Four human facial muscles, platysma, m. levator labii, zygomaticus major and orbicularis oris, obtained during head and neck surgery, revealed no qualitative differences from normal human limb muscles, but differences with regard to fiber type distribution and fiber size. Mean fiber diameters of each muscle studied were largely 50% of those encountered in normal human limb muscles. Histographic analysis revealed that type II fibers were more frequent than type I fibers but that type IIB fibers were extremely scarce in number. The myofiber diameter spectrum was also larger in facial than in limb muscles, as myofibers produced variability coefficients around 325. The frequent presence of intramuscular nerve twigs and motor endplates may provide the opportunity of studying pre and postsynaptic pathology in future studies of denervated facial muscles.

Keywords:
Facial muscles, Enzyme histochemistry, Fiber typing, Normal myofiber patterns
This content is only available via PDF.
© 1982 S. Karger AG, Basel
1982
Copyright / Drug Dosage / Disclaimer
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.
You do not currently have access to this content.