The pterygoid venous plexuses.

The pterygoid venous plexuses are closely adjacent to the lateral pterygoid m. and occupy a considerable part of the infratemporal fossa (ITF). We have conducted a study after injection of colored latex in 10 unemblamed subjects in order to define the arrangement of the venous network and to assess the frequency of the different types of plexuses found. In all the subjects symmetry was noted between the right and left plexuses, with predominance of the venous layer in the upper part of the ITF. The pattern most often encountered was plexiform and complex. The development of these plexuses follows that of the masticatory muscles, whose contraction promotes drainage and represents an alternative venous pathway for drainage of the cranial cavity.