Tooth eruption is the process by which teeth move from their developmental position within the jaw into their functional position in the mouth. For parents, it’s one of the most consistent sources of questions across the first two decades of a child’s life, from the appearance of the first baby tooth at around six months through to wisdom teeth in early adulthood.
This guide covers the full eruption process, what to expect at each stage, what signs indicate a problem worth investigating, and how to care for teeth as they come through.
The Two Phases of Tooth Eruption
Primary Teeth (Baby Teeth)
The first phase of eruption begins around six months of age, when the lower central incisors typically appear. The remaining primary teeth follow in a broadly predictable sequence over the next two to two-and-a-half years, with the full set of 20 primary teeth usually complete by age three.
Primary teeth play a more important role than many parents realise. They hold space for the permanent teeth developing beneath them, guide jaw growth, support speech development, and allow normal chewing function during the critical early years of childhood. Decay in baby teeth is not a minor issue, it affects the bone and tissue surrounding the developing permanent tooth and can have lasting consequences.
Permanent Teeth
The second phase begins around age six, when the first permanent molars erupt at the back of the mouth and the lower central incisors start to replace the baby teeth at the front. This phase continues progressively through childhood and early adolescence, with the full set of 28 permanent teeth typically in place by age 13. Wisdom teeth, if they develop, emerge between ages 17 and 21.
The full eruption timeline for both baby and adult teeth, including typical age ranges for each tooth type, is covered in the complete guide to when children lose their baby teeth.
Signs That a Tooth Is About to Erupt
The signs vary depending on age and whether a baby or adult tooth is emerging.
For baby teeth, the earliest indicators are often behavioural rather than visible: increased drooling, a tendency to chew and gnaw on objects, gum swelling and redness at the eruption site, and mild irritability in the days before the tooth breaks through. Some babies experience very little discomfort; others are noticeably unsettled. A slight rise in temperature is sometimes associated with teething, though a true fever is not caused by eruption and always warrants separate medical attention.
The detailed guide to baby teething covers the full sequence of primary tooth eruption and symptom management in practical detail.
For adult teeth, the most common early sign is visible movement of the gum tissue at the eruption site, often visible before the tooth breaks through. Some children experience pressure or mild soreness. It is also common to notice the baby tooth becoming noticeably loose before the adult tooth is visible, this is the root resorbing as the permanent tooth pushes upward.
What Is Normal Variation in Timing?
There is meaningful natural variation in when teeth erupt, and most deviations from the average timeline are not cause for concern. A tooth appearing a month or two earlier or later than the average age for that tooth type is common and generally unremarkable. Variation tends to run in families.
Early eruption of baby teeth is not problematic. A tooth emerging ahead of schedule should be monitored to ensure it comes through in a normal position and receives the same brushing care as any other tooth. Early erupted teeth may be more exposed to the oral environment before the surrounding teeth provide support, so regular monitoring for early decay is sensible.
Late eruption becomes worth investigating in specific circumstances. If a baby tooth hasn’t appeared by 12 to 13 months, or if there is a significant asymmetry where one side is erupting noticeably later than its equivalent on the other side, a dental assessment with X-rays can establish whether the tooth is present and properly positioned. The same applies to permanent teeth: if a permanent tooth hasn’t erupted within six months of the corresponding baby tooth falling out, professional assessment is appropriate.
The “Shark Tooth” Presentation
One of the most common eruption concerns parents bring to the dentist is the appearance of a permanent tooth emerging behind the baby tooth while it is still in place. This is sometimes called a “shark tooth” presentation and is more common in the lower front teeth.
In most cases, the baby tooth loosens and falls out naturally within a few weeks of the permanent tooth beginning to erupt. The tongue’s pressure against the baby tooth typically helps it along. If the baby tooth hasn’t noticeably loosened after six to eight weeks, a dental review is recommended as a simple extraction may be needed to clear the path.
When to Seek Professional Assessment
Most eruption progresses without requiring clinical intervention. The following situations warrant prompt professional review at Simply Dental Chatswood’s paediatric dental service:
- First tooth hasn’t appeared by 12 to 13 months of age
- Significant delay compared to the corresponding tooth on the other side
- Permanent tooth hasn’t appeared within six months of the baby tooth falling out
- tooth is erupting in an unusual position or angle
- Visible swelling, pus, or signs of infection around the eruption site
- Fever accompanying eruption symptoms, which suggests an unrelated infection needing medical attention
- Trauma or injury to a tooth in the process of erupting
If a child’s teeth are erupting in crowded or irregular positions, early orthodontic assessment can identify whether interceptive treatment would prevent more complex alignment issues later. The Australian Dental Association recommends a first orthodontic assessment at around age seven, not because treatment necessarily begins at this point, but to establish a baseline and monitor jaw development.
How to Care for Teeth During Eruption
Good dental hygiene begins before the first tooth appears. Wiping the gums with a clean damp cloth after feeds helps remove milk residue and familiarises the baby with the sensation of having their mouth cleaned.
Once teeth start emerging:
Brush from day one. As soon as a tooth appears, it needs brushing. Use a soft infant toothbrush and a rice-grain sized smear of fluoride toothpaste twice daily. Children under eight typically need supervision and assistance to ensure all surfaces are cleaned properly.
Floss when teeth are touching. Once adjacent teeth make contact, flossing removes the plaque that brushing cannot reach between them. This is where early decay most commonly begins in children.
Diet. Limit sugary drinks and snacks, particularly between meals. Put children to bed with water only, never milk, formula, or juice, as pooling of these liquids against the teeth overnight is a primary driver of early childhood decay.
Attend regular check-ups. Professional monitoring every six months from around 12 months of age allows fissure sealants to be applied to newly erupted molars, fluoride treatments to be provided, and any eruption concerns to be identified and managed early.
According to the Australian Dental Association, establishing a dental home in the first year of life is one of the most effective strategies for lifelong oral health, with early visits consistently associated with lower rates of treatment intervention throughout childhood.
Welcoming Families From Across the North Shore
Our paediatric dental team at Simply Dental Chatswood regularly sees children from infancy through adolescence for eruption monitoring and preventive care. If your family is based in Willoughby, Artarmon, or Castlecrag, our Chatswood practice is easy to reach.
Questions About Your Child’s Dental Development?
Whether your child is cutting their first tooth, you have concerns about timing, or you’ve noticed something that doesn’t look quite right, our team is here to help. Booking an appointment at our children’s dental clinic gives you access to the professional guidance and monitoring that makes a real difference to long-term outcomes.
Book your child’s appointment and give their teeth the best possible start.
