When does tooth P come in and fall out?
The lower baby central incisors usually come in at 6–10 months and fall out at 6–7 years (ADA). The AAPD chart gives 5–8 months to come in and 6–7 years to fall out.
In the ADA chart, they are among the first to come in, and they are among the first to fall out, along with the upper baby central incisors.
Tooth P is replaced by tooth 25, the lower right central incisor, which usually comes in at 6–7 years (ADA). Under the gum, tooth P starts to harden in the 4th month of pregnancy and is fully formed by about 18–24 months (AAPD).
When tooth P gets loose
Lower baby central incisors are usually among the first baby teeth to fall out, at 6–7 years (ADA).
As the adult tooth underneath grows, it slowly dissolves the baby tooth's root. That is why a baby tooth gets loose before it falls out.
An adult tooth behind it. The adult tooth (tooth 25) sometimes comes in behind the baby tooth instead of pushing it out from below. In one study of children aged 5 to 7½ with this pattern, about 7 in 10 lost the baby teeth on their own without treatment, and about 15% needed a baby tooth removed.
The same tooth on the left side, tooth O, has its own section on first teeth, teething and natal teeth.
Where is tooth P?
Tooth P is one of the two bottom front teeth right in the middle of your child's mouth: the one on their right side.
"Left" and "right" always mean the child's own sides, so when you face your child, tooth P is on your left.
Right next to it, across the middle, is tooth O, the other lower baby central incisor. Behind it is tooth Q, the lower right baby lateral incisor.
Its mirror twin on the left side is tooth O. The tooth in the same spot in the upper jaw is tooth E, the upper right baby central incisor.
Dental charts show the patient's right side on the left, so tooth P sits just left of the center line of the bottom row. Lower right teeth finish the circle, from P (the front tooth) to T (the back molar).
What does the lower baby central incisor do?
Baby incisors are the front teeth young children use to bite and cut soft food. Baby teeth matter even though they fall out: children need them to chew, speak and smile, and they help the adult teeth come in correctly.
How many roots does tooth P have?
One small root, which dissolves as the adult tooth grows underneath.
Common problems with lower baby central incisors
- Injuries. Worldwide, about 1 in 5 children (22.7%) injure at least one baby tooth. In baby teeth the most common injury is a tooth pushed out of position (a luxation) rather than a broken tooth.
- Cavities. The AAPD advises repairing decayed baby teeth when possible, rebuilding each tooth to its original shape so it keeps its place until the adult tooth is ready.
If a baby tooth is knocked loose or out in a fall, or your child has swelling, fever or pain, call your dentist. Never put a knocked-out baby tooth back in (Knocked-Out Tooth Rescue explains why). Swelling that makes it hard to breathe or swallow is an emergency: call 911. These are typical problems for this kind of tooth, not a diagnosis.
Tooth P in FDI and Palmer notation
| System | Tooth P is written | What it means |
|---|---|---|
| Universal (ADA, used in the US) | P | Baby teeth are lettered A–T around the mouth, starting at the upper right back molar. |
| FDI / ISO 3950 (international) | 81 | First digit 8 = lower right quarter (baby teeth use 5–8); second digit 1 = first baby tooth from the middle. Said "eight-one". |
| Palmer | A┐ (often typed LRA) | The ┐ bracket marks the lower right quarter; A = first baby tooth from the middle. |
Palmer stops at E. Palmer letters only run from A to E in each quarter, so a "P" can only be a Universal letter.
FDI baby teeth start with 5 to 8. The first digit 8 marks the lower right baby quarter, so FDI 81 can't be mixed up with an adult tooth.
Letters and numbers don't line up. P is letter 16 of the alphabet, but baby tooth P is replaced by adult tooth 25, not tooth 16.
All baby teeth in the lower right quarter
From the front of the mouth to the back:
| Universal | FDI | Palmer | Tooth |
|---|---|---|---|
| P | 81 | A┐ (LRA) | Baby central incisor (this tooth) |
| Q | 82 | B┐ (LRB) | Baby lateral incisor |
| R | 83 | C┐ (LRC) | Baby canine |
| S | 84 | D┐ (LRD) | Baby first molar |
| T | 85 | E┐ (LRE) | Baby second molar |
The Tooth Number Chart & Converter converts any tooth between the three systems.
Tools for tooth P
- Teething Calculator: which baby teeth are due at your baby's age.
- Baby Teeth Tracker: log each tooth in and out.
- Kids Fluoride Calculator: how much toothpaste to use; the ADA says a rice-grain smear until age 3, then a pea-size amount.
- Tooth Fairy Calculator: what families give for a lost tooth.
- Dental Treatment Plan Decoder: plain English for treatment-plan shorthand like "#30 MOD comp".
Frequently asked questions
What tooth is letter P?
When does tooth P come in?
When does tooth P fall out?
What if the adult tooth comes in behind tooth P?
Sources
- American Dental Association (MouthHealthy). Permanent Tooth Development (eruption chart). 2012. Accessed October 26, 2026.
- American Dental Association (MouthHealthy). Primary Tooth Development (eruption chart). 2012. Accessed October 26, 2026.
- American Academy of Pediatric Dentistry. Dental Growth and Development (chronology after Logan & Kronfeld 1933, adapted 2003). Accessed October 26, 2026.
- American Academy of Pediatric Dentistry. Management of the Developing Dentition and Occlusion in Pediatric Dentistry (Reference Manual of Pediatric Dentistry). latest revision 2024. Accessed October 26, 2026.
- World Health Organization. Oral health surveys: basic methods, 5th edition (tooth notation after ISO 3950). 2013. Accessed October 26, 2026.
- Nelson SJ. Elsevier. Wheeler's Dental Anatomy, Physiology and Occlusion, 11th edition. 2019.
- American Dental Association. ADA Dental Claim Form (tooth designation systems). Accessed October 26, 2026.
- Dentalcare.com (continuing education course CE500). An Overview of Dental Anatomy: Types of Teeth and their Functions. Accessed October 26, 2026.
- American Dental Association (MouthHealthy). Tooth Decay with Baby Bottles. Accessed October 26, 2026.
- Levin L et al. (International Association of Dental Traumatology). Dental Traumatology 36(4):309–313. IADT guidelines for the management of traumatic dental injuries: General introduction. 2020. Accessed October 26, 2026.
- Petti S, Glendor U, Andersson L. Dental Traumatology 34(2):71–86. World traumatic dental injury prevalence and incidence, a meta-analysis. 2018. Accessed October 26, 2026.
- Aminabadi NA, Farahani RM, Sohrabi A, Pouralibaba F. Journal of Contemporary Dental Practice 10(1):25–32. Lingual eruption of mandibular permanent incisors: a space correlated phenomenon?. 2009. Accessed October 26, 2026.
Last reviewed by the Dental Health Time editorial team, against the sources above. How we review.