STRUCTURE AND POSITION

• Each of the Ethmoid Sinus is present between the thin Nasal and Orbital Plates. Their separations are thin walls. They are present inside the Ethmoid Bone hence named so.
• Ethmoidal Air sinuses form small cavities inside the Labyrinth (mass) of the Ethmoid Bone. They are of different shape and size on both sides.
• They are covered and completed at sides by Frontal (superiorly), Palatine (inferiorly), Lacrimal (medially), Maxilla (laterally) and Sphenoidal (posteriorly) bones.
• Each of the Ethmoid Sinus is further divided into three parts. Anterior, Middle and Posterior.

FUNCTION AND SIGNIFICANCE

• Air sinuses like Ethmoid Sinus make the skull lighter. They also help in the resonance of voice.
• Ethmoid Sinus can get infected in Children and this condition is known as Acute Ethmoiditis.
• Ethmoidal Carcinoma is malignancy of the Ethmoid bone and sinus. It can spread to the nearby organs like Brain or Eyes.