This paper presents some new observations on the Krapina Neandertal dental sample. A number of lower third premolars from this site are rotated in comparison to their expected position relative to the other teeth. We developed a method for accurately describing the rotation for teeth, whether they are in mandibles, included in dental sets or isolated. We compare the frequencies of rotated P3s in the Krapina sample with those observed in a modern human population and in the available Neandertal population specimens. It appears that the two latter have comparable frequencies of P3
rotation whereas rotations found in the Krapina sample have a much higher frequency, whether in relation to the total number of teeth or the number of individuals. Bootstrapping in the comparative samples shows that the probabilities of finding the frequencies of rotated P3s observed at Krapina within the modern and Neandertal lineage groups are very low, below the significance threshold. The Krapina sample thus appears to be unique in its proportion of rotated P3s. After rejecting a mechanical hypothesis (i. e. lack of space) for explaining this condition, we propose a genetic origin for this condition. We discuss the implications of related individuals utilizing the cave over a long period of time
