Evaluation of osifix software with craniofacial anthropometric purposes.

Abstract

Forensic Facial Reconstruction is a branch of Forensic Anthropology that attempts to approximate the appearance of an unknown individual through soft tissue reconstruction, after anthropological craniofacial analysis is carried out. The reconstruction publicized in the media aims at a recognition, which can trigger formal human identification. Knowing the anthropometric relationships between hard and soft tissues is useful to increase the accuracy of reconstructions. It was sought to evaluate the performance of the software OsiriX as a tool for anthropometric analysis of both hard and soft tissues. In cone beam CBCT scans of eight individuals, seven linear distances, determined by 14 anatomical landmarks on hard and soft tissues were measured. Intra-observer and inter-observer variation were evaluated by two criteria: reproducibility of landmark location on skull surface and reproducibility of measurement values in millimeters. For intra-observer evaluation, the sample was measured twice within an interval of two weeks. To assess inter-observer variation three independent operators performed measurements once. For reproducibility of anatomical landmarks, the metadata containing the distance in millimeters from each point to the origin of the x, y and z axis were obtained from the software. Means and standard deviations for the set of linear measurements and coordinates of the points were analyzed, and the difference between the standard deviations was used to classify reproducibility. For intra and inter-observer variations, most of the landmarks were located with less than 0.5mm of difference between measurements. For the corresponding measurements, made between these landmarks, most were repeated with less than 1.5 mm of difference for both intra and inter-observer variation. In practical terms, the differences detected did not hamper the use of the software as a tool for anthropometric studies. The use of OsiriX is an alternative for anthropological study of craniofacial hard and soft tissues from CBCT.