Parents of children (aged six or under)
Tooth transition

When children enter the tooth transition period, their deciduous teeth will loosen due to the resorption of the roots and will sequentially fall off. The permanent teeth will gradually erupt into the space left by the deciduous teeth. Tooth transition period starts approximately at the age of 6, and ends at around the age of 12 or 13.

The alignment and eruption time of permanent teeth

There are altogether 32 permanent teeth. Since dentine is usually slightly yellowish, and the enamel in permanent teeth is more transparent than that of deciduous teeth, the colour of permanent teeth is more yellowish than deciduous teeth. As the thickness of dentine grows as a person ages, the teeth will also become more yellowish.

Eruption Time of Permanent Teeth

Permanent Teeth Eruption Time
Central Incisor 6 to 8 years
Lateral Incisor 61/2 to 9 years


81/2 to 121/2 years
First Premolar 8 to 12 years
Second Premolar 81/2 to 13 years
First Molar 5 to 7 years
Second Molar 10 to 14 years
Third Molar (Wisdom tooth) 17 to 25 years
Points to note during tooth transition
  • At about the age of 6, the first permanent molar will erupt behind the four ends of deciduous teeth; it is also called the ‘six-year molar'. At this time, parents must remember to remind their children to clean the ‘six-year molar' by brushing the very back tooth with a toothbrush and fluoride toothpaste and thoroughly brush all the tooth. This could avoid gum inflammation and caries on the ‘six-year molar'.
  • Generally speaking, deciduous teeth will exfoliate by themselves. There is no need to extract them because premature loss of deciduous teeth will lead to irregular permanent teeth.
  • Teeth will become loose during tooth transition. There may be mild bleeding during brushing. Parents should remember to advice their children to continue to keep good oral hygiene, including the area around the loose deciduous teeth, to avoid gum inflammation.
Common problems during teething
  • Why is the newly erupted front teeth serrated on the edge?
    It is normal for newly erupted front teeth to appear saw-shaped on the edge. It will be naturally grinded and become flat after a period of time.
  • My child's upper front teeth are flared with a gap in between. Does he/she need orthodontic treatment?
    This is a transitional period called ‘the ugly duckling stage'. Under normal circumstances, when the upper jaw develops well and the canines on both sides erupt, the front teeth will straighten and the gap will close up.
  • My child's lower permanent front tooth erupted behind the deciduous front tooth. Is it necessary to extract the deciduous front tooth?
    Generally speaking, the deciduous front tooth will naturally exfoliate and the permanent front tooth will erupt into the space. The tip of tongue will push the permanent front tooth forward into the space left by the deciduous tooth. Therefore, there is no need to extract the deciduous front tooth.
  • The newly erupted permanent front teeth are not well aligned. Can the neighbouring deciduous teeth be extracted to allow front teeth to align correctly?
    Since permanent teeth are bigger than deciduous teeth, and jawbones are not completely developed in children, the newly erupted permanent teeth may not have enough room to align properly and they look crowded. However, we usually cannot determine whether the permanent teeth will have a good alignment until the first premolar are erupted and jawbones' development have stabilized If you have any queries please ask your dentist for further advice.
  • My child's has irregular teeth. When is the suitable time for him/her to have orthodontic treatment?
    Generally speaking, we cannot assure whether the tooth alignment is irregular or not until all the permanent teeth have replaced the deciduous teeth and the development of jawbones have stabilized. Then, we could decide whether an orthodontic treatment is needed.
  • Is there a problem if tooth transition happens later in my child than his/her friends of the same age?
    You don't need to worry since the timing of tooth transition varies between different individuals. If your have any queries regarding tooth transition, you may consult your dentist.

Related topics:
Queries on Tooth Transition ( PDF Leaflet)
Two sets of teeth in a lifetime (PDF Leaflet)