Temporal bone

The temporal bone is situated on the sides and base of the skull, flanking the brain’s temporal lobe. It plays a crucial role not only in forming the cranial cavity but also in sheltering the structures of the ear.

This complex bone has various parts: the squamous, mastoid, petrous, and tympanic sections:

• The squamous portion, which is the largest and positioned at the top, makes up part of the cranial vault and the temple area. It includes the zygomatic process that contributes to forming the zygomatic arch.

• The mastoid part, is a noticeable bump located towards the back. It contains mastoid air cells, which differ in size and number from person to person, and can be felt behind the ear’s auricle. Medial to the mastoid process is the pointed styloid process, which projects out from the lower border of the temporal bone. Both mastoid and styloid processes serve as attachment sites for important muscles of the head and neck region.

• The petrous segment, shaped like a pyramid and very dense, encases the middle and inner ear components, which are crucial for hearing and balance.

• The tympanic part is found beneath the origin of the zygomatic process from the squamous temporal bone. It features the external acoustic opening leading into the external acoustic meatus or the ear canal. The tympanic part forms the front and lower sides of the ear canal and supports the ear drum, i.e. the tympanic membrane.