Individuality of Human Palatal Rugae

Abstract

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. The team approach significantly reduced the time required to make correct matches; it appears that the palatal rugae pattern is sufficiently characteristic to discriminate between individuals; and this study supports the hypothesis that palatal rugae are unique and identification could be based upon their comparison.

Application of Palatal Rugae Morphology in Forensic Identification

“…In the field of forensic stomatologia, individual identification is a changeling task. Palatal rugae morphology for forensic individual identification can be considered when individual identification by fingerprints or teeth is hardly performed (English et al, 1988;Rath & Reginald, 2014;Mishra et al, 2014).…”

Uso da rugoscopia palatina como ferramenta biométrica: um estudo populacional em Niterói-RJ, Brasil

“…A sua formação tem início por volta do terceiro mês de vida intrauterina. As rugosidades palatinas permanecem por toda a vida e ainda resistem vários dias após a morte, por sua natureza fibrosa 4,5 . Na espécie humana, o conjunto de rugosidades palatinas é assimétrico, ao contrário do que acontece em outros animais; ainda, em gêmeos monozigotos, há comprovação de que estas são individuais 4 .…”

“…Este processo deve obedecer aos parâmetros biológicos de unicidade, perenidade e imutabilidade, e aos critérios técnicos de classificabilidade e de praticabilidade 4,6 . A unicidade é a condição de não se repetir em outro indivíduo o conjunto de caracteres pessoais; a perenidade é a capacidade de certos elementos resistirem à ação do tempo; a imutabilidade é a inalterabilidade dos caracteres por toda a existência; a praticabilidade é o que torna o processo prático de ser aplicável na rotina pericial, minimizando custos e facilitando a obtenção de dados; a classificabilidade determina o conjunto de caracteres individuais próprios, facilitando o arquivamento de dados e a sua rapidez de localização [4][5][6] .…”

“…O uso de métodos biométricos tem despertado interesse na área de Odontologia Legal, no intuito de identificação individual e para vítimas de desastres em massa, em que, muitas vezes, há particular dificuldade pela limitação das técnicas habituais ou pela natureza da ação traumática 4,7,8 . Nesse sentido, a rugoscopia palatina seria uma vantajosa ferramenta biométrica.…”

The application of affine transformations in matching distorted forensic samples with a common origin

“…The deformation can be the result of a time delay, postural change [4,5], poor photographic technique or physical changes to the evidence [2,6]. These comparisons can be between the dentition of a suspect/ victim and bite marks on inanimate objects/skin [1,3], two radiological images [7], palatal rugae patterns [8][9][10], dental arches, lip prints [8,11] and other unique situations which are presented in forensic odontological cases.…”