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Teeth development – a timeline

 bone Teeth development happens long before we are born.  We then spend nearly two decades working through a complex multi-phase process that sees all teeth in place by about the time we transition into adulthood.

It’s a fascinating timeline where a number of factors are at play. So, here’s an insight into how teeth develop and the role an orthodontist has in ensuring they arrive at their ideal position.

The Timeline of Teeth Development

Before birth

Teeth are among the many human features that have their beginning very early in a baby’s development in the womb.

Researchers note baby teeth (primary teeth) actually start to form between the sixth and eighth week of prenatal development. Permanent teeth, meanwhile, begin to form about halfway through the gestation period at 20 weeks.

Although they’re there and waiting, we don’t see primary teeth begin to emerge until about eight months after a child is born, while the permanent teeth beneath them only start erupting at about six years of age.

Tooth eruption

Teeth are as individual as the people they belong to so the timeline of teeth eruption can vary from one person to another, but there is a general timeframe when teeth tend to make an appearance.

The first stage involves the arrival of those all-important baby teeth. Baby teeth play an important role in development. Their job is to facilitate speech, eating and facial formation while maintaining the space and position that will be later for the permanent teeth. 

Baby teeth

Humans have 20 baby teeth, which erupt over the course of about two years. As these teeth hold the space required for adult teeth, it’s important they are well cared for.


  • Lower central incisors (bottom front teeth) – about 8 months
  • Upper central incisors (top front teeth) – about 10 months
  • Upper lateral incisors – about 11 months
  • Lower lateral incisors – about 13 months
  • Lower canines – about 10 months
  • Upper canines – about 19 months
  • First upper molars – about 16 months
  • First lower molars – about 16 months
  • Second lower molars – about 27 months
  • Second upper molars – about 29 months

Adult teeth

Including the wisdom teeth, adults have 32 permanent teeth, which begin to erupt from about the time a child is six or seven. Again, this timeframe can vary depending on the individual.

  • The lower central incisors – 6 to 7 years
  • The upper central incisors – 7 to 8 years
  • The lower lateral incisors – 7 to 8 years
  • The upper lateral incisors – 8 to 9 years
  • The lower canine teeth – 9 to 10 years
  • The upper canine teeth – 11 to 12 years
  • The first upper pre-molars – 10 to 11 years
  • The first lower pre-molars – 10 to 12 years
  • The second upper pre-molars – 10 to 12 years
  • The second lower pre-molars – 11 to 12 years
  • The first upper molars – 6 to 7 years
  • The first lower molars – 6 to 7 years
  • The second lower molars – 11 to 13 years
  • The second upper molars – 12 to 13 years
  • The upper and lower third molars (wisdom teeth) – 17 to 21 years

The teeth timeline and orthodontics

From the time adult teeth begin erupting, orthodontists are the professionals who keep a watchful eye on teeth development, spacing and placement. These are the highly qualified individuals best suited to ensuring those teeth and the bite are correctly aligned to ensure a beautiful smile that lasts a lifetime.

So, what are the key teeth development milestones wherein one should consult an orthodontist?

At aged 7 to 10

The Australian Society of Orthodontists recommends children first see an orthodontist when they are between the ages of 7 and 10.

At this stage, some of the permanent teeth are in place. This allows an orthodontist to gauge any potential issues that could become problems, and in some cases, early orthodontic intervention might be of benefit.

Early assessment and intervention may mean less invasive treatments are required at a later date.

If a baby tooth is lost prematurely

If your child prematurely loses a baby tooth due to trauma or decay, an orthodontist is among the professionals who can assist.

As mentioned, baby teeth hold the space required for the adult teeth that are yet to emerge. It’s a function that should not be underestimated in the formation of a properly aligned jaw and straight smile.

If a baby tooth is lost prematurely, other teeth can move in to fill this position which has the potential to create overcrowding and improper alignment later down the track.

To mitigate this risk an orthodontist may recommend your child has a space maintainer inserted to “hold” the correct position for the adult tooth that will later emerge. 

When a child reaches their teens

The teen years are generally the prime time for orthodontic work. At this stage, almost all adult teeth other than the wisdom teeth have erupted.   The upper palette though has not yet fused, and the jaw structure is still malleable enough to easily correct.

If they have not seen an orthodontist beforehand, ithe recommendarion is for your child to undergo assessment in their early teens to find out whether they require orthodontic treatment.

When wisdom teeth are imminent

Regardless of whether you have naturally straight teeth or you have had braces and other orthodontic treatment, dental professionals recommended teens check in again with their orthodontist from about the age of 15 or 16 to determine what’s happening with the wisdom teeth.

In many cases catering to these last teeth to the dental party is as simple as wearing a retainer to ensure the other teeth stay in position. However, in some cases, wisdom teeth may be impacted and require removal.

About Norwest Orthodontics

Norwest Orthodontics specialises in helping you achieve a great smile, no matter your age. We feature a range of orthodontic treatments that span from early intervention right through to remedial adult work.

We also have a suite of treatments available that include discreet, removable Invisalign braces, and welcome the opportunity to work with you to achieve the smile you’ve always dreamed of.

You can learn more about our services, or contact us here to make an appointment here.

Teeth development – a timeline

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