arrow, tongue-like filiform papilla; downward-facing dart arrow, conical filiform papilla; upward-facing dart arrow, lingual wall; arrowhead, lingual groove; star, filiform papilla root.
1, conical filiform papilla; 2, lingual groove; 3, dorsal surface; 4, forage; 5, secondary papilla; q, swing angle.
1, tongue-like filiform papilla; 2, lingual groove; 3, dorsal surface; 4, forage; 5, conical papilla; H, lingual wall.
The analy- sis of clinical and radiographic characteristics of the double teeth showed three morphological types, large crown with a large root and root canal with labio- lingual grooves
, two fused crowns with deep labio- lingual grooves
and two roots and a partially vertical separated large crown with single root and with labio- lingual grooves