Multidirectional lip-closing force in adults with mandibular deviation.

The purpose of this study was to investigate the relationship between multidi-rectional lip-closing force and facial soft tissue morphology in adults with mandibular deviation. Fifteen Japanese adults with mandibular deviation participated in this study. The deviation value was defined as the horizontal distance between soft tissue menton and the facial midline. The side of the soft tissue menton relative to the facial midline was defined as the deviated side and the opposite side as the non-deviated side. The signals of directional lip-closing force (DLCF) were investigated in 8 directions. Total lip-closing force (TLCF) was calculated by adding DLCFs in 8 directions. Correlations and differences between the variables were analysed statistically. Significant positive correlations between TLCF and DLCFs were determined in six directions with the exception of the horizontal direction. Significant positive correlations for seven pairs of opposing DLCFs were found. The lower non-deviated DLCF was smaller than the three pairs of opposing lip-closing forces. Negative significant correlation was found between the deviation value and the upper deviated DLCF (P < 0·05). In individuals with mandibular deviation, lip-closing force in the lower non-deviated direction was found to be smaller than the opposing lip-closing forces. When mandibular deviation was greater, the upper deviated lip-closing force was smaller.

Analgesic effects of D-amino acids in four inbred strains of mice.

1. Prominent strain differences of mice were found in analgesic effects of D-amino acids. 2. In C57BL/6CrSlc and C3H/HeSlc mice, pain threshold, which was determined by using a hot-plate method, increased to 140-175% of the control after the systemic treatment of all three D-amino acids employed, such as D-phenylalanine, -leucine and -methionine, whereas in DBA/2CrSlc or BALB/cCrSlc mice, out of three only one D-amino acid, D-phenylalanine or -leucine, produced significant increase of pain threshold. 3. This lack of ability to perceive analgesic effects of specific amino acids observed in the latter two strains suggests that there probably exist different analgesia-inducing mechanisms for each of three D-amino acids in mice and the latter two strains lack two of them.