Abstract
Dentists engaged in prosthodontic practice often encounter cases in which a mandibular first molar tooth is missing. However, not all the patients complain about difficulty in chewing food. This is probably because the rest of the teeth are in place and their investing and supporting tissues are healthy.
The present study was carried out to re-evaluate the functional merits of the fixed prosthodontic treatment usually given to the patients with a missing lower first molar. For this purpose, we used a newly developed software to examine the changes in masticatory function with the lapse of time after loss of the mandibular first molar tooth, based on the analysis of masticatory rhythm, which is regarded as a common method for assessing the physiology of mastication.
At the same time, with the use of the same software, the changes were assessed by analyzing the stability among the components of the masticatory force applied by the muscles attached to the mandible during mastication, because the parameters for masticatory rhythm use the time element only.
The results were as follows:
1. The software made it possible to automatically analyze masticatory rhythm and stability of muscle forces.
2. The normal ranges of both masticatory rhythm and stability of muscle activity values were made clear.
3. Changes in masticatory function after loss of a mandibular first molar were favorably affected with the replacement by the artificial substitute that is not easily removable. Chewing rhythm and stability of muscular activities were improved. This tendency was particularly notable in the latter.
