Survival of maxillary and mandibular bonded retainers 10 to 15 years after orthodontic treatment: a retrospective observational study

Progress in Orthodontics

Table 4 Cox regression for the effect of retainer type on mandibular lingual retainer survival adjusted for age at T₃ and gender

Predictor		Hazard ratio	95% CI		P value
Type of retainer	.016″ × .022″ braided SS	Reference
	.027″ TMA	0.42	0.22	0.81	0.009
Age at T₃ (per unit = 1 year)		1.09	0.98	1.2	0.121
Gender	Male	Reference
Gender	Female	0.55	0.28	1.1	0.085