Comparison 2. Cervical pull headgear versus minor interceptive procedures (control).

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
2.1 Mandibular incisor crowding (pre‐treatment, 2 years, 4 years, 8 years, 13 years)	1		Mean Difference (IV, Fixed, 95% CI)	Subtotals only
2.1.1 Pre‐treatment	1	64	Mean Difference (IV, Fixed, 95% CI)	‐1.09 [‐2.53, 0.35]
2.1.2 2 years	1	64	Mean Difference (IV, Fixed, 95% CI)	0.33 [‐0.60, 1.26]
2.1.3 4 years	1	64	Mean Difference (IV, Fixed, 95% CI)	‐0.03 [‐0.86, 0.80]
2.1.4 8 years	1	54	Mean Difference (IV, Fixed, 95% CI)	0.52 [‐0.35, 1.39]
2.1.5 13 years	1	34	Mean Difference (IV, Fixed, 95% CI)	0.26 [‐1.35, 1.87]
2.2 Change in maxillary arch length	1		Mean Difference (IV, Fixed, 95% CI)	Subtotals only
2.2.1 2 years	1	64	Mean Difference (IV, Fixed, 95% CI)	1.98 [1.80, 2.16]
2.2.2 8 years	1	54	Mean Difference (IV, Fixed, 95% CI)	2.28 [2.05, 2.51]
2.3 Change in mandibular arch length	1		Mean Difference (IV, Fixed, 95% CI)	Subtotals only
2.3.1 2 years	1	64	Mean Difference (IV, Fixed, 95% CI)	1.30 [1.17, 1.43]
2.3.2 8 years	1	54	Mean Difference (IV, Fixed, 95% CI)	1.52 [1.30, 1.74]
2.4 Change in lower incisor to mandibular plane (0‐1 years and 0‐2 years)	1		Mean Difference (IV, Fixed, 95% CI)	Subtotals only
2.4.1 0 to 1 year	1	64	Mean Difference (IV, Fixed, 95% CI)	2.30 [0.67, 3.93]
2.4.2 0 to 2 years	1	64	Mean Difference (IV, Fixed, 95% CI)	1.40 [‐0.42, 3.22]
2.5 Change in upper incisor to maxillary plane	1		Mean Difference (IV, Fixed, 95% CI)	Subtotals only
2.5.1 0 to 1 year	1	64	Mean Difference (IV, Fixed, 95% CI)	4.00 [1.97, 6.03]
2.5.2 0 to 2 years	1	64	Mean Difference (IV, Fixed, 95% CI)	4.50 [1.36, 7.64]