Mandibular shape was compared by the technique of medial axis transformation between four inbred strains of mice fed upon ‘hard’ and ‘soft’ diets. Multivariate analysis of component medial axis lengths showed the interstrain contrasts to be slightly greater between animals maintained on ‘hard’ as opposed to ‘soft’ diets. The mandibular shape contrasts primarily reflected differences of the ramus compared with the corpus, although the reasons for such changes have yet to be ful