Over many years various theories of growth have been proposed for the craniofacial complex.
The Genetic theory, Scott’s Hypothesis, Sicher’s Sutural Dominance theory, Functional matrix theory attempt to explain the growth of the cranofacial complex with different growth determinants and have their own limitations.
The Servosystem theory of growth is based on a factorial qualitative analysis which takes into account various factors which determine a coordinated growth of the craniofacial complex as a whole.
The Servosystem theory attempts to explain craniofacial growth and the modus operandi of Functional appliances.
GENETIC CONTROL THEORY:
Genotype supplies all the information required for phenotype expression.
Does not address the question of local and general factors modifying gene expression.