Ans. B: Pressure Abrasion Teeth marks in biting and ligature marks in hanging and strangulation are example of imprint, pressure or contact abrasion Abrasion It as also known as - Graze or Scratch or Impression. An abrasion is a superficial injury to the skin which involves the loss of superficial epithelial layer (Uppermost layers of the cells of skin) of skin. Abrasions are produced by ? - Blow - Fall on some rough and hard substance - Dragging as in vehicular accidents. - Scratching with finger nails, bites and thorns etc. - Friction on some hard substance. Pressure of rope or cord as is found in strangulation and hanging etc. - Rubbing. - Indenting of the objects. Varieties of Abrasions Scratches- They are due to a sharp or a pointed object pressing across the skin, moving the surface layers in front of it and causing the heaping up of layers of skin. Grazes- They are modified scratches. - In this, the broader surface of skin comes in contact with the uneven rough object. - In this, the depth may vary at different places. - The direction is indicated by presence of clean commencement and tag at the finishing end. Impact Abrasions/Pressure Abrasions - They are also known as "Imprint abrasions". - They are caused by the stamping of some object against the skin like radiators of cars in vehicular accidents or - They may be caused by pressure on the skin which is accompanied by movements as found in? Ligature in cases of hanging or strangulation. Injuries caused by lashes with whip Sites of Abrasions ? The abrasions resulting from friction against rough surface during a fall are generally found on the bony pas and are accompanied with contusions or lacerations The abrasions caused by finger nails are seen on the exposed of body like - Face near forearm, hands, thighs etc. They are cresentric in shape, when finger nails are used. Ecchymosis is a common accompaniment. The abrasions caused by teeth bite are elliptical or circular in shape and often present separate marks. Typical impression of teeth by different sets of teeth (Deciduous or permanent) is marked. The intervening area is only a bruised area. The abrasions from radiators are honey-comb in appearance and are .commonly found in vehicular accidents Difference between Antemoem and Postmoem Bruise Antemoem abrasions will show signs of inflammation and repair whereas these will be absent in postmoem abrasions.