Risk Indicators and Interceptive Treatment Alternatives for Palatally Displaced Canines

The present article reviews diagnostic, prognostic, and therapeutic aspects related to palatal displaced canines (PDCs) and their possible evolution to palatally impacted canines (PICs). Through the analysis of the relevant literature, a series of dental anomalies can be identified that present with a significant clinical association with PDC. Because these tooth disturbances may appear before PDC, they represent risk indicators for the occurrence of the eruption anomaly of the maxillary permanent canine. The second part of this work describes comparatively the effectiveness of several interceptive treatment approaches to PDC to avoid the evolution from PDC to PIC. In particular, the extraction of the deciduous canine, alone or in combination with orthodontic forces aimed to prevent the physiological mesial movement of the upper permanent molar, appears to be able to increase by 2 to 3 times the rate of eruption of PDCs (diagnosed on a panoramic radiograph) with respect to that which occurs in untreated subjects with PDC (spontaneous eruption in about one third of the cases). Rapid maxillary expansion in the early developmental stages may represent a valid alternative for the interceptive treatment of PDCs (diagnosed on a posteroanterior cephalogram). Although genetic factors are known to play a fundamental role in the etiology of PDC (and subsequent PIC), it appears that environmental local factors can be affected by orthodontic/orthopedic approaches during the pathogenetic evolution process leading from PDC to final PIC.