Malleus and Components

Otoscopic examination of a healthy 57-year-old male reveals this image. Can you identify the malleus and its components? The malleus (commonly called the “hammer”) is the first bone in a chain of three middle-ear bones that translate movement of the tympanic membrane to the inner ear. The malleus is the most prominent landmark visible in the middle ear space. The malleus is also an anatomical compass in that it “points” to the face. This allows you to determine that this is the left ear. The portions of the malleus that are visible on otoscopic examination include the umbo, manubrium, and the short process. The short process is often the last portion of the malleus that is discernable in cases of infection as in this example. All of these portions are attached to the tympanic membrane (eardrum). As the tympanic membrane vibrates from sound waves, the malleus converts this vibration into a rotary motion at the head (not visible) that is connected to the incus and then to the stapes.