An experimental study on the neuromuscular effects of an intraoral mandibular repositioning device

This thesis is part of a research project titled "Intraoral Device Evaluation'' (IDE). The purpose of the project is to determine if creating a 3-mm vertical and anterior occlusion of the mandible can increase strength capabilities. The standardized device used in this study is The EDGE. Big Picture, Inc produced the EDGE and the placebo used in this project.

To accomplish this purpose a double-blind placebo study was conducted using a series of tests to measure the strength capabilities of muscles during isometric grip strength and clenching and the surface electromyography (EMG) activity of the muscles during the isometric testing. The approach was to have subjects perform a series of isometric tests where both the muscle groups being tested and the antagonistic muscle groups were monitored via surface EMGs. The tests were designed to measure the anterior temporalis, massater, digastricus, sternocleidomastoidues, biceps and triceps muscles of various subjects. There were two types of tests used in the study, bio-assessment and grip strength. The bio-assessment tests consisted of an analysis of the subjects tempromandibular joint (TMJ) to determine if a preexisting TMJ dysfunction existed and isometric jaw clenching to monitor the face and neck muscles using surface EMGs. The isometric grip strength test measured muscle capabilities and monitored the upper arm muscles using surface EMGs. There were 123, 88 male and 35 female, participants in the grip strength test. There were six trials for each test, three with a device and three without a device. The percent change in grip strength and EMG activity was calculated for each set and analyzed as a unit-less measure.

The analysis of the grip strength and EMG data concluded there was not a statistically significant difference between The EDGE and the placebo at an α = 0.05 level for the given test parameters. The average percent change in grip strength for the male population using The EDGE and the placebo was 2.780 and 2.816 respectively. The standard deviation in the average percent change in grip strength for the male population using The EDGE and the placebo was 5.436 and 6.563 respectively. The average percent change in grip strength for the female population using The EDGE and the placebo was 6.606 and 2.235 respectively. The standard deviation in the average percent change in grip strength for the male population using The EDGE and the placebo was 3.982 and 8.229 respectively. The trend of the data shows a larger increase in percent change in muscle capability for women using The EDGE and a smaller standard deviation than for any other category.