Abstract:
The odontoid process of
C2 projects upward from the superior
roof of the body of C2. There is
a confusion about the inferior border
of the odontoid. The aims of this
clinical study were to describe the
inferior border of the odontoid
process based on the remnant of
dentocentral synchondrosis in
adults, and the estimation of the
odontoid/body ratio in pediatric and
adult ages. Sixty-six cases were included
for this study. Forty-four of
them were in adult ages and the
remaining 22 of them were in pediatric
ages. The region of occiput, C1,
C2, and C3, was examined with the
magnetic resonance imaging (MRI)
in all cases. The length of the
odontoid process was estimated by
using radiological images of MR
from the tip of the odontoid to the
remnant of dentocentral synchondrosis.
The portion located under the
level of synchondrosis was consid
ered as the body of C2. The average
length of the odontoid was 18. 6 mm
in pediatric and 21. 3 mm in adult
cases. In adult females, the length of
the odontoid process (19. 1 mm in
length) was smaller than those of
adult males (23. 6 mm in length).
The average ratio of odontoid/body
was two in pediatric and 1.8 in adult
cases. This study demonstrated that
the neck of the odontoid segment at
the level of superior articulating
facets is not the synchondrosis between
the odontoid process and the
body of C2. The synchondrosis is
located well below the level of
superior articulating facets. It can be
demonstrated with sagittal and
coronal images of MR in both of
pediatric and adult individuals.
