The human dentition consists of two sets of teeth. One is the set which one starts getting as infant and one is which one starts getting from the age of 5-6 years. The first set of teeth also called as milk teeth or primary teeth or decidous dentition gives ways to permanent teeth. The complete details are as under
PRIMARY OR DECIDUOUS DENTITION OR MILK TEETH
SECONDARY OR PERMANENT DENTITION
Primary teeth or baby teeth or deciduous teeth are called the first baby teeth of a child (sometimes also called milk teeth). The number of baby teeth is 20. They are ten in each jaw but much less than the number of the adult teeth. The primary teeth are replaced at a baby's later age by a set of 32 permanent
Primary Teeth Eruption - Baby Teeth Chart
Around the 8th week after conception, oval-shaped tooth buds start to form and harden in the embryo's mouth. Although the baby teeth aren't visible when a child is born, both the primary and permanent teeth are partially formed below the gums. The tooth crown develops first and after it is fully grown, the root begins to develop. Then between about six months and 1 year old, the deciduous teeth begin to push through the gums. This process is called baby teeth eruption or teething. A child gets his first complete set of primary teeth by the age of 3. The first baby teeth to erupt are usually the two lower front teeth.
The baby teeth chart shows the average age that each primary tooth is expected to erupt. But not all baby teeth follow these rules. Some infants may have their first primary tooth (usually one of the bottom middle teeth) erupted as early as 3 months. Others may reach their first birthday or more without getting their first deciduous tooth. If there is no sign of teething by this age you should ask for a pediatrician's advice. That kind of late development of primary teeth is more common in premature babies. In some rare cases (1 every 2.000) infants are born with one or more teeth (called natal teeth) or may have teeth emerge within the first month (called neonatal teeth). A dentist should evaluate the teeth's condition, as they could be loose, interfere with feeding or irritate the baby's tongue.
TOOTH MORPHOLOGY OF PRIMARY TEETH
The primary teeth are 20, ten at every jaw, 8 incisors, 4 canines and 8 primary molars. The deciduous teeth of the primary dentition are smaller than the teeth of the same type in the permanent dentition, but they generally resemble in form.
PERMANENT HUMAN DENTITION
The eruption of permanent teeth starts around the age of 6. From then until the child becomes twelve years old, all the primary teeth loosen and come out while the permanent teeth come through in their place. Up to the age of 13 years the 28 out of 32 permanent teeth will appear.

The full dentition of adult human teeth is completed much later. The 4 last adult teeth, one at the back of every side will appear between 17-21 years. That's why they are called wisdom teeth Grown-ups have a set of 32 permanent teeth, of four different teeth types.
Sixteen at the top and sixteen at the bottom jaw:
8 Incisors,
4 Canines,
8 Premolars
12 Molars
The dentition plays a vital role in a person’s physical as well as mental health because the tooth play a key role in a persons appearance so it becomes very important for maintaining good oral health. Tooth care should start at an early age and parents should make it a habit to avoid caries from nursing bottle caries stage onwards Child should be made to undergo fluoride treatment for prevention of caries. Pits and fissure caries should be looked into dealt with to avoid further damage using pits and fissure sealants etc.