Notice: this is the author’s version of a work that was accepted for publication in Journal of Orthodontics. Changes resulting from the publishing process may not be reflected in this document. Final version available in Journal of Orthodontics. Vol. 40, Issue 4, (December 2013). DOI 10.1179/1465313313Y.0000000067."Objective: To investigate whether there is an association between dental development anomalies (DDAs) and the different manifestations of Class II Division 2 (CII/2) malocclusion incisor retroclination. This information may clarify whether the different CII/2 phenotypes, with regard to maxillary incisor retroclination, are a single clinical entity or etiologically different entities.
Design: Retrospective comparative study.
Setting: Private orthodontic practice in the regions of Lisbon and Porto, Portugal
Subjects and Methods: The sample comprised 115 CII/2 malocclusions distributed into 2 groups on the basis of incisor retroclination: Group I composed of 48 CII/2 with retroclination exclusively of both maxillary central incisors; Group II composed of 67 CII/2 with retroclination of all four maxillary incisors. Using the initial orthodontic records, it was determined for each patient the presence of the following DDAs: tooth impaction, tooth agenesis, maxillary lateral incisor microdontia, tooth transpositions and supernumerary teeth.
Results: 55.0% of patients were diagnosed with at least one of the DDAs studied. In the total sample the prevalence rates were determined as follows: 20.0% of palatal maxillary canine impaction, 27.4% of third molar agenesis, and 15.7% of maxillary lateral incisor microdontia. No patient exhibited any transpositions or supernumerary teeth. The distribution of the DDAs studied by groups revealed a strong association of palatal canine impaction, tooth agenesis and maxillary lateral incisor microdontia with Groups II but not with Group I.
Conclusion: The association of DDAs with CII/2 malocclusion is not common to all types of maxillary incisor retroclination, suggesting different etiologic bases among the different manifestations of CII/2 malocclusion incisor retroclination.
