A diagnostic proposal to support early treatment of ectopically erupting maxillary canines

Although early diagnosis is essential for the correction of ectopically erupting canines, it is difficult to determine whether the condition of a canine is within acceptable normal limits, particularly in children aged 10 years or younger. The purpose of the present study was to ascertain the appropriate time for a preventive procedures, such as extraction of the predecessor, in order to avert impaction of maxillary canines. Orthopantomograms of 225 normal children without dental anomalies were examined to compare the eruption stages of mandibular and maxillary canines. Sixty-four patients with 68 unerupted and/or impacted maxillary canines were examined. In normal children, mandibular canines exhibited earlier movement toward oral emergence than maxillary canines on the same side. This tendency was particularly prominent after exfoliation of the mandibular primary canine. In contrast, nearly half of the patients with anomalies were treated before oral emergence of the mandibular canine through simple procedures such as extraction of the primary canine or exposure of the affected canine. The present findings may provide a useful supplemental rule for early diagnosis and aid in decisions whether to treat ectopically erupting maxillary canines, particularly when the anomaly is obscure.