Evaluation of bovine hemimandible morphology by means of elliptic Fourier descriptors

Abstract

The aim of this research was to compare size (area) and shape variations of bovine hemimandibles according to age. Digital photographs were obtained for 34 hemimandibles belonging to different European breeds of cattle. The specimens were classified according to age, as determined by molar eruption: 6 months ("young", M1 erupting, n=8), 10 months ("immature", M2 erupting, n=9) and over 24 months ("adult", M3 fully erupted, n=17). Captured images were then digitally analysed based on elliptic Fourier descriptors, which mathematically characterise the area and shape. Hemimandibular areas only showed significant differences between the adults (2752.3 cm2 ± 250.4) and young subjects (2373.8 cm2 ± 300.2). The areas for each age group were not linked to linear shape modifications, which was the same for all age groups. So, bovine hemimandibular form change is mainly related to size changes. Shape variability is centred on the condylar ramus.