The parotid duct, also known as the Stensen's duct, crosses the masseter muscle transversely and extends to the oral cavity. The facial artery can be palpated in the groove anterior to the mandibular angle. The facial vein lies anterior to the artery, passing toward the angle of the lips, but does not ascend in close proximity to the masseter. All of the other vessels are located more deeply and cannot be palpated.