THE ORGANIC ELEMENTS OF THE ENAMEL

IV. THE GROSS MORPHOLOGY AND THE HISTOLOGICAL RELATIONSHIP OF THE LAMELLAE TO THE ORGANIC FRAMEWORK OF THE ENAMEL

¹ Harvard School of Dental Medicine, Boston, Mass.

1. The enamel lamellae have been studied grossly, in spreads, and in paraffin sections of successfully demineralized teeth from rats, monkeys, and man.

2. In erupted teeth organic bands are very frequently found in regions where the enamel has suffered from traumatic injury. The failure of the lamellae to follow the pattern of enamel formation and their absence in unerupted teeth contradict the belief that the lamellae are formative defects.

3. The lamellae are found in the region between the enamel prisms corresponding to the prism sheaths (areas of least resistance) and do not consist of uncalcified prisms.

4. It is suggested that the organic membranes which infiltrate and cover prism surfaces exposed by traumatic injuries to the enamel may serve as a nucleus for a crude reparative mineralization of such defects.