Euclidean-distance matrix analysis (EDMA) was used to analyse the dental arch form in 50 men and 45 women aged 20-27 yr with sound dentitions. Fourteen landmarks, corresponding to the centres of gravity (centroids) of the occlusal surfaces of all permanent teeth (right second molar to left second molar), were identified on the dental casts of subjects. All the possible linear distances between pairs of teeth were computed and maxillary/mandibular arch differences within sex were tested by EDMA. In both sexes, the maxillary arch was larger than the mandibular arch; arch shape was also significantly different. All teeth contributed to the shape difference between arches regardless of gender. EDMA also separated the influence of anterior and posterior teeth in the determination of upper/lower arch characteristics.