Malleus

Malleus

Also known as: hammer

The largest and most lateral auditory ossicle ("hammer"), whose handle is embedded in the tympanic membrane and whose head articulates with the incus.

Show on body map Ear — Coronal Section

Overview

Length≈8–9 mm

Mass≈23–27 mg

The malleus (≈8–9 mm long) has a rounded head lying in the epitympanic recess, a constricted neck, a long handle (manubrium) firmly attached to the fibrous layer of the tympanic membrane down to the umbo, a short lateral process that bulges the upper drum (seen on otoscopy), and a slender anterior process attached by ligament to the petrotympanic fissure.

The head articulates posteriorly with the body of the incus at the saddle-shaped incudomallear joint (synovial). The malleus is suspended by superior, lateral and anterior ligaments; together with the incus it rotates about an axis through the anterior ligament of the malleus and the posterior ligament of the incus. The tensor tympani tendon inserts on the upper handle; the chorda tympani passes medial to the neck/handle.

Location: Lateral-most ossicle: handle within the tympanic membrane, head in the epitympanic recess.

Parts & subdivisions

Head
In the attic; articulates with the incus.
Neck
Constriction below the head; chorda tympani passes medial to it.
Handle (manubrium)
Attached to the tympanic membrane; tip forms the umbo; tensor tympani inserts near its root.
Lateral process
Projects against the upper drum; boundary of pars flaccida.
Anterior process
Attached by the anterior ligament of malleus.

Anatomy

Innervation: Mucosa via tympanic plexus (IX); tensor tympani via V3.
Articulations: Incudomallear joint (saddle-type synovial) with the body of the incus.
Ligaments: Superior, lateral and anterior ligaments of the malleus.
Ossification: Ossifies from a single centre around 16 weeks; ossicles reach adult size before birth.
Development: First pharyngeal arch (Meckel cartilage) — together with the incus, the anterior ligament of the malleus being a remnant of Meckel cartilage (as is the sphenomandibular ligament).

Function

Receive vibrations from the tympanic membrane
Act as the longer arm of the ossicular lever (≈1.3:1)
Transmit vibration to the incus

Clinical significance

Ossicular fixation and discontinuity

Malleus head fixation (attic tympanosclerosis) causes conductive loss; erosion by cholesteatoma or chronic otitis media may require ossiculoplasty with a prosthesis.

Compiled from standard anatomy and physiology references — see the Special Senses sources. For education only; not medical advice.