fa ارتودنسی Orthodontics پژوهشي Research <p> <strong>Introduction</strong></p><p>  The aims of this study were to investigate whether there is a different transverse morphologic pattern of dental arches among patients with different manifestations of Class II Division 2 incisor retroclination and to evaluate to what extent the pattern of smaller-than-average teeth in Class II Division 2 malocclusion is common to all groups studied. This information might clarify whether different Class II Division 2 phenotypes represent a single etiology or multiple etiologies. </p><p> <strong>Methods</strong> </p><p> The sample comprised 108 subjects with Class II Division 2 malocclusions, divided into 2 groups according to the type of incisor retroclination: group I included 43 Class II Division 2 subjects with retroclination exclusively of the maxillary central incisors, and group II included 65 Class II Division 2 subjects with retroclination of the 4 maxillary incisors. Maxillary and mandibular intercanine and intermolar widths as well as mesiodistal crown dimensions of the 4 maxillary and mandibular incisors were determined from the patients' initial study models. Mean values of all variables were compared between the 2 groups by sex with analysis of variance.</p><p> <strong> Results</strong></p><p>  From the comparison between these 2 groups, no statistically significant differences were found for all transverse measurements (P >0.05). For all mesiodistal measurements analyzed, statistically significant differences between the groups were only found for the mean value of both maxillary lateral incisors' mesiodistal dimensions in both sexes (P <0.05). </p><p> <strong>Conclusions</strong></p><p>  It is not possible to attribute a characteristic pattern of dental arch-width and incisor mesiodistal dimensions to the different manifestations of incisor retroclination in Class II Division 2 malocclusion. </p><hr><p></p><p> <strong>Source: </strong>American Journal of Orthodontics & Dentofacial Orthopedics </p><p> <a href="http://www.ajodo.org/article/S0889-5406(12)01092-X/abstract" target="_blank"><font color="#0000ff">Full Text</font></a></p> 0 0 http://idai.ir/browse.php?a_code=A-10-32-1749&slc_lang=fa&sid=1 Pedro Mariano Pereira 10031947532846008239 10031947532846008239 Yes Department of Orthodontics, Egas Moniz High Institute for Health Science, Lisbon, Portugal; postgraduate student, Faculty of Dental Medicine, University of Porto, Porto, Portugal Afonso Pinhão Ferreira 10031947532846008240 10031947532846008240 No Department of Orthodontics; dean, Faculty of Dental Medicine, University of Porto, Porto, Portugal Purificação Tavares 10031947532846008241 10031947532846008241 No Faculty of Dental Medicine, University of Porto, Porto, Portugal Ana Cristina Braga 10031947532846008242 10031947532846008242 No Department of Production and Systems, School of Engineering, University of Minho, Braga, Portugal