Occlusal variation in the Zuni: a pre-contact North American population

Abstract

Abstract Background: Reports of occlusal variation in ancient populations consistently show a low prevalence of malocclusion coupled with heavy attritive wear. Materials and methods: The dentitions of 28 individual remains from a pre-contact native North American population were examined and the extent and nature of occlusal variation recorded. Results: The prevalence of malocclusion was low (mean IOTN = 2.14) and where crowding existed, was limited to intra-arch variability as opposed to inter-arch discrepancies. Increased overbites, overjets and other classical features of Class II malocclusions were almost entirely absent. These findings suggest that the ideal mutually protected Class I occlusion occurs only as a transient juvenile arrangement in nature, where, due to rapid attrition following establishment of the occlusion, there is an increasing tendency towards mild Class III, edge-to-edge incisor and buccal segment relationships. Conclusion: Whilst of limited therapeutic benefit, an understanding of the anthropology of malocclusion provides an insightful perspective, and suggests that function may be of more importance than heredity in its aetiology. It is suggested that future occlusal studies in ancestral populations would benefit from the use of a standard methodology.