Table 3.
The absolute values of error, distribution of error, accuracy percentage, and degree of accuracy for each landmark
| Compartment | Land-mark | Absolute value of error (Err) | Distribution | Accuracy | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Mean ± SD (mm) | Excellent (Err <1.0 mm) |
Good (1.0 ≤ Err < 1.5 mm) |
Fair (1.5 ≤ Err < 2.0 mm) |
Acceptable (2.0 ≤ Err < 2.5 mm) |
Unacceptable (2.5 mm ≤ Err) |
Accuracy percentage | Degree of accuracy | ||||||
| Skeletal landmark | Cranial base | Nasion | 0.59 ± 0.48 | 157 (85.3) | 18 (9.8) | 4 (2.2) | 3 (1.6) | 2 (1.1) | 175 (95.1) | Very high | |||
| Sella | 0.46 ± 0.23 | 180 (97.8) | 4 (2.2) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 184 (100) | Very high | |||||
| Porion | 1.07 ± 0.69 | 103 (56.0) | 37 (20.1) | 24 (13.0) | 14 (7.6) | 6 (3.3) | 140 (76.1) | High | |||||
| Orbitale | 1.21 ± 1.01 | 92 (50.0) | 44 (23.9) | 21 (11.4) | 12 (6.5) | 15 (8.2) | 136 (73.9) | High | |||||
| Basion | 1.64 ± 1.61 | 82 (44.6) | 34 (18.5) | 21 (11.4) | 13 (7.1) | 34 (18.5) | 116 (63.1) | Medium | |||||
| Maxilla | Anterior | ANS | 1.39 ± 1.01 | 72 (39.1) | 48 (26.1) | 23 (12.5) | 14 (7.6) | 27 (14.7) | 120 (65.2) | Medium | |||
| A point | 1.41 ± 0.99 | 86 (46.7) | 30 (16.3) | 22 (12.0) | 18 (9.8) | 28 (15.2) | 116 (63.0) | Medium | |||||
| Posterior | PNS | 1.19 ± 0.89 | 97 (52.7) | 37 (20.1) | 24 (13.0) | 13 (7.1) | 13 (7.1) | 134 (72.7) | High | ||||
| Mandible | Anterior | B point | 1.15 ± 0.96 | 106 (57.6) | 36 (19.6) | 21 (11.4) | 8 (4.3) | 13 (7.1) | 142 (77.2) | High | |||
| Pogonion | 0.79 ± 0.68 | 140 (76.1) | 28 (15.2) | 7(3.8) | 1 (0.5) | 8 (4.3) | 168 (91.3) | Very high | |||||
| Bottom | Menton | 0.77 ± 0.44 | 143 (77.7) | 29 (15.8) | 8 (4.3) | 3 (1.6) | 1 (0.5) | 172 (93.5) | Very high | ||||
| Posterior | Articulare | 0.77 ± 0.45 | 138 (75.0) | 34 (18.5) | 10 (5.4) | 1 (0.5) | 1 (0.5) | 172 (93.5) | Very high | ||||
| Dental landmark | Maxillary dentition | Anterior | Mx1C | 0.44 ± 0.37 | 178 (96.7) | 2 (1.1) | 2 (1.1) | 1 (0.5) | 1 (0.5) | 180 (97.8) | Very high | ||
| Mx1R | 1.55 ± 1.09 | 63 (34.2) | 43 (23.4) | 36 (19.6) | 12 (6.5) | 30 (16.3) | 106 (57.6) | Medium | |||||
| Posterior | Mx6D | 1.43 ± 1.08 | 76 (41.3) | 42 (22.8) | 23 (12.5) | 17 (9.2) | 26 (14.1) | 118 (64.1) | Medium | ||||
| Mx6R | 1.68 ± 1.08 | 51 (27.7) | 44 (23.9) | 35 (19.0) | 19 (10.3) | 35 (19.0) | 95 (51.6) | Medium | |||||
| Mandibular dentition | Anterior | Md1C | 0.49 ± 0.64 | 172 (93.5) | 7 (3.8) | 0 (0.0) | 2 (1.1) | 3 (1.6) | 179 (97.3) | Very high | |||
| Md1R | 1.57 ± 1.04 | 64 (34.8) | 43 (23.4) | 29 (15.8) | 18 (9.8) | 30 (16.3) | 107 (58.2) | Medium | |||||
| Posterior | Md6D | 1.67 ± 1.24 | 54 (29.3) | 41 (22.3) | 33 (17.9) | 30 (16.3) | 26 (14.1) | 95 (51.6) | Medium | ||||
| Md6R | 2.03 ± 1.35 | 46 (25.0) | 30 (16.3) | 25 (13.6) | 28 (15.2) | 55 (29.9) | 76 (41.3) | Low | |||||
| Total | 1.17 ± 1.04 | 2,100 (57.1) | 631 (17.1) | 368 (10.0) | 227 (6.2) | 354 (9.6) | 2,731 (74.2) | High | |||||
Values are presented as number (%).
Err, absolute value of error; SD, standard deviation; Accuracy percentage (AP); error range within 1.5 mm was considered accurate.
The degree of accuracy was defined as very high (90% ≤ AP), high (70% ≤ AP < 90%), medium (50% ≤ AP < 70%), and low (AP < 50%).
See Table 2 for definitions of each landmark.