What is the smallest bone in the body?
At about 3.3 millimeters in length, the stapes – or “stirrup” bone – is the smallest bone in the body. In the middle ear, the stapes, malleus (hammer) and incus (anvil) increase and transfer sound vibrations from the eardrum to the sensitive hair cells in the inner ear.
About 1 percent of the population develops a symptomatic form of a condition called otosclerosis. In these people, the stapes bone develops growths that interfere with its movement against the fluids of the inner ear, leading to hearing loss.
- Dizziness, balance problems or tinnitus – ringing, roaring or buzzing in the ears – also may occur. Otosclerosis is often treated through surgery to bypass the diseased bone with a prosthetic. Hearing aids also may be useful.
Sources: Department of Otolaryngology, Head and Neck Surgery at the University of Washington; National Institute on Deafness and Other Communication Disorders
