| Landmarks | Variables | Description |
| 1 2 | LR1R LR1L | Length of the right first ruga Length of the left first ruga |
| 3 4 | LR3R LR3L | Length of the right third ruga Length of the left third ruga |
| 5 | DM1 | Transverse linear distance between the medial points of the right and left first rugae |
| 6 | DM3 | Transverse linear distance between the medial points of the right and left third rugae |
| 7 | DL1 | Transverse linear distance between the lateral points of the right and left first rugae |
| 8 | DL3 | Transverse linear distance between the lateral points of the right and left third rugae |
| 9 | APMR13 | Anteroposterior distance between the medial points of the right first and third rugae |
| 10 | APML13 | Anteroposterior distance between the medial points of the left first and third rugae |
| 11 | APLR13 | Anteroposterior distance between the lateral points of the right first and third rugae |
| 12 | APLL13 | Anteroposterior distance between the lateral points of the left first and third rugae |
| 13 | C-C | Distance between the occlusal tips of the canines |
| 14 | M-M | Distance between the mesio-buccal cusps of the first permanent molar |
| 15 | CR-MR | Distance of tips of the right canine and mesio-buccal cusp of first permanent molar |
| 16 | CL-ML | Distance of tips of the left canine and mesio-buccal cusp of first permanent molar |
| 17 | CR-ML | Distance of tips of the right canine and mesio-buccal cusp of left first permanent molar |
| 18 | CL-MR | Distance of tips of the left canine and mesio-buccal cusp of right first permanent molar |