[Microscopic-anatomic changes of the temporomandibular joint structure in miniature swine due to unilateral occlusion disorders]. / Mikroskopisch-anatomische Veränderungen der Kiefergelenkstrukturen am Miniaturschwein durch unilaterale Okklusionsstörungen.

The influence of artificial unilateral occlusal disturbances on the structure of the temporomandibular joint (TMJ) condyle cartilage was investigated by an experimental study using the miniature pig "MINI-LEWE". After a burden over 20 weeks the side exposed to occlusal disturbance (right TMJ) turned out to have unchanged histological proportions in comparison with control animals. The condyles of the side with pressure loading (left TMJ) exhibited but a changed histological picture. Cartilage resorptions as well as accumulations of large blown chondrocytes indicate an increased tissue reaction within the chondroblastic layer near spongiosa. The morphometric investigations confirm these results. A significant increase was observed in cell density within the chondroblastic layer of the most superior point of the left condylus due to the permanent disturbance of the normal masticatory function.

[Changes in the fine structure of the masseter muscle as affected by unilateral occlusal disorders]. / Veränderungen im feinstrukturellen Aufbau des M. masseter durch unilaterale Okklusionsstörungen.

Biopsy specimens from the masseter muscle of the miniature pig "Mini-LEWE" were analysed histochemically before and after unilateral occlusal disturbances. The percentages of different fibre types and the cross-sectional area of fibres were determined with the myosin-ATPase reaction after acid preincubation. The capillary membranes were visualized by means of modified PAS-reaction. There was demonstrated a significant increase from the percentage portion of ST-fibre types, especially of the side of occlusal disturbance, under experimental conditions. This indicates an increased isometric contraction of the masseter muscle. The size of FT-fibre types and the capillarity increase significantly on the side without occlusal disturbances, due to the dislocation of the masticatory efforts to this side. The masseter muscle fine structure is shown to be adapted good to the disturbed functional conditions. No significant side differences were found in the dry mass of the masticatory muscles, at the end of experiments.