The fallacy of facial measurements of occlusal height in edentulous subjects.

A controlled trial was made using fifteen subjects and making 120 measurements with a caliper gauge between marks disposed on the upper lip and the point of the chin when maxillo-mandibular relationships were altered vertically by known amounts within a range of 6 mm. It was found that mean facial measurements could account for only half of the skeletal movement involved. The variability of soft tissue translation in relation to skeletal movement led to the conclusion that such facial measurements are inappropriate to clinical practice.