Dental formulae are used to indicate the number of each type of tooth for a given species. Because the jaw is bilaterally symetrical, only one half of the jaw is described. The incisors are indicated first, followed by the canine, promolars and molars. The maxillary arcade or upper jaw is listed over the mandibular arcade or lower jaw. For instance, a dog has 3 incisors, 1 canine, 4 premolars and 2 molars on one side of the upper jaw and 3 incisors, 1 canine, 4 premolars and 3 molars on one side of the lower jaw, so the dental formula would be: