Clinical Study
A Comparative Study of Palatal Rugae Patterns among Igbo and Ikwerre Ethnic Groups of Nigeria: A University of Port Harcourt Study
Table 1
-test of proportionality difference in rugae pattern distribution between Ikwerre and Igbo males.
| Pattern | Tribe | Obs. population () | Sampled population () | Obs. proportion | -value (calculated) | critical | value (obs.) | Inference |
| Wavy | Ikwerre | 119 | 335 | 0.356 | −3.98 | 1.96 | <0.0001 | Significant difference in proportions
*
| Igbo | 161 | 312 | 0.511 |
| Curvy | Ikwerre | 151 | 335 | 0.451 | 4.53 | 1.96 | <0.0001 | Significant difference in proportions
*
| Igbo | 87 | 312 | 0.279 |
| Circular | Ikwerre | 12 | 335 | 0.036 | −1.49 | 1.96 | 0.136 | No significant difference in proportions | Igbo | 19 | 312 | 0.061 |
| Straight | Ikwerre | 33 | 335 | 0.099 | 1.76 | 1.96 | 0.078 | No significant difference in proportions | Igbo | 19 | 312 | 0.061 |
| Converging | Ikwerre | 7 | 335 | 0.021 | −0.89 | 1.96 | 0.373 | No significant difference in proportions | Igbo | 10 | 312 | 0.032 |
| Diverging | Ikwerre | 13 | 335 | 0.039 | −0.77 | 1.96 | 0.441 | No significant difference in proportions | Igbo | 16 | 312 | 0.051 |
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The asterisks were used to demonstrate values with significant difference.
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