The tooth shape deviations are rare dental anomaly described in premolars, characterized by to show simultaneously an increased mesio-distal dimension and decreased bucco-lingual dimension when compared with other normal teeth. The presence of such teeth with variation in size may be related to malocclusions, since there is a reduction in circumference of the dental arch. This report describes a rare case of bilateral tooth shape deviations in the two mandibular first premolars and discusses the prevalence of this condition and the eventual clinical consequences associated with this dental anomaly.