Which statement about ankylosed primary molars is NOT true?

Ankylosed primary molars exhibit unique characteristics, including their firm fixation to the alveolar bone and the solid sound produced when tapped, which indeed contrasts with the sounds of normal adjacent teeth. This characteristic arises because, in ankylosis, the periodontal ligament is lost, leading to the tooth fusing directly to the bone. The sound on percussion is an important diagnostic indicator, as it reflects the absence of the normal cushioning effect provided by the periodontal ligament in healthy teeth. Therefore, the statement regarding their solid sound being an indication of their ankylosed state is accurate.

The other statements highlight important clinical considerations when dealing with ankylosed primary molars. Evaluating the prevalence between different racial groups and considering extraction when they block the eruption path of permanent teeth are both relevant aspects of treatment planning. Similarly, the consideration for extraction in the absence of a corresponding permanent tooth is clinically relevant, as it addresses potential complications in dental development.