Not your average baby teeth
It's not entirely unusual for a 4-month-old baby to have a few teeth, unless those teeth are lodged in the baby's brain.
An infant in Maryland had teeth form in his brain as a result of a specific type of rare brain tumor. Doctors were able to remove the tumor and the boy made a full recovery, according to a report published in the New England Journal of Medicine in February 2014.
Doctors suspected something might be going on inside the boy's brain when his head appeared to grow faster than was usual for his age. A scan of the child's brain revealed a tumor that contained what looked like teeth normally found in the lower jaw. And indeed, when doctors removed the tumor they extracted several fully formed teeth with it.
While teeth do sometimes appear in tumors, the type of tumor removed from the infant's brain — a craniopharyngioma — wasn't known to host these strange additions.