Enamel spindle are

Apart from this primary curvature the tubules show smaller undulations called secondary curvatures all along their course. Also, all along the course the tubules show lateral branches and terminal branches at their terminal end. The odontoblastic process which contain microtubules, microfilaments, and mitochondria extends into these branches. Few of the odontoblastic process cross the DEJ and they are known as enamel spindles