Individuality of human palatal rugae

Investigators have implied that palatal rugae are unique to each individual. However, these researchers have disagreed as to whether or not legal identification could be based solely on palatal rugae. Previous studies used poor duplicating materials and may not have considered the effects of growth, extractions, palatal expansion, or some combination of these. The inadvertent use of other features of the cast, such as teeth, edentulous ridge morphology, muscle attachments, vestibular depth, or some combination of these, to aid in the identification, may have influenced their results. The purpose of this investigation was to determine if palatal rugae can be relied upon for identification. Twenty-five orthodontic cases were selected with pre- and post-treatment casts; orthodontic treatment had taken eighteen to sixty months. One hundred casts were randomly selected as variables. All casts were trimmed so that all areas except for the rugae area of the hard palate were removed. The twenty-five post-orthodontic casts were dispersed within 100 randomly selected casts. Nine investigators were given the twenty-five pre-orthodontic casts and asked to compare them to the other one hundred and twenty-five casts for possible matches. Data were collected as to percentage of correct matches and time required for comparison. Each set of pre- and post-orthodontic casts was properly identified (100%) by 8 investigators, and the remaining investigator correctly matched 22 out of 25 casts (88%). These conclusions were drawn.(ABSTRACT TRUNCATED AT 250 WORDS)