Craniofacial Muscles-differentiation and Morphogenesis

Unraveling the complex nature of tissue interactions is essential to generate structural and functional diversity present among craniofacial muscles. There are various distinct skeletal muscles in craniofacial region, the development of which are closely co-ordinated with other craniofacial tissues. The head musculature is known to originate from the cranial paraxial mesoderm (CPM) located anterior to the somites, and lacks any overt signs of segmentation. A consortium of transducting signals is required for the differentiation of skeletal muscle establishing spatially and temporally diverse myogenic populations. The induction, differentiation, and morpho-differentiation of these muscles is a relatively untouched area for experimentation with a cascades of signaling molecules, growth factors and genes. Various regulatory factors like Myf5, MyoD, Pax3, Pax7, Pitx2, Tbx1, Musculin and Tcf21 play a vital role in craniofacial muscle embryogenesis and morphogenesis. The relationship between craniofacial muscles and craniofacial morphology would seem to confirm the functional matrix theory of form and function. This review has been to highlight the classification, embryonic origin, differentiation and myogenesis, as well as the role of craniofacial muscles in growth of the craniofacial skeleton.