In order to clarify the functional role and adaptive significance of shovelling in the maxillary incisors, three analyses were performed on the basis of its variation. The first two were principal component analyses of tooth crown characters based on Japanese samples, and the third analysis attempts to infer the relations between shovelling and climatic factors as well as ways of life on the basis of the incidences of shovelling in modern populations worldwide.

From the first analysis, it was deduced that shovelling likely had the greatest functional effect under the condition of edge-to-edge bite and was functionally independent of the mesiodistal crown dimension and of the spines of the lingual tubercle in the incisor. The second analysis suggested that shovelling most probably occurred in response to an adaptive demand on the anterior teeth independent of variation in the whole dentition or posterior teeth. Through the third analysis, it was inferred that well-developed hovelling evolved as part of a facial structure which could withstand powerful biting orces, and that such a structure was likely associated with hunting activities with a eavy reliance on meat-eating.