parietalbone-200613.pdf

Parietal bone

1. Parietal
Bone
Skeletal System
Neurocranium
Dr. Aves Khan
Oral & Dental
Surgeon

2. Introduction of
Parietal Bone
Theparietal bone(latin:os parietale) is located on each side of the skull
right behind the frontal bone.
Bothparietal bonestogether form most of the cranial roof and sides of
the skull.
Eachparietal bonetakes an irregular quadrilateral shape and has four
angles, four margins, and two surfaces.

3. Angles of
Parietal Bone
Thefouranglesoftheparietalboneare:
Frontalangle:itsanteriorsuperiorangle
Sphenoidalangle:Itistheanteriorinferiorangle,andthemost
sharpestangleoftheparietalbone.
Occipitalangle:itsposteriorsuperiorangle.
Mastoidangle:Itistheposteriorinferiorangleoftheparietal
bone.

4. Margins of
Parietal Bone
The four margins or borders of theparietal boneare the following:
Frontal margin: It forms its anterior border.
Occipital margin: It forms the posterior border of theparietal
bone.
Squamous margin: It is the inferior margin of theparietal bone.
Sagittal margin: It is its upper, medial margin.

5. Surfaces and
landmarks of
parietal bone
Theparietal bonehas an external and an internal surface.
Theexternal surface of theparietal bonefeatures the following
landmarks:
parietal tuber,
superior temporal line,
inferior temporal line,
parietal foramen.
Theinternal surfaceof theparietal bonefeatures:
Groove for superior sagittal sinus
Granular foveolae
Groove for sigmoid sinus
Impressions of cerebral gyri
Arterial grooves

6. Theexternal
surface of the
parietal bone
Theparietaltuber(orparietaleminence)isaprominencelocated
nearthemiddleoftheexternalsurfaceoftheparietalbone.
Thesuperiortemporallineisacurvedlineseenontheexternal
surfaceoftheparietalboneforattachmentofthetemporal
fascia.Thesuperiortemporallinealsorepresentstheupper
marginofthetemporalplane.
Theinferiortemporallineisacurvedlineontheexternalsurface
oftheparietalboneforattachmentofthetemporalismuscle.
Theparietalforamenisanopeningoccasionallypresentatthe
backpartoftheparietalbone,thatservesasapassageforthe
parietalemissaryvein,whichdrainsintothesuperiorsagittal
sinus.

7. Anatomical
views of the
Parietal bone

8. Dr. Aves Khan
Oral & Dental
Surgeon