Table 2.
Landmarks and measurements.
| Parameter | Description |
|---|---|
| Landmarks | |
| C2o | The most superior point of the odontoid process |
| C2–4lm | The most superior points of the lower border of the bodies of C2–4 |
| C2–4la, C2–4lp | The most anterior (a) and posterior (p) points on the lower border of the bodies of C2–4 |
| C2–4ua, C2–4up | The most superior points of the anterior (a) and posterior (p) borders of the bodies of C2–4 |
| C2–4um | The middle of the upper border of the bodies of C2–4 |
| C2–4am | The middle of the anterior border of the bodies of C2–4 |
| Ratios | |
| AH2–4/H2–4 | Ratio of AH2–4/H2–4 |
| H2–4/PH2–4 | Ratio of H2–4/PH2–4 |
| AH2–4/PH2–4 | Ratio of AH2–4/PH2–4 |
| UW2–4/W2–4 | Ratio of UW2–4/W2–4 |
| W2–4/LW2–4 | Ratio of W2–4/LW2–4 |
| UW2–4/LW2–4 | Ratio of UW2–4/LW2–4 |
| AH2–4/UW2–4 | Ratio of AH2–4/UW2–4 |
| H2–4/UW2–4 | Ratio of H2–4/UW2–4 |
| PH2–4/UW2–4 | Ratio of PH2–4/UW2–4 |
| AH2–4/W2–4 | Ratio of AH2–4/W2–4 |
| H2–4/W2–4 | Ratio of H2–4/W2–4 |
| PH2–4/W2–4 | Ratio of PH2–4/W2–4 |
| AH2–4/LW2–4 | Ratio of AH2–4/LW2–4 |
| H2–4/LW2–4 | Ratio of H2–4/LW2–4 |
| PH2–4/LW2–4 | Ratio of PH2–4/LW2–4 |
| OH/UW2 | Ratio of OH/UW2 |
| OH/AH2 | Ratio of OH/AH2 |
| OH/H2 | Ratio of OH/H2 |
| OH/PH2 | Ratio of OH/PH2 |
| OH/UW2 | Ratio of OH/UW2 |
| OH/W2 | Ratio of OH/W2 |
| OH/LW2 | Ratio of OH/LW2 |
| OH/PH2 | Ratio of OH/PH2 |
| (OH + AH2)/UW2 | Ratio of (OH + AH2)/UW2 |
| (OH + AH2)/W2 | Ratio of (OH + AH2)/W2 |
| (OH + AH2)/LW2 | Ratio of (OH + AH2)/LW2 |
| (OH + H2)/UW2 | Ratio of (OH + H2)/UW2 |
| (OH + H2)/W2 | Ratio of (OH + H2)/W2 |
| (OH + H2)/LW2 | Ratio of (OH + H2)/LW2 |
| (OH + PH2)/UW2 | Ratio of (OH + PH2)/UW2 |
| (OH + PH2)/W2 | Ratio of (OH + PH2)/W2 |
| (OH + PH2)/LW2 | Ratio of (OH + PH2)/LW2 |