“Good white teeth generally accompany a normal thyroid secretion. A hypersecretion of the pituitary sometimes leads to very large and separated incisors. Insufficient secretion from the sexual glands is generally associated with small lateral incisors, and adrenal hypersecretion makes for large sharp canines. Here again light can probably influence the shape, the color and the regularity of tooth eruption by influencing the balance of the internal secretions.”