Incisors are teeth with straight cutting edges whose function is to bite and shear food articulate speech and support the lips. The human mouth contains 32 teeth 16 upper and 16 lower. The teeth are arranged in upper maxillary and lower mandibular arches. Each arch is divided into two quadrants. There are four incisors per arch two per quadrant. The incisors are usually the first teeth to emerge.
The central incisors are located in the middle front of the upper and lower jaw and the lateral incisors are beside (lateral to) the central ones. The maxillary central incisors are the most prominent teeth in the mouth and feature straight edges and a slightly curved shape. The lateral incisors are narrower than the central ones but otherwise are similar in appearance. The mandibular central incisors are the smallest teeth in the dental arch. These teeth are long narrow and symmetrical with straight edges. The mandibular lateral incisors are larger and more rounded than the central ones.