Biomaterial Database

The immediate effect of hard and soft splints on the EMG activity of the masseter and temporalis muscles. 1999

F A al-Quran, and M F Lyons

Dental School, University of Glasgow, UK.

The aim of this study was to compare the effects of hard and soft splints on the activity of the anterior temporalis and masseter muscles. Surface EMG recordings were made from these muscles during clenching at 10% of maximum, 50% of maximum and at maximum clench, both before and after insertion of a hard splint. This sequence was then repeated with a soft splint. The relative level of activity in the anterior temporalis and masseter muscles at all three activity levels was quantified by means of an Activity Index, which provides a measure of the balance of activity in the masseter relative to the activity in the anterior temporalis muscle. It was found that hard splints led to a decrease in EMG activity in relation to activity with no splint in both muscles at maximum clench and particularly the anterior temporalis. Soft splints produced a slight increase in activity of both muscles, but particularly the masseter muscle. The Activity Index indicated a shift in the balance of activity away from the anterior temporalis muscles with both splints, particularly at 10% of the maximum clenching level. It is possible that the decrease in activity of the temporalis muscles relative to the masseter muscles may be a factor in the therapeutic effect of both a hard and a soft splint, although the decrease is clearly greater with the hard splint.

UI	MeSH Term	Description	Entries
D008406	Masseter Muscle	A masticatory muscle whose action is closing the jaws.	Masseter Muscles,Muscle, Masseter,Muscles, Masseter
D012016	Reference Values	The range or frequency distribution of a measurement in a population (of organisms, organs or things) that has not been selected for the presence of disease or abnormality.	Normal Range,Normal Values,Reference Ranges,Normal Ranges,Normal Value,Range, Normal,Range, Reference,Ranges, Normal,Ranges, Reference,Reference Range,Reference Value,Value, Normal,Value, Reference,Values, Normal,Values, Reference
D004566	Electrodes	Electric conductors through which electric currents enter or leave a medium, whether it be an electrolytic solution, solid, molten mass, gas, or vacuum.	Anode,Anode Materials,Cathode,Cathode Materials,Anode Material,Anodes,Cathode Material,Cathodes,Electrode,Material, Anode,Material, Cathode
D004576	Electromyography	Recording of the changes in electric potential of muscle by means of surface or needle electrodes.	Electromyogram,Surface Electromyography,Electromyograms,Electromyographies,Electromyographies, Surface,Electromyography, Surface,Surface Electromyographies
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000180	Acrylic Resins	Polymers of high molecular weight which are derived from acrylic acid, methacrylic acid or other related compounds and are capable of being molded and then hardened to form useful components.	Acrylic Resin,Resin, Acrylic,Resins, Acrylic
D000328	Adult	A person having attained full growth or maturity. Adults are of 19 through 44 years of age. For a person between 19 and 24 years of age, YOUNG ADULT is available.	Adults
D013703	Temporal Muscle	A masticatory muscle whose action is closing the jaws; its posterior portion retracts the mandible.	Muscle, Temporal,Muscles, Temporal,Temporal Muscles
D017090	Occlusal Splints	Rigid or flexible appliances that overlay the occlusal surfaces of the teeth. They are used to treat OBSTRUCTIVE SLEEP APNEA, clenching, BRUXISM, and their sequelae, and to provide temporary relief from muscle or temporomandibular joint pain.	Dental Night Guard,Mandibular Advancement Devices,Mandibular Advancement Splints,Splints, Occlusal,Advancement Device, Mandibular,Advancement Devices, Mandibular,Advancement Splint, Mandibular,Advancement Splints, Mandibular,Dental Night Guards,Device, Mandibular Advancement,Devices, Mandibular Advancement,Guard, Dental Night,Guards, Dental Night,Mandibular Advancement Device,Mandibular Advancement Splint,Night Guard, Dental,Night Guards, Dental,Occlusal Splint,Splint, Mandibular Advancement,Splint, Occlusal,Splints, Mandibular Advancement
D018709	Statistics, Nonparametric	A class of statistical methods applicable to a large set of probability distributions used to test for correlation, location, independence, etc. In most nonparametric statistical tests, the original scores or observations are replaced by another variable containing less information. An important class of nonparametric tests employs the ordinal properties of the data. Another class of tests uses information about whether an observation is above or below some fixed value such as the median, and a third class is based on the frequency of the occurrence of runs in the data. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed, p1284; Corsini, Concise Encyclopedia of Psychology, 1987, p764-5)	Kolmogorov-Smirnov Test,Kruskal-Wallis H Statistic,Mann-Whitney U Test,Rank-Sum Tests,Spearman Rank Correlation Coefficient,Wilcox Test,Wilcoxon Rank Test,Non-Parametric Statistics,Nonparametric Statistics,Statistics, Non-Parametric,Kolmogorov Smirnov Test,Mann Whitney U Test,Non Parametric Statistics,Rank Sum Tests,Rank Test, Wilcoxon,Rank-Sum Test,Statistics, Non Parametric,Test, Kolmogorov-Smirnov,Test, Mann-Whitney U,Test, Rank-Sum,Test, Wilcox,Test, Wilcoxon Rank,Tests, Rank-Sum,U Test, Mann-Whitney