Adequacy of maxillary dental arch width in patients with palatally displaced canines

This study investigates maxillary dental arch width in subjects with palata lly displaced canines, Pretreatment dental casts of orthodontic patients wi th one or both maxillary canines palatally displaced (n = 31; male, 10; fem ale, 21) were collected. This sample was matched according to sex and age w ith pretreatment dental casts from unaffected orthodontic patients. Arch wi dths were recorded between the maxillary first premolars and between the ma xillary first molars. Interpremolar arch width and intermolar arch width co mparisons between the sample with palatally displaced canines and the refer ence sample showed no statistically significant differences in their means, thus indicating that there was no statistically significant difference in the anterior and posterior arch width between the affected subjects and the control subjects. Thus, affected patients exhibit adequacy of maxillary de ntal arch width. This evidence refutes earlier conclusions that deficiency in maxillary transverse arch width is an associated contributing factor in the genesis of the anomaly of palatally displaced canines. Clinically, adeq uacy of dental arch width helps explain the "nonextraction" diagnostic appe arance of most of these patients when they present for treatment.