Dental Formula, Adaptation of Mammalian Teeth for Feeding and Dental Care

DENTAL FORMULA

[Photo credit: Dozenist]

Dental formula can be defined as the number and types of teeth an animal has in one half of each jaw. Different mammals have different dental formulae depending on their diet. In the following formulae:

i=incisors
c=canine
p=premolar
m=molar

The numerator represents the upper jaw and the denominator represents the lower jaw.

The dental formula of omnivores, e.g man is: i=2/2, c=1/1, p=2/2, m=3/3.
The total number of teeth is 32.

The dental formula of carnivores, e.g dog is: i=3/3, c=1/1, p=4/4, m=2/3.
The total number of teeth is 42.

The dental formula of herbivores, e.g rabbit is: i=2/1, c=0/0, p=3/2, m=3/3.
The total number of teeth is 28. (Herbivores do not have canine)

Note: The total number of teeth is obtained by multiplying the total number of teeth in the dental formula by 2. The formula is for half of the each jaw.

ADAPTATION OF MAMMALIAN TEETH FOR FEEDING

The Teeth of Man
Man is an example of an omnivore, i.e, he feeds on both flesh and vegetables and the teeth, 32 in number, is adapted to the kind of diet it feeds on.

1. Incisors are sharp and broad for cutting food.
2. Canines are bluntly pointed and are used for gripping and tearing food.
3. Premolars and molars have strong cusps for chewing and grinding food.

The Teeth of Dog

Dog is a carnivorous animal, i.e. it feeds on flesh. Hence, its teeth, 42 in number, is adapted to the kind of food it eats.

1. Incisors are small and pointed, and are used for cutting small pieces of meat from bones.
2. Canines are long, curved, large and pointed. They are used for attack, defence as well as allowing the animal to seize its prey and tear off flesh from bones.
3. Premolars and molars are broad and thick. The last premolar in the upper jaw and the first molar in the lower jaw are large and modified to form carnassial teeth. They possess sharp cutting edges which are used to cut up meat and tear it away from bones. They are used also for cracking bones. Premolars and molars are cusped, blunt with flat surfaces, used mainly for cutting and grinding.

The Teeth of Rabbit

The rabbit is an herbivorous animal, i.e, it feeds mainly on vegetables. Hence, its teeth, 28 in number, is adapted to the kind of food it eats.

1. Its incisors are flat with sharp cutting edges for the cutting of vegetables or grasses.
2. The canines are absent. The space created by their absence is called the diastema. The diastema allows the manipulation of grasses in the mouth.
3. Premolars and molars are large, closely packed and have large rigid surface area for cutting and grinding.

DENTAL CARE

Teeth can easily decay because germs readily grow on bits of food that tend to stick to the teeth after meal. The germs breakdown food particles (especially carbohydrates) to produce acids. 

The acids wear away the nerves and blood vessels in the pulp cavity. The tooth begins to ache and the gum becomes infected. Finally the tooth falls off. 

Once a permanent tooth falls off, it cannot be replaced b another tooth. Therefore it is very important to take care of our teeth.

The decaying of teeth by bacteria and other fermentation of starch within the teeth can be prevented by adequately caring for the teeth. The teeth can therefore be cared for in the following ways:

1. The teeth should be cleaned with brush or chewing stick and tooth paste at least twice a day, especially after meal and before going to bed.
2. Stains due to eating kola or tobacco smoking should be removed by using hydrogen peroxide to wash the mouth.
3. Vitamins and minerals containing food such as green vegetables, fresh fruits, butter, cheese, milk and eggs should be taken regularly.
4. Sugary foods and drinks like sweet, ice cream, soft drinks, etc. should be avoided because bacteria feed on sugar and in the process turn them into acid which attack the teeth.
5. The dentist should be visited for regular check-up at least twice a year.
6. Artificial teeth should be always removed and washed with germicide solution after each meal.
7. Food particles or meat should be removed from teeth after meal.
8. Misuse of teeth such as opening bottle cork or cracking large bones that ma cause damage to the enamel should be avoided.

Categories: Biology, Digestion, Digestive System