The buccinator muscle: an original morphogenetical study

The buccinator muscle, a cutaneous muscle derived from the second arc, is innervated by the facial nerve. It is made of 3 bundles extended into the cheek, from the pterygo-mandibular ligament to the modiolus. It is used for diverse buccal functions. This study attempts to give a better insight of the embryogenesis and the development of the muscle. After taking samples by microdissection under binocular microscope, of this region of embryos and foeti, we performed histological sections. They were then coloured by Masson's trichome for their observation under photon microscopy. From seventieth week we observed the presence of a peri-mucous mesenchyma between the cartilaginous condensation of the "pre premier arc" and Meckel's cartilage. The buccinator presents an insertion on the modiolus, sliding under the latter it runs forwards, it is at the origin of the formation of the orbicularis internus of the lips (musculus orbicularis oris). This muscle displaces its posterior insertion downwards, with the development of the face in the child and the adolescent, notably with the modification in vertical dimension due to the arrival of the deciduous teeth before the permanent dentition. Furthermore it appears that buccinator does not play a role as a sphincter in the secretion of the parotid glands.