Incidence and clinical risk factors of Bednar's aphthae in Japanese newborns.

This is the first report of the prevalence of Bednar's aphthae among Japanese neonates. Vaginal delivery was identified as the strongest risk factor. Although confounding between mode of delivery and mechanical stimuli associated with sucking was not found in this study, the findings pave the way for a better understanding of the etiology of Bednar's aphthae.