Resorption of maxillary lateral incisors caused by ectopic eruption of the canines. A clinical and radiographic analysis of predisposing factors.

Factors predisposing to resorption of adjacent permanent lateral incisors caused by ectopic eruption of maxillary canines were evaluated. The subjects consisted of two groups: one with 40 lateral incisors with resorption caused by ectopic eruption and a control group of 118 ectopic eruption cases with no lateral incisor resorption. The mean age of the children in the two groups differed by only 0.7 of a year and ranged from 10.0 to 15.0 years, covering the normal eruption period of the maxillary canine. Resorption of lateral incisors was three times as common in girls as in boys. The resorption cases showed a more advanced dental development, a more medial canine position in the dental arch, and a slightly more mesial horizontal path of eruption (an average of 10 degrees) than that of the control cases. Factors such as the width of the dental follicle and proclination or distal tilting of the lateral incisor showed no correlation to the resorption. Potential resorption cases are always those in which the canine cusp in periapical and panoramic films is positioned medially to the midline of the lateral incisor. Such situations should be carefully investigated with polytomography if necessary. The risk of resorption also will increase with a more mesial horizontal path of eruption. From 10 years of age or younger, annual clinical examination by palpation of the canine eruption path is recommended. This clinical examination should be supplemented with a stepwise extended radiographic procedure in cases in which ectopic eruption of the maxillary canines is suspected.