Tanaka–Johnston online — space prediction

M. M. Tanaka, L. E. Johnston · 1974

Сменный прикус

Tanaka–Johnston estimates unerupted canine and premolar size from erupted incisors. CephCalc runs it in the mixed-dentition biometrics workflow.

Try biometrics free All biometric indices

5 free patient slots · try it in practice · no subscription

What the index measures

Tanaka and Johnston proposed prediction formulas without measuring unerupted teeth on every film.

Clinical focus

Mixed-dentition space forecast.

When to apply

Space maintenance, serial extraction, observation. Confirm with radiographs when anatomy is atypical.

Reference norms

Predicted canine–premolar sums for upper and lower arches

Try biometrics free

Calculate on your models

Open the biometrics module in CephCalc, choose the dentition stage, and enter measurements for “Tanaka–Johnston”. The PDF saves to the patient chart next to the treatment plan.

Interactive arch diagram
Outputs and PDF without Excel
Links to plan, braces and aligners
5 free patient credits to start

Start free Pricing

FAQ

Does Tanaka–Johnston replace radiographs?

No. It is an incisor-based estimate. Check films when tooth buds look atypical.