Arterial supply of the masseter muscle in the lion (Panthera leo).

There are few reports on the vascular system of the lion or Panthera leo except for that on the facial artery investigated by Lin and Takemura (1990). Morphological analysis of the masseter muscle of the lion according to the muscle-tendon theory has been performed only by Takemura et al. (1991). The present authors attempted to elucidate the blood supply of the masseter, using 3 lion heads injected with acryl plastic into the carotid system by the plastic vascular injection method. This description is based on examination of the detailed laminar formation of the masseter. The findings are discussed in comparison with those of the felid family in carnivorae. Masseteric branches of the superficial temporal, buccal and facial arteries were distributed to the primary sublayer of the superficial layer, those of the above arteries and the masseteric artery to its secondary sublayer, the intermediate layer and the anterior and posterior portions of the deep layer, and those of the superficial temporal and masseteric arteries to the primary sublayer of the posterior portion of the deep layer. The maxillomandibularis muscle was supplied by the buccal and masseteric arteries and the zygomaticomandibularis by the superficial temporal and posterior auricular arteries as well. No gross differences between the lion and cat were observed in arterial supply of the masseter proper and improper, although the superficial temporal artery was distributed only to the superficial and intermediate layers in the cat but to all the deep layers in the lion.