THE ORIGIN AND DISTRIBUTION OF THE LABIAL AND BUCCAL GLANDS IN THE HUMAN FETUS

¹ Department of Anatomy, College of Medicine, University of Illinois, Chicago, Ill.

The superior and inferior labial glands arise early in the third month of human development. They develop from epithelial buds of the vestibular epithelial plate before there is an open alveolo-labial sulcus. A group of buccal or molar glands arises at the same time. They are associated with the termination of the parotid duct and lie, therefore, in the mucosa of the upper cheek. The retromolar glands develop later, early in the fifth fetal month. They are located on the medial side of the retromolar papilla. In the fetus with its primitive mandible and low ramus the papilla is a relatively broad fold, directly continuous with the soft palate.

The major salivary glands (submandibular, parotid, and sublingual) arise earlier, usually in that order, during the latter part of the second embryonic month.

The topographic relations of the labial and molar glands are portrayed in a fetus of the fifth month.