicated sex and sugary-snacking habits were related to the dental caries experience (p