During tooth development, which structure gives rise to the tooth when it interacts with ectomesenchyme?

• A. Enamel organ
• B. Ectomesenchyme
• C. Dental papilla
• D. Dental lamina

Answer: (C)

Tooth formation hinges on signaling between the epithelial part of the tooth germ and the surrounding ectomesenchyme. The swelling inside the tooth germ that comes from ectomesenchyme is the dental papilla. It is the tissue that ultimately becomes the dentin and dental pulp. Odontoblasts arise from cells of the dental papilla in response to cues from the overlying inner enamel epithelium of the enamel organ, while the enamel organ itself develops enamel. So, when the ectomesenchyme interacts with this epithelial component, the dental papilla provides the essential mesenchymal tissue that generates the tooth’s dentin and pulp, making it the structure that ultimately gives rise to the tooth’s core tissues.