Holographic measurement of tooth mobility in three dimensions

A new method to study the displacements of human teeth in three-dimensional space is presented. This non-invasive technique uses recent developments in the double-exposure pulsed laser holography to measure the displacements of maxillary central incisors of the human with an accuracy of 0.05 μm. The incisor was loaded with a force of 300 grams in the lingual-labial direction parallel to the occlusal plane. The holographically determined displacements at a point on a crown were then reduced to obtain the center of rotation and also to compute the displacements at the alveolar crestand the apex.