Tooth Number Chart (Universal, FDI and Palmer)

The Universal Numbering System is the tooth numbering chart dentists use in the United States. It gives each of the 32 adult teeth a number from 1 to 32. Counting starts with the upper right third molar (the wisdom tooth at the very back on the patient's right side) as tooth 1, moves along the upper arch to the upper left third molar, tooth 16, then drops to the lower jaw.

On the lower arch the count continues from the patient's left: the lower left third molar is tooth 17, the two lower front teeth are 24 and 25, and the count ends with the lower right third molar, tooth 32. Because the numbers run in one continuous loop, the two upper front teeth are 8 and 9, and teeth on the right side always sit at the start and end of the sequence.

Dental charts are drawn from the dentist's point of view, as if you are facing the patient. That is why the patient's right side appears on the left of the chart in this tool. If you hold a mirror up to your own mouth, your view matches the chart.

Each quarter of the mouth (quadrant) holds the same eight types of adult tooth, counted from the front: central incisor, lateral incisor, canine, first premolar, second premolar, first molar, second molar and third molar. In Universal numbering the same tooth type gets a different number in each quadrant, which is why it helps to see them side by side. The ages below are the typical ranges listed on the ADA permanent teeth eruption chart.

• Central incisors: 8 and 9 (upper), 24 and 25 (lower); typically 7–8 years upper and 6–7 years lower.
• Lateral incisors: 7 and 10 (upper), 23 and 26 (lower); typically 8–9 years upper and 7–8 years lower.
• Canines: 6 and 11 (upper), 22 and 27 (lower); typically 11–12 years upper and 9–10 years lower.
• Premolars: 4, 5, 12 and 13 (upper), 20, 21, 28 and 29 (lower); typically between 10 and 12 years.
• First molars: 3 and 14 (upper), 19 and 30 (lower); typically 6–7 years.
• Second molars: 2 and 15 (upper), 18 and 31 (lower); typically 12–13 years upper and 11–13 years lower.
• Third molars (wisdom teeth): 1 and 16 (upper), 17 and 32 (lower); typically 17–21 years.

Children have 20 baby (primary) teeth, and the Universal system labels them with capital letters instead of numbers so they are never confused with adult teeth. The letters follow the same loop as adult numbering: A is the upper right second baby molar, E and F are the two upper front teeth, J is the upper left second molar, K is the lower left second molar, O and P are the two lower front teeth, and T is the lower right second molar.

Each quadrant has five baby teeth: central incisor, lateral incisor, canine, first molar and second molar. Switch the chart to Baby teeth (20) to see the letters in place, or type a letter such as B or S into the lookup to find the tooth and its typical ADA age window for coming in and falling out.

Most countries outside the United States use the FDI system (ISO 3950), so dental records from abroad often look different. FDI uses two digits. The first digit is the quadrant: 1 upper right, 2 upper left, 3 lower left and 4 lower right for adult teeth, and 5 to 8 in the same order for baby teeth. The second digit is the tooth's position counted from the midline, where 1 is the central incisor and 8 is the third molar.

That makes FDI easy to decode once you know the pattern. Universal 30, the lower right first molar, is FDI 46. Universal 3, the upper right first molar, is FDI 16, and Universal 8 and 9, the upper front teeth, are FDI 11 and 21. Palmer notation writes the quadrant plus a number from 1 to 8 for adult teeth or a letter from A to E for baby teeth. This tool shows it as text, such as UR6 for the upper right first molar or ULB for the upper left baby lateral incisor.

Treatment plans, insurance paperwork and referral letters often name teeth by number rather than by description. Looking a number up before your appointment helps you follow the conversation and spot anything that does not match what you discussed with your dentist. If a plan from another country lists a two-digit number, choose FDI in the lookup before you search.

Tooth numbers describe positions in the mouth, not the teeth themselves. When teeth are missing, extra or have moved, your dentist decides which number applies, so a chart like this one is a reference, not a substitute for asking. If something on your paperwork looks wrong, ask the office to confirm the tooth before treatment starts.