CAMBIOS ESTRUCTURALES DEL COMPLEJO ARTICULAR TEMPOROMANDIBULAR (CATM) EN DISTINTAS EDADES GESTACIONALES

summary:structural changes in temporomandibular articular complexe of 16, 18, 24 and 37 week-old human fetuses were studied with the aim to establishing the possible relationship between the tissular maturity level and its capacity for mandibular movements. histochemical and immunostaining techniques were used. the antibodies employed were: neurofilament proteins (ne14), vimentin and myoglobin, avidin-biotin system, dab. the variations between the different ages mainly occurred at the level of the articular disk and mandibular condyle. between the sixteenth and eighteenth week, the disk showed schiff-periodic acid (pas) positive fibrils and abundant argyrophile fibres in plexus arrangement. elastic fibres were scarce and thin in the bilaminar postero-superior area. in the twenty-fourth week, the disk showed a high proportion of collagen and elastic fibres, whereas the argyrophile fibres had a laxer arrangement. nerves immunoreactive with ne14 were observed both in the anterior and postero-inferior areas next to the condyle. in thirty seven old specimens, the sagittal sections of the isolated disk showed different areas according to the collagen fibres thickness and arrangement. some bundles of pterigoid muscles displayed a zig-zag pattern, thus having an appearance of semicontraction, though the expression of myoglobin was negative. in the twenty-fourth week, the components of the articulation had similar characteristics to those of a newborn child. this suggests that the articular and muscular tissues are capable of performing mandibular opening and closing activities from this prenatal stage