What the index measures
Wayne A. Bolton (1958) described anterior (6/6) and overall (12/12) ratios of mandibular to maxillary tooth widths.
Biometric index
Bolton index online — 6/6 and 12/12
6/6 · 12/12
The Bolton index shows relative tooth-material excess on the upper or lower arch. In CephCalc you enter mesiodistal widths on the diagram and see anterior and overall ratios, millimetre discrepancy, and a PDF in the patient chart.
Clinical focus
Inter-arch tooth-size ratios — not arch width or skeletal class.
When to apply
IPR, restorations, finishing. Often with Pont and space planning. Skeletal questions stay in lateral cephalometrics.
Reference norms
- Anterior (6/6): about 77.2%
- Overall (12/12): about 91.3%
Try biometrics free
Calculate on your models
Open the biometrics module in CephCalc, choose the dentition stage, and enter measurements for “Bolton”. 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
FAQ
What is the difference between 6/6 and 12/12?
6/6 covers incisors and canines. 12/12 adds premolars and first molars. Both use the same measurement diagram in CephCalc.
Do I need a cephalogram for Bolton?
No. You need mesiodistal widths from models or a scan. Cephalometrics lives in a sibling module on the same chart.