An application of the density standard and scaled–pixel–counting protocol to assess the radiodensity of equine incisor teeth affected by resorption and hypercementosis: preliminary advancement in dental radiography

Table 2 The accuracy of the differentiation of radiographic signs of selected EOTRH 0 – 3 grades based on the numbers of pixels (NP) of the selected pixel brightness (PB) in consecutive steps of density standard (S1–S10). Sensitivity (Se), specificity (Sp), positive predictive value (PPV), and, negative predictive value (NPV) were calculated using two thresholds (mean and |mean – SD|)

Step	EOTRH		Se	Sp	PPV	NPV	Se	Sp	PPV	NPV
Step	lower	higher	mean				\|mean – SD\|
S1	0	3	0.25	1.00	1.00	0.70	0.25	1.00	1.00	0.70
S2	0	3	0.30	0.99	0.95	0.71	0.30	0.96	0.82	0.70
S3	0	3	0.31	0.96	0.83	0.71	0.41	0.96	0.86	0.74
S4	0	3	0.36	0.95	0.81	0.72	0.49	0.89	0.71	0.75
S5	0	3	0.23	0.93	0.67	0.68	0.52	0.74	0.54	0.73
S6	0	3	0.38	0.82	0.55	0.69	0.67	0.68	0.55	0.78
S7	0	3	0.38	0.79	0.51	0.69	0.97	0.40	0.48	0.95
S8	0	3	0.34	0.78	0.48	0.67	0.98	0.46	0.51	0.98
S1	1	3	0.25	0.96	0.65	0.80	0.25	0.96	0.65	0.80
S2	1	3	0.30	0.94	0.60	0.81	0.30	0.91	0.51	0.81
S6	1	3	0.38	0.79	0.36	0.80	0.67	0.57	0.33	0.85
S7	1	3	0.38	0.74	0.32	0.79	0.97	0.32	0.31	0.97
S8	1	3	0.34	0.76	0.31	0.79	0.98	0.31	0.31	0.98
S3	2	3	0.30	0.90	0.65	0.67	0.39	0.83	0.59	0.68
S4	2	3	0.34	0.85	0.59	0.67	0.46	0.74	0.53	0.68
S5	2	3	0.33	0.80	0.51	0.65	0.33	0.75	0.46	0.64
S3	0	1	0.17	0.94	0.85	0.38	0.08	0.96	0.79	0.36
S4	0	1	0.21	0.91	0.82	0.38	0.16	0.94	0.84	0.38
S5	0	1	0.25	0.80	0.70	0.36	0.23	0.82	0.70	0.36

ISSN: 1746-6148