Effects of premolar extractions on Bolton index overall ratios
Wei, Z.-l.; Wang, Y.-l.; Zhang, W.-m.
Shanghai Kou Qiang Yi Xue 23(4): 485-488
2014
ISSN/ISBN: 1006-7248 PMID: 25338804 Document Number: 677524
To investigate the effect of premolar extraction on Bolton index overall ratios. Bolton index overall ratios were measured in 198 randomly chosen dental casts of three types of Angle's malocclusions before and after 4 combinations of hypothetical premolar extractions. The data was processed using SPSS 17.0 software package. The overall ratios decreased in each class of Angle's malocclusion after all combinations of premolars extraction, and the decreases in combinations of 5/5 and 5/4 extractions were significantly greater than that of 4/4 and 4/5 combinations (P<0.05), but no significant difference was found between different types of malocclusion (P>0.05). When formulating a treatment plan involving premolar extractions, orthodontists should consider that the Bolton overall ratios may decrease.