Curve of Spee found to be a result of the features associated with Alveolar Prognathism in modern humans

The curve of Spee (COS) is a mesio-distally curved alignment of the canine through distal molar cusp tips in certain mammals including modern humans and some fossil hominins.

In humans, the alignment varies from concave to flat, and previous studies have suggested that this difference reflects craniofacial morphology, including the degree of alveolar prognathism. However, the relationship between prognathism and concavity of the COS has not been tested in craniofacially variant populations. The team of scientists tested the hypothesis that greater alveolar prognathism covaries with a flatter COS in African-American and European-American populations. They further examined this relationship in fossil Homo including Homo neanderthalensis and early anatomically modern Homo sapiens, which are expected to extend the amount of variation in the COS from the extant sample.

Spatial determinants of the mandibular curve of Spee in modern and archaic Homo

Myra F. Laird, Nathan E. Holton, Jill E. Scott, Robert G. Franciscus,Steven D. Marshall and Thomas E. Southard

DOI: 10.1002/ajpa.23020

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