Middle ear ossicles

Last revised by Bahman Rasuli ◉ on 10 Dec 2020

Citation, DOI, disclosures and article data

Citation:

Gaillard F, Rasuli B, Deng F, et al. Middle ear ossicles. Reference article, Radiopaedia.org (Accessed on 30 May 2023) https://doi.org/10.53347/rID-1789

DOI:

https://doi.org/10.53347/rID-1789

Permalink:

https://radiopaedia.org/articles/1789

rID:

1789

Article created:

2 May 2008, Frank Gaillard ◉ ◈

Disclosures:

At the time the article was created Frank Gaillard had no recorded disclosures.

View Frank Gaillard's current disclosures

Last revised:

10 Dec 2020, Bahman Rasuli ◉

Disclosures:

At the time the article was last revised Bahman Rasuli had no recorded disclosures.

View Bahman Rasuli's current disclosures

Revisions:

21 times, by 9 contributors - see full revision history and disclosures

Systems:

Head & Neck

Sections:

Anatomy

Tags:

stub, refs

Synonyms:

Ossicular chain

There are three tiny articulating bones in the middle ear known as ossicles (from lateral to medial):

Their role is to mechanically amplify the vibrations of the tympanic membrane and transmit them to the cochlea where they can be interpreted as sound. They are located in the middle ear cavity and articulate with each other via two tiny synovial joints. The stapes also articulates with the oval window via the stapediovestibular joint, which is a syndesmosis ³; this joint transmits the ossicular vibrations to the endolymph in the vestibule.

Interestingly, they are the only bones in the body that do not grow after birth and are also the smallest bones in the body (variant tiny sesamoids aside).

Radiographic features

CT

On axial images (in the plane of the lateral semicircular canal), the normal landmarks of the ossicles can be remembered with the following mnemonic, from superior to inferior ^4,5:

ice cream cone (level of horizontal tympanic segment of facial nerve): incudomallear joint involving head of malleus (ice cream) and body of incus (top of cone), and short process of incus (tip of cone)
two dots (level of oval window): neck of malleus (lateral dot) and long process of incus (medial dot)
two dashes: handle/manubrium of malleus (lateral line), incudostapedial joint involving lenticular process of incus and head of stapes (medial line)