Final answer:
A sunken anterior fontanel in a 5-month-old is an abnormal finding that may indicate dehydration or malnutrition.
Step-by-step explanation:
A sunken anterior fontanel in a 5-month-old is an abnormal finding. The fontanels in a newborn's skull are large areas of fibrous connective tissue that allow for the growth and flexibility of the skull. The anterior fontanel is located at the top front of the skull and typically closes by 9 to 18 months after birth. A sunken anterior fontanel may indicate dehydration or malnutrition and should be evaluated by a healthcare professional.