Abstract
Background
Palatal rugae patterns are useful in the field of forensic dentistry. Ethnicity has a significant effect on the development and final morphological pattern of palatal rugae. This study focused on a morphological analysis of the palatal rugae in a Saudi population to determine if any differences based on age and gender could support identifying an individual.
Materials and methods
This cross-sectional study conducted at the College of Dentistry, King Saud bin Abdul Aziz University for Health Sciences, was undertaken to evaluate 496 dental casts from the participant database of Saudi nationals from Riyadh. The rugae were delineated using a sharp graphite pencil under adequate light and magnification. The rugae patterns were classified based on the length, shape, and direction of the rugae by two observers as per Thomas and Kotze's criteria.
Results
The asymptotic chi-square McNemar test indicated bilateral symmetry for all the characteristics of the palatal rugae, except for the backward and forward directions of the rugae. Two-way analysis of variance (ANOVA) revealed a statistically significant interaction between the effects of age group and gender on the primary rugae count (F(3, 488) = 7.466, p <0.05)). In addition, age had a statistically significant effect on the fragmentary rugae (p <0.05), and gender had a statistically significant effect on the circular and backward patterns of the rugae (p<0.05). The females had a higher incidence of backward-directed rugae and the males had more circular rugae. No other significant difference was evident, based on gender. The logistic regression analyses showed a significant association between the circular (OR=1.298; 95% CI= 1.061-1.588) and backward (OR= 0.898; 95% CI= 0.828-0.975) palatal rugae and gender. Also, there was a significant association of the fragmentary palatal rugae (PR) (OR=1.274; 95% CI= 1.084-1.498) with the age group younger than 16 years.
Conclusion
In a Saudi Arabian ethnic group, the varying type of length of the palatal rugae patterns can be used to identify the age group while the direction and shape can be used to determine gender, although with limited accuracy. Post-mortem identification may benefit from using them along with other reliable forensic tools. There is a need to conduct continued research on diverse populations and ethnic groups in order to evaluate the PR potential in forensic dentistry.