title: Influence of metabolic-linked early life factors on the eruption timing of the first primary tooth.
abstract: OBJECTIVE
  Early eruption of permanent teeth has been associated with childhood obesity and diabetes mellitus, suggesting links between tooth eruption and metabolic conditions. This longitudinal study aimed to identify pre-, peri- and postnatal factors with metabolic consequences during infancy that may affect the eruption timing of the first primary tooth (ETFT) in children from an ethnically heterogeneous population residing within the same community.
  
  
  METHODS
  Participants were recruited (n = 1033) through the GUSTO (Growing Up in Singapore Towards healthy Outcomes) birth cohort (n = 1237). Oral examinations were performed at 3-month intervals from 6 to 18 months of age. Crude and adjusted analyses, with generalized linear modelling, were conducted to link ETFT to potential determinants occurring during pregnancy, delivery/birth and early infancy.
  
  
  RESULTS
  Overall mean eruption age of the first primary tooth was 8.5 (SD 2.6) months. Earlier tooth eruption was significantly associated with infant's rate of weight gain during the first 3 months of life and increased maternal childbearing age. Compared to their Chinese counterparts, Malay and Indian children experienced significantly delayed tooth eruption by 1.2 and 1.7 months, respectively.
  
  
  CONCLUSIONS
  Infant weight gain from birth to 3 months, ethnicity and maternal childbearing age were significant determinants of first tooth eruption timing. Early life influences can affect primary tooth development, possibly via metabolic pathways.
  
  
  CONCLUSIONS
  Timing of tooth eruption is linked to general growth and metabolic function. Therefore, it has potential in forecasting oral and systemic conditions such as caries and obesity.
authors.affiliation: Discipline of Oral Sciences, Faculty of Dentistry, National University of Singapore, Singapore, Singapore.
authors.forename: Carolina
authors.initials: C
authors.lastname: Un Lam
authors.affiliation: Discipline of Oral Sciences, Faculty of Dentistry, National University of Singapore, Singapore, Singapore. denhsus@nus.edu.sg.
authors.forename: Chin-Ying Stephen
authors.initials: CS
authors.lastname: Hsu
authors.affiliation: Discipline of Oral Sciences, Faculty of Dentistry, National University of Singapore, Singapore, Singapore.
authors.forename: Robert
authors.initials: R
authors.lastname: Yee
authors.affiliation: Saw Swee Hock School of Public Health, National University of Singapore, Singapore, Singapore.
authors.forename: David
authors.initials: D
authors.lastname: Koh
authors.affiliation: Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
authors.forename: Yung Seng
authors.initials: YS
authors.lastname: Lee
authors.affiliation: Singapore Institute for Clinical Sciences, Agency for Science and Technology Research (A*STAR), Brenner Centre for Molecular Medicine, Singapore, Singapore.
authors.forename: Mary Foong-Fong
authors.initials: MF
authors.lastname: Chong
authors.affiliation: Discipline of Oral Sciences, Faculty of Dentistry, National University of Singapore, Singapore, Singapore.
authors.forename: Meijin
authors.initials: M
authors.lastname: Cai
authors.affiliation: Department of Maternal Fetal Medicine, KK Women's and Children's Hospital (KKH), Singapore, Singapore.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Kwek
authors.affiliation: Discipline of Oral Sciences, Faculty of Dentistry, National University of Singapore, Singapore, Singapore.
authors.forename: Seang Mei
authors.initials: SM
authors.lastname: Saw
authors.affiliation: Medical Research Council Lifecourse Epidemiology Unit and NIHR Southampton Biomedical Research Centre, University of Southampton and University Hospital Southampton NHS Foundation Trust, Southampton, UK.
authors.forename: Keith
authors.initials: K
authors.lastname: Godfrey
authors.affiliation: Discipline of Oral Sciences, Faculty of Dentistry, National University of Singapore, Singapore, Singapore.
authors.forename: Peter
authors.initials: P
authors.lastname: Gluckman
authors.affiliation: Department of Obstetrics and Gynaecology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
authors.forename: Yap Seng
authors.initials: YS
authors.lastname: Chong
mesh_terms: D005006:Ethnicity; D005260:Female; D006801:Humans; D007223:Infant; D008137:Longitudinal Studies; D008297:Male; D008423:Maternal Age; D012307:Risk Factors; D012846:Singapore; D013997:Time Factors; D014078:Tooth Eruption; D014094:Tooth, Deciduous; D015430:Weight Gain
keywords: Birth; Infancy; Metabolic links; Pregnancy; Primary dentition; Tooth eruption