Table 2 Landmarks and definitions based on two-dimensional coordinates
Landmarks | Definitions | |
|---|---|---|
Level | ||
L1 | The apical root level of the cuspid | |
L2 | The mid root level of the cuspid | |
L3 | The cervical root level of the cuspid | |
Root | ||
A1 | The apical point of the cuspid | |
A2 | The mid root point of the cuspid | |
A3 | The 4 mm point below the CEJ of the cuspid | |
D | The intersection of the long axis of the cuspid and the CEJ | |
M2 | The labial tangent point of the root at the L2 level | |
N2 | The palatal tangent point of the root at the L2 level | |
M3 | The labial tangent point of the root at the L3 level | |
N3 | The palatal tangent point of the root at the L3 level | |
Alveolar | ||
Q1 | The alveolar bone midpoint of the L1 section | |
Q3 | The alveolar bone midpoint of the L3 section | |
OB1 | The outer edge of the labial bone cortex at the L1 level | |
OB2 | The outer edge of the labial bone cortex at the L2 level | |
OB3 | The outer edge of the labial bone cortex at the L3 level | |
IB1 | The inner edge of the labial bone cortex at the L1 level | |
IB2 | The inner edge of the labial bone cortex at the L2 level | |
IB3 | The inner edge of the labial bone cortex at the L3 level | |
OP1 | The outer edge of the palatal bone cortex at the L1 level | |
OP2 | The outer edge of the palatal bone cortex at the L2 level | |
OP3 | The outer edge of the palatal bone cortex at the L3 level | |
IP1 | The inner edge of the palatal bone cortex at the L1 level | |
IP2 | The inner edge of the palatal bone cortex at the L2 level | |
IP3 | The inner edge of the palatal bone cortex at the L3 level |