Table 4.

The relationship between risk factors and OGE by univariate and multivariate analysis

Variables	Univariate analysis			Multivariate analysis
	OR	95% CI	P value	OR	95% CI	P value
Age	1.045	0.221–1.772	0.377
Treatment duration	1.007	0.989–1.104	0.116
Sex	0.626	0.973–1.042	0.688
Malocclusion
Class I	Reference
Class II	0.793	0.370–1.701	0.551
Class III	0.944	0.271–3.289	0.928
IPR in anterior teeth
0 mm	Reference
0–2 mm	1.801	0.747–4.340	0.190
≥ 2 mm	0.806	0.337–1.923	0.626
IPR in incisors
0 mm	Reference
0–1 mm	1.439	0.606–3.420	0.410
≥ 1 mm	1.030	0.435–2.442	0.946
IPR in central incisors
0 mm	Reference
> 0 mm	0.847	0.410–1.751	0.654
Attachments in anterior teeth
0	Reference
1–2	9.414	1.141–77.652	0.037*	9.555	1.157–78.923	0.036*
> 2	11.781	1.450–95.738	0.021*	9.578	1.156–79.368	0.036*
Attachments in incisors
0	Reference
1–2	0.755	0.335–1.699	0.497
> 2	2.540	0.685–9.432	0.163
Attachments in central incisors
0	Reference
1	0.943	0.260–3.424	0.929	0.776	0.209–2.876	0.704
2	11.550	1.370–97.365	0.024*	9.501	1.081–83.522	0.042*

IPR interproximal enamel reduction

P value < 0.05 was considered significant (*) given in Bold