Around the age of six, the development of permanent teeth in the maxillary bone causes the resorption of the roots of temporary teeth to the point where they become mobile, are then exfoliated and replaced one by one by similar teeth, except for the temporary molars that are replaced by the premolars.
This stage is called the period of mixed teeth (the presence of both deciduous and permanent teeth in the arcade). It lasts until around the age of 12 when the last temporary tooth has disappeared and only the permanent ones remain.
It is very important for parents to periodically examine the child's mouth, especially during mixed dentition. But how do we figure out which teeth are going to fall and which have already been replaced? We need to know some differences between the two types of teeth.
First, permanent teeth are larger and more globular than primary ones, and the latter often show signs of atriation (they look worn-out).
Also, since the dentin is yellow (the inner layer) and the permanent teeth enamel (the outer layer) is more transparent than the primary ones', the color of the new teeth will be more yellow than the temporary teeth. As the thickness of the dentin increases with age, the teeth will become more and more yellowish.
In most cases, the milk teeth will exfoliate on its own. It is not recommended to be extracted before their age of exfoliation because the premature loss of temporary teeth will lead to irregular eruption of permanent teeth, so they need to stay in place until they become mobile to keep their space on the dental arch. When they start to get loose, there may be a slight bleeding during brushing, but it is best to maintain a good oral hygiene, including in the area around mobile milk teeth, to avoid any gum inflammation that may occur.
In total, the final teeth contain 32 teeth. Excluding the wisdom teeth, whose dental buds may or may not exist and which may erupt anytime after the age of 18, even at older ages, permanent teeth erupt in the following periods:
Upper dental arch:
• Central incisors - 7-8 years
• Lateral incisors - 8-9 years
• Cuspids - 11-12 years
• First premolars - 10-11 years
• Second premolars - 10-12 years
• First molars - 6-7 years
• Second molars - 12-13 years
Lower dental arch:
• Central incisors - 6-7 years
• Lateral incisors - 7-8 years
• Cuspids - 9-10 years
• First premolars - 10-12 years
• Second premolars - 11-12 years
• First molars - 6-7 years
• Second molars - 11-13 years
At the age of 6, the first permanent molars will erupt behind the four temporary second molars. They are also called the "six-year molars".
At this point, parents have to tell or even help their children to brush their teeth and the gum around them with a toothbrush and toothpaste. This is very useful in avoiding cavities and gum inflammation on these molars.
Should I worry if my child's teeth erupt later than those of his colleagues or friends of the same age with him ?
You do not have to worry because the eruption schedule of permanent teeth varies between different people. If you have any questions about your child, you can schedule a consultation at our clinic.
Why do permanent front teeth have jagged incision edges ?
It is perfectly normal for the freshly erupted front teeth to have the incisal edge in the form of a saw. It will naturally wear-out and will become liniar after a period of time.
The upper teeth of my child's upper teeth are spaced apart. Does he need orthodontic treatment ?
This is only a transition period called the "ugly duckling". Under normal circumstances, when the upper jaw develops well and the canines on both sides erupt correctly, the front teeth will straighten and the spaces will close.
The front lower tooth erupted behind the milk tooth. Does the baby tooth need to be extracted ?
Typically, the primary tooth will naturally exfoliate, and the permanent front tooth will erupt in the remaining space. The tip of the tongue will then push over time the tooth forward into the space left by the temporary one. Therefore, there is no need to remove the tooth. But there are situations in which there is no root resorption of the primary tooth, and although the permanent one has almost ended its eruption, the temporary one does not show any signs of mobility. In this situation, it is recommended to extract the primary one.
The newly erupted front teeth are not well aligned. Can the neighboring milk teeth be extracted to allow them to align properly?
Since the permanent teeth are larger than the temporary teeth, and the maxillary bones are not fully developed in children, the newly emerging teeth don't always have enough space to properly align. However, it is usually not possible to determine if the permanent teeth will have a good alignment until the first premolar has erupted and the development of the bones has stabilized. For more information, it is advisable to consult a dentist.
The mixed dentition period is the one in which it is most appropriate to seal the newly erupted teeth. You can learn more about this procedure at Sealing Out Tooth Decay.
Published: June 18th, 2017