Figure 2.

Detailed characteristics of the deep inferior tendon (DIT). (A) The DIT was located deep to the superficial muscle belly of the superficial part of the masseter. (B) The muscle fibers originated from the superficial aponeurosis of the masseter muscle, descended, and then changed into the tendon structure attaching to the inferior mandibular border. White arrowheads indicate the muscle fibers that originate from the deep to the superficial aponeurosis of the masseter muscle. A: anterior; S: superior; OOr: orbicularis oculi muscle.