Peg-shaped tooth 7
Some people have small, cone-shaped upper lateral incisors called "peg laterals". A review of 36 studies found them in about 1.8% of people. They were more common in women (1.35 times as often as in men) and in orthodontic patients (2.7%).
When only one side has a peg lateral, the review found it on the left twice as often as on the right (0.4% vs 0.2% of people).
A peg lateral can be built up to a normal shape with bonding, a veneer or a crown. It is also one of the signs that tell a dentist to check whether the canine next to it is coming in on course.
A fold inside the tooth. Upper lateral incisors are the teeth most often affected by dens invaginatus, where the outer layers of the tooth fold inward as it forms. The fold may raise the risk of nerve (pulp) problems and make a root canal harder.
The same tooth on the left side, tooth 10, has its own section on a lateral incisor that never formed.
Where is tooth 7?
Tooth 7 is in your upper jaw on your right 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 right side.
In a mirror, tooth 7 shows on the right side of your reflection. Someone looking into your mouth sees it on their left.
In front of it (toward the middle) is tooth 8, the upper right central incisor. Behind it is tooth 6, the upper right canine.
Its mirror twin on the left side is tooth 10. The tooth in the same spot in the lower jaw is tooth 26, the lower right lateral incisor.
Dental charts show the patient's right side on the left, so tooth 7 sits on the left half of the top row. Universal numbers start here: upper right teeth run from 1 (the wisdom tooth) to 8 (the front 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 7 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 7 come in?
Both the ADA and AAPD charts give 8–9 years for the upper lateral incisors.
Tooth 7 replaces the upper right baby lateral incisor (tooth D), 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 7 have?
One root.
Tooth 7 in FDI and Palmer notation
| System | Tooth 7 is written | What it means |
|---|---|---|
| Universal (ADA, used in the US) | 7 | Adult teeth are numbered 1–32 around the mouth, starting at the upper right wisdom tooth. |
| FDI / ISO 3950 (international) | 12 | First digit 1 = upper right quarter; second digit 2 = second tooth from the middle. Said "one-two". |
| Palmer | 2┘ (often typed UR2) | The ┘ bracket marks the upper right quarter; 2 = second tooth from the middle. |
A lone "7" can only be Universal. FDI codes always have two digits, so 7 on its own is never an FDI number.
On a US chart, "12" is a different tooth. Universal 12 is the upper left first premolar (tooth 12), so "tooth 12" 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 UR) makes it this one.
All adult teeth in the upper right quarter
From the front of the mouth to the back:
| Universal | FDI | Palmer | Tooth |
|---|---|---|---|
| 8 | 11 | 1┘ (UR1) | Central incisor |
| 7 | 12 | 2┘ (UR2) | Lateral incisor (this tooth) |
| 6 | 13 | 3┘ (UR3) | Canine |
| 5 | 14 | 4┘ (UR4) | First premolar |
| 4 | 15 | 5┘ (UR5) | Second premolar |
| 3 | 16 | 6┘ (UR6) | First molar |
| 2 | 17 | 7┘ (UR7) | Second molar |
| 1 | 18 | 8┘ (UR8) | Wisdom tooth |
The Tooth Number Chart & Converter converts any tooth between the three systems.
Tools for tooth 7
- 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 7?
Is tooth 7 the same as tooth 12?
At what age does tooth 7 come in?
What is a peg lateral?
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.
- Alani A, Bishop K. International Endodontic Journal 41(12):1123–1136. Dens invaginatus. Part 1: classification, prevalence and aetiology. 2008. Accessed October 26, 2026.
Last reviewed by the Dental Health Time editorial team, against the sources above. How we review.