Predicting changes in mandibular length and total anterior facial height using IGF-1, cervical stage, skeletal classification, and gender

Progress in Orthodontics

Table 2 Results of regression analysis to predict annual change in total anterior face height

Independent variables	Parameter estimate	Error	p value
Intercept	6.08452	8.35131	0.47
Average IGF-1 in μg/L	0.00929	0.0061	0.14
IGF-1 change in μg/L	0.01033	0.00437	0.02
Initial total anterior facial height in mm	−0.06665	0.07285	0.37
Male (female is the reference group)	1.75912	0.97007	0.08
Skeletal class I (reference group)	Reference
Skeletal class II	0.30974	1.00557	0.76
Skeletal class III	1.89294	1.46272	0.20
Cervical group A	−0.88972	1.22983	0.47
Cervical group B	2.45562	1.42716	0.09
Cervical group C (reference group)	Reference