A mother's emotional health and education level during her child's earliest years influence oral health at age 14, says a new study.

Researchers at the Case Western Reserve University, US, started with the oral health of the teenagers and worked backwards to age three to find out what factors in their past influenced their oral health outcomes.

While mothers were interviewed, lead investigator Suchitra Nelson, professor of community dentistry at the Case Western Dental School, believes it can apply to whoever is the child's primary caregiver, the Journal of Dental Research reports.

Nelson's team examined the teeth of 224 adolescent participants in a longitudinal study that followed very low birth weight and normal birth weight children.

Over the years, researchers gathered health and medical information from the children and their mothers to assess the child's wellbeing at age three, eight and now 14 years.

Researchers analysed the teen's oral health by counting the number of decayed, filled or missing permanent teeth and assessed the level of dental plaque, a symptom for poor oral hygiene, according to a Case Western statement.

Mothers completed a questionnaire about preventative treatments from sealants to mouthwashes, sugary juice or soft drink consumption and access to dental care and frequency of dental visits.

The data revealed that even with access to dental insurance, fluoride treatments and sealants as young children, it did not always prevent cavities by the age of 14, said Nelson.