Geometric morphometric 3D shape analysis and covariation of human mandibular and maxillary first molars.

摘要: Dental casts of 160 Greek subjects (80 males, 80 females) were scanned by a structured-light scanner. The upper and lower right first molar occlusal surface 3D meshes processed using geometric morphometric methods. A total 265 274 curve sliding semilandmarks placed on the surfaces, respectively. Principal component analysis partial least square performed to assess shape parameters. Molars tended vary between an elongated more form. two principal components (PCs), comprising almost 1/3 variation, related mesiodistal-buccolingual ratios relative cusp position. Distal cusps displayed greatest variability. males larger than those females (2.8 3.2% for molars respectively), but no dimorphism was observed. Upper sizes significantly correlated (r(2) = 0.689). Allometry observed both teeth. Larger associated with shorter cusps, expansion distal cusp, constriction mesial (predicted variance 3.25%). weaker allometry 1.59%). covariation proved significant (RV 17.26%, P < 0.0001). main parameter in axis 1, contributing 30% covariation, height, contrast primary variability traits exhibited PC1 PC2. aim this study evaluate variation including sexual dimorphism, maxillary mandibular permanent surfaces.