This investigation used a multivariate survival model, which allowed for dependent caries data with possible censoring, to analyse the impact of timing of tooth emergence, gender and several reported oral hygiene and dietary habits on the incidence of cavity formation in permanent first molars (PFM) in young children. A 6-yr prospective oral health screening project in Flanders, Belgium, provided clinical and questionnaire data on 4,468 children. The results revealed that PFM in children who reported frequent brushing, who had no visible caries experience in the primary dentition, and who presented without occlusal plaque on the PFM had the best survival estimates. Girls had a higher incidence than boys of cavity formation in mandibular molars. The multiple survival analysis confirmed the major impact of the caries status of the deciduous dentition and self-reported oral hygiene habits on the incidence of cavities in permanent first molars.