Average right and left posterior fossa horn breakdown by age
| Age Range (yr) | No. | Average L Posterior Fossa Horn (mm) | Average R Posterior Fossa Horn (mm) |
|---|---|---|---|
| 0–1 | 35 | 5.8 (SD, 2.2) | 6.7 (SD, 2.7) |
| 1–2 | 58 | 5.5 (SD, 2.8) | 6.0 (SD, 2.7) |
| 2–3 | 43 | 3.5 (SD, 2.5) | 3.9 (SD, 2.4) |
| 3–4 | 30 | 2.5 (SD, 2.2) | 2.7 (SD, 2.3) |
| 4–5 | 22 | 2.0 (SD, 1.7) | 2.6 (SD, 1.4) |
| 5–6 | 18 | 1.8 (SD, 1.3) | 2.1 (SD, 1.6) |
| 6–7 | 14 | 1.6 (SD, 1.7) | 1.2 (SD, 1.3) |
| 7–8 | 14 | 1.8 (SD, 1.7) | 1.5 (SD, 1.6) |
| 8–9 | 8 | 1.2 (SD, 1.4) | 1.1 (SD, 1.3) |
| 9–10 | 4 | 1.0 (SD, 1.2) | 1.0 (SD, 1.2) |
| 10–11 | 8 | 1.9 (SD, 1.9) | 1.8 (SD, 1.7) |
| 11–12 | 5 | 1.0 (SD, 1.0) | 1.0 (SD, 1.0) |
| 12–13 | 10 | 1.8 (SD, 1.3) | 1.2 (SD, 1.2) |
| 13–14 | 6 | 1.6 (SD, 0.9) | 0.8 (SD, 0.7) |
| 14–15 | 3 | 1.9 (SD, 1.8) | 1.9 (SD, 1.2) |
| 15–16 | 2 | 2.6 (SD, 2.2) | 1.6 (SD, 0.8) |
| 16–17 | 2 | 0.0 | 0.0 |
| >17 | 4 | 0.9 (SD, 0.6) | 1.0 (SD, 1.2) |
Note:—L indicates left; R, right.