Akio Yasui

Concentrations of Muscle Fiber Type-specific Proteins of Masseter Muscle in Jaw Deformity. Part 1 -Facial Asymmetry.

Facial asymmetry is considered to be caused by the intervention of masticatory muscles, especially the masseter muscle, in some way or another. In skeletal muscles, several proteins, identified immunobiochemically, have been found in specifically high concentrations. A difference in concentration of these muscle proteins in fast-twitch and slow-twitch muscles was found; M-subunit of creatine kinase (CKM) and β-enolase were abundant in fast-twitch muscle, whereas αB-crystallin, S-100a0 and B-subunit of creatine kinase (CKB) were abundant in slow-twitch muscle. In the present study, the masseter muscles of 5 patients with mandibular asymmetry were immunobiochemically analyzed using muscle fiber type-specific proteins.Method: Bilateral masseter muscles of the patients were sampled during orthodontic surgery. All samples were kept frozen at -80°C until analysis.Concentrations of CKM, β-enolase, αB-crystallin, S-100a0 and CKB were determined by the recentlydeveloped sandwitch-type enzyme immunoassay systems. The results showed that the concentration of αB-crystallin and S-100a0 on the deviated side was much higher than on the opposite side. The concentrations of CKM, CKB, and β-enolase were not significantly different.