There are three teeth in humans: the lacteal teeth, the mixed teeth and the final teeth. The lacteal dentition, which therefore includes milk teeth or temporary teeth, is made up of 20 teeth divided into 4 quadrants of 5 teeth each: 2 incisors, 1 canine and 2 molars.

It starts around the 15^st week of intrauterine life, period when calcification of the central incisors begins, until the establishment of the lacteal molars at the age of about 30 months.

Here is the physiological eruption schedule for baby teeth:

· Lower central incisors: 6 to 8 months.

· Lower lateral incisors: 7 to 9 months.

· Upper central incisors: 7 to 9 months.

· Upper lateral incisors: 9 to 11 months.

First molars: 12 to 16 months

Canines: from 16 to 20 months.

· Second molars: from 20 to 30 months.

In general, lower (or mandibular) teeth erupt earlier than upper (or maxillary) teeth.^1-2 . With each teething, the child is likely to be grumpy and salivate more than usual.

The dental eruption is divided into 3 phases:

—          The preclinical phase. It represents all the movements of the tooth germ to reach the contact with the oral mucosa.

—          The clinical eruption phase. It represents all the movements of the tooth from its emergence to the establishment of contact with its opposing tooth.

—          The phase of adaptation to the occlusion. It represents all the movements of the tooth throughout its presence in the dental arch (egression, version, rotation, etc.).

By age 3, all temporary teeth have erupted normally. This state will last until the age of 6, the date of the appearance of the first permanent molar. We then move on to mixed dentition which will spread until the loss of the last baby tooth, generally around the age of 12 years.

It is during this period that the child will lose his baby teeth, which are gradually replaced by permanent teeth. The root of milk teeth is resorbed under the effect of the underlying eruption of the permanent teeth (we speak of rhizalyse), sometimes resulting in exposure of the dental pulp due to the tooth wear that accompanies the phenomenon.

This transitional phase often hosts various dental disorders.

Here is the physiological eruption schedule for permanent teeth:

Lower teeth

– First molars: 6 to 7 years

– Central incisors: 6 to 7 years

– Lateral incisors: 7 to 8 years

– Canines: 9 to 10 years old.

– First premolars: 10 to 12 years.

– Second premolars: 11 to 12 years old.

– Second molars: 11 to 13 years old.

– Third molars (wisdom teeth): 17 to 23 years old.

Upper teeth

– First molars: 6 to 7 years

– Central incisors: 7 to 8 years

– Lateral incisors: 8 to 9 years

– First premolars: 10 to 12 years.

– Second premolars: 10 to 12 years old.

– Canines: 11 to 12 years old.

– Second molars: 12 to 13 years old.

– Third molars (wisdom teeth): 17 to 23 years old.

This calendar remains above all indicative: there is indeed a great variability in eruption ages. In general, girls are ahead of boys. 

The general structure of the deciduous tooth does not differ much from that of permanent teeth. However, there are some differences^{3 4} :

– The color of milk teeth is slightly whiter.

– The email is thinner, which exposes them more to decay.

– The dimensions are obviously smaller than their final counterparts.

– The coronary height is reduced.

The temporary dentition favors the evolution of swallowing which passes from a primary state to a mature state. It also ensures chewing, phonation, plays a role in the development of the facial mass and growth in general.

Brushing milk teeth should start as soon as the teeth appear, mainly to familiarize the child with the gesture because it is not very effective at the start. On the other hand, regular checks should start from 2 or 3 years old to get the child used to it. 

Children are at high risk for shock, which can lead to dental complications years later. When the child begins to walk, he usually has all his “front teeth” and the slightest shock can have consequences. Such incidents should not be minimized on the pretext that they are milk teeth. Under the effect of the shock, the tooth can sink into the bone or become mortified, eventually causing a dental abscess. Sometimes the germ of the corresponding definitive tooth can even be damaged.

According to several studies, 60% of the population undergoes at least one dental trauma during their growth. 3 in 10 children also experience it on milk teeth, and particularly on the upper central incisors which represent 68% of traumatized teeth.

Boys are twice as prone to trauma as girls, with a peak in trauma at age 8. Concussions, subluxations and dental dislocations are the most common traumas.

Can a decayed baby tooth have consequences on future teeth?

An infected baby tooth can damage the germ of the corresponding definitive tooth in the event that the pericoronal sac is contaminated. A decayed tooth should be visited by the dentist or pediatric dentist.

Why do you sometimes have to pull out baby teeth before they fall out on their own?

There may be several reasons for this:

– The baby tooth is too decayed.

– The baby tooth is fractured as a result of a shock.

– The tooth is infected and the risk is too great that it will infect the final tooth.

– There is a lack of space due to stunted growth: it is preferable to clear the way.

– The germ of the final tooth is late or is misplaced.

The loss of the first baby tooth is a new confrontation with the idea that the body can be amputated of one of its elements and can therefore constitute a distressing episode. This is the reason why there are so many legends and tales which transcribe the emotions experienced by the child: the fear of being in pain, surprise, pride….

La little mouse is a very popular myth of Western origin which aims to reassure the child who loses a baby tooth. According to legend, the little mouse replaces the baby tooth, which the child places under the pillow before falling asleep, with a small room. The origin of this legend is not very clear. It could have been inspired by a tale of Madame d’Aulnoy in the XNUMXth century, The Good Little Mouse, but some believe that they derive from a very old belief, according to which the final tooth takes the characteristics of the animal that swallows the corresponding baby tooth. We hoped then that it was a rodent, known for the strength of its teeth. For this, we threw the baby tooth under the bed in the hope that a mouse would come and eat it.

Other legends exist all over the world! The legend of Tooth Fairy, more recent, is an Anglo-Saxon alternative to the little mouse, but is modeled on the same model.

The American Indians used to hide the tooth in a tree in the hope that the final tooth will grow straight like a tree. In Chile, the tooth is transformed by the mother into bijou and should not be exchanged. In the countries of southern Africa, you throw your tooth in the direction of the moon or the sun, and a ritual dance is performed to celebrate the arrival of your final tooth. In Turkey, the tooth is buried near a place that we hope will play a big role in the future (the garden of a university for brilliant studies, for example). In the Philippines, the child hides his tooth in a special place and has to make a wish. If he manages to find her a year later, the wish will be granted. Many other legends exist in different countries of the world.