Dentition is the development of teeth and their arrangement in the mouth. Humans have up to four distinct types of teeth the incisor the canine the premolar and the molar.
Incisors (Cutting teeth) - these are the front most teeth in the jaw and are primarily used for the initial biting of food. They have a straight sharp cutting edge and one root.
Canines (Stabbing teeth) ﾖ there are normally only 2 pairs of canines (one each side) per jaw. They have a sharp pointed edge and are used with the incisors to bite into food and or to kill prey. Like incisors they have one root.
Premolars ﾖ these are generally similar to molars in form and function. Premolars are the teeth we use to crush and grind our food. The upper surfaces of premolars have a broad lumpy top instead of a sharp biting edge. These small irregular lumps are called cusps. Premolars are also called bicuspids in some cases because in most cases they have two cusps. The first upper premolars normally have two roots and other premolars have one root.
Molars - these are larger than premolars and extremely variable depending on diet. Like premolars they are used for crushing and grinding food and like premolars their upper surfaces have ridges called cusps on them. Molars normally have three to five cusps and two or three roots. In humans we call the third molars those closest to the back of the mouth 'Wisdom Teeth'. If the jaw bone is not large enough to accommodate all the teeth in it as sometimes happens these wisdom teeth can become painfully wedged between the back of the jaw bone and the 2nd molars. This condition is known as 'impacted wisdom teeth'.
Humans have distinct types of teeth and are heterodont. Some animals do not have distinct teeth and are homodont. The number of teeth of each type is written as a dental formula and the human dental formula is:
2 1 2 3 ------- 2 1 2 3
Teeth are embedded in the upper and lower jawbones. They are arranged in each jaw in the form of an arch so that when a person closes their mouth the teeth of the upper and lower arches come together a term called occlusion.
