In models where eruption is prevented, which structure remains present and is widened by osteoclast activity?

• A. The gubernacular canal
• B. The dental lamina
• C. The enamel organ
• D. The alveolar crest

Answer: (A)

The key idea is that eruption uses a preformed pathway through the jawbone that osteoclasts widen as the tooth moves into place. When eruption is prevented, the route itself remains—the gubernacular canal—and osteoclasts continue to resorb bone along this channel, widening it. This shows that the eruption path is already established by the gubernacular canal and is actively enlarged by bone resorption, even if the tooth doesn’t erupt. The other structures are not the preformed eruption route: the dental lamina and enamel organ are parts of tooth development that don’t function as the eruption pathway, and the alveolar crest refers to the bone ridge around teeth rather than a widening eruption channel.