Paranasal sinus development and implications for imaging.

Because the paranasal sinuses continue to develop throughout childhood, radiologists encounter significant anatomical variation when confronted with pediatric imaging studies. Knowledge of the stages of sinus growth is vital to differentiate normal development from abnormally large, hypoplastic or malformed sinuses. Understanding how the paranasal sinuses develop and their expected appearance at different patient ages is important for accurate interpretation of diagnostic imaging. To that end, we provide a brief review of paranasal sinus anatomy and discuss the mechanisms by which each paranasal sinus develops, as well as the implications for imaging. We also provide a practical guide for assessing normal paranasal sinuses in children based on the relationship of the sinuses to anatomical landmarks at various stages of development in order to help pediatric radiologists provide accurate interpretation of diagnostic imaging.