Palatal rugae patterns in orthodontically treated cases, are they a reliable forensic marker?

The specialization of forensic odontology is fast emerging as a branch that helps in personal identification of both living as well as dead individuals and also in crime scene investigations. Establishing a person's identity can be a challenging task in cases of road accidents or acts of terrorism or mass disaster scenario. It is an established fact that palatal rugae are unique for each individual and can be reliably used in the forensic field for personal identification. The present study was undertaken to evaluate the post-treatment stability of palatal rugae pattern in individuals subjected to orthodontic treatment with and without extractions and palatal expansion.

A total of 137 pre- and post-orthodontically treated casts of patients were obtained from our institute, which were divided into 50 cases each of extraction and non-extraction, 37 cases of palatal expansion involving both extraction and non-extraction. Palatal rugae patterns of all the cases were compared pre- and post-treatment.

Chi-square test was applied for comparison of changes with respect to shape of rugae patterns. Maximum changes were seen in palatal expansion and extraction group and minimum changes in non-extraction group both on right and left sides. All three groups were compared involving all three parameters by Chi square test. About 89.19% and 84% of the study group showed changes in palatal expansion and extraction cases respectively. Although, a 62% of study subjects showed changes in non-extraction group with a P = 0.00041.

Orthodontic treatment has an impact on the stability of palatal rugae so investigator should be aware of this fact when analyzing for identification reasons.