Fig. 2From: Application of botulinum toxin in maxillofacial field: Part II. Wrinkle, intraoral ulcer, and cranio-maxillofacial painIt is very important to understand the origin and insertion of expression muscles of the face in wrinkle treatment. Especially, one should carefully observe the origin and insertion of frontalis muscles, corrugator supercilii m., procerus m., orbicularis oculi m., and orbicularis oris m.Back to article page