'Epigenetic factors' controlling the growth of skeleton are:

Epigenetic factors include: (1) All of the extrinsic, extra-organismal, macro-environmental factors impinging on vital structures (e.g. food, light and temperature), including mechanical loadings and electromagnetic fields. (2) All of the intrinsic, intra-organismal, biophysical, biomechanical, biochemical and bioelectric microenvironmental events occurring on, in, and between individual cells, extracellular materials, and cells and extracellular substances.  The craniofacial skeleton develops initially and later grows in direct response to the extrinsic epigenetic environment. Moss states that bones do not grow—bones are grown. More precisely, the FMH claims that epigenetic, nonskeletal factors or process are the prior, proximate, extrinsic and primary cause of all adaptive, secondary responses of skeletal tissues and organs. FMH – Functional matrix hypothesis. Ref: Orthodontics: Diagnosis and Management of Malocclusion and Dentofacial Deformities, THIRD EDITION Om P. Kharbanda pdf no 622, Textbook of orthodontics Sreedhar Premkumar pg no 63