Three-dimensional facial simulations and measurements: changes of facial contour and units associated with facial expression.

Recent innovations in laser scanning technology provide a potentially useful technique for accurate three-dimensional documentation of the face. In this study, linear and area measurements of the facial contour and facial units have been recorded in a variety of chosen facial postures using surface laser scanning combined with three-dimensional lighting techniques on seven healthy volunteers and three patients with facial nerve paralysis. Three-dimensional surface measurement of the face was taken using a laser light scanner. Computer graphics lighting techniques were used to produce facial images constituted by highlights and shadows, which emboss facial contour and units. Then quantitative measurement of changes in facial angles and areas were made to analyze morphological changes of the face accompanying facial expression. Changes of angles and widths of the cheek and nasal units were found to be associated with dimensional changes imposed by the action of the underlying mimetic muscles. This system has potential value for both dynamic monitoring and evaluation of facial contour, units, and movement.