The development of facial muscles and nerves in relation to the Möbius syndrome.

This paper discusses descriptive and experimental embryologic material that may be of relevance in understanding the pathologic findings of, and attempting treatment of, congenital facial paralysis. The embryology of the human facial nerves and muscles is described. In experimental animals muscles undergo early stages of morphogenesis and differentiation in the absence of nerves and then undergo gradual atrophy. In th absence of muscle fibers, the bulk of embryonic motor nerves that would normally innervate the muscle die.