The parietal bone remains the most common donor site for a bone graft
in treating facial bone fractures, especially those involving orbital
walls. Despite this potential clinical usefulness, anthropometric data
on the parietal bone is lacking. Only one Korean and a few foreign st
udies report on its thickness, measured at two and three points of eac
h of two parietal bones in a given subject, respectively. These studie
s, however, fall short of offering enough information for locating the
optimal harvest point of the parietal bone for bone grafting. This st
udy was thus aimed at constructing a thickness map that provides the m
ean parietal bone thickness at various points and determines the diffe
rence between them. Eighty-eight parietal bones were obtained from 44
Korean adult skulls for this study. Parietal bone thickness was measur
ed at 15 points, spaced at regular intervals on each parietal bone of
a given skull, using a Techlock GM 21 caliper gauge. The mean bone thi
ckness at each of the 15 points of the bone and at the corresponding p
oints of the opposite parietal bone was obtained in all skulls studied
. The mean thickness at each point of measurement on two opposite pari
etal bones was compared using the paired Student's t test. Mean thickn
ess did not differ significantly. The thickness in the same bone varie
d widely depending on the points of measurement. The thickest part, th
e posteromedial region of the parietal bone near the lambda, was 6.67
+/- 1.41 mm (mean +/- standard deviation [SD]) thick, and it became th
inner toward the diagonal (anterolateral) direction, to the thinnest p
art, 4.73 +/- 1.19 mm (mean +/- SD) thick, near the pterion. It is hop
ed that our thickness map can serve as a practical guide for choosing
an ideal site on the parietal bone for a bone graft of desired thickne
ss.