A simple method of nose tip shape validation for facial approximation.

Despite numerous papers relating to the prediction of nose projection for the purposes of facial approximation, there is little guidance for nose tip shape that has been evaluated on a known data set. This study presents a novel, simple technique for validation of the reconstructed nose tip shape based on methods used in actual approximation practice. The data set was comprised of 25 full-head computed tomography (CT) patient scans. In 22 of the 25 patients across all age and sex groups, when the head is tilted so that soft tissue pronasale is superimposed on hard tissue rhinion, the curvature of the nose tip was found to mimic the curvature of the superior portion of the nasal aperture. This occurs when the head is tilted dorsally by approximately 60° (55.87±5.91). Individuals with snub noses presented a much wider tip curvature. The method was highly repeatable and was evaluated through inter- and intra-observer studies (error=3.15%).

Virtual determination of sex: metric and nonmetric traits of the adult pelvis from 3D computed tomography models.

Examination of the adult os coxae and sacrum is one of the most common methods of sex estimation from bone. Medical imaging, such as computed tomography (CT), provides the opportunity for three-dimensional (3D) imaging of the skeleton from clinical scans of known individuals in situ. In this study, a randomly selected subset of abdominopelvic CT-derived models were used to evaluate simple, repeatable metric methods of sex estimation based on a combination of obstetric measurements and the traditionally nonmetric Phenice-derived traits. A four-variable discriminant function for sex estimation was developed based on statistical analyses. Overall, the cross-validated accuracy of this method was 100%, with inter-observer error showing an average of only 2.2%. Comparative analysis was run on the data set using FORDISC 3.0. This study shows that current sex determination standards from the pelvis should be updated to include more in vivo data to increase the accuracy of identification.