Kinds of teeth “primary teeth or milky teeth ”

The teeth have the most important role and the hardest structure in human's jaws and many other spinescent animals. The main function of the teeth is cutting and grinding the food pieces. Further more, they help us in speaking properly.

Two kinds of teeth grow during every human's life cycle:

1-primary teeth.

2-permanent teeth .

The number of primary teeth is 20 which are distributed equally in the two jaws.

After a while, the 32 permanent teeth are replaced the primary ones gradually.

As the primary teeth are the base of the permanent teeth, having good oral hygiene is necessary.

   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 . A child gets his first complete set of primary teeth by the age of 3. 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 advise. 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.

1-primary teeth (baby or Milky teeth):

The first teeth which are shed and replaced by permanent teeth.the first teeth begin to break through the gums at about 6 months of age. Usually, the first two teeth to erupt are the two bottom central incisors (the two bottom front teeth). Next, the top four front teeth emerge. After that, other teeth slowly begin to fill in, usually in pairs - one each side of the upper or lower jaw - until all 20 teeth (10 in the upper jaw and 10 in the lower jaw) have come in by the time the child is 2 ½ to 3 years old. The complete set of primary teeth is in the mouth from the age of 2 ½ to 3 years of age to 6 to 7 years of age.

Other primary tooth eruption facts:

•     A general rule of thumb is that for every 6 months of life, approximately 4 teeth will erupt.
•     Girls generally precede boys in tooth eruption
•    Lower teeth usually erupt before upper teeth.
•    Teeth in both jaws usually erupt in pairs ? one on the right and one on the left
•    Primary teeth are smaller in size and whiter in color than the permanent teeth that will follow
•    By the time a child is 2 to 3 years of age, all primary teeth should have erupted

Shortly after age 4, the jaw and facial bones of the child begin to grow, creating spaces between the primary teeth. This is a perfectly natural growth process that provides the necessary space for the larger permanent teeth to emerge. Between the ages of 6 and 12, a mixture of both primary teeth and permanent teeth reside in the mouth.

When tooth falls out	When tooth emerges	Upper Teeth
6 to 7 years	8 to 12 months	Central incisor
7 to 8 years	9 to 13 months	Lateral incisor
10 to 12 years	16 to 22 months	Canine (cuspid)
9 to 11 years	13 to 19 months	First molar
10 to 12 years	25 to 33 months	Second molar
		Lower Teeth
10 to 12 years	23 to 31 months	Second molar
9 to 11 years	14 to 18 months	First molar
9 to 12 years	17 to 23 months	Canine (cuspid)
7 to 8 years	10 to 16 months	Lateral incisor
6 to 7 years	6 to 10 months	Central incisor

The table shows when the primary teeth emerges.