Biomaterial Database

Further histochemical studies on masticatory muscles. 1980

C Vignon, and J F Pellissier, and G Serratrice

This paper describes a histochemical and histographic analysis of the masticatory muscles obtained from 78 early autopsy samples from subjects from 4 days to 87 years old. Five groups of muscles have been stuied: the temporalis, the medial and lateral pterygoid, the superficial bundle of the masseter and the mylohyoideus. All adult muscles have consistently shown a markedly increased number oftype II fibres and a disparity in the size of the two main fibre types, the average diameter of type II fibres being about half that of type I fibres. Fibres of intermediate size and stain were observed with myofibrillar ATPase at pH 9.40. A negative relation between the percentage of type II fibres and intermediate fibres was found, but not between the percentage of type I fibres and of intermediate fibres. Another negative relation was found between the number and the size of type II fibres, again not present in type I nor in intermediate fibres. In children, from 6 days old, an increased number of type II fibres and a definite disparity in the size of the two main fibre types were found. Intermediate fibres were present on the 17th day. Up to the age of 13 years, their diameter was greater than that of type I fibres. The analysis of the distribution and size modifications of the various fibre types seems to indicate a progressive adaptation of the masticatory muscles. This adaptation of the fibres to the successive reactions and to the various movements of the masticatory system is then discussed.

UI	MeSH Term	Description	Entries
D007223	Infant	A child between 1 and 23 months of age.	Infants
D007231	Infant, Newborn	An infant during the first 28 days after birth.	Neonate,Newborns,Infants, Newborn,Neonates,Newborn,Newborn Infant,Newborn Infants
D008406	Masseter Muscle	A masticatory muscle whose action is closing the jaws.	Masseter Muscles,Muscle, Masseter,Muscles, Masseter
D008410	Masticatory Muscles	Muscles arising in the zygomatic arch that close the jaw. Their nerve supply is masseteric from the mandibular division of the trigeminal nerve. (From Stedman, 25th ed)	Masticatory Muscle,Muscle, Masticatory,Muscles, Masticatory
D008875	Middle Aged	An adult aged 45 - 64 years.	Middle Age
D009246	NADH Tetrazolium Reductase	Catalyzes the reduction of tetrazolium compounds in the presence of NADH.	NAD(P)H Nitroblue Tetrazolium Reductase,NADH2 Tetrazolium Reductase,Reductase, NADH Tetrazolium,Reductase, NADH2 Tetrazolium,Tetrazolium Reductase, NADH,Tetrazolium Reductase, NADH2
D009247	NADH, NADPH Oxidoreductases	A group of oxidoreductases that act on NADH or NADPH. In general, enzymes using NADH or NADPH to reduce a substrate are classified according to the reverse reaction, in which NAD+ or NADP+ is formally regarded as an acceptor. This subclass includes only those enzymes in which some other redox carrier is the acceptor. (Enzyme Nomenclature, 1992, p100) EC 1.6.	Oxidoreductases, NADH, NADPH,NADPH Oxidoreductases NADH,Oxidoreductases NADH, NADPH
D011626	Pterygoid Muscles	Two of the masticatory muscles: the internal, or medial, pterygoid muscle and external, or lateral, pterygoid muscle. Action of the former is closing the jaws and that of the latter is opening the jaws, protruding the mandible, and moving the mandible from side to side.	Muscle, Pterygoid,Muscles, Pterygoid,Pterygoid Muscle
D002648	Child	A person 6 to 12 years of age. An individual 2 to 5 years old is CHILD, PRESCHOOL.	Children
D002675	Child, Preschool	A child between the ages of 2 and 5.	Children, Preschool,Preschool Child,Preschool Children