VASCULARITY OF THE HUMAN ENAMEL ORGAN

¹ Departments of Stomatology and Pathology, Children's Hospital and Infants' Hospital, Boston, Mass.

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1. Vascular penetration of the two intermediate layers in the enamel organs of the deciduous and permanent molars is almost invariably noted in infants up to fourteen months of age. Thirteen representative examples are reported. 2. The vascularization of the enamel organ occurs approximately at the time enamel formation begins or shortly thereafter. 3. The vessels appear first in the vicinity of the cusps, subsequently over the occlusal grooves and fossae, and only later, after a considerable amount of enamel has been formed, do they appear on the lateral surfaces of the teeth. 4. In one instance penetration of the stellate reticulum of a mandibular deciduous lateral and canine occurred before the outer enamel epithelium had come to lie upon the stratum intermedium. 5. The earliest examples of vascular penetration are associated with the presence of perivascular spaces. These may be either large lymphatic sinuses or areas of beginning resorption of the stellate reticulum. 6. In support of the suggestion of Lepkowski and Kingery a hypothesis is advanced that vascular penetration of the enamel organ in mammals depends first on the form of the tooth and its enamel-forming area with respect to that of the outer enamel epithelium and, second, on the amount of stellate reticulum and the extent of development of a papillary layer in the outer enamel epithelium.