Table 1 Factors related to change of cross sectional masseter muscle area
|  | Average ± SD (range) | r2 | P value |
|---|---|---|---|
Physical factors | |||
Age | 24.5 ± 8.7 (15–46) | 0.1368 | 0.1085 |
Body mass index (BMI) | 20.5 ± 1.8 (18.1–25.5) | 0.0156 | 0.5998 |
Morphological factors | |||
Overjet (mm) | − 1.2 ± 1.8 (− 4.4–3.0) | 0.0009 | 0.8964 |
Overbite (mm) | 1.0 ± 2.3 (− 2.5–6.7) | 0.0395 | 0.4006 |
SNA angle (°) | 80.4 ± 3.4 (72.3–84.2) | 0.2577 | 0.0223* |
SNB angle (°) | 81.5 ± 3.5 (75.6–88.1) | 0.0196 | 0.5536 |
ANB angle (°) | − 1.2 ± 2.9 (− 7.3–3.3) | 0.1736 | 0.0676 |
GZN angle (°) | 89.4 ± 5.6 (77.1–100.6) | 0.0003 | 0.9416 |
SN-MP angle (°) | 39.6 ± 4.9 (30.8–50.1) | 0.0292 | 0.4716 |
DFFM at Menton (mm) | 1.7 ± 1.9 (0–6.0) | 0.0634 | 0.2840 |
Ul-Ll deviation (mm) | 1.6 ± 1.2 (0–4.0) | 0.0002 | 0.9423 |
Treatment factors | |||
Treatment duration (days) | 14.7 ± 6.4 (4–29) | 0.0010 | 0.6769 |
Change of overjet (mm) | − 1.9 ± 2.8 (− 8–2.3) | 0.0007 | 0.9091 |
Change of overbite (mm) | − 1.7 ± 2.2 (− 6–1.7) | 0.2260 | 0.0341* |