Fissure
Fissure is a groove, natural division, deep furrow, or cleft found in the brain, spinal cord, and liver; or an unnatural tract found most commonly in the anus. In dentistry, a fissure is a break in the tooth enamel.
Natural Fissure
Various types of fissure are:
Abnormal Fissure
Fissure can also mean unnatural tract or ulcer, most commonly found in the anus. One of the most common types of fissure is anal fissure.