title: Comparison of phosphocreatine concentration in the human masseter and medial pterygoid muscles by 31P-CSI.
abstract: The aim of this study is to compare phosphocreatine (PCr) concentrations of human masseter and medial pterygoid muscles by a recently developed localized magnetic resonance spectroscopy (MRS) method, chemical shift imaging (CSI). The characteristic spectra of phosphorous metabolites including PCr and beta-ATP from the superficial part of the masseter (SM) and the deep part of the masseter (DM) and the medial pterygoid muscles (MPt) from 11 volunteers, 20-27-year-old were obtained. The study clearly demonstrated higher PCr/beta-ATP in the SM and MPt than in the DM both in mean values (P < 0.01) and in individual subjects. The results indicate that SM and MPt are power producers. There were no significant differences in the mean values of the PCr/beta-ATP ratios in SM and MPt, however, the PCr/beta-ATP ratios varied individually and the subjects could be divided into three distinct groups: values of MPt higher than SM (group A, 4 subjects); values of MPt almost equal to SM (group B, 3 subjects); and values of MPt lower than SM (group C, 4 subjects). There appears to be a close relationship between the PCr content as determined in the groups here and occlusal guidance.
authors.affiliation: Department of Prosthetic Dentistry I, Dental Hospital, Hokkaido University, Kita-ku, Sapporo, Japan. kanayama@den.hokudai.ac.jp
authors.forename: T
authors.initials: T
authors.lastname: Kanayama
authors.forename: K
authors.initials: K
authors.lastname: Minowa
authors.forename: N
authors.initials: N
authors.lastname: Inoue
authors.forename: T
authors.initials: T
authors.lastname: Yamaguchi
authors.forename: T
authors.initials: T
authors.lastname: Tamura
authors.forename: S
authors.initials: S
authors.lastname: Yoshida
authors.forename: T
authors.initials: T
authors.lastname: Kawasaki
mesh_terms: D000255:Adenosine Triphosphate / Q000032:analysis; D000328:Adult; D019412:Anatomy, Cross-Sectional; D003766:Dental Occlusion; D005583:Fourier Analysis; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008406:Masseter Muscle / Q000378:metabolism*; D008563:Membrane Lipids / Q000032:analysis; D010725:Phosphocreatine / Q000032:analysis*; D010743:Phospholipids / Q000032:analysis; D010759:Phosphorus Isotopes; D011626:Pterygoid Muscles / Q000378:metabolism*; D015203:Reproducibility of Results; D013223:Statistics as Topic; D013403:Sugar Phosphates / Q000032:analysis
chemical_list: D008563:Membrane Lipids; D010743:Phospholipids; D010759:Phosphorus Isotopes; D013403:Sugar Phosphates; D010725:Phosphocreatine; D000255:Adenosine Triphosphate