The masseteric nerve passes laterally, above the Pterygoideus externus, in front of the temporomandibular articulation, and behind the tendon of the Temporalis; it crosses the mandibular notch

Mandibular notch

The upper border of the ramus of mandible is thin, and is surmounted by two processes, the coronoid process anteriorly and the condyloid process posteriorly, separated by a deep concavity, the mandibular notch...

 with the masseteric artery

Masseteric artery

The masseteric artery is small and passes laterally through the mandibular notch to the deep surface of the masseter muscle, which it supplies.It anastomoses with the masseteric branches of the external maxillary artery and with the transverse facial artery....

, to the deep surface of the Masseter, in which it ramifies nearly as far as its anterior border.

It is a branch of the mandibular nerve (V3).

It gives a filament to the temporomandibular joint

Temporomandibular joint

The temporomandibular joint is the joint of the jaw and is frequently referred to as TMJ. There are two TMJs, one on either side, working in unison. The name is derived from the two bones which form the joint: the upper temporal bone which is part of the cranium , and the lower jaw bone called the...

.