permanent dentition · lower left quadrant
Tooth number 24
In the ADA Universal system, tooth 24 is the lower left central incisor. It is written 31 in FDI notation and ┌1 in Palmer notation.
Notation
- Universal (ADA)
- 24
- FDI (ISO 3950)
- 31
- Palmer
- ┌1
- Tooth type
- incisor
- Arch
- lower
- Side
- left
- Position from midline
- 1 of 8
Surfaces of tooth 24
As an anterior tooth it has an incisal (biting) edge and a facial (lip) surface. It has no occlusal table.
- M Mesial — The side facing the front of the mouth, toward the midline.
- D Distal — The side facing the back of the mouth, away from the midline.
- F Facial — The lip or cheek side. On front teeth this is also called labial.
- L Lingual — The tongue side. On upper teeth it is also called palatal.
- I Incisal — The biting edge. Incisors and canines only.
24 is ambiguous on its own
The number 24 is valid in both numbering systems and means a different tooth in each. In the Universal system it is the lower left central incisor. In the FDI system it is the upper left first premolar — Universal 12.
If a chart does not state its system, a bare 24 does not identify a tooth. Look for numbers above 32 or letters A–T elsewhere on the chart: those only appear in one system and settle it.
How tooth 24 is written on a chart
Each of these is a valid entry for this tooth. Select one to open it in the decoder.
A combination such as MID on tooth 24 names its mesial, incisal and distal surfaces. Anterior teeth take I, not O. See what MOD means and the full surface reference.
Where tooth 24 sits
- 1 18 upper right third molar
- 2 17 upper right second molar
- 3 16 upper right first molar
- 4 15 upper right second premolar
- 5 14 upper right first premolar
- 6 13 upper right canine
- 7 12 upper right lateral incisor
- 8 11 upper right central incisor
- 9 21 upper left central incisor
- 10 22 upper left lateral incisor
- 11 23 upper left canine
- 12 24 upper left first premolar
- 13 25 upper left second premolar
- 14 26 upper left first molar
- 15 27 upper left second molar
- 16 28 upper left third molar
- 32 48 lower right third molar
- 31 47 lower right second molar
- 30 46 lower right first molar
- 29 45 lower right second premolar
- 28 44 lower right first premolar
- 27 43 lower right canine
- 26 42 lower right lateral incisor
- 25 41 lower right central incisor
- 24 31 lower left central incisor
- 23 32 lower left lateral incisor
- 22 33 lower left canine
- 21 34 lower left first premolar
- 20 35 lower left second premolar
- 19 36 lower left first molar
- 18 37 lower left second molar
- 17 38 lower left third molar