<prompt> A narrow continuous line of brown dots which follow contour of gingival margin of posterior teeth in children is known as:Burtonian lineMesenteric lineNeonatal lineDevelopmental line  <response>: A black strain in the form of a fine line adjacent to the free gingival margin, which is not related to smoking, has been called metabolic strain and mesenteric line.This stain may occur as a broad thin black line following the contour of the free gingival margin onto the interproximal surface of the teeth. 