Functional Analysis of the Masticatory System of the Dog with Relation to the Human / 체질인류학회지

ABSTRACT

The aim of this study is to identify the species characteristics of the dog mastication compared to the human by analyzing 8 landmarks on the heads from seven beagle dogs. The masticatory unit of the dog was relatively located posterior than the human. The predominance of horizontally-oriented fibers of the temporalis of the dog was shown in spite of vertical mandibular movement. The biomechanics of the coronoid process and the temporalis of the dog revealed but not superiorly-elevating like the human backward rotating the coronoid process. The masseter was also obliquely -oriented and the temporalis was observed in distinct two-layers. In the dogs, the higher coronoid process compared to the condyle was observed; the vertical difference of them was larger than human. The temporalis performs stronger action than masseter and related with marked horizontal action of the temporalis. These morphologies indicated that the mastication of the dog needs strengthened horizontal stability and it was taken by the cervical muscles attached backwardly to the skull. Thickened temporalis is adapted in feeding. The dentition of dog was longer and farther from the condyle and the pterygoid muscles were not well-developed than human, indicated unfavourable lateral movement. These findings were consistent with evolutionary tendency, feeding without hands and narrow skull.