TOPIC FOR THE SEMINAR MUSCLES OF FACE, NECK AND TONGUE

Under the guidance of Respected Dr. C S Bal

Presented By HARSHDEEP SINGH

29TH JULY 2013

MUSCLES OF FACE, NECK AND TONGUE

1. INTRODUCTION2. DEVELOPMENT

1. MUSCLES OF FACE 2. MUSCLES OF NECK3. MUSCLES OF TONGUE

3. DETAILED ANATOMY AND MORPHOLOGY :1. THE MUSCLES OF FACE2. MUSCLES OF NECK AND3. MUSCLES OF TONGUE

4. EXAMINATION OF THE MUSCLES5. NERVE SUPPLY , BLOOD SUPPLY AND LYMPHATIC DRAINAGE6. DISORDERS OF THE MUSCLES OF FACE, NECK AND TONGUE7. CLINICAL SIGNIFICANCE OF THE KNOWLEDGE OF THE MUSCLES OF FACE NECK AND

TONGUE.8. RECENT ADVANCES9. REFERENCES

INTRODUCTION• The Facial muscles are a group of striated muscles innervated by the facial nerve

that , among other things , control facial expression. These muscles are also called Mimetic muscles.

• The facial muscles are concerned with an array of facial expressions & other functions.

• These muscles are different from other muscle organizations in lacking of deep fascia beneath the skin of face.

• Neck connects the head to the trunk . It is a conduit for blood vessels, nerves, and hollow organs

• To facilitate the seemingly complicated area, the neck is divided into two major areas, or triangles, by the sternocleidomastoid muscle

• The muscles of the TONGUE are grouped into Extrinsic and Intrinsic groups and serve to facilitate its movements.

DEVELOPMENT OF MUSCLES OF FACE

• During the fourth week of gestation, as the maxillary and mandibular processes of the first pharyngeal arch are developing and growing an teriorly, a median bulge covering the brain enlarges and grows forward. This frontonasal prominence develops just above the stomadeum.

Development of the face illustrating derivatives of embryologic development.Approximately 8 weeks of development.Adult. Median nasal process (1). Lateral nasal process (2). Maxillary process (3). Mandibular process (4).

DEVELOPMENT OF MUSCLES OF TONGUE• The tongue forms in the floor of the pharynx beginning in the 4th week of gestation

, first as a median swelling, the TUBERCULUM IMPAR, bounded by two LATERAL LINGUAL SWELLINGS.These structures develop on the dorsal aspect of the mandibular arch.

DEVELOPMENT OF MUSCLES OF NECK• As the branchial apparatus develops, the first and second arches grow in a cranial

to caudal fashion, creating the epipericardial ridge. The epipericardial ridge contains the mesodermal rudiments of the sternocleidomastoid, trapezius, and the infrahyoid and lingual musculature. The nerves of the epipericardial ridge are the hypoglossal and spinal accessory. The proliferation of mesoderm in this area eventually causes overgrowth and narrowing of the third, fourth, and sixth arches into an ectodermal pit, known as the cervical sinus of His.

MUSCLES OF FACE

THE CRANIOFACIAL MUSCLES

They are grouped as:• 1. Epicranial• 2. circumorbital and palpebral• 3. nasal• 4. buccolabial

The EPICRANIUS is made up of two main parts:• Occipitofrontalis• Temporoparietalis

2. CIRCUMORBITAL AND PALPEBRAL MUSCLES• This group of muscle if composed of the following:• orbicularis oculi,• corrugator supercilii, • and levator palpebrae superioris.

3. NASAL MUSCLES• The nasal muscle group is composed of the following muscles:• 1. Procerus• 2. Nasalis• 3. Depressor septi

4. BUCCOLABIAL MUSCLES• The shape of the buccal orifice and the posture of the lips are controlled by a complex

three-dimensional assembly of muscular slips. These include:• Elevators, retractors, and evertors of the upper lip • Depressors, retractors, and evertors of the lower lip• A compound sphincter

1. ELEVATORS, RETRACTORS, AND EVERTORS OF THE UPPER LIP :• Levator labii superioris alaque nasi, levator labii superioris,zygomaticus

major and minor , levator anguli oris , and risorius 2. DEPRESSORS, RETRACTORS, AND EVERTORS OF THE LOWER LIP :• Depressor labii inferioris , depressor anguli oris , and mentalis. 3. A COMPOUND SPHINCTER:• Orbicularis oris , accessory muscles to the orbicularis oris ,incisivus

superior, and Incisivus inferior.

VARIOUS FACIAL EXPRESSIONS AND RELATED MUSCLES

THE MUSCLES OF THE TONGUE

MUSCLE ORIGIN INSERTION NERVE SUPPLY ACTION

INTRINSIC MUSCLES

Longitudinal

Transverse

Vertical

EXTRINSIC MUSCLES

Median septum and submucosa

Mucous membrane

Hypoglossal nerve

Alters shape of tongue

Genioglossus Superior genial spine of mandible

Blends with other muscles of tongue

Hypoglossal nerve Protrudes apex of

tongue through mouth

Hyoglossus Body and greater cornu of hyoid bone

Blends with other muscles of tongue

Hypoglossal nerve

Depresses tongue

Styloglossus Styloid process of temporal bone

Blends with other muscles of tongue

Hypoglossal nerve Draws tongue

upward and backward

Palatoglossus Palatine aponeurosis

Side of tongue Pharyngeal plexus Pulls roots of

tongue upward and backward, narrows oropharyngeal isthmus

• A SUMMARY OF THE ACTIONS OF THE TONGUE• Protrussion: genioglossus• Retrussion: hyoglossus, styloglossus, genioglossus• Depression : genioglossus, hyoglossus• Elevation : styloglossus• Shortening : longitudinal intrinsic fibers• Narrowing : transverse intrinsic fibers• Flattening : vertical intrinsic fibers

REGIONS OF THE NECK• To facilitate the seemingly complicated area, the neck is

divided into two major areas, or triangles, by the sternocleidomastoid muscle.

These are:1. Anterior triangle

- the area anterior to the SCM and below the inferior border of the mandible2. Posterior triangle

- the area posterior to the SCM and is limited posteriorly by the trapezius muscle.

ANTERIOR TRIANGLE OF THE NECK

SUBDIVISIONS OF THE ANTERIOR TRIANGLE • DIGASTRIC TRIANGLE• CAROTID TRIANGLE• MUSCULAR OR INFERIOR CAROTID TRIANGLE• SUBMENTAL TRIANGLE

MUSCLES OF THE ANTERIOR TRIANGLE OF THE NECK• INFRAHYOID MUSCLES

MUSCLE ORIGIN INSERTION ACTION NERVE SUPPLY

Omohyoid Inferior belly:Superior border of the scapulaSuperior belly:Intermediate tendon

Inferior belly:Intermediate tendonSuperior belly:Lower border of the body of the hyoid bone

Depresses the hyoid bone and larynx

Ansacervicalis (APR of C1, C2, C3)

Sternothyroid Manubrium of the sternum, posterior aspect

Oblique line of thyroid cartilage

Depresses the larynx

Ansacervicalis (APR of C1, C2, C3)

Thyrohyoid Oblique line of thyroid cartilage

Body and greater horn of hyoid bone, lower border

Depresses the hyoid bone

Thyrohyoid branch of the hypoglossal nerve

Sternohyoid Manubrium of the sternum, posterior aspect

Lower border of the body of the hyoid bone

Depresses the hyoid bone and larynx

Ansacervicalis (APR of C1, C2, C3)

• SUPRAHYOID MUSCLESMUSCLE ORIGIN INSERTION ACTION NERVE SUPPLY

Stylohyoid Styloid process Greater horn of hyoid bone

Elevates hyoid bone Facial nerve

Digastric (Posterior belly)

Digastric notch of the temporal bone at the base of the skull

Intermediate tendon

Raises the hyoid bone

Facial nerve

Digastric(anterior belly)

Intermediate tendon

Digastric fossa of the mandible

Elevates the hyoid bone

Nerve to the mylohyoid muscle

Mylohyoid Mylohyoid line on the medial aspect of mandibular body

Median raphe and body of hyoid

Elevates the hyoid bone, base of the tongue, and floor of the mouth

Nerve to mylohyoid muscle

Geniohyoid muscle Inferior border genial tubercle of the mandible

Body of hyoid bone Elevates hyoid bone, protracts hyoid bone

APR of C1

THE POSTERIOR TRIANGLE OF THE NECK

SUBDIVISIONS OF THE POSTERIOR TRIANGLE :• OCCIPITAL TRIANGLE• SUPRACLAVICULAR TRIANGLE

MUSCLE ORIGIN INSERTION ACTION NERVE

Platysma Superficial fascia of the deltoid and pectoral regions

Inferior border of the mandible, some fibers sweep upward and blend with risorius

Stretches tight the skin of the neck, depresses the mandible

Facial nerve

Splenius capitis Lower part of the ligamentum nuchae, lower cervical spines

Mastoid process and the superior nuchal line

Bilateral:Extends the headIndividual:Flexes the head laterally

Cervical spinal nerves

Levator scapulae Transverse processes of C1 to C4

Superior portion of the vertebral border of the scapula

Elevates and rotates the scapula

Dorsal scapular nerves

Scalenius posterior Transverse processes of C5 and C6

Superior aspect of the second rib

Flexes the neck APR of C5 to C8

Scalenius Medius Transverse processes of C2 to C7

Superior aspect of the first rib

Flexes the neck APR of C3 and C4

Scalenius anterior Transverse processes of C3 to C6

Scalene tubercle of the first rib

Participates in forced inspiration by elevating the ribs and sternum

APR of C5 to C8

MUSCLES OF THE POSTERIOR TRIANGLE OF THE NECK

BLOOD SUPPLY, NERVE SUPPLY AND LYMPHATIC DRAINAGE OF THE MUSCLES OF FACE

• VEINS, ARTERIES, AND LYMPHATICS OF THE FACE• The physiology of the human face is complex. A series of arteries and veins provide circulation

of blood to the various tissues of the face and also the face includes some lymphatic tissues.The following are the major arteries of the face :• Supratrochlear artery• Supraorbital artery• Mental artery• Transverse facial artery• Zygomaticoorbital artery• Facial artery• Submental artery• Inferior labial • Superior labial artery• Lateral nasal artery• Angular artery• Occipital artery• Posterior auricular artery:• Maxillary artery• Inferior alveolar artery• Infraorbital artery• Superficial temporal artery:

IMPORTANT VEINS IN THE FACE INCLUDE THE FOLLOWING:• Angular vein• Facial vein• Maxillary vein• Superficial temporal vein• Retromandibular vein• Posterior auricular vein• Supraorbital and supratrochlear veins

LYMPHATIC NODES ARE CATEGORIZED INTO SEVERAL GROUPS:• Submental lymph nodes• Submandibular lymph nodes• Parotid lymph nodes

NERVE SUPPLY OF MUSCLES OF FACE

• The facial nerve is the seventh (VII) of twelve paired cranial nerves• The main function of the facial nerve is motor control of most of

the muscles of facial expression. It also innervates the posterior belly of the digastric muscle, the stylohyoid muscle, and the stapedius muscle of the middle ear.

• . It emerges from the brainstem between the pons and the medulla, and controls the muscles of facial expression, and functions in the conveyance of taste sensations from the anterior two-thirds of the tongue and oral cavity

BLOOD SUPPLY , NERVE SUPPLY AND LYMPHATIC DRAINAGE OF THE MUSCLES OF TONGUE

Blood supply.• The main artery is the lingual artery , a branch of the external carotid. It is

accompanied by lingual veins. The deep lingual vein (or ranine vein) can be seen in the floor of the mouth at the side of the frenulum. The various veins of the tongue drain ultimately into the internal jugular.

Lymphatic drainage.• The drainage is to the submental, submandibular, and deep cervical

nodes, and extensive communications occur across the median plane.

Sensory innervation • The anterior two thirds of the tongue is supplied by (1) the lingual nerve (of

the mandibular nerve) for general sensation and by (2) the chorda tympani (a branch of the facial nerve that runs in the lingual nerve) for taste. The posterior third of the tongue and the vallate papillae are supplied by the glossopharyngeal nerve for both general sensation and taste. The nerves for taste are cranial nerves VII, IX, and X. The internal branch of the vagus is responsible for general sensation and taste near the epiglottis.

BLOOD SUPPLY ,NERVE SUPPLY AND LYMPHATIC DRAINAGE OF MUSCLES OF NECK

Blood Supply to the Neck• The neck and head is mainly supplied by the common carotid artery. Branches of the external carotid artery:• Superior thyroid artery• Ascending pharyngeal artery• Lingual artery• Facial artery• Occipital artery• Posterior auricular artery• Maxillary artery• Superficial temporal arteryVenous Drainage of the Head and Neck• The maxillary, superficial temporal, posterior auricular and occipital

veins all drain into the external jugular veins• The facial vein drains into the internal jugular veins

• Nerves of the Neck• Both the cervical plexus and the accessory nerve (CN XI) emerge

from the posterior neck triangle.• The cervical nerve plexus is a plexus of the ventral rami of the first

four cervical spinal nerves which are located from C1 to C4 cervical segment in the neck.

• Nerves formed from the cervical plexus innervate the back of the head, as well as some neck muscles.

• The branches of the cervical plexus emerge from the posterior triangle at the nerve point, a point which lies midway on the posterior border of the Sternocleidomastoid.

• The accessory nerve is a nerve that controls specific muscles of the neck, it nerve provides motor innervation from the central nervous system to the Sternocleidomastoid muscle and the Trapezius muscle.

Lymphatics of the Neck

- Deep Lymph Nodes• Submental• Submandibular

- Anterior Cervical Lymph Nodes (Deep)• Prelaryngeal• Thyroid• Pretracheal• Paratracheal

- Deep Cervical Lymph Nodes• Lateral jugular• Anterior jugular• Jugulodigastric

- Inferior Deep Cervical Lymph Nodes• Juguloomohyoid• Supraclavicular

CLINICAL EXAMINATION OF MUSCLES OF FACE

• A thorough head and neck examination is paramount, with occasional use of tests for salivation, tearing, and taste; these are the first steps in determining the site of injury. Physical examination findings reveal affected facial musculature movement.

• Tests for facial innervation include the following:• Forehead wrinkling (frontalis muscle)• Eye closure (orbicularis oculi muscle)• Wide smile• Whistling• Blowing (eg, buccinator muscle, orbicularis oris muscle, zygomatic muscle)

House-Brackmann scale• Clinically, injury to the infratemporal facial nerve can be classified by

degree. Multiple classifications of facial nerve injury are found in the literature. The most frequently used is the House-Brackmann scale

HOUSE-BRACKMANN CLASSIFICATION OF FACIAL FUNCTION Grade CharacteristicsI. Normal Normal facial function in all areas

II. Mild dysfunction Slight weakness noticeable on close inspectionMay have slight synkinesisAt rest, normal symmetry and toneMotionForehead - Moderate to good functionEye - Complete closure with minimal effortMouth - Slight asymmetry

III. Moderate dysfunction Obvious but not disfiguring difference between sidesNoticeable (but not severe) synkinesis, contracture, or hemifacial spasmAt rest, normal symmetry and toneMotionForehead - Slight to moderate movementEye - Complete closure with effortMouth - Slightly weak with maximum effort

IV. Moderately severe dysfunction

Obvious weakness and/or disfiguring asymmetryAt rest, normal symmetry and toneMotionForehead - NoneEye - Incomplete closureMouth - Asymmetrical with maximum effort

V. Severe dysfunction Only barely perceptible motionAt rest, asymmetryMotionForehead - NoneEye - Incomplete closureMouth - Slight movement

VI. Total paralysis No movement

CLINICAL EXAMINATION OF THE MUSCLES OF TONGUE• Weakness of the tongue manifests itself as a slurring of speech. The patient

complains that their tongue feels "thick", "heavy", or "clumsy."

• Lingual sounds (i.e., l's, t's, d's, n's, r's, etc.) are slurred and this is obvious in conversation even before direct examination.

• Examination of the tongue first involves observation for atrophy and fasciculationsAtrophy and fasciculations in combination suggest disease or damage to the motor neurons of the brain stem, but can be seen with peripheral nerve damage as well.

• Fasciculations are fine, random, multifocal twitches of muscle. They are evaluated by observing the tongue while it is at rest in the floor of the mouth. They are best seen along the lateral aspect of the tongue.

• Protrusion frequently causes a fine tremor in the normal tongue, which can obscure or mimic fasciculations. Simply having the patient protrude their tongue in the midline tests strength of the tongue

• A repetitive or complex lingual sound (e.g., "la la la la" or "Methodist artillery") often shows impediment when any part of the vocal apparatus is affected (e.g., Broca's region, motor cortex, basal ganglia, cerebellum, brain stem, nucleus, or nerve).

CLINICAL EXAMINATION OF THE MUSCLES OF NECK

• When examining the SCM muscle, the bulk and outline of the muscle should be observed. Atrophy is common in damage to the nerve and fasciculations may be seen especially if the motor neurons are diseased.

• The SCM muscle rotates the head away from the side of contraction. Testing entails having the subject turn their head against the examiner's hand, which is pressed against the patient's chin . The bulk of the muscle is then easily seen and palpated, and its strength can be determined.

• A, testing of right sternomastoid muscle. B, testing upper portion of trapezius muscles.

• Paralysis of this muscle will produce weakness, although not complete loss of ability to rotate the head away from the lesion

• .The two sternocleidomastoids contracting together will flex the head toward the chest. Bilateral weakness may prevent the patient from lifting their head off a pillow and the head may be inclined posteriorly for lack of flexor tone

• The spinal accessory nerve innervates the trapezius muscles, which elevate the shoulders and rotate the scapula upward during abduction of the arm.

• Denervation is evidenced by atrophy and often fasciculations. The shoulder droops on the side of the weak muscle and there is downward displacement of the scapula posteriorly.

• Shrugging the shoulders against resistance is the standard way of testing the upper trapezius

CLINICAL SIGNIFICANCE OF THE KNOWLEDGE OF THE MUSCLES OF FACE NECK AND TONGUE

• A patient who has damage to the muscles of the head and neck region may have various issues, which may in turn affect the management of dental hygiene treatment.

• The cervical muscles change the way in which a patient’s head and neck are positioned. The patient may not have the ability to place his/her body in a traditional or ergonomically correct position for the dentist

• The muscles of facial expression give an individual the ability to laugh, cry, smile, and frown. Damage to these muscles, which would impact these basic functions, could bring about inconvenience and distress to a patient. As the patient’s oral health-care provider, the Dentist must be aware of this and handle the situation with sensitivity

• .An injury to the muscles of facial expression may lead to abnormal movements of this region. Twitching, spasm, weakness, or paralysis would not be uncommon. The patient may experience altered taste sensation and dryness of the mouth.

• If a patient does not have the ability to close his/her lips, he/she may experience excessive drooling. A familiar cause of facial weakness is Bell’s pal

• The hyoid muscles and the muscles of the tongue will impact the patient’s ability to properly masticate, swallow, speak, and position his/her tongue. The tongue may become atrophied in severe cases. A dentist must allow the patient to communicate to the best of his/her ability. This may take additional time. The dentist must also consider the tongue’s position when doing procedures such as taking impressions.

DISORDERS OF MUSCLES OF FACE NECK AND TONGUE• BELL’S PALSY – A form of temporary facial paralysis, Bell's palsy results from

damage or trauma to one of the two facial nerves and is the most common cause of facial paralysis, Bell's palsy affects only one of the paired facial nerves and one side of the face.

• HEMIFACIAL SPASM – Hemifacial spasm is a neuromuscular disorder characterized by frequent involuntary contractions of the muscles on one side of the face. The first symptom of hemifacial spasm is usually an intermittent twitching of the eyelid muscle that can lead to forced closure of the eye

• MOTOR NEURON DISEASES – The motor neuron diseases (MNDs) are a group of progressive neurological disorders that destroy cells that control essential muscle activity such as speaking, walking, breathing and swallowing

• MUSCULAR DYSTROPHY – the muscular dystrophies (MD) are a group of more than 30 genetic diseases characterized by progressive weakness and degeneration of the skeletal muscles that control movement. Symptoms of muscular dystrophy nerve damage vary with the different types of muscular dystrophy.

• MYASTHENIA GRAVIS – This chronic, autoimmune, neuromuscular disease is characterized by varying degrees of weakness of the skeletal (voluntary) muscles of the body. The hallmark symptom of myasthenia gravis is muscle weakness that increases during periods of activity and improves after periods of rest. The cause of myasthenia gravis nerve damage is a defect in the transmission of nerve impulses to muscles.

• SPEECH AND LANGUAGE DISORDERS – The inability to form sounds or articulate words correctly or the inability to comprehend another's speech.

• TORTICOLLIS is a fixed or dynamic tilt, rotation or flexion of the head and/or neck. The type of torticollis can be described depending on the positions of head and neck as

laterocollis : the head is tipped towards the shoulder rotational torticollis : the head rotates along the longitudal axis anterocollis : forward flexion of the head and neck retrocollis : hyperextension of head and neck backward A multitude of conditions may lead to the development of Torticollis; including muscular fibrosis, congenital spine abnormalities or toxic or traumatic brain injury.• WHIPLASH. Whiplash often involves pain and stiffness in the neck, but may also affect the surrounding muscles in your head, mid-back, chest, shoulders, and arms. Whiplash injuries can be mild or severe, temporary or permanent. Whiplash is often referred to as “soft tissue injuries,” as the damage is usually limited to the ligaments, muscles, and tendons of the neck and upper back and does not involve the fracture of any bones or vertebrae.

RECENT ADVANCES• RECENT PROGRESS IN FACIAL ESTHETIC SURGERY Rev Stomatol Chir Maxillofac. 1998 Jul;99 Suppl 1:38-71Recent advances offer a new approach to cosmetic surgery of the frontal, cervico-facial and orbito-palpebral areas. Conservative frontal lifting procedures displace the entire frontal muscle (without section or resection) over the underlying bone and periosteal planes by raising the galea and the antagonist muscles. This repositioning reduces or eliminate wrinkles by preventing hyperfunction of the frontal muscle. The risk of sensorial or motor nerve lesions is reduced and the forehead and eyelids have a natural appearance• ADVANCES IN FACIAL REANIMATIONCurrent Opinion in Otolaryngology & Head & Neck Surgery: August 2006 - Volume 14 - Issue 4 The options for dynamic reanimation of the paralyzed face must be examined in the context of several patient factors, including age, overall health, and patient desires. The best functional results asre obtained with direct facial nerve anastomosis and interpositional nerve grafts. In long-standing facial paralysis, temporalis muscle transfer gives a dependable and quick result. Microvascular free tissue transfer is a reliable technique with reanimation potential whose results continue to improve as microsurgical expertise increases. Postoperative results can be improved with ancillary soft tissue procedures, as well as botulinum toxin.

• ADVANCES IN MUSCLE RECONSTRUCTION OF THE LIP IN THE PRIMARY SURGICAL TREATMENT OF CLEFT LIP

Hellenic Orthodontic Review. 2008, Vol. 11 Issue 1• Recently, the improvements of the intrauterine experimental surgery offered a new

perspective for the application of this technique on humans. Fetuses respond to injuries with a fundamentally different fashion; collagen is deposited in a scarless way by wound healing during early gestation .This may lead to a more unobstructed growth of the maxilla. It is assumed that, after an intrauterine repair of a cleft lip and palate,the need for secondary surgical treatment of the lip and/or the maxilla or for additional treatments as orthodontic or orthopedic treatment, will be minimal oral most unnecessary (Papadopoulos et al., 2002a;Papadopulos et al., 2003).Very recently it has been shown that when bone graft healing takes place following intrauterine surgical repair of cleft lip and alveolar like defects in sheep fetuses, a tendency of almost normal maxillary growth can be observed.

• EMG STUDY FOR PERIORAL FACIAL MUSCLES FUNCTION DURING MASTICATION Journal of Oral Rehabilitation. Mar2008, Vol. 35 Issue 3• This study aimed to clarify the temporal and quantitative modulation in the orbicularis

oris (OO) and buccinator (BUC) muscle activities during mastication. • Electromyograms (EMGs) of the facial muscles were recorded with fine wire

electrodes when chewing the chewing gum (one to four sticks) and peanuts (one to five pieces). Surface EMGs of the masseter (MAS) and digastric muscles were recorded simultaneously. EMGs of the OO and BUC showed rhythmic single-peaked bursts corresponding to the jaw-opening phase of chewing cycles.

• . The changes of the OO and BUC activities may derive from chewing-generated sensory inputs in accordance with the physical property of food in part, which would relate to the function of these muscles during mastication

MASTICATORY FEATURES, EMG ACTIVITY AND MUSCLE EFFORT OF SUBJECTS WITH DIFFERENT FACIAL PATTERNSJournal of Oral Rehabilitation. Nov2010, Vol. 37 Issue 11, p813-819• The aims of this study were to evaluate masticatory performance, mandibular

movement, electromyographic (EMG) activity and muscle effort of masseter and anterior temporal muscles during mastication. Seventy-eight dentate subjects were selected and divided into three groups according to vertical facial pattern: brachyfacial, mesofacial and dolichofacial.Electromyographic activities of masseter and anterior temporal muscles were evaluated during mastication, and muscle effort was calculated by the percentage of activity required for mastication based on maximum muscle effort. It was concluded that the vertical facial pattern influences masticatory performance, mandibular movement during mastication and the effort masticatory muscles required for chewing.

EFFECTIVENESS OF CIRCUMORAL MUSCLE EXERCISES IN THE DEVELOPING DENTOFACIAL MORPHOLOGY IN ADENOTONSILLECTOMIZED CHILDREN: AN ULTRASONOGRAPHIC EVALUATION.• Journal of the Indian Society of Pedodontics & Preventive Dentistry. Apr2009, Vol. 27 Issue 2, p94-

103• Alterations in the functions of the facial muscle can establish changes in facial skeleton and in the

development of occlusion. The effect of mouth breathing on the facial morphology is probably greatest during the growth period. Removal of nasal obstruction, adenoids, and tonsils have not given beneficial results in the reversion of the habit unless intercepted with various muscle exercises. Hence, this study was conducted to ultrasonographically evaluate the effectiveness of circumoral muscle exercises in the developing dentofacial morphology in adenotonsillectomized children.

• OCCLUSION, STEMOCLEIDOMASTOID MUSCLE ACTIVITY, AND BODY SWAYCRANIO: The Journal of Craniomandibular Practice. Jan2006, Vol. 24 Issue 1, p43-49. 7p.• In normal gravitational conditions, information from the neck and stomatognathic apparatus

play a role in maintaining the body's balance and equilibrium. The current piiot study used normalgravity conditions to investigate the hypothesis of a functional coupling between occiusion and neck muscles and body postural oscillations. The immediate effect of modified occiusal surfaces on the contraction pattern of the sternocieidomastoid muscles during maximum voluntary cienching and on theoscillation of the center of foot pressure was analyzed in 11 male astronauts

• Occlusal splints were prepared using impressions of their dental arches. The splints were modeled on the mandibular arch, had only posterior contacts, and were modified to obtain a more symmetric, standardized contraction of the masseter and temporalis muscles during teeth clenching. Surface EMG activity of the stemocleidomastoid muscles was recorded during a maximal voluntary clench with and without the splint ,A functionally more symmetric maxillo-mandibular position resulted in a more symmetric sternocieidomastoid muscle contraction pattern and less body sway. Modifications in the contraction of the masticatory muscles may therefore affect the whole body

REFERENCES• Clinical Anatomy by Regions by Richard S. Snell 8th edition• Textbook of Human Anatomy by B.D. Chaurasia 3rd edition• Textbook of Head and Neck Anatomy by Hiatt and Gartner• Inderbir S. textbook of Embryology 2nd edition• Head and Neck Anatomy for Dental Medicine (THIEME Atlas of

Anatomy Series) • McMinn's Color Atlas of Head and Neck Anatomy, 4e • Current Opinion in Otolaryngology & Head & Neck Surgery: August

2006 - Volume 14 - Issue 4 • Hellenic Orthodontic Review. 2008, Vol. 11 Issue 1, p35-53. • Journal of the Indian Society of Pedodontics & Preventive Dentistry.

Apr2009, Vol. 27 Issue 2• Journal of Oral Rehabilitation. Nov2010, Vol. 37 Issue 11• CRANIO: The Journal of Craniomandibular Practice. Jan2006, Vol. 24

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