By its very nature, vitamin A causes drying of the skin and exfoliation. A bevy of prescription and OTC vitamin A topical preparations make use of this side effect to treat a variety of skin concerns. The term Retinoid refers to any Vitamin A based molecule. It's a category, similar to saying antibiotic. They may be related, but some are stronger and more effective than others.
Pototype sheets for Weld Quality Workmanship Standard. Undercut. Definition: A groove cut at the toe of the weld by the welding arc and left. unfilled. Depth of undercut shall not exceed 1/32.
undercut, n 1. the portion of a tooth that lies between its height of contour and the gingivae, only if that portion is of less circumference than the height of contour.2. the contour of a cross-section of a residual ridge of dental arch that would prevent the placement of a denture or other prosthesis.ndercut, unusable, n the area of an abutment tooth or soft tissue across which a unit of the removable partial denture must pass without interference and hence must be blocked out (filled with wax or clay) before the master cast is duplicated.