The timing of tooth eruption varies from child to child, and delays of a few months are usually normal. Still, going beyond certain limits or a marked difference between the right and left sides may call for an assessment.
Late eruption of baby teeth
In most babies the first baby tooth appears between 6 and 10 months. If no tooth has come through by 12 months, this is mostly a family trait; however, for delays beyond 15–18 months an assessment by a paediatrician and a dentist is recommended.
Late eruption of permanent teeth
Permanent teeth usually start around age 6 with the lower front incisors and the first molars and continue until 12–13. An assessment is useful in the following situations:
- No permanent tooth coming through more than 6 months after a baby tooth falls out
- A tooth on one side has come through but its partner on the other side has not for a long time
- A baby tooth staying in place for a long time without becoming loose
- A permanent tooth coming through behind the baby tooth or in a different direction
Possible causes
- Family traits: The parents' teeth may also have come in late.
- Lack of space: A tooth may struggle to erupt if there is not enough room in the jaw.
- Impacted tooth: Upper canines in particular tend to remain impacted.
- Congenitally missing tooth: The bud of some permanent teeth may never have formed.
- Extra teeth or a cyst: These can block eruption.
- Early loss of a baby tooth: Thickened gum in the area can delay eruption.
- Some general health conditions and hormonal causes
How is it diagnosed?
At the examination, the eruption status of the teeth is assessed; if needed, a panoramic X-ray is used to look at the buds, position and eruption direction of the permanent teeth. An X-ray allows missing or impacted teeth to be spotted early.
Why does it matter for orthodontics?
When impacted or misdirected teeth are spotted early, simple steps such as making space or removing a baby tooth can help the tooth erupt on its own. That is why a first orthodontic check-up is recommended at about age 7. For details, see our early orthodontic treatment page.
