Vertical crown-root fracture of the mandibular first primary molar in a one-year-old child.

A vertical crown-root fracture of the mandibular first primary molar in a 21-month-old child is presented. The mandibular primary first molar was fractured vertically and split into 2 pieces. The tooth fracture had not been noticed for about 5 months after the accident, and the tooth was left without any treatment. The pulp tissue of the mesial root maintained its vitality, but the distal root was nonvital.