May 23, 2005 (San Diego) -- Infants with smaller jaws may be at risk of experiencing problems with breathing, choking, or gagging, Boston researchers report.
"There was an association with smaller jaws and life-threatening events in these babies," says Mary Horn, RN, a nurse and respiratory therapist at Children's Hospital Boston. "What we suspect is that the tongue is falling back or there may be mucus in the airway in addition to a smaller mouth cavity. The jaw may be pushed further back during feeding."
J. Randall Curtis, MD, MPH, American Thoracic Society program chairman, says: "The smaller jaw size correlated to occurrence of life-threatening events. It appears that something occurs that further narrows the airways in infants whose airways may already be compromised."
The infants had experienced breathing problems during sleep, characterized by an episode of blueness in the face, loss of muscle tone, or choking and gagging for no apparent reason. The researchers noticed that all the infants had shorter jawbones than the 50 normal infants they studied.
After they evaluated four measurements of the lower jawbone, they found that babies who had suffered life-threatening events had jaws that were 3 millimeters shorter on the left side and 2.8 millimeters shorter on the right side than babies without life-threatening events.
Taking into account differences in infant size and age, the researchers found that babies who had life-threatening events had smaller jaws than the babies without life-threatening events, says Horn.
"What we suspect is that the tongue is falling back at a time when something else is happening," says Horn. "The baby may have mucus in the airway of the jaw that is being pushed back, further blocking off the airway due to pressure from breast feeding or bottle feeding. The infants don't have as much airway to breathe through."
To reduce the risk in babies with small jaws, mothers might sit them more upright when feeding or use a finger to pull the chin forward while feeding, she says. "This would allow more room."
"Life-threatening events do not happen with every baby with a small jaw," according to Horn. "But in babies with life-threatening events, every baby had a small jaw."
Horn said it may be that babies with short jaws without the life-threatening events have "not been placed in the situation that can push them over the edge. The mothers may be holding them in a position that prevents events."
It may be that infants -- as they grow and the jaw enlarges -- may outgrow the problem, she says.