Geometric morphometric assessment of face shape in 6.0-8.0 year olds
Presentation Category
Research
Introduction/Context/Diagnosis
Delineating the focal point of growth in the developing craniofacial complex is relevant to general dentistry, orthodontics, and craniofacial surgery. Geometric morphometrics allows shape variation to be explored mathematically by subjecting the data to either or both principle components analysis (PCA) or thin plate transformations. Here we explore three-dimensional shape change in order to delineate idiosyncratic and progressive growth variation in 6.0-8.0 year old faces.
Methods/Treatment Plan
Our cross-sectional sample (N=44) comprises children and juvenile skulls in four age groups: 5.8-6.3, 6.4-6.7, 6.8-7.3, and 7.4-7.9 years. We used a 3D digitizer to collect 99 craniometric points on the craniofacial complex. Data was analyzed in Morphologika 2.5. Procrustes-aligned shape variables were analyzed via principle components analysis and thin plate spline transformations.
Results/Outcome
PC 1-4 explain 12.7, 10.2, 8.54, and 7.09% of the variance, respectively. PC1 reflects a significant repositioning of the face (lowering of the face, raises the medial mandible) associated with a broadening of the mid-to-upper face. PC2 shows that both facial height and the degree of superoinferior facial curvature change with a lengthening of the mandibular corpus, the latter is associated with tooth eruption. On PC3 the gonial angle becomes more obtuse while the mid-to-upper face become anteroposteriorly elongated.
Significance/Conclusions
Geometric morphometric allows for visualization of shape change in the craniofacial complex. Progressive re-analysis of the data results in the delineation of specific points where growth is occurring. These data allow for the delineation and isolation of idiosyncratic and sex based changes in the growing craniofacial complex.
Format
Event
Geometric morphometric assessment of face shape in 6.0-8.0 year olds
Delineating the focal point of growth in the developing craniofacial complex is relevant to general dentistry, orthodontics, and craniofacial surgery. Geometric morphometrics allows shape variation to be explored mathematically by subjecting the data to either or both principle components analysis (PCA) or thin plate transformations. Here we explore three-dimensional shape change in order to delineate idiosyncratic and progressive growth variation in 6.0-8.0 year old faces.
