Pederson Difficulty (Third Molar)
Pederson Difficulty Index (Pederson 1988): predicts difficulty of impacted mandibular third-molar (wisdom tooth) removal.
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- Angulation
- Mesioangular
- Depth
- Level B (mid)
- Ramus relationship / space
- Class II (reduced space)
Result: Pederson 5 of 10 — moderately difficult extraction.
The tool opens with these values already filled in. Replace them with your own.
What the result means
- Bands
- 3-4 slightly difficult, 5-6 moderately difficult, 7-10 very difficult.
What you enter
- Angulation (points)
- Depth (points)
- Ramus relationship / space (points)
How this is calculated
- Points
- angulation (mesio 1 / horizontal 2 / vertical 3 / disto 4) + depth (A 1 / B 2 / C 3) + ramus (I 1 / II 2 / III 3) = 3-10.
Pederson GW. Oral Surgery. Philadelphia: WB Saunders; 1988. (Pederson difficulty index, combining Winter angulation and Pell & Gregory depth/ramus classifications.) Read the source ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.