ABNORMALITIES ENCOUNTERED IN DISSECTION OF THE HEAD AND NECK OF AN ANENCEPHALIC MONSTER

¹ Department of Dental Research, Harvard University Dental School

Investigation of the head and neck of an anencephalic monster disclosed marked abnormalities which in some instances resembled an embryonic arrangement of tissue. This is readily understood when it is recognized that the function of the embryo is organogenesis and that in this instance arrest in development was due to absence of the influence of the central nervous system during fetal life (8). The quoted observations of Chase relative to pigmentation of the enamel caps suggest that the embryonic phase of enamelization was involved. The histologic evidence of poor calcification of the dentine as evidenced by a lack of globuli in the dentine matrix, and a tendency of the ameloblasts and odontoblasts to degenerate, further substantiates the opinion that the tooth buds exhibited an arrest in development.

The following abnormalities were encountered: Absence of brain, calvarium, and Gasserian ganglion; undifferentiated facial muscle group—quadratus labii superioris, zygomaticus major, and caninus; terminal branches of n. facialis distributed through facial muscle group instead of in its usual path through the parotid gland; embryonic arrangement of platysma fibers (sphincter colli); abnormal development of parotid gland and its duct; occluded incisor foramen; absence of anterior palatine and naso-palatine nerves; arrest in development of the tooth buds. Additional interesting, but not abnormal findings, were a villus of mucous membrane in region of upper canine, and possibly a third infra-orbital foramena.