The development of a novel Orthodontic Alignment Index and its use to evaluate the effect of residual overjet on the stability of the alignment of the maxillary anterior dentition

Progress in Orthodontics

Table 4 Linear regression analysis of the effect of a residual overjet (T1) on post-treatment stability (T2) using the Orthodontic Alignment Index (OAI) and Little’s Irregularity Index (LII), adjusting for baseline alignment (T0) and confounding factors (Coef: coefficient)

Indices	Independent variable	Coef	P	95% Confidence interval
Indices	Independent variable	Coef	P	Lower	Upper
OAI	Overjet (T1)	0.56	0.389	− 0.70	1.86
	Age (T0)	0.57	0.388	− 0.74	1.87
	Gender	0.53	0.409	− 0.73	1.79
	Extraction (yes/no)	0.56	0.403	− 0.77	1.90
	Extraction pattern	0.54	0.439	− 0.84	1.92
	Retention regime	0.50	0.455	− 0.82	1.82
	Retention compliance	0.65	0.340	− 0.69	1.98
LII	Overjet (T1)	0.14	0.577	− 0.36	0.63
	Age (T0)	0.15	0.540	− 0.33	0.63
	Gender	0.13	0.592	− 0.35	0.61
	Extraction (yes/no)	0.12	0.625	− 0.38	0.62
	Extraction pattern	0.09	0.721	− 0.42	0.61
	Retention regime	0.18	0.477	− 0.32	0.67
	Retention compliance	0.06	0.824	− 0.44	0.55