Tegmen tympani

The tegmen tympani, also known as the tegmental wall or roof of the tympanic cavity, is a thin plate of the petrous part of the temporal bone that separates the intracranial compartment and middle ear.

Gross anatomy

Relations and/or Boundaries

• anteriorly, roof of the canal for the tensor tympani muscle 
• posteriorly, roof of mastoid antrum  (other parts of the tegmen: tegmen mastoideum or tegmen antri)
• laterally, squamous part of temporal bone (petrosquamous suture) 
• superiorly, dura of middle cranial fossa
• inferiorly, epitympanum (attic of middle ear cavity)

Related pathology

• acquired cholesteatoma: the structure can be eroded by an enlarging cholesteatoma
• cerebrospinal fluid leak, meningocele or meningoencephalocele to the middle earcan be caused by interruption of the structure

History and etymology

Tegmen is derived from the Latin word tegere, to cover.