Table 4.

Outcomes of binary regression analysis for poor prognosis (perforation and severe complications).

	Perforation				Severe complications
	B	S.E	Exp(B)	P value	B	S.E	Exp(B)	P value
Gender	0.473	0.319	0.859–2.998	0.138	0.389	0.411	0.659–3.305	0.44
Age	0.024	0.010	1.005–1.044	0.014*	0.053	0.014	1.026–1.083	<0.001***
DOI	0.025	0.004	1.016–1.034	<0.001***	0.009	0.003	1.003–1.015	0.003**
DFI	0.041	0.030	0.982–1.104	0.174	0.063	0.039	0.987–1.148	0.104
Lmax	0.017	0.021	0.976–1.060	0.423	0.050	0.023	1.004–1.100	0.033*
Lmin	0.071	0.045	0.983–1.171	0.114	0.059	0.057	0.949–1.186	0.301
Lmax/Lmin	0.249	0.080	1.098–1.500	0.002**	0.057	0.099	0.872–1.287	0.563
Sharpness	—	—	—	—	0.639	1.216	0.175–20.527	0.599
Shapes of two pressure points
Pin	0.509	0.608	0.505–5.472	0.403	1.362	0.908	0.658–23.160	0.134
Spindle	1.273	0.563	1.156–6.746	0.024*	1.666	0.775	1.159–24.146	0.032*

DOI: duration of impaction; DFI: distance from incisor; LOS: length of stay; Lmax: length of major axis; Lmin: length of minor axis *P < 0.05; **P < 0.01; ***P < 0.001. The sharpness was not included in the regression analysis for perforation, because all 18 blunt cases were in the non-perforation group.