Tympanic part of temporal bone

The tympanic part of the temporal bone is situated inferiorly to the squamous part and anteriorly to the mastoid part.

Gross anatomy

The tympanic part of the temporal bone is composed of anterior and posterior surfaces and superior, inferior and lateral borders.

Anterior surface

Its anterior surface forms the posterior (non-articular) part of the mandibular fossa. The anterior surface is continuous with the squamous part of the temporal bone at the tympanosquamous fissure, and medially, it continues as the petrotympanic fissure, where it fuses to the petrous part of the temporal bone.

Posterior surface

The posterior surface surrounds the external auditory meatus, forming the anterior wall, floor and some of the posterior wall of the bony external acoustic meatus.

Borders

• superior: tympanosquamous fissure
• inferior: extends medially and bifurcates along the base of the styloid process as the vaginal process
• lateral: gives the attachment to the cartilaginous part of the external acoustic meatus, and fuses posteriorly with the mastoid part of the temporal bone, via the tympanomastoid fissure