Malleus is the outermost and largest of the three small bones in the middle ear and reaches an average length of about eight millimeters. It is informally referred to as a hammer, owing to it being a hammer-shaped ossicle or small bone that is connected to the ear. It is composed of the head, neck, anterior process, lateral process, and manubrium. When sound reaches the tympanic membrane, the malleus transmits these sound vibrations from the eardrum to the incus, and then to the stapes, which is connected to the oval window. As the malleus is directly connected to the eardrum, it is unlikely that it will be the cause of hearing loss; however, if the malleus is incapable of being vibrated in the first place, it is easy for the malleus to not function correctly. In cases of atticoantral disease, the ossicular chain (malleus, incus, and stapes) is often affected by cholesteatoma, hereby causing loss of hearing. The malleus and or incus may be sacrificed if they are extensively involved by cholesteatoma. In cases like these, a planned second-stage reconstruction is generally applicable.
Written and medically reviewed by the Healthline Editorial Team
In Depth: Malleus