Since the early 1990s, British dentists described the presence of the sphenomandibular muscle as a chewing muscle, then it was studied by Brazilian and Bolivian dentists, still exists the erroneous idea that his presence is real and has been questioned as an independent muscle. Objective: To demonstrate the presence of muscle sphenomandibular as independent muscle and its relationship with the temporal muscle. Material and methods: Followed a special dissection process suggested by Campohermoso et al, to verify the sphenomandibular muscle; they worked with seven human hemicabezas. Results: all specimens studied showed muscle sphenomandibular, checking an insertion in the front part of the bone pterygoid process sphenoid retromaxillary very close to the cleft sphenoidal close to the entrance of the common ocular motor nerve, and an insert lower on the crest o...