bolton analysis

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Bolton Analysis

The Bolton Analysis Determines the ratio of the mesiodistal widths of the maxillary versus the mandibular teeth (i.e., tooth size discrepancy) On account of the importance for the canine relation as well as for overbite and overjet relationship

Overall Ratio The relationship of the 12 mandibular teeth to the 12 maxillary teeth is assessed Second and third molars are exclude Overall ratio = Sum mand 12 (m-d) x 100 Sum max 12 (m-d)

If the calculated ratio is greater than 91,3 %, the mandibular teeth are too wide compared to the maxillary teeth If the ratio is reduced, the maxillary teeth are relatively too large

Anterior Ratio Further analysis is performed to evaluate the ratio between the six upper and lower anterior teeth Anterior ratio = Sum mand 6 (m-d) x 100 Sum max 6 (m-d)

If the ratio is greater than 77,2% the total width of the lower six anterior teeth is relatively too large If the index value is reduced, the discrepancy is due to an excess in maxillary tooth material

It is postulated that the relatively smaller tooth material is the correct one Disharmony between the width of upper and lower teeth can be improved by 1. extractions 2. interdental stripping 3. in extreme cases, by increasing the mesiodistal tooth size

Bolton Table

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