Functional Matrix Theory
A developmental theory proposing that the growth of skeletal structures is driven by the functional demands of the soft-tissue matrices they support or protect.
Full Definition
Proposed by Melvin Moss in the 1960s, the Functional Matrix Theory posits that bone and cartilage do not grow autonomously but respond to the functional requirements of associated soft tissues, capsules, and spaces—collectively termed 'functional matrices.' For example, the cranial vault grows in response to brain expansion, and the alveolar process develops in response to tooth eruption and masticatory forces. In dentofacial orthopedics, the theory underpins the rationale for functional appliances that redirect soft-tissue forces to modify skeletal growth. Editors should note that 'functional matrix' is a technical concept and must not be used loosely to mean any soft-tissue influence on bone. It appears in textbook introductions, literature reviews, and theoretical frameworks of case reports.
Usage
Usage note: Capitalise 'Functional Matrix Theory' when referring specifically to Moss's named theory. Lowercase 'functional matrix' when used descriptively.
In Context
- "The author cited Functional Matrix Theory to justify the use of a lip bumper in redirecting perioral muscle forces." — Literature review
- "An understanding of Functional Matrix Theory is foundational to interpreting the biomechanical rationale in the methods section." — Editorial note