[Masticatory forces and maximum jaw closure forces of complete denture wearers before and after bite opening]

The maximum jaw closure forces and the masticatory forces during the comminution of soft and though food were measured with changing vertical dimensions. The maximum jaw closure force was reduced by a mean 25% in all patients after the vertical dimension had been increased. Significant reductions in the masticatory forces were found only on the working side with the forces decreasing rather during the chewing of soft than tough food. Thus, in chewing sour drops the average masticatory force was 32.9 N as against 46.6 N, whereas in chewing bread it dropped to 21.3 N as against 42.8 N. The study showed that increasing the vertical dimension in endentulous patients up to an interocclusal clearance of 0 mm resulted in a functional impairment of speech and mastication and, above all, in sore spots and inflammations of the mucosa.