Fig. 117.—Profile of a child.
Fig.—118. A child of ten months.
Fig. 119.—The same, 13 years old.
As for the mechanics of expression, they consist of the facial nerve, and the surface muscles stimulated by it, which are: the frontal muscle, which covers the entire forehead and merges above into the epicranial aponeurosis; the superciliary muscle extending transversely along the superciliary arch and concealed by the orbicular muscle of the eyelids (m. orbicularis palpebrarum), which surrounds the eye-socket like a ring; the pyramidal muscle (m. pyramidalis nasi), which is connected with the point of origin of the frontal muscle at the inner angle of the eyebrow, and separates below into four symmetrical fasciæ, two of which are attached to the ala or wing of the nose, and the other two to the upper lip.
Fig. 120.—The Muscles of the Head and Face.