soft-tissue augmentation lends another dimension to facial rejuvenation. human collagen tissue matrix offers the most physiologic solution to dermal volume depletion, structural soft-tissue malposition, and the correction of facial rhytides and various soft-tissue contour defects. results with the use of dermalogen have been comparable with other injectable dermal agents with the most natural effects. the absolute longevity or persistence of human tissue collagen matrix has not been established fully and depends on facial region, technique, and total volume administered. the natural fate of most related bio-materials suggest that internal dosing is required to maintain maximum effects.