LATERAL ASYMMETRY IN CANINE MASTICATION AS EVIDENCED BY BONE WEIGHT

The weights of certain skull bones (mandible, maxilla, frontal, parietal, temporal, zygomatic and palatine) giving attachment to muscles of mastication have been studied in six young dogs. The weights are unequal on the two sides. On the basis of difference between the right and left total bone weights, and the number of individual bones heavier on a particular side, one side can be said to be dominant in four out of six animals studied. The left side is far more frequently dominant than the right side. Analysis of the weights of individual bones in these animals shows that the mean weights of all bones are greater on the dominant side. The differences in mean weights are statistically significant for parietal, temporal and zygomatic bones.