Parietal Notch Of The Temporal Bone, Superior View

Description

Parietal notch (incisura parietalis) of the temporal bone is centered in this superior aspect, marking the articular gap where the squamous part (pars squamosa) meets the mastoid part (pars mastoidea). Along the superoposterior margin, the notch forms the temporal contribution to the parietomastoid suture, while the adjacent squamous border continues anteromedially toward the squamous (temporoparietal) suture. Posterior to the notch, the mastoid portion broadens inferiorly toward the mastoid process, but the emphasis here stays on the suture-bearing superior surface and its bony seams. Sharp sutural edges are the focus. For neuroanatomy and skull-surface teaching, the parietal notch helps anchor the asterion region, where parietal, temporal, and occipital bones approximate and where the transverse and sigmoid dural venous sinuses lie deep to the cranial wall. In operative planning, that relationship matters when placing a retrosigmoid burr hole or working near the mastoid during a posterior fossa approach, because millimeters of error can shift a craniotomy toward the sinus groove rather than solid bone. The superior viewpoint reduces ambiguity between the squamous and mastoid parts and makes their contact plane readable without distracting external landmarks. Anatomy faculty often pair this illustration with suture maps of the calvaria to teach cranial bone identification, sutural nomenclature, and the practical meaning of the parietomastoid junction. It also fits well in otologic and neurosurgical atlases discussing temporal bone fractures, mastoidectomy orientation, and safe zones for burr-hole placement relative to the asterion and underlying venous sinuses. Anatomical accuracy verified by SciePro's Medical Advisory Board.