ANATOMICAL RELATIONSHIP BETWEEN THE PAROTID DUCT AND THE BUCCINATOR MUSCLE IN HUMANS.

: In this study, anatomical and histological examination were performed to investigate the relationship between the parotid duct and the buccinator muscle. Twenty cadaveric buccinator muscles with the parotid ducts were dissected and examined. Histological sections were stained with Hematoxylin-eosin and Masson’s trichrome stains. In 60% of specimens a longitudinal bundle of muscle fibers extended from the superficial surface of the buccinator to the proximal portion of the duct while in 40% this bundle extended along the lateral surface of the proximal portion of the duct till about its middle. In all dissections, shortly after the duct penetrated the buccinator, the muscle fibers were arranged into three groups. The first group of these fibers was arranged in an elliptical manner around the duct and looked like an external sphincter. The second group was longitudinally arranged around the whole circumference of the duct, the deepest fibers of which were spirally arranged around the duct and attached to its wall. The third group of muscle fibers was arranged radially around the duct and appeared as separate bundles of the buccinator. Its fibers were attached to the wall of the duct as well as to the mucous membrane of the mouth vestibule anchoring it to the duct. Histological study revealed the absence of inner muscle sphincter around the distal portion of the duct. It could be concluded that the muscle fibers of the buccinator may have a sphincteric control on the parotid duct and may play a role in regulation saliva transmission through the duct.