Inter-relationships of the Dental Tissues The tooth germ has three main components -the enamel organ, the dental papilla and the dental follicle (Fig. 1). The enamel organ is an epithelial structure derived from the ectoderm that lines much of the oral cavity. The dental papilla and the dental follicle are ectomesen chymal (mesectodermal), being partly derived from cells that mi grated from the neural crest early in embryogenesis. Both the gross morphology of the tooth germ and the differentiation of its cells de pend upon a complex pattern of inductive interactions between the epithelium and...

There are two major differences in concept between this volume and others in the International Histological Classification of Tu mours series. The first of these is the inclusion of more clinical aspects than has usually been the case and the second is a con centration on a more limited range of conditions. There are sev eral reasons for adopting this approach. With regard to both cancer and pre cancer of the oral mucosa, we believe it is impor tant that general pathologists, in whose interests this volume has primarily been written, should be informed of the significance of the clinical...