Bolton analysis is used to assess tooth-size discrepancies by comparing which of the following?

Bolton analysis is used to assess tooth-size discrepancies by comparing which of the following?

• A. The sum of mesiodistal widths of upper and lower teeth
• B. Arch length discrepancy
• C. Root morphology
• D. Crown height differences

Answer: (A)

Bolton analysis looks at tooth-size discrepancies by comparing how wide the teeth are from mesial to distal in the upper versus lower arches. On study models you measure each tooth’s mesiodistal width and sum them for the two arches. Two key ratios come from this: one uses the six front teeth (anterior) in each arch, and the other uses all teeth from first molar to first molar in each arch (overall). If the upper-to-lower sums (as a ratio) fall outside normal values, there’s a tooth-size discrepancy that can guide treatment decisions, such as whether enamel reduction or extractions are needed to balance the arches. This is exactly what Bolton analysis measures—the comparison of the sums of mesiodistal widths between the upper and lower teeth.

Bolton analysis looks at tooth-size discrepancies by comparing how wide the teeth are from mesial to distal in the upper versus lower arches. On study models you measure each tooth’s mesiodistal width and sum them for the two arches. Two key ratios come from this: one uses the six front teeth (anterior) in each arch, and the other uses all teeth from first molar to first molar in each arch (overall). If the upper-to-lower sums (as a ratio) fall outside normal values, there’s a tooth-size discrepancy that can guide treatment decisions, such as whether enamel reduction or extractions are needed to balance the arches. This is exactly what Bolton analysis measures—the comparison of the sums of mesiodistal widths between the upper and lower teeth.