A 3-Dimensional Model of the Human Round Window Membrane

Area of Science:

• Anatomy
• Biomedical Engineering
• Histology

Background:

• The round window membrane (RWM) is a critical structure in the inner ear, but its small size poses challenges for detailed morphological study.
• Understanding the RWM's intricate structure is essential for research in hearing loss and auditory prosthetics.

Purpose of the Study:

• To clarify the morphologic aspects and characteristics of the human round window membrane (RWM).
• To create and examine a 40x magnified 3-dimensional (3D) model of the RWM.

Main Methods:

• A human RWM specimen was obtained from a formalin-fixed, decalcified temporal bone.
• Laser scanning microscopy data were used to create a 3D printed model of the RWM.
• The 3D model was analyzed for surface striae, curvatures, thickness, and area, with histological cross-sections for comparison.

Main Results:

• The RWM model exhibited an approximately elliptic contour with a saddle shape.
• Distinct anterior (dark) and posterior (clear) portions were observed on the surface facing the fossula, separated by a line of inflection along the short axis.
• Collagen fiber orientation varied: parallel to the borderline in the posterior portion and fanned out in the anterior portion.

Conclusions:

• A magnified 3D model effectively clarifies the gross anatomy and characteristics of the RWM.
• This 3D model serves as valuable educational material for understanding small anatomical structures like the RWM.