PREVALENCE OF AGENESIA OF THE POSTERIOR ARC OF DRY ATLAS OF ADULTS BELONGING TO AN OSTEOLOGICAL COLLECTION FROM THE NORTHEAST REGION OF BRAZIL.

Abstract

In Anatomy, anatomical variation is a deviation from the normal morphology of an organ or structure of an individual, and among the various anatomical variations, we observed some in the first cervical vertebra, such as the presence of agenesis of the posterior arch found between 0.9% and 3 .9% of the population according to the literature. Therefore, in the present study we intend to describe the prevalence of agenesis of the posterior arch of the atlas in an Osteological Collection in the Northeast Region of Brazil. For our study, 231 dry atlases of adults were used, 81 females and 150 males. All vertebrae belong to the collection of the Forensic Anthropology Center of the Faculty of Medicine of FAP-Araripina, located in the State of Pernambuco, Brazil. To collect the data, the inductive approach method was used with a systematic and direct observation technique for data collection and a descriptive procedure for analyzing them. After collecting the data, we verified the following results. Regarding the total sample (n=231), we observed the absence of agenesis in 223 vertebrae, representing 96.5% of cases. In 8 vertebrae (3.5%) we found the presence of a median fissure in the posterior arch. In males, the posterior fissure was found in 6 vertebrae, representing 4% of cases. In females, the fissure appeared in 2 vertebrae, with 2.5% of the cases studied. Due to the great importance of this structure for the clinic, further studies in our population are necessary to identify these variations.