Lower-face asymmetries may help identify early life stress

Research has repeatedly confirmed that the first 1,000 days after conception strongly influence a person's life expectancy and susceptibility to chronic diseases. The primary marker used to identify early life stress is low birth weight, which can, for instance, indicate poor nutrition of the mother during pregnancy.

But low birth weight is a marker only until birth, about 280 days -- far short of a measurement useful for the first thousand days.

New research from University of Washington investigators suggests that an asymmetric lower face is a novel marker that also captures early life stresses that occur after birth.

"Asymmetries in the skull and teeth have been used for decades by anthropologists to mark environmental stress, but they have only rarely been used in living populations," said Philippe Hujoel, the corresponding author. "Such lower-face asymmetries can be assessed by looking at the dental bite in the permanent teeth -- an exam that can be completed in seconds and with more certainty than a mother's recall of birth weight and more ease than a search for a birth certificate."

Backward-biting asymmetries, the most common lower-face asymmetry in the U.S. population, were found to fluctuate randomly between the left and right sides of the face. Such randomness is evidence for early life stress, he said.

Hujoel emphasized that crooked teeth, overbites and underbites are different than an asymmetric bite. Those conditions can be associated with asymmetric and symmetric bites, the latter of which is largely a reflection of genetics, not environmental stress, he said.

Hujoel, Erin Masterson and Anne-Marie Bollen researched data gathered from 1966 to 1970, a sample of 6,654 12- to 17-year-olds involved in a National Health Examination Survey. The study found that one in four of the U.S. adolescents had lower-face asymmetries.

"Lower-face asymmetries were common in a generation that became typified by an epidemic of diabetes and obesity in adulthood," noted Hujoel, an adjunct professor of epidemiology in the School of Public Health.

The team had to look back four decades for data because in the 1970's, he said, dental researchers in charge of designing U.S. surveys began to disregard the value of diagnosing facial asymmetry, and stopped taking those measurements.

"From a biological perspective, this decision resulted in an inability to reliably track trends in the U.S.," Hujoel said. "We don't have current information on the prevalence of lower-face asymmetries in the U.S. population."

Further research is needed to identify whether lower-face asymmetries are predictive of chronic diseases in living populations in the same way that skull asymmetries have been associated with degenerative diseases in long-deceased populations.

Comments

The opinions expressed here are the views of the writer and do not necessarily reflect the views and opinions of News Medical.
Post a new comment
Post

While we only use edited and approved content for Azthena answers, it may on occasions provide incorrect responses. Please confirm any data provided with the related suppliers or authors. We do not provide medical advice, if you search for medical information you must always consult a medical professional before acting on any information provided.

Your questions, but not your email details will be shared with OpenAI and retained for 30 days in accordance with their privacy principles.

Please do not ask questions that use sensitive or confidential information.

Read the full Terms & Conditions.

You might also like...
Brazilian research uncovers how liver nerves regulate glucose production under stress