Morphometric covariation between palatal shape and skeletal pattern in children and adolescents: a cross-sectional study.

OBJECTIVE: To assess shape covariation of the palate and craniofacial complex (CFC) in children and adolescents. METHODS: Pre-treatment lateral cephalometric radiographs and corresponding maxillary casts of 100 children (8-10 years) and 100 adolescents (15-20 years) were digitized. Exclusion criteria were previous orthodontic treatment, craniofacial syndromes, mouth breathing, finger sucking, crossbite, tooth agenesis, and tooth impaction. Palatal shape was described with 239 surface and curve semilandmarks and craniofacial shape with 10 fixed landmarks and 117 curve semilandmarks. Procrustes superimposition and principal component analysis were applied for evaluation of shape variability. Shape covariation between palate and CFC was assessed with partial least squares analysis. RESULTS: The first five principal components explained 77 per cent (palate) and 60 per cent (CFC) of total shape variability. The palate varied mainly in height (adolescent group) and width-length (both groups), whereas the CFC varied mainly in the vertical dimension. Significant covariation was found between the craniofacial and palatal components (RV coefficient: 0.27, children; RV: 0.23, adolescents). Variation of the CFC in the vertical and anteroposterior direction was mainly related to variation in the height-width and the width-length ratio of the palate, respectively. LIMITATIONS: The use of lateral cephalometric radiographs eliminated the transverse dimension from the craniofacial shape analysis. The study was cross-sectional, so the observed intergroup differences should be interpreted with caution. CONCLUSIONS: Covariation strength and pattern were similar in children and adolescents. The closer a subject was to the high-angle end of the variability spectrum, the higher and narrower was the palate, and conversely.