From ethmoidal air cells to ethmoturbinal passages

Area of Science:

• Anatomy
• Embryology
• Surgical Anatomy

Background:

• The traditional concept of ethmoidal sinuses as air cells conflicts with their embryological origin.
• Paranasal sinus development post-birth differs significantly from ethmoid sinus embryogenesis.
• Ethmoid sinuses are primarily involved in olfaction, unlike other paranasal sinuses involved in respiration.

Purpose of the Study:

• To clarify the distinct embryological origin and function of the ethmoid sinus.
• To describe the compartmentalized structure of the ethmoid sinus resulting from human bipedalism.
• To outline a surgical approach to the ethmoid sinus based on its embryological structure.

Main Methods:

• Comparative analysis of embryological development and post-natal formation (MRI) of ethmoid sinuses.
• Examination of the functional roles of ethmoid sinuses versus other paranasal sinuses.
• Description of the ethmoidal labyrinth structure, including ethmoturbinals and olfactory clefts.
• Surgical anatomical description of ethmoid passages accessible via the middle, superior, and supreme meati.

Main Results:

• Ethmoid sinus development is distinct from ethmoidal air cells and other paranasal sinuses.
• Human bipedalism led to ethmoidal compartmentalization into olfactory clefts and the ethmoturbinal labyrinth.
• Ethmoturbinals, crucial for olfaction, form passages within the ethmoidal labyrinth.
• These passages are surgically accessible, enabling a specific ethmoidectomy technique.

Conclusions:

• The ethmoid sinus's embryological origin and structure are unique, serving olfaction.
• Understanding the ethmoturbinal passages is essential for effective ethmoid surgery.
• A surgical technique based on the ethmoid's embryological structure is presented for teaching purposes.