Predictive Factors and Ideal Timing for Spontaneous Eruption of Displaced Canine after Primary Canine Extraction: A Literature Review

The extraction of the primary canine in mixed dentition is an interceptive procedure to reduce the incidence of palatally displaced canines. The aim of this study is to evaluate the predictive factors and the ideal timing for spontaneous eruption of the palatally displaced canine after primary canine extraction. The literature search was conducted using the PubMed and Scopus databases. The PICOS criteria were used to select studies. To ensure the effectiveness of primary canine extraction in promoting the spontaneous eruption of the permanent canine, the following factors should be considered: biological variables (with higher probability of success if extraction is performed between 10 and 11 years old), radiological parameters (α angle between 20° and 30° and sectors 2 and 3 concerning the segmentation method of Ericson and Kurol; stage of dental development: before complete eruption of mandibular canine of same side as maxillary canine and primary canine root resorption more than half or oblique) and clinical parameters (crowding reduces spontaneous eruption of maxillary canine). The extraction of the primary canine is an effective interceptive measure for facilitating the eruption of palatally impacted canines. Ideal timing and favorable predictive factors can influence the success of this interceptive treatment.