Critical Reviews in Oral Biology & Medicine, Vol 9, 224-244, Copyright © 1998 by International & American Associations for Dental Research
Neuro-osteology
I. Kjaer
Department of Orthodontics, School of Dentistry, Faculty of Health Sciences, University of Copenhagen, Denmark.
Neuro-osteology stresses the biological connection during development
between nerve and hard tissues. It is a perspective that has developed
since associations were first described between pre-natal peripheral nerve
tissue and initial osseous bone formation in the craniofacial skeleton
(Kjaer, 1990a). In this review, the normal connection between the central
nervous system and the axial skeleton and between the peripheral nervous
system and jaw formation are first discussed. The early central nervous
system (the neural tube) and the axial skeleton from the lumbosacral region
to the sella turcica forms a unit, since both types of tissue are
developmentally dependent upon the notochord. In different neurological
disorders, the axial skeleton, including the pituitary gland, is malformed
in different ways along the original course of the notochord. Anterior to
the pituitary gland/sella turcica region, the craniofacial skeleton
develops from prechordal cartilage, invading mesoderm and neural crest
cells. Also, abnormal development in the craniofacial region, such as tooth
agenesis, is analyzed neuro-osteologically. Results from pre-natal
investigations provide information on the post-natal diagnosis of children
with congenital developmental disorders in the central nervous system.
Examples of these are myelomeningocele and holoprosencephaly. Three steps
are important in clinical neuro-osteology: (1) clinical definition of the
region of an osseous or dental malformation, (2) embryological
determination of the origin of that region and recollection of which
neurological structure has developed from the same region, and (3) clinical
diagnosis of this neurological structure. If neurological malformation is
the first symptom, step 2 results in the determination of the osseous
region involved, which in step 3 is analyzed clinically. The relevance of
future neuro-osteological diagnostics is emphasized.
