Morphological changes in palatal rugae patterns following orthodontic treatment

• Morphometric changes are inflicted on palatal rugae by orthodontic treatment.
• The morphometric changes induced by orthodontic treatment do not affect the individuality of palatal rugae patterns.
• Orthodontic treatment may undermine the use of palatal rugae patterns in human identification.

This study investigated the morphometric changes that occur in palatal rugae during orthodontic treatment. The potential impact of these changes on the individuality of the palatal rugae patterns and on the use of palatal rugae patterns in human identification was also explored. Fifty pairs of pre- and post-orthodontic treatment dental casts were used. The palatal rugae patterns were compared between each pre-treatment cast and its post-treatment counterpart to reveal any morphometric changes. In addition, the individuality of the pre- and post-treatment sets of the casts was evaluated. Finally, a matching test of the palatal rugae patterns was performed in which the ability to match each post-treatment cast with its duplicate was compared with the ability to match that post-treatment cast with its pre-treatment counterpart. Statistical analysis of the results revealed the incidence of several morphometric changes, including segmentation (22%); unification (20%); changes in orientation (6%), shape (6%), and length (28%); anteroposterior displacement of the medial (54%) and lateral (60%) end of the ruga; and mediolateral displacement of the medial end of ruga (20%). The individuality of the palatal rugae patterns was confirmed in both pre- and post-treatment sets of casts. Finally, the mean percentage of correct matches was found to be significantly higher when the post-treatment casts were matched with their duplicates compared to when they were matched with their pre-treatment counterparts. The study revealed that Orthodontic treatment induces various morphometric changes in the palatal rugae patterns. These changes may potentially complicate palatal rugae-based human identification.