A baby tooth that is still in place in adulthood is usually there for one reason: the adult tooth that should have replaced it never formed. With no successor to push it out, the baby tooth can stay put and, if it is healthy, often serves well for many years. The main questions are whether it is still sound, whether it is sinking below the bite line, and whether and when it should be replaced.
Key takeaways
- A retained baby tooth in an adult most often means the permanent successor is missing, a condition present from birth.
- The teeth most often involved are the lower second baby molar and the upper baby canine or incisor region.
- A healthy retained baby tooth can be kept and monitored, sometimes for decades.
- Replacement is considered when the tooth sinks below the bite, its root wears down, or it becomes unhealthy.
Why a baby tooth stays
Baby teeth are normally pushed out when the adult tooth beneath them erupts and resorbs their roots. When the adult successor never developed, a condition called hypodontia, there is nothing to trigger this process, so the baby tooth simply remains. Studies of retained baby teeth find a missing successor in roughly two thirds of cases. The lower second baby molar is the classic example, because the second premolar that should replace it is one of the most commonly missing adult teeth. A retained baby tooth often runs alongside other developmental differences, such as small or peg-shaped teeth, which is why a dentist looks at the whole picture. Our guide on missing teeth explains the underlying pattern.
Keep it or replace it?
This is the central decision, and it depends on the condition of the tooth rather than its age. A retained baby tooth that is firm, healthy, well-positioned and has a good root can be a perfectly good tooth, and keeping it avoids the cost and complexity of replacing it. Over time, though, some retained baby teeth begin to sink relative to the neighbouring teeth, wear down, or develop root resorption, and at that point replacement enters the conversation. The table sets out the usual considerations.
| Situation | Usual approach |
|---|---|
| Firm, healthy, good root, level with the bite | Keep and monitor with regular reviews and X-rays |
| Sinking below the bite line (infraocclusion) | Assess for build-up or planned replacement |
| Root resorbing or tooth becoming loose | Plan removal and a replacement option |
| Decayed or repeatedly problematic | Weigh restoration against removal and replacement |
How a sinking tooth is managed
When a retained baby tooth starts to sit lower than its neighbours, it is often because it has fused to the bone and stopped keeping pace as the jaw grows, a process called ankylosis. A mild case can sometimes be built up with tooth-coloured material to restore the bite height and appearance. A more marked case, or one where the root is failing, is usually planned for removal followed by a replacement. Options include an implant once jaw growth is complete, a bridge, or closing the space with orthodontics, and the best choice depends on the gap, the bite and the person’s preferences. Our guide on an ankylosed or submerged baby tooth explains the sinking process in more detail, and you can read about dental implants on our service page.
Looking after a retained baby tooth
If you have a baby tooth that has stayed into adulthood, the practical advice is straightforward: care for it exactly as you would any other tooth, with twice-daily brushing, cleaning between the teeth, and regular check-ups. The value of those check-ups is that your dentist can track the tooth with occasional X-rays and spot early signs of it sinking or its root wearing down, which allows any replacement to be planned calmly rather than rushed. Many people keep a healthy retained baby tooth for a very long time. This is general information, and the right plan for your tooth depends on an examination.
Frequently asked questions
Why do I still have a baby tooth as an adult?
Most often because the adult tooth that should have replaced it never formed, so there was nothing to push the baby tooth out. It can then stay in place for years.
Do I need to have it removed?
Not if it is healthy, firm and level with your bite. Many retained baby teeth are kept and monitored. Removal is considered if the tooth sinks, its root wears down, or it becomes unhealthy.
How long can a retained baby tooth last?
A healthy one can last many years and sometimes decades. Regular reviews with occasional X-rays help track it so any change is caught early.
What are the replacement options?
If a retained baby tooth needs removing, options include a dental implant once jaw growth is complete, a bridge, or closing the space with orthodontics, depending on the gap and your preferences.
Why is my baby tooth lower than the others?
It may have fused to the bone and stopped keeping pace as the jaw grew, so it now sits below the bite line. A dentist can assess whether to build it up or plan a replacement.
If you have a baby tooth still in place as an adult, the team at Lumi Dental in Melrose Park can assess it and talk through whether to keep or replace it. Learn about our general dental care or see our current deals. We do not publish prices in our articles and are happy to provide a written estimate after an examination.
This article is general information only and is not a substitute for personalised dental advice. Please see a dentist about your own situation.
