Space Maintainers
- Band & loop — for a single (unilateral) posterior primary tooth loss.
- Lingual arch — bilateral mandibular space maintenance (needs permanent incisors erupted).
- Nance appliance / TPA — bilateral maxillary maintenance.
- Distal shoe — guides eruption of the first permanent molar when the second primary molar is lost before the 6-year molar erupts.
Leeway Space (Nance)
The combined mesiodistal width of primary canine + molars exceeds that of their permanent successors. Leeway space ≈ 1.7 mm per side in the mandible (~0.9 mm maxilla), useful for late crowding resolution.
Exam Tips ⭐
Band & loop = unilateral posterior; distal shoe = 2nd primary molar lost early; leeway ≈ 1.7 mm/side mandible.