Will tooth 16 ever come in?
Not always. A meta-analysis of 63,314 people found that about 23% (22.6%) are missing at least one wisdom tooth. Upper wisdom teeth were missing 36% more often than lower ones, and women were 14% more likely than men to be missing one.
Not enough room. When it does form, an upper wisdom tooth may be blocked by another tooth (impacted) or only partly come through the gum.
What can go wrong: pain and swelling, gum infection around the tooth (pericoronitis), trapped food, tooth decay, gum disease, and cysts or abscesses.
Left alone if it's no trouble. A wisdom tooth that causes no problems is usually left in place and checked at routine visits.
The same tooth on the right side, tooth 1, has its own section on what removing an upper wisdom tooth involves.
Where is tooth 16?
Tooth 16 is the very last tooth at the back of your upper jaw on your left side: the eighth tooth from the middle, behind the 12-year molar. Some wisdom teeth never fully come through, and some people never develop this tooth at all.
In a mirror, tooth 16 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 15, the upper left second molar. No tooth sits behind it.
Its mirror twin on the right side is tooth 1. The tooth in the same spot in the lower jaw is tooth 17, the lower left wisdom tooth.
Dental charts show the patient's right side on the left, so tooth 16 sits at the far right end of the top row. Universal numbers continue across the top: upper left teeth run from 9 (the front tooth) to 16 (the wisdom tooth).
Common problems with upper wisdom teeth
- Sinus link. The roots of upper back teeth can reach up into the maxillary sinus, with only a thin layer of tissue between them. Because of that, a long-lasting infection at the root tip can sometimes spread into the sinus (odontogenic sinusitis).
If tooth 16 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 16 come in?
The upper wisdom teeth usually come in at 17–21 years according to the ADA chart. The AAPD chart gives 17–30 years.
The NHS says wisdom teeth usually start coming through in the teens or early 20s. By age 21, all 32 adult teeth have usually come in (ADA), though some wisdom teeth never fully come through.
In the ADA chart, they are among the last to come in, along with the lower wisdom teeth. In the AAPD's 13-step order, from the first molars (step 1) to the wisdom teeth (step 13), they are step 13.
Under the gum, according to the AAPD chart, it starts to harden (calcify) at about 7–9 years of age.
How many roots does tooth 16 have?
Often a single, cone-shaped root formed by fused roots. When the roots stay separate, there are usually three.
What does a wisdom tooth do?
Wisdom teeth are third molars. When they come in straight and have room, they chew like any other molar. Some people never develop some or all of their wisdom teeth, and the ones that do form vary in size and shape.
Tooth 16 in FDI and Palmer notation
| System | Tooth 16 is written | What it means |
|---|---|---|
| Universal (ADA, used in the US) | 16 | Adult teeth are numbered 1–32 around the mouth, starting at the upper right wisdom tooth. |
| FDI / ISO 3950 (international) | 28 | First digit 2 = upper left quarter; second digit 8 = eighth tooth from the middle. Said "two-eight". |
| Palmer | └8 (often typed UL8) | The └ bracket marks the upper left quarter; 8 = eighth tooth from the middle. |
"16" in FDI is a different tooth. Read as an FDI code, 16 means the upper right first molar (tooth 3 in Universal). Charts and X-ray reports from outside the US often use FDI, so check which system is in use.
On a US chart, "28" is a different tooth. Universal 28 is the lower right first premolar (tooth 28), so "tooth 28" only means this tooth when the chart uses FDI.
Palmer needs the bracket. Every quarter of the mouth has a tooth 8 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 |
| 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 (this tooth) |
The Tooth Number Chart & Converter converts any tooth between the three systems.
Tools for tooth 16
- Wisdom Teeth & Extraction tools: recovery, dry socket and aftercare tools.
- Wisdom Teeth Recovery Tracker: day-by-day healing after removal.
- Dry Socket Checker: symptoms vs normal healing; dry socket is less common after upper teeth.
- When Can I…? After a Tooth Extraction: when you can eat, use a straw or exercise.
- Dental Emergency Checker: how soon to see a dentist if it hurts or breaks.
- Dental Treatment Plan Decoder: plain English for treatment-plan shorthand like "#30 MOD comp".
Frequently asked questions
What tooth is number 16?
Is tooth 16 the same as tooth 28?
Does everyone have tooth 16?
Are upper wisdom teeth missing more often than lower ones?
Sources
- American Dental Association (MouthHealthy). Permanent Tooth Development (eruption chart). 2012. Accessed October 26, 2026.
- American Dental Association (MouthHealthy). Eruption Charts. Accessed October 26, 2026.
- American Academy of Pediatric Dentistry. Dental Growth and Development (chronology after Logan & Kronfeld 1933, adapted 2003). 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.
- NHS (UK). Wisdom tooth removal. page reviewed 12 June 2024. Accessed October 26, 2026.
- Merck Manual Professional Edition. Postextraction Problems. full review August 2026. Accessed October 26, 2026.
- Carter K, Worthington S. Journal of Dental Research 94(7):886–894. Morphologic and Demographic Predictors of Third Molar Agenesis: A Systematic Review and Meta-analysis. 2015. Accessed October 26, 2026.
- Ordinola-Zapata R, Azevedo B, Tataryn RW, Versiani MA. Otolaryngologic Clinics of North America 57(6):927–939. Maxillary Dental Anatomy and Physiology: Endodontic and Periodontal. 2024. Accessed October 26, 2026.
Last reviewed by the Dental Health Time editorial team, against the sources above. How we review.