Table 8. Details of the performed subgroup analyses, according to gender, beginning of the functional appliance therapy and post-retention period duration.
| Outcome | Subgroups | Overall effect | Heterogeneity | ||||||
|---|---|---|---|---|---|---|---|---|---|
| N_s | MD | 95% CI | P | Tau2 | Chi2 | P | I2 | ||
| Males Vs females | |||||||||
| SNA (degrees) | Males | 2 | -0.85 | -1.96, 0.27 | 0.14 | 0.00 | 0.50 | 0.48 | 0% |
| Females | 1 | -3.20 | -5.25, -1.15 | 0.00 | NA | ||||
| Total (95% CI) | 3 | -1.62 | -3.17, -0.07 | 0.04 | 1.02 | 4.42 | 0.11 | 55% | |
| Subgroup differences: | 3.92 | 0.05 | 75% | ||||||
| Co-Gn (mm) | Males | 1 | 1.30 | -2.71, 5.31 | 0.52 | NA | |||
| Females | 1 | -3.50 | -5.41, -1.59 | 0.00 | NA | ||||
| Total (95% CI) | 2 | -1.44 | -6.09, 3.22 | 0.55 | 8.95 | 4.49 | 0.03 | 78% | |
| Subgroup differences: | 4.49 | 0.03 | 78% | ||||||
| ANB (degrees) | Males | 2 | -1.26 | -3.11, 0.60 | 0.18 | 1.41 | 4.55 | 0.03 | 78% |
| Females | 1 | -2.00 | -3.11, -0.89 | 0.00 | NA | ||||
| Total (95% CI) | 3 | -1.48 | -2.72, -0.25 | 0.02 | 0.84 | 6.92 | 0.03 | 71% | |
| Subgroup differences: | 0.45 | 0.50 | 0% | ||||||
| Early Vs late treatments according to age | |||||||||
| SNA (degrees) | 7 < age < 11 | 7 | -1.34 | -2.11, -0.57 | 0.00 | 0.66 | 20.39 | 0.00 | 71% |
| 12 < age < 16 | 2 | 0.04 | -0.90, 0.98 | 0.93 | 0.20 | 1.66 | 0.20 | 40% | |
| Total (95% CI) | 9 | -1.03 | -1.88, -0.18 | 0.02 | 1.28 | 50.87 | 0.00 | 84% | |
| Subgroup differences: | 4.99 | 0.03 | 80% | ||||||
| Co-Gn (mm) | 7 < age < 11 | 7 | 1.81 | -0.61, 4.23 | 0.14 | 9.08 | 55.68 | 0.00 | 89% |
| 12 < age < 16 | 1 | 1.60 | 0.62, 2.58 | 0.00 | NA | ||||
| Total (95% CI) | 8 | 1.79 | -0.05, 3.64 | 0.06 | 5.73 | 57.49 | 0.00 | 88% | |
| Subgroup differences: | 0.02 | 0.88 | 0% | ||||||
| ANB (degrees) | 7 < age < 11 | 8 | -1.43 | -2.07, -0.79 | 0.00 | 0.61 | 26.11 | 0.00 | 73% |
| 12 < age < 16 | 2 | 0.16 | -0.81, 1.13 | 0.74 | 0.34 | 3.13 | 0.08 | 68% | |
| Total (95% CI) | 10 | -1.11 | -1.82, -0.40 | 0.00 | 1.07 | 57.36 | 0.00 | 84% | |
| Subgroup differences: | 7.15 | 0.01 | 86% | ||||||
| Early Vs late treatments according to the cervical vertebral maturation method | |||||||||
| SNA (degrees) | CVSM 1-2 | 2 | -1.61 | -2.96, -0.25 | 0.02 | 0.80 | 5.40 | 0.02 | 81% |
| CVSM 2-3 | 2 | 0.04 | -0.97, 1.05 | 0.93 | 0.23 | 1.63 | 0.20 | 39% | |
| Total (95% CI) | 4 | -0.85 | -2.35, 0.64 | 0.26 | 2.06 | 40.60 | 0.00 | 93% | |
| Subgroup differences: | 3.67 | 0.06 | 73% | ||||||
| Co-Gn (mm) | CVSM 1-2 | 2 | 1.71 | -2.39, 5.80 | 0.41 | 7.67 | 7.66 | 0.01 | 87% |
| CVSM 2-3 | 2 | 3.26 | -0.16, 6.69 | 0.06 | 5.57 | 11.11 | 0.00 | 91% | |
| Total (95% CI) | 4 | 2.61 | 0.76, 4.47 | 0.01 | 2.85 | 19.83 | 0.00 | 85% | |
| Subgroup differences: | 0.33 | 0.57 | 0% | ||||||
| ANB (degrees) | CVSM 1-2 | 2 | -0.15 | -0.73, 0.43 | 0.62 | 0.00 | 0.43 | 0.51 | 0% |
| CVSM 2-3 | 2 | -0.57 | -2.92, 1.78 | 0.63 | 2.72 | 17.66 | 0.00 | 94% | |
| Total (95% CI) | 4 | -0.36 | -1.33, 0.61 | 0.47 | 0.81 | 18.10 | 0.00 | 83% | |
| Subgroup differences: | 0.12 | 0.73 | 0% | ||||||
| 3-4 Vs 5-10 years after active functional appliance therapy | |||||||||
| SNA (degrees) | 3-4 years | 2 | -0.92 | -3.47, 1.62 | 0.48 | 3.29 | 36.06 | 0.00 | 97% |
| 5-10 years | 7 | -0.90 | -1.40, -0.40 | 0.00 | 0.00 | 5.72 | 0.46 | 0% | |
| Total (95% CI) | 9 | -1.03 | -1.88, -0.18 | 0.02 | 1.28 | 50.87 | 0.00 | 84% | |
| Subgroup differences: | 0.00 | 0.98 | 0% | ||||||
| Co-Gn (mm) | 3-4 years | 2 | 2.59 | 0.63, 4.55 | 0.01 | 1.73 | 7.46 | 0.01 | 87% |
| 5-10 years | 6 | 1.46 | -1.63, 4.55 | 0.35 | 13.01 | 46.89 | 0.00 | 89% | |
| Total (95% CI) | 8 | 1.79 | -0.05, 3.64 | 0.06 | 5.73 | 57.49 | 0.00 | 88% | |
| Subgroup differences: | 0.37 | 0.55 | 0% | ||||||
| ANB (degrees) | 3-4 years | 3 | -0.53 | -2.06, 1.00 | 0.50 | 1.67 | 25.46 | 0.00 | 92% |
| 5-10 years | 7 | -1.37 | -2.11, -0.63 | 0.00 | 0.74 | 24.20 | 0.00 | 75% | |
| Total (95% CI) | 10 | -1.11 | -1.82, -0.40 | 0.00 | 1.07 | 57.36 | 0.00 | 84% | |
| Subgroup differences: | 0.94 | 0.33 | 0% | ||||||
SNA, SNA angle; Co-Gn, Co-Gn distance; ANB, ANB angle
7 < age < 11; early treatments, commencing in children aged between 7 and 11 years; 12 < age < 16; late treatments, beginning in adolescents aged between 12 and 16 years
CVSM 1–2; early treatments, with patients presenting with Cervical Vertebral Maturation Stage (CVMS) 1 or 2 at the first observation; CVSM 2–3, late treatments, with subjects presenting with CVMS 2 or 3
N_s, number of studies or subgroups; MD, mean differences; 95% CI, 95% confidence intervals; P, P value.