Which statement about pediatric sinus development is true?

Which statement about pediatric sinus development is true?

• A. The maxillary and ethmoid sinuses are present at birth
• B. Only the ethmoid sinuses are present at birth
• C. Sphenoid sinuses develop by 18-24 months
• D. Frontal and sphenoid sinuses begin to appear between age 3 and 4 years

Answer: (D)

Understanding how paranasal sinuses develop in children helps explain why this statement is true. In kids, not all sinuses are present or fully formed at birth. The ethmoid and maxillary sinuses are the ones most evident early on, while the frontal and sphenoid sinuses begin to pneumatize later, typically starting around ages 3 to 4 and then enlarging over time. Because both the frontal and sphenoid sinuses start to appear in that early childhood window, the statement that they begin to appear between 3 and 4 years is the best reflection of their development pattern. The other statements don’t fit the typical timeline: sphenoid development by 18–24 months is usually too early, and frontal sinus appearance is not reliably present from birth and often becomes evident a bit later than the 3–4 year mark in many children.

Understanding how paranasal sinuses develop in children helps explain why this statement is true. In kids, not all sinuses are present or fully formed at birth. The ethmoid and maxillary sinuses are the ones most evident early on, while the frontal and sphenoid sinuses begin to pneumatize later, typically starting around ages 3 to 4 and then enlarging over time. Because both the frontal and sphenoid sinuses start to appear in that early childhood window, the statement that they begin to appear between 3 and 4 years is the best reflection of their development pattern.

The other statements don’t fit the typical timeline: sphenoid development by 18–24 months is usually too early, and frontal sinus appearance is not reliably present from birth and often becomes evident a bit later than the 3–4 year mark in many children.