This book provides a comprehensive scientific investigation into every aspect of craniomandibular muscle function in both human and experimental animal studies. Topics discussed cover three broad areas: the anatomical, physiological, and histochemical aspects of these muscles; the special importance of these muscles to resting mandibular posture and mastication; and their role in clinically relevant problems involved with occlusion, craniomandibular disorders, and the growth and development of the cranioskeleton. Over 150 figures and tables are used to illustrate the concepts in these three areas. Methods for studying craniomandibular muscles are examined in depth, and the use of classically defined techniques such as electromyography and newer approaches using magnetic resonance spectroscopy and immunological identification of contractile proteins are discussed. Specialists in oral biology, orthodontics, oral surgery, prosthodontics, and craniomandibular disorders in schools and in private practice should consider this book an indispensable resource for their work and studies.
CRANIOMANDIBULAR MUSCLE ANATOMY.CRANIOMANDIBULAR MUSCLES AS SKELETAL MUSCLES. Cellular Definition. Sarcomere as Functional Unit. ANATOMY OF THE HUMAN CRANIOMANDIBULAR MUSCLES. Definition. Temporalis Muscle. Masseter Muscle. Medial Pterygoid Muscle. Lateral Pterygoid Muscles. Digastric Muscle. BIOMECHANICS OF MUSCLE CONTRACTION. Principles of Function. Vectors and Torque. Mechanical Advantage. Three Dimensional Biomechanical Analysis. Computer Models of Force Development. ADAPTATION OF CRANIOMANDIBULAR MUSCLES WITH GROWTH. MUSCLE FIBER CHARACTERISTICS. DEFINING MUSCLE FIBERS BY HISTOCHEMISTRY. Defining Muscle Fiber Types. Defining Muscle Fibers by Immunochemistry. Jaw-Closing Muscles in Human. Jaw-Closing Muscles in Rhesus Monkey. Lateral Ptergyoid Muscle in Human. Digastric Muscle in Human. Digastric Muscle in Rhesus Monkey. ADAPTATIONS IN MUSCLE FIBER TYPES. Abnormal Vertical Dimension in the Human. Altering the Mandibular Posture in the Rhesus Monkey. Dentures and Edentulous Condition in the Human. Chronic Edentulous Condition in the Rhesus Monkey. Muscle Detachment in the Rhesus Monkey. Altering Muscle Length in the Rhesus Monkey. Muscle Activity and Histochemical Composition in the Rhesus Monkey. Onset of Function and Postnatal Development. Regeneration and Myosin Gene Expression. SIGNIFICANCE AND IMPLICATIONS. Relation of Histochemical Properties to Physiological Parameters. Conditions for Changing Composition of Muscle Fiber Types. MAGNETIC RESONANCE SPECTROSCOPY. ELECTROMYOGRAPHY. INNERVATION OF THE CRANIOMANDIBULAR MUSCLES. ELECTROMYOGRAPHY OF CRANIOMANDIBULAR MUSCLES. Definition of Electromyography. EMG Recordings Related to Muscle Fibers. MUSCLE TENSION. Muscle Tension as Related to Sarcomere Length. Muscle Tension as Related to EMG. Bite Force and Relation to Muscle Force. OBJECTIVE ANALYSIS OF THE ELECTROMYOGRAM. Rectification and Integration. Power Spectral Analysis. EVOKED POTENTIALS WITH CENTRAL STIMULATION. MANDIBULAR REST POSITION. DEFINING MANDIBULAR REST POSITION. Definition of Rest Position. Mandibular Incisor Tracking. Contribution of Passive Forces. Contribution of Active Forces: Changing Head Position. Contribution of Active Forces: Changing Visual Input. Contribution of Active Forces: Various Mandibular Muscles. Relevance of Proprioceptive Input. MANDIBULAR MUSCLE FUNCTION AND RECRUITMENT. INDIVIDUAL CRANIOMANDIBULAR MUSCLES. Value of Electromyographic Assessment. Temporalis Muscle Function. Masseter Muscle Function. Medial Pterygoid Muscle Function. Lateral Pterygoid Muscle Function. Digastric Muscle Function. COACTIVATION IN CRANIOMANDIBULAR MUSCLE FUNCTION. Clenching. Wide Opening. Laterotrusion. Protrusion. Retrusion. ONSET OF MUSCLE FUNCTION. EMG WITH DECIDUOUS DENTITION. FATIGUE AND CRANIOMANDIBULAR MUSCLE FUNCTION. MASTICATION AND DEGLUTITION. MASTICATION. Mandibular Movement in Mastication. Mandibular Muscle Activity. Central Neural Control of Mastication. Relevance of Peripheral Sensory Input. DEGLUTITION. Oral and Pharyngeal Phases. Esophageal Phase. CRANIOMANDIBULAR MUSCLE SENSORY INPUT. PROPRIOCEPTORS. Muscle Spindle. Masseteric Reflex. Joint Proprioception. Mandibular Kinesthesia. Mandibular Kinesthesia and Craniomandibular Disorders. OTHER MECHANORECEPTORS. Complex Reflex Response-Silent Period. Complex Reflex in Subjects with Craniomandibular Disorders. Jaw Opening Reflex. RELATION BETWEEN OCCLUSION AND MUSCLE RECRUITMENT. EFFECT OF OCCLUSAL CONTACTS. Number and Type of Occlusal Contacts. Recruitment of Mandibular Muscles. DUAL BITE. CROSS BITE. FUNCTIONAL APPLIANCES AND CRANIOMANDIBULAR MUSCLE FUNCTION. EFFECT OF MALOCCLUSIONS ON MUSCLE FUNCTION. DENTURES, MUSCLE RECRUITMENT AND FORCE. RELEVANCE OF OCCLUSION AND MORPHOLOGY TO CRANIOMANDIBULAR MUSCLE FUNCTION. MANDIBULAR MUSCLE PAIN AND CRANIOMANDIBULAR MUSCLE FUNCTION. SUBJECTS WITH MUSCLE PAIN. Resting Muscle Activity. Masticatory Muscle Activity. Effect of Sustained Muscle Activity. Muscle Fatigue. Bite Force in Subjects with Muscle Pain. Muscle Function as Related to the Temporomandibular Joint. Relevance of Craniomandibular Muscle Function to Muscle Pain. BRUXISM AND CRANIOMANDIBULAR MUSCLES. Bruxism and Symptoms. Frequency of Occurrence. Bruxism as Related to Direction and Level of Muscle Force. OCCLUSAL SPLINT. Effect of Occlusal Splint in Normal Subjects. Effect of Occlusal Splint in Subjects with Muscle Pain. OCCLUSION AND CRANIOMANDIBULAR MUSCLE INTERACTION. HEADACHES AND CRANIOMANDIBULAR MUSCLES. CRANIOMANDIBULAR MUSCLE FUNCTION AND MORPHOLOGY. EFFECT OF IMPAIRING OR ELIMINATING THE NEUROMUSCULAR SYSTEM. Effect of Removal of One Mandibular Muscle. Effect of Removing Several Muscles. Interpretation of the Muscle Deletion and Impairment Studies. HUMAN MORPHOLOGY AND MUSCLE RECRUITMENT. Cephalometric Measurements and Muscle Activity. Craniomandibular Form and Muscle Area. Change in Muscle Function and Cranioskeletal Morphology. PRIMATE MORPHOLOGY AND CRANIOMANDIBULAR MUSCLES. Muscle Recruitment as Related to Bone Strain. Altering Mandibular Position: Clockwise Rotation and Opening. Altering Mandibular Position: Chronic Protrusive Position. Altering Muscle Vector and Morphology. DIET AND CRANIOMANDIBULAR MORPHOLOGY. Effect of Soft Diet on the Condyle. Distinction Between Species on Soft Diet. Mechanism of Soft Diet Changing Function. CONDYLAR GROWTH PATTERNS AND MUSCLE FUNCTION. Replacement or Modification of the Condyle. Relevance of the Lateral Pterygoid Muscle to the Condyle. MOUTH BREATHING, CRANIOMANDIBULAR MUSCLE FUNCTION AND INTERACTION WITH MORPHOLOGY. Morphological Characteristics of Human Mouth Breathing. Experimental Studies Inducing Chronic Oral Respiration. Neuromuscular Changes Before and After Inducing Experimental Oral Respiration. Interpretation of the Experimental Mouth Breathing Model. ALTERING MANDIBULAR VERTICAL POSITION BY MODIFYING ORAL SENSATION. EFFECT OF MUSCLE CONTRACTION ON MORPHOLOGY. Muscle Contraction with Tooth Contact. Muscle Contraction without Tooth Contact. EFFECT OF ALTERING MANDIBULAR FORCES IN THE MEDIO-LATERAL PLANE ON MORPHOLOGY. Premature Contact Inducing Mandibular Shift. Complete Mandibular Occlusal Splint. MUSCLE FUNCTION IN HUMAN CRANIOFACIAL ANOMALIES. Neuromuscular Adaptation in Subjects with Unilateral Loss of the Condylar Cartilage and Disk. Neuromuscular Adaptation in Subjects with Complete Loss of the Condylar Process. Interpretation of the Neuromuscular Findings in Hemifacial Microsomia. FINITE ELEMENT ANALYSIS.