Missing tooth 10
Leaving out wisdom teeth, the upper lateral incisor is the second most commonly missing adult tooth, after the lower second premolar. Overall, 4.4% to 13.4% of people are born without at least one adult tooth, depending on where they live.
Peg on one side, missing on the other. A review of 36 studies found that when only one upper lateral incisor is peg-shaped, it is the left one twice as often as the right. In about 55% of people with one peg lateral, the lateral incisor on the other side never formed.
Two main options. A dentist or orthodontist can move the canine forward to stand in for the missing tooth, or open and hold the space for an implant or bridge later. Holding the space needs less tooth movement, but the gap must be kept open with a temporary tooth, especially if an implant is planned. The AAPD notes that patients generally prefer closing the space over implants.
The same tooth on the right side, tooth 7, has its own section on peg-shaped lateral incisors.
Where is tooth 10?
Tooth 10 is in your upper jaw on your left side. It is the second tooth from the middle: start at the gap between the two top front teeth and count 2 teeth toward the back on your left side.
In a mirror, tooth 10 shows on the left side of your reflection. Someone looking into your mouth sees it on their right.
In front of it (toward the middle) is tooth 9, the upper left central incisor. Behind it is tooth 11, the upper left canine.
Its mirror twin on the right side is tooth 7. The tooth in the same spot in the lower jaw is tooth 23, the lower left lateral incisor.
Dental charts show the patient's right side on the left, so tooth 10 sits on the right half of the top row. Universal numbers continue across the top: upper left teeth run from 9 (the front tooth) to 16 (the wisdom tooth).
What does the upper lateral incisor do?
Incisors have a thin, straight biting edge for cutting into food. They are the most visible teeth in the mouth. Upper lateral incisors sit between the big front teeth and the canines. They are smaller than the central incisors and vary more in size and shape from person to person.
Common problems with upper lateral incisors
- Pressure from a stuck canine. An upper canine that can't come in normally can press on this tooth's root and wear it away (root resorption).
- Cavities and chips. Small cavities are fixed with a filling. If decay or an injury reaches the nerve, root canal treatment can save the tooth, often followed by a crown.
If tooth 10 hurts, feels loose, or the gum around it swells, the Dental Emergency Checker can help you decide how soon to see a dentist. Swelling that spreads to the eye or neck, or makes it hard to breathe or swallow, is an emergency: call 911. These are typical problems for this kind of tooth, not a diagnosis.
When does tooth 10 come in?
Both the ADA and AAPD charts give 8–9 years for the upper lateral incisors.
Tooth 10 replaces the upper left baby lateral incisor (tooth G), which usually falls out at 7–8 years (ADA).
In the ADA chart, they usually come in after the lower lateral incisors (7–8 years) and before the lower canines (9–10 years). In the AAPD's 13-step order, from the first molars (step 1) to the wisdom teeth (step 13), they are step 5.
Under the gum, according to the AAPD chart, it starts to harden (calcify) at about 10–12 months, has a finished crown by 4–5 years and has a finished root by about 11 years, a few years after it comes into the mouth.
How many roots does tooth 10 have?
One root.
Tooth 10 in FDI and Palmer notation
| System | Tooth 10 is written | What it means |
|---|---|---|
| Universal (ADA, used in the US) | 10 | Adult teeth are numbered 1–32 around the mouth, starting at the upper right wisdom tooth. |
| FDI / ISO 3950 (international) | 22 | First digit 2 = upper left quarter; second digit 2 = second tooth from the middle. Said "two-two". |
| Palmer | └2 (often typed UL2) | The └ bracket marks the upper left quarter; 2 = second tooth from the middle. |
There is no FDI tooth 10. In FDI the second digit only runs from 1 to 8, so 10 can only be a Universal number.
On a US chart, "22" is a different tooth. Universal 22 is the lower left canine (tooth 22), so "tooth 22" only means this tooth when the chart uses FDI.
Palmer needs the bracket. Every quarter of the mouth has a tooth 2 in Palmer notation; only the └ (or the letters UL) makes it this one.
All adult teeth in the upper left quarter
From the front of the mouth to the back:
| Universal | FDI | Palmer | Tooth |
|---|---|---|---|
| 9 | 21 | └1 (UL1) | Central incisor |
| 10 | 22 | └2 (UL2) | Lateral incisor (this tooth) |
| 11 | 23 | └3 (UL3) | Canine |
| 12 | 24 | └4 (UL4) | First premolar |
| 13 | 25 | └5 (UL5) | Second premolar |
| 14 | 26 | └6 (UL6) | First molar |
| 15 | 27 | └7 (UL7) | Second molar |
| 16 | 28 | └8 (UL8) | Wisdom tooth |
The Tooth Number Chart & Converter converts any tooth between the three systems.
Tools for tooth 10
- Knocked-Out Tooth Rescue: first aid for a knocked-out adult tooth.
- Dental Emergency Checker: how soon to see a dentist if it hurts or breaks.
- Adult Teeth Predictor: likely dates for your child's adult teeth.
- How Long Does Dental Work Last?: how long fillings, crowns, veneers and implants usually last, from long-term studies.
- Dental Treatment Plan Decoder: plain English for treatment-plan shorthand like "#30 MOD comp".
Frequently asked questions
What tooth is number 10?
Is tooth 10 the same as tooth 22?
At what age does tooth 10 come in?
What if tooth 10 never grew in?
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.
- Cleveland Clinic. Teeth: Anatomy, Types, Function & Care. last updated January 26, 2023. Accessed October 26, 2026.
- Schroder AGD et al. Journal of the American Dental Association 149(9):765–777. To what extent are impacted canines associated with root resorption of the adjacent tooth? A systematic review with meta-analysis. 2018. Accessed October 26, 2026.
- Hua F, He H, Ngan P, Bouzid W. American Journal of Orthodontics and Dentofacial Orthopedics 144(1):97–109. Prevalence of peg-shaped maxillary permanent lateral incisors: a meta-analysis. 2013. Accessed October 26, 2026.
Last reviewed by the Dental Health Time editorial team, against the sources above. How we review.