Can early-life family income influence lifelong dental pain?

Lower socioeconomic status is known to negatively affect various health outcomes, but scant information is available on its relationship to dental pain. To learn more, researchers of a new study investigated the effects of family income early in life and parental education on dental pain in adulthood.

The researchers analyzed data from two previous oral health studies of children to explore the relationship between their family's income and their experience of dental pain later in life. They found that there was indeed a connection between socioeconomic disadvantage early in life and dental pain incidence. The results implied that improving socioeconomic status might decrease the chances of experiencing dental pain throughout a patient's lifetime, according to the study authors.

"Relative socioeconomic disadvantage at early life might not only influence dental pain experience at early life but may also affect dental pain into adulthood," they wrote in the Australian Dental Journal (May 30, 2017).

The study was conducted by Zahra Ghorbani, PhD, who was previously a postdoctoral research associate at the Australian Research Centre for Population Oral Health at the University of Adelaide in Australia, and her colleagues at the center. She is currently an assistant professor of community oral health at Shahid Beheshti University of Medical Sciences in Tehran, Iran.

Money changes everything

People with lower socioeconomic levels appear to experience greater morbidity and mortality because of a range of health outcomes. Socioeconomic position or status during childhood and adolescence may affect environmental exposures at home, in neighborhoods, and at school that may influence adult health later through psychological, behavioral, or physiological pathways, studies have found.

Dental pain is a highly prevalent and preventable public health problem, but little research is available on how socioeconomic conditions during childhood may affect this pain throughout life. Since family income has been used in some studies as an indicator of socioeconomic status, the authors of the current study analyzed data from two previous studies and sought to determine whether family income early in life affects the experience of dental pain in adulthood.

They started with data from the Child Fluoride Study, a prospective cohort study conducted in South Australia with a random sample of 9,875 children ages 4 to 17 years. As part of this study, the children underwent clinical oral examinations, and their parents completed questionnaires in 1991 through 1992. Researchers of the follow-up Life Course study were able to track down 7,678 of the original participants (76.7%) 14 years later and sent these participants another questionnaire, of which 2,466 completed and returned. The participants were later asked to undergo a clinical oral examination in 2007 through 2008.

The researchers of those studies collected data on dental pain experience for each study participant at three times: baseline, follow-up, and a midpoint of time, referred to as the index age obtained at the follow-up questionnaire. This was age 13 for those 4 to 8 years at baseline, age 17 for those 9 to 12 years at baseline, and age 21 for those 13 to 17 years at baseline.

At baseline, parents were asked: "Has your child ever had toothache?" In the follow-up study, participants were asked, "Have you had a toothache in the last 12 months?" and "As best as you can recall, did you ever have a toothache in your 'index age'?"

The first study included data on family income obtained from parents at baseline. Those with a household income in the lowest third ($25,000 Australian or less per year) were classified as poor. The researchers also collected data at baseline on the highest level of education attained by both parents as an indicator of socioeconomic status and data on the oral health habits of the child.

At baseline, the mean age of the children was 9.5 years, with more than 40% between the ages of 4 and 8, more than 38% were between 9 and 12 years, and just over 20% were between 13 and 17 years. Almost 48% participants in the study were female, and almost 28% were classified as poor at baseline.

Additional baseline data indicated that more than 40% of children brushed their teeth at least twice a day, 55.5% of them had started brushing before age 1, and more than 19% had visited a dentist by age 3. In terms of education status, more than 23% of the parents had some college or university education.

Dental pain was experienced by 22.8% of participants at baseline, and pain was more prevalent among those who were female, those whose parents did not have at least some university education, and those who brushed their teeth less frequently as children.

Among the 2,426 participants with follow-up data, 35.6% were poor at baseline. Dental pain was more prevalent at all three time points among those who were poor, with 19.3% reporting dental pain at their index age and 39.3% in the 12 months prior to completing the follow-up questionnaire. Those from poor families had 51% greater odds of experiencing lifetime dental pain or 45% after adjusting for covariates.

"The findings from this prospective study in South Australia showed that early-life family income is associated with dental pain experience across a 14-year period," wrote the authors of the current study.

They explained that children who grow up in poor families are more likely to be raised in poor housing conditions in crowded and less affluent areas and to attend lower quality schools.

"All these situations can influence a child's emotional, social, behavioral, and physical development, which can, in turn, compromise their overall, as well as their oral, health," they wrote.

How to reduce pain

The authors acknowledged some limitations of their study. These include that it would be better to have a more narrowly defined birth cohort to better explore the exact timing of socioeconomic status and oral health outcomes, and loss to follow-up is a problem in prospective cohort studies.

Nonetheless, the results provide some implications about how changes in socioeconomic status may affect dental pain.

"Improving socioeconomic circumstances in childhood and adolescence could decrease lifetime dental pain experience," the authors concluded. "This could, in turn, improve oral health-related quality of life, reduce time lost from school or work due to dental pain, and thereby improve societal productivity."