Craniofacial shape from pre- to post-adolescence.

Aim: Craniofacial growth demonstrates significant variation and is difficult to predict. The aim of the present investigation was twofold: (1) to assess the association (covariation) between craniofacial shape at pre- and post-adolescence and (2) to evaluate if pre-adolescent craniofacial shape is related (covaries) with growth magnitude and direction.

Subjects And Methods: One hundred fifty subjects (86 males and 64 females) untreated orthodontically were selected from AAOF Craniofacial Growth Legacy Collection.

Three-dimensional facial capture using a custom-built photogrammetry setup: Design, performance, and cost.

Introduction: Although stereophotogrammetry is increasingly popular for 3-dimensional face scanning, commercial solutions remain quite expensive, limiting its accessibility. We propose a more affordable, custom-built photogrammetry setup (Stereo-Face 3D, SF3D) and evaluate its variability within and between systems.

Methods: Twenty-nine subjects and a mannequin head were imaged 3 times using SF3D and a commercially available system.

ROC surface assessment of the ANB angle and Wits appraisal's diagnostic performance with a statistically derived 'gold standard': does normalizing measurements have any merit?

Objective: To assess the ANB angle's and Wits appraisal's diagnostic performance using an extended version of Receiver Operating Curve (ROC) analysis, which renders ROC surfaces. These were calculated for both the conventional and normalized cephalometric tests (calculated by exchanging the patient's reference landmarks with those of the Procrustes superimposed sample mean shape).The required 'gold standard' was derived statistically, by applying generalized Procrustes superimposition (GPS) and principal component analysis (PCA) to the digitized landmarks, and ordering patients based upon their PC2 scores.

Connecting the new with the old: modifying the combined application of Procrustes superimposition and principal component analysis, to allow for comparison with traditional lateral cephalometric variables.

Objective: The combination of generalized Procrustes superimposition (GPS) and principal component analysis (PCA) has been hypothesized to solve some of the problems plaguing traditional cephalometry. This study demonstrates how to establish the currently unclear relationship between the shape space defined by the first two principal components to the ANB angle, Wits appraisal, and GoGnSN angle, and to elucidate possible clinical applications thereof.

Methods: Digitized landmarks of 200 lateral cephalograms were subjected to GPS and PCA, after which the sample mean shape was deformed along/parallel to principal components (PC) 1 and 2, recording the ANB, Wits, and GoGnSN value at each location.