Craniofacial Muscles A New Framework for Understanding the Effector Side of Craniofacial Muscle Control

The craniofacial musculature, including the extraocular muscles, muscles associated with the

auditory system, the masseter, the tongue, and the laryngeal and pharyngeal muscles, all

participate in functions that are critical to life: vision, intact of nutrition, breathing, and hearing.

Despite their critical importance, the majority of research on skeletal muscle basically has

ignored this collection of muscles. This is most likely due to their complexity in form,

development, fiber types, physiology, and disease profiles. All these make these muscles

extremely difficult to study.

Vision depends on voluntary and reflexive eye movements initiated by the oculomotor system.

The effector arm of this motor system includes the extraocular muscles and their motor neurons.

Mastication, and therefore food intake, depends on the complex movements of the masseter and

tongue musculature. The effector arm of this motor system includes the masseter and tongue

muscles and their motor neurons. Respiration, human phonation, as well as gestation, depend on

the laryngeal and pharyngeal musculature. The effector arm of these motor systems includes the

intrinsic and extrinsic laryngeal muscles and the pharyngeal muscles and their motor neurons.

Recently there has been a renewed interest in understanding the basic cell biology and

pathologies associated with these unusual skeletal muscles. This book will highlight novel

findings on the development of these muscles and their innervation, metabolic design, functional

consequences of their structural organization, and potential reasons for their differential response

to various neuromuscular diseases. In addition, critical areas for future studies will be identified.