Table 4.
Trait prevalence in the lower permanent molars
Prävalenz von Merkmalen der unteren bleibenden Molaren
| Trait / Grade | First molars | Second molars | χ2 test | |||||
|---|---|---|---|---|---|---|---|---|
| (laterality) | (dimorphism) | |||||||
| LM1 (r) | LM1(l) | LM2 (r) | LM2 (l) | LM1 | LM2 | LM1 | LM2 | |
| GROOVE PATTERN, n (%) | ||||||||
| Y. Cusps 2 and 3 are in contact | 94(74.0) | 97(77.6) | 38(27.3) | 37(27.8) | 0.623 | 0.685 | 0.247 | 0.067 |
| +. Cusps 1–4 are in contact | 22(17.3) | 21(16.8) | 57(41.0) | 60(45.1) | ||||
| X. Cusps 1 and 4 are in contact | 11(8.7) | 7(5.6) | 44(31.7) | 36(27.1) | ||||
| HYPOCONULID, n (%) | ||||||||
| 0. Absent | 22(13.8) | 19(11.9) | 104(91.2) | 89(94.7) | 0.994 | 0.692 | 0.204 | 0.070 |
| 1. Very small | 11(6.9) | 13(8.2) | 1(0.9) | 1(1.1) | ||||
| 2. Small | 34(21.4) | 33(20.8) | 6(5.3) | 2(2.1) | ||||
| 3. Medium-sized | 72(45.3) | 74(46.5) | 3(2.6) | 2(2.1) | ||||
| 4. Large | 17(10.7) | 17(10.7) | – | – | ||||
| 5. Very large | 3(1.9) | 3(1.9) | – | – | ||||
| CUSP 6, n (%) | ||||||||
| 0. Absent | 150(94.3) | 151(94.9) | 107(100.0) | 87(100.0) | 0.908 | – | 0.168 | – |
| 1. Much smaller than cusp 5 | 4(2.5) | 3(1.9) | – | – | ||||
| 2. Smaller than cusp 5 | 3(1.9) | 2(1.3) | – | – | ||||
| 3. Equal in size to cusp 5 | 2(1.3) | 3(1.9) | – | – | ||||
| CUSP 7, n (%) | ||||||||
| 0. Absent | 155(96.9) | 157(98.1) | 147(98.7) | 141(98.6) | 0.733 | 0.967 | 0.091 | 0.050* |
| 1. Faint cusp | 1(0.6) | 1(0.6) | 2(1.3) | 2(1.4) | ||||
| 2. Small | 1(0.6) | – | – | – | ||||
| 3. Medium-sized | 2(1.3) | 2(1.3) | – | – | ||||
| 4. Large | 1(0.6) | – | – | – | ||||
| PROTOSTYLID, n (%) | ||||||||
| 0. Smooth surface | 144(90.0) | 146(91.3) | 141(97.9) | 143(97.9) | 0.701 | 0.986 | 0.701 | 0.999 |
| 1. Pit present | 16(10.0) | 14(8.7) | 3(2.1) | 3(2.1) | ||||
| ANTERIOR FOVEA, n (%) | ||||||||
| 0. Absent | 77(55.4) | 76(53.1) | 66(46.1) | 56(39.4) | 0.983 | 0.708 | 0.591 | 0.184 |
| 1. Trace with a weak ridge | 14(10.1) | 15(10.5) | 18(12.6) | 19(13.4) | ||||
| 2. Essential ridges on trigonid developed | 43(30.9) | 47(32.9) | 55(38.5) | 63(44.4) | ||||
| 3. Essential ridges pronounced | 5(3.6) | 5(3.5) | 4(2.8) | 4(2.8) | ||||
| DEFLECTING WRINKLE, n (%) | ||||||||
| 0. Absent | 45(33.6) | 44(31.9) | 111(77.1) | 111(77.6) | 0.871 | 0.795 | 0.437 | 0.932 |
| 1. Midpoint constriction | 45(33.6) | 49(35.5) | 19(13.2) | 21(14.7) | ||||
| 2. Deflected distally | 37(27.6) | 35(25.4) | 14(9.7) | 11(7.7) | ||||
| 3. L-shaped ridge | 7(5.2) | 10(7.2) | – | – | ||||
| DISTAL TRIGONID CREST, n (%) | ||||||||
| 0. Absent | 130(97.0) | 132(97.1) | 123(87.2) | 113(81.3) | 0.983 | 0.172 | 0.002* | 0.0003* |
| 1. Present | 4(2.9) | 4(2.9) | 18(12.8) | 26(18.7) | ||||
L lower, M molar, 1 first, 2 second, (r) right, (l) left
*Statistical difference (p ≤ 0.05)