In mammalian oral anatomy, the canine teeth, also called cuspids, dog teeth, fangs, or (in the case of those of the upper jaw) eye teeth, are relatively long, pointed teeth. However, they can appear more flattened, causing them to resemble incisors and leading them to be called incisiform. They developed and are used primarily for firmly holding food in order to tear it apart, and occasionally as weapons. They are often the largest teeth in a mammal's mouth. Most species that develop them normally have four per mammal, two in the upper jaw and two in the lower, separated within each jaw by its incisors; humans and dogs are examples. In most species, canines are the anterior-most teeth in the maxillary bone. Narwhals provide an extreme example, where one canine tooth, usually the left, erupts into a long spiral horn up to nine feet (2.7 metres) long.The four canines in humans are the two maxillary canines and the two mandibular canines.