Anomalies of form and number, fused primary teeth, a correlation of the dentitions.

Fusion is rare in the primary dentition (range .14 percent to 3 percent). Patients with fused primary lateral incisors and canines have about a 75 percent chance of lacking the succedaneous lateral incisor. Patients with fused incisors have less than a 20 percent chance of having a missing permanent tooth.