Permanent tooth germs develop in relation to deciduous teeth on which surface?

• A. On the buccal aspect of deciduous teeth
• B. On the lingual aspect of deciduous teeth
• C. Between roots of deciduous teeth
• D. In front of deciduous crowns

Answer: (B)

Permanent tooth germs form on the lingual (tongue-side) surface of the deciduous teeth. This placement keeps the developing permanent crown tucked toward the tongue as it grows, and when eruption occurs it moves into the space in front of or beside the deciduous crown as the deciduous roots resorb. The lingual position also helps guide the eruption path so the permanent tooth can take its place in the arch after the primary tooth is lost. The other surfaces described don’t reflect where the germ typically develops relative to the deciduous tooth.