Jemt T
Swed Dent J Suppl. 1984;23:1-52.
The aims of this thesis were, firstly, to develop a method for three-dimensional recording of mandibular movements based on available optoelectronic devices, and to evaluate the accuracy of the method in a clinical setting, and secondly, to study the habitual chewing pattern in individuals with complete natural dentitions by repeated registrations and compare them with persons suffering from different degrees of tooth loss before and after prosthetic treatment. This methodological approach imposes minimal constraint upon movement and permits three-dimensional registration of the movements of a point on the mandible for study of the overall pattern and analysis of chewing rate, mandibular displacement and velocity. The total error of the system was less than 1 per cent of the recorded area, where the movements of the reference system, attached to spectacle frames in the clinical test, were shown to be minimal. The methodological error had minimal influence on the data yielded. Great intra- and interindividual variations were observed in the overall pattern as well as in different parameters studied, but the individual chewing performance was relatively consistent in short-term registrations. A tendency towards adaptation of the chewing performance was observed in repeated registrations. The changes indicated an increased mandibular velocity and displacement, analogous to changes in the movement pattern induced by prosthetic rehabilitation but not so pronounced. The findings in this series of investigations indicate that oral function is reflected in quantitative parameters, e.g. mandibular velocity and displacement, within a relatively consistent overall chewing pattern. Thus, increased mandibular velocity and displacement could be interpreted as improved oral comfort.
