Gnarled enamel is a description of enamel seen in histologic sections of a tooth underneath a cusp. This is optical appearance of enamel. The appearance of enamel appears different and very complex under the cusp, but this is not due to a different arrangement of dental tissues. Instead, the enamel still has the same arrangement of enamel rods. The strange appearance results from the lines of enamel rods directed vertically under a cusp and from their orientation in a small circumference.