Do dental arches lengths, widths and perimeters affect Bolton’s ratios?

Arch-perimeter-sum-of-six-segments-represented-as-continuous-lines-and-arch-depth-1.png - Digital repository

Background: The main objectives in treating any orthodontic case are establishing stable occlusion with
normal overjet and overbite class I canines relationship and good teeth interdigitation with appropriate
proportion of maxillary and mandibular teeth widths. Bolton in 1958 introduced his analysis depending on
the study models of fifty five cases with excellent occlusion, of which 44 cases where treated orthodontically
(non-extraction) and 11 cases were untreated. He developed two ratios one related the whole teeth anterior
to the second molars and the other from canine to canine. The aim of this study was to test whether Bolton’s
tooth size ratios were affected by the maxillary and mandibular dental arch widths, lengths and perimeter.
Materials and Method: This investigation was performed on a sample of dental casts belong to sixty Iraqi
individuals. Anterior and overall tooth size ratios, dental arches widths, lengths and perimeters of maxillary
and mandibular arches were measured using digital caliper. Pearson’s correlation coefficient test was used to
test the relation between the anterior and overall Bolton’s ratios with the dental arches parameters. Results:
The mean values of anterior and overall Bolton’s ratios were near to that reported by original study of Bolton.
Statistically, there was no relationship between dental arch parameters and Bolton’s ratios. Conclusions:
Dental arch widths, lengths, perimeter had no effect on Bolton’s ratios.
Key words: Bolton’s ratio, arch widths, arch lengths, arch perimeters, tooth size.
DOI: 10.5958/0976-5506.2019.01174.4