The Lateral Pterygoid Muscle, a Heterogeneous Unit Implicated in Temporomandibular Disorder: A Literature Review

Abstract

Based on its anatomical relationships, the lateral pterygoid muscle is strongly linked with the temporomandibular joint (TMJ). It plays a major role in mastication. Embryological, histological, and anatomical knowledge define the lateral pterygoid muscle as a single muscle with a penniform structure. The various results of electromyographic (EMG) studies describe a complex physiology with a chronological contraction of the layers during the masticatory cycle. The sequential contraction of the layers of the lateral pterygoid muscle is the result of a selective neuronal activation induced by the masticatory Central Pattern Generator (mCPG). This neurophysiological theory highlights the essential role of the reticular formation in oral motor control. The sensitivity of those neurological structures to chronic emotional stress is one of the possible explanations for the appearance of oral parafunctions accompanied by a modification of pain perception and a disorganized muscular activation, determining factors in temporomandibular disorders.

Additional information

Notes on contributors

Sophie Desmons

Dr. Sophie Desmons received her D.D.S. degree from the Faculty of Dental Surgery, University of Lille, France in 2002. She is a Ph.D. student in the School of Biology and Health at the University of Lille. Since 2002, she worked on the faculty and as being an assistant clinical professor in the Department of Prosthodontic Dentistry. She is also a member of the Department of the Diagnosis and Management of Temporomandibular Joint Disorders.

François Graux

Dr. François Graux received his D.D.S. degree from the Faculty of Dental Surgery at the University of Lille, France in 1984. He is qualified in oral biology and in prosthodontic dentistry from the University of Paris. He has been a senior lecturer in the Department of Prosthodontic Dentistry in the Faculty of Dental Surgery at the University of Lille since 1996. Currently, he maintains a private practice and heads the Temporomandibular Joint Disorders Unit at the University Hospital of Lille.

Mounir Atassi

Dr. Mounir Atassi received his D.D.S. from the Faculty of Dentistry at the University of Aleppo, Syria in 2002. He is a specialist in prosthodontics from the University of Paris VI and is now a post graduate student in the Temporomandibular Joint Disorders Unit at the University Hospital of Lille.

Philippe Libersa

Professor Philippe Libersa, Ph.D., received his D.D.S. degree from the Faculty of Dental Surgery at the University of Lille, France in 1985. He has been a professor since 2004, and he is the director of the Department of Anatomic Sciences, Oral Physiology, Occlusion, Radiology and Biomaterials in the Faculty of Dental Surgery at the University of Lille. He works as a clinician in the University Hospital of Lille and in the Hospital of Seclin. He is the vice-dean of the Faculty of Dental Surgery of the University of Lille, France.

Pierre-Hubert Dupas

Professor Pierre-Hubert Dupas, Ph.D., graduated from the Faculty of Dental Surgery at the University of Lille, France in 1971. He has a private practice where he has specialized in the diagnosis and the management of temporomandibular joint disorders since 1976. He is a professor of occlusion and prosthodontic dentistry and created the Temporoman-dibular Joint Disorders Unit at the University Hospital of Lille in 1984. Currently, he is the dean of the Faculty of Dental Surgery at the Uni-versity of Lille, France. Dr. Dupas is the author of numerous national and international publications.