Vol 70, No 3 (2011)
Original article
Published online: 2011-08-24
Interparietal and pre-interparietal bones in the population of south coastal Andhra Pradesh, India
Folia Morphol 2011;70(3):185-190.
Abstract
The squamous occipital bone consists of two parts: a cartilaginous supraoccipital
part below and a membranous interparietal (IP) part above the highest nuchal
line. The IP part develops from two pairs of ossification centres which form the
two lateral plates and a median central piece. Any anomalous ossification of
these centres gives rise to IP bones. Occasional separate ossified part of the IP
region give rise pre-interparietal (PIP) bones which, when present, should be
within the territory of the lambdoid suture. The present study was undertaken to
observe the incidence of IP and PIP bones in skulls belonging to the south coastal
population of Andhra Pradesh, India, hitherto unreported. In a total of 84 skulls,
IP bones were found in 8 (9.5%) skulls and PIP bones in 6 (7.1%) skulls. The
occurrence of IP and PIP bones can be correlated with the development of the
squamous part of the occipital bones, and any alterations in the fusion of its
ossification centres and its nuclei result in these anomalous bones. Knowledge of
these bones may be important in dealing with situations resulting from fractures
of occipital bones, and to rule out their incidence between races or populations
in different parts of the world. (Folia Morphol 2011; 70, 3: 185–190)
Keywords: squamous occipital boneinterparietal boneoccipital anomaliesskull development