Clinical predictors of maxillary canine impaction: a novel approach using multivariate analysis.

Background: Ectopic eruption and/or impaction of maxillary permanent canines is a frequent problem in clinical dentistry. Previous studies aimed to identify potential associated factors and predictors for impacted maxillary canines have only used conventional univariate statistics, which does not allow the analysis of the interaction between and within variables. Multivariate data analysis (MVDA) is a better and more powerful tool for the integration and interpretation of complex datasets. Aim: The aim of this study was to validate previously explored predictors of permanent maxillary canine impaction using MVDA. Subjects and methods: This cohort study included all the patients referred during 2011 to Mölndal Hospital, Sweden for surgical exposure of impacted canines (N = 45). Age- and gender-matched orthodontic patients (N = 45) with normally erupting canines comprised the control group. The age range for both groups was 11-17 years. The positions of the canine teeth (orthopantograms), the skeletal variables (profile radiographs), and dentoalveolar traits (casts) were evaluated as potential predictive factors for impaction. Results: None of the parameters evaluated with either profile radiography or casts were positively correlated with impacted maxillary canines, with the exception of the location of the already impacted canines, as identified by orthopantogram. Conclusion: No correlation between clinical variables and impaction was found using MVDA. Therefore, these variables could not be used as predictors of canine impaction. Other types of parameters, such as inheritance and molecular factors that regulate the biological mechanisms of the eruption process, need to be further investigated. [ABSTRACT FROM AUTHOR]