Dental numbering

Universal · FDI/ISO 3950CTPanorex

Figures · click to enlarge

Universal numbering on a panoramic radiograph. Image: Francis Deng, Radiopaedia.org, CC BY-NC-SA

Tooth names and eruption landmarks. Image: Francis Deng, Radiopaedia.org, CC BY-NC-SA

Universal (US) numbers permanent teeth 1–32 clockwise from the patient’s upper right third molar. FDI uses two digits: quadrant then tooth (1 = central incisor, 8 = third molar).

Permanent dentition (patient’s right on the left of chart)

Upper rightUpper left

118

217

316

415

514

613

712

811

921

1022

1123

1224

1325

1426

1527

1628

3248

3147

3046

2945

2844

2743

2642

2541

2431

2332

2233

2134

2035

1936

1837

1738

Lower rightLower left

Bold = Universal · small = FDI

Tooth (each quadrant)	FDI digit	Universal, upper right	Universal, lower right
Central incisor	1	8	25
Lateral incisor	2	7	26
Canine	3	6	27
First premolar	4	5	28
Second premolar	5	4	29
First molar	6	3	30
Second molar	7	2	31
Third molar	8	1	32

Primary (deciduous) teeth

Universal: letters A–T, A = upper right second molar → J = upper left second molar; K = lower left second molar → T = lower right second molar.
FDI: quadrants 5 (UR), 6 (UL), 7 (LL), 8 (LR); teeth 1–5 from central incisor to second molar.

Sources

ISO 3950:2016. Dentistry — Designation system for teeth and areas of the oral cavity. International Organization for Standardization.

Radessential summarizes published classification systems for practicing radiologists. Summaries are condensed; confirm details against the cited source before relying on them for patient care.