Why do the new incisors have serrated edges like a saw?
This is normal for new incisors. The serrated edges will be naturally grinded smooth in time.
The erupting upper incisors are flared and there is spacing between them. Is an orthodontic treatment required?
This is called the 'Ugly Duckling Stage' which is transitional only. Usually when the upper canines on both sides has erupted, the front teeth will straighten and the gap between them will close up.
A lower permanent front tooth has erupted behind the deciduous front tooth, is it necessary to extract the deciduous front tooth?
Commonly, the deciduous tooth will become loose by itself. The tongue will push the permanent front tooth forward into position. Gradually, the deciduous tooth will exfoliate by itself, the permanent tooth will align itself into normal position. Therefore, it usually do not need to remove the deciduous tooth in this kind of situation.
What can we do if the permanent front teeth are irregular (in malocclusion)?
Since permanent teeth are bigger than deciduous teeth, and jawbones are not yet completely developed in children, there may not temporarily have enough room to align the newly erupting permanent teeth properly and they look crowded. However, we can usually confirm there is a malalignment only when all the deciduous teeth are replaced by permanent teeth. If you have any queries, please ask your dentist for further information.
My teeth erupt later than my peers, is it a problem?
Don’t worry, the eruption time of the permanent teeth varies from person to person, even the difference of a year is considered normal.
Queries on Tooth Transition (Leaflet) (PDF)
Two sets of teeth in a lifetime (Leaflet) (PDF)
If you have any problems in mixed dentition stage, ask your parents to take you to a dentist!