ElectromyographyElectromyography
INDIAN DENTAL ACADEMY
Leader in continuing dental education
www.indiandentalacademy.com
w...
Contents
• Introduction
• History
• Background of emg/electromyography
• Emg defintion
• Purpose of emg
• Uses of emg
• Ex...
Continued ..
• Emg electrodes
•
• Precautions
• Preparations
– After care
• Risks
• Normal results
• Abnormal results
• Em...
Introduction
• Electromyography is the earliest useful technique
in clinical neurophysiology
• Emg is a valuable diagnosti...
History of emg
• The most important development in history of
study of muscle action potential fallowed the
development of...
• Hoefer and guttaman in 1944 recorded
spontaneous in patients with spinal cord injuries
and found it useful in localizing...
• The first report of nerve conduction potential in
response to median and ulnar nerve stimulation
was published in 1937
•...
www.indiandentalacademy.com
Emg definition
• Also called as myogram
• Recording and study of intrinsic electrical
properties of skeletal muscle by mea...
Back ground of emg
• Skeletal muscle performs mechanical work
• Stimulated to contract when brain or spinal cord
activates...
Purpose of emg
• determine -A particular muscle is responding to
stimulation & whether a muscle remains inactive
when not ...
Continued..
• Distinguish b/n primary muscle diseases and
dennervation –myopathies from neuropathies
• Identify muscle dys...
Obtaining an emg
• At ,rest when there is no spontaneous
muscle activity
• During slight muscle contraction - to asses
the...
Emg helps in diagnosis of…
• Muscular dystrophy
• Congenital myopathies
• Metabolic myopathies
• Myotonias
• Radiculopathi...
Experimental objectives of emg
• To observe,record and correlate motor units
recruitment with increase power of skeletal
m...
Emg types
• Kinesiological emg
• Diagnostic emg
•
www.indiandentalacademy.com
• Kinesiological emg
• Used for
• functional anatomy
• force development
• reflex contraction of muscle
•
www.indiandental...
• Diagnostic emg
• Test the nerve and muscle integrity
• Nerve conduction velocity for nerve damage
compression
• Firing c...
Motor unit action potential
• Represent sum of the muscle action potentials supplied by
anterior horn cell
• Muscle fibers...
Nerve conduction test
Slightly different test is often performed
at same time with emg
specially helpful - pain / sensory ...
Sharp positive waves
• Triphasic pattern a-
positive-crossing,b-
negative-leaving,c-
recording –in a normal
muscle
• In ab...
Emg electrodes types-surface and needle
• Needle electrode
• Superior to as quality
of image better
• Lesser technical
art...
Types of needle electrodes
• Concentric
• Monopolar
• Single fiber
• Macro electrode
www.indiandentalacademy.com
• Precautions
• no special precautions
• patient with the history of bleeding
disorder
• a muscle biopsy is - of the diagn...
• Preparations
• no special preparations
• using creams /lotions on the day of the
test
• Doctor should give information a...
Emg recording
• It was einthoven
muscle contraction gives off
an idiomusclular current - action potential
• Structural bas...
www.indiandentalacademy.com
• Electrode hand set
• Hand dynamometer
• Disposable electrodes
Emg accessories
www.indiandentalacademy.com
www.indiandentalacademy.com
Emg recording technique
• A needle electrode is inserted through skin
into muscle.
• Recordings -while muscle is at rest –...
www.indiandentalacademy.com
www.indiandentalacademy.com
• EMG-raw signal-voltage difference in
electrical potential measured b/n record
electrodes
• Origin-electrical activity –t...
Nerve
Muscle
Tendon
Raw EMG Signal
Electrode
Electrode
Tendon
Skin
www.indiandentalacademy.com
www.indiandentalacademy.com
• After care
• Minor pain &bleeding
• Muscle-tender
• Risks
• no significant risks-needle insertion
• Normal results
• som...
EMG in orthodontics
• History
• 1 st effort apply emg by robert e moyers
• observed normal relations of teeth to each othe...
Allen Brodie-if we could learn to
control the musculature through
critical period of growth, we might be
able to expect th...
EMG its application-orthodontics
• Diagnosis-habits-tongue thrusting
• lip &cheek activity,sucking habits
• swallowing
• p...
EMG activity in class 2
malocclusion patients
• Graber –in contrast to cl 1, cl 2 patients-abnormal
muscle activity,especi...
Pancherz analyzed-emg activity in
masticatory muscles –cl 2div1 and
normal occlusion-maximal biting in
centric occlusion a...
High positive-b/n emg activity –maximal biting
and chewing for both muscles of 2 groups
Impaired muscle activity in cl2 –a...
www.indiandentalacademy.com
Emg –on cl 3
• It is believed-correction of anterior cross bite-cl3-
increased emg –of masseter and
temporalis/bilateral i...
Emg –on functional appliance
therapy
• Neuromuscular reaction
seen in patients wearing
appliance on full time-as
‘pterygoi...
• Decrease –post temporalis
• increase-masseter
• significant increase-function-
lateral pterygoid
• As expt-progressed pt...
Lacouture,et,al-action of 3 types functional
appliance on activity of masticatory muscles
• Used-herbst,twin
block,frankel...
• Sessle bj,wood side
dg.-univer
toronto,canada
• Studied –functional
appliance-change in
postural emg activity of
muscle
...
www.indiandentalacademy.com
Emg activity-swallowing
• Showed characteristic differences-normal and
abnormal swallowing
• In mature swallow-
• During t...
www.indiandentalacademy.com
Emg in cerebral palsy
• Useful in children with cerebral palsy
patients
• Paralysis/hyper kinetic activity of muscle
assoc...
Effect of pain –orthodontic treatment
• Effect from archwire jaw muscle is unclear
• Goldrich et al evaluated effect-on ma...
• Negan –assessed muscle pain and emg activity
before and after treatment with orthopedic
retraction head gear
• 800 gm fo...
Emg activity in cleft lip and
palate patients
• Li et al evaluated-
muscle activity in
operated unilateral
cleft lip and p...
• In harmonious activity masticatory
muscles during mandibular border
movement
• Higher asymmetry index of masseter and
te...
Emg on buccinator activity
• In cl 2 div 1 buccinator contracts
excessively and hyper active mentalis
muscle
• Post fibers...
Influence of activator on emg
activity of mandibular elevator
• Mirallis r burger faculty of medicine-univ of
chile
• Emg ...
Muscle response-twin block
• Aggarwal p –aims .delhi
• Significant increase in activity of masseter
and temporalis
• Enhan...
Emg study on mand movement –
unilateral cleft lip and palate
patients-
• Saksmoto t ohtsuakak dept of ortho tokoyo
japan
•...
Emg – Herbst appliance
• Dept of ortho tokoyo medical and dental
univ japan
• Examine functional muscular adaptation to
ch...
Emg on post orthodontic stability
• J adwt ortodontic orthognathic surgery
2002.17[4]307-13
• To prevent relapse after ort...
Muscular equilibrium and
orthognathic surgery
• Evaluate modifications of muscular activity b/n
pre surgical and during ye...
• Existence of significant modification after
surgery often reveals a craniomandibular
dysfunction
• Emg activity during t...
Surface emg on TMJ
• More specifically delineate and define hypertronic
musculature in the compromised TMJ patients
• Seri...
www.indiandentalacademy.com
Emg on lip and cheek activity in
sucking habits
• Ahlgeren –study on lip and cheek activity in
sucking habits
• Profound l...
conclusion
• Role of musculature in malocclusion is very
important
• Facial muscles have various functions that are
equall...
• Emg helps to identify impaired muscle activity in
malocclusion patients compared to normal and
also muscle activity duri...
References
• A text book of clinical neuro physilogy by U K
mishra
• Electromyography and its applications in
orthodontics...
• Int j adult orthodon orthognathic surg 2002
17[4] 307-13
• Orth fr 2000 jan 71 [1] 37-48
• Am j ortho dentofacial orth 1...
ThankThank
youyou
www.indiandentalacademy.com
For more details please visit
www.indiandentalacademy.com
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Emg (2) /certified fixed orthodontic courses by Indian dental academy

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The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.

Indian dental academy provides dental crown & Bridge,rotary endodontics,fixed orthodontics,
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  • An electrical signal is produced in the nerve through a series of chemical events
    The signal propagates along the nerve fiber to the muscle
    Another series of chemical events occur allowing the signal to transfer to the muscle
    The electrical signal commands the muscle to contract
    Muscles are attached to bone via tendons, and thus when the muscle contracts, the bones move through their joints and movement occurs
    Electrodes
    act as sensors to the electrical activity
    Can be surface electrodes, as I have drawn here, or indwelling electrodes are like needles and are inserted into the muscle
    The result is a raw EMG signal that can be processed further into linear envelopes, or used to estimate muscle tension, or undergo fourier analyses to determine frequency information
  • Emg (2) /certified fixed orthodontic courses by Indian dental academy

    1. 1. ElectromyographyElectromyography INDIAN DENTAL ACADEMY Leader in continuing dental education www.indiandentalacademy.com www.indiandentalacademy.com
    2. 2. Contents • Introduction • History • Background of emg/electromyography • Emg defintion • Purpose of emg • Uses of emg • Experimental objectives of emg • Emg types • Emg technique www.indiandentalacademy.com
    3. 3. Continued .. • Emg electrodes • • Precautions • Preparations – After care • Risks • Normal results • Abnormal results • Emg in orthodontics and its applicationswww.indiandentalacademy.com
    4. 4. Introduction • Electromyography is the earliest useful technique in clinical neurophysiology • Emg is a valuable diagnostic aid in recording the muscular activity under diverse functional conditions • Emg changes help in documenting the topography of diseases process by recording electrical activity evoked in a muscle by electrical stimulation of its nerve www.indiandentalacademy.com
    5. 5. History of emg • The most important development in history of study of muscle action potential fallowed the development of sensitive recording equipment • In 1987 cathode ray tube was invented by braun • Einthoven designed string galvanometer in1903 • Cathode ray oscilloscope was invented by gasser and erlanger in 1922-most significant advances as it eliminated limitations of galvanometer • Another major advance in clinical emg came lord adrian and delton blockwho concentric needle electrode in 1929 • Adrian also introduced use of loud speakers in emg www.indiandentalacademy.com
    6. 6. • Hoefer and guttaman in 1944 recorded spontaneous in patients with spinal cord injuries and found it useful in localizing lesions • Denmark reported differences in neurogenic and myogenic emg changes in 1941 • The invest of war injury patients by herburt in canada resulted in in development of monopolar needle electrodes • Interaction of jasper,gold seth and fizell paved the way for development of emg which was introduced in 1948 by goldseth • In1944 harvey and kuffer applied nerve conduction studies in patients in peripheral neuropathy www.indiandentalacademy.com
    7. 7. • The first report of nerve conduction potential in response to median and ulnar nerve stimulation was published in 1937 • Sensory nerve conduction velocity became an integral part of electro diagnostic study by 1960 www.indiandentalacademy.com
    8. 8. www.indiandentalacademy.com
    9. 9. Emg definition • Also called as myogram • Recording and study of intrinsic electrical properties of skeletal muscle by means of surface/needle electrode in resting and contracting states which aids in diagnosis of neuromuscular diseases • Electromyograph is the instrument used in emg • Eletromyogram is record obtained by emg www.indiandentalacademy.com
    10. 10. Back ground of emg • Skeletal muscle performs mechanical work • Stimulated to contract when brain or spinal cord activates motor units • An action potential motor neuron causes activation of muscle fiber • Activation of motor units by action potential generates stochastic voltage signals in muscle www.indiandentalacademy.com
    11. 11. Purpose of emg • determine -A particular muscle is responding to stimulation & whether a muscle remains inactive when not stimulated • Help to diagnosis different diseases causing weakness – a test of motor system ,may help identify abnormalities of nerves/spinal nerve roots that may be associated with pain /numbness www.indiandentalacademy.com
    12. 12. Continued.. • Distinguish b/n primary muscle diseases and dennervation –myopathies from neuropathies • Identify muscle dysfunction and be treated • Asses health of muscles and nerves that control muscles • Differentiates primary muscle conditions from muscles weakness caused by neurological diseases • Emg is a extension of clinical neurological examination www.indiandentalacademy.com
    13. 13. Obtaining an emg • At ,rest when there is no spontaneous muscle activity • During slight muscle contraction - to asses the size, duration of activity of motor units www.indiandentalacademy.com
    14. 14. Emg helps in diagnosis of… • Muscular dystrophy • Congenital myopathies • Metabolic myopathies • Myotonias • Radiculopathies • Peripheral neuropathies • Nerve lesions • Spinal muscular atrophy • myasthenia's www.indiandentalacademy.com
    15. 15. Experimental objectives of emg • To observe,record and correlate motor units recruitment with increase power of skeletal muscle contraction • To record emg when inducing fatigue www.indiandentalacademy.com
    16. 16. Emg types • Kinesiological emg • Diagnostic emg • www.indiandentalacademy.com
    17. 17. • Kinesiological emg • Used for • functional anatomy • force development • reflex contraction of muscle • www.indiandentalacademy.com
    18. 18. • Diagnostic emg • Test the nerve and muscle integrity • Nerve conduction velocity for nerve damage compression • Firing characteristics of motor units, including analysis of motor units action potential - fibrillations, fasciculation and sharp positive waves www.indiandentalacademy.com
    19. 19. Motor unit action potential • Represent sum of the muscle action potentials supplied by anterior horn cell • Muscle fibers discharge in a synchrony adjacent to needle electrodes • MUP-has higher amplitude and longer duration than action potential produced by single muscle fiber www.indiandentalacademy.com
    20. 20. Nerve conduction test Slightly different test is often performed at same time with emg specially helpful - pain / sensory complains www.indiandentalacademy.com
    21. 21. Sharp positive waves • Triphasic pattern a- positive-crossing,b- negative-leaving,c- recording –in a normal muscle • In abnormal muscle-a large positive sharp wave fallowed by low and prolonged negativity www.indiandentalacademy.com
    22. 22. Emg electrodes types-surface and needle • Needle electrode • Superior to as quality of image better • Lesser technical artifact • More risks of infection • May be painful • Surface electrodes • Preferred –non- invasiveness • Chances of loosening of electrodes during nerve stimulation • Errors – • Less of infection www.indiandentalacademy.com
    23. 23. Types of needle electrodes • Concentric • Monopolar • Single fiber • Macro electrode www.indiandentalacademy.com
    24. 24. • Precautions • no special precautions • patient with the history of bleeding disorder • a muscle biopsy is - of the diagnostic work , emg should not be performed at the same site www.indiandentalacademy.com
    25. 25. • Preparations • no special preparations • using creams /lotions on the day of the test • Doctor should give information about symptoms, medical conditions, suspected diagnosis and other test results www.indiandentalacademy.com
    26. 26. Emg recording • It was einthoven muscle contraction gives off an idiomusclular current - action potential • Structural basis of emg is motor unit. • The current generated is so small -amplified many thousands times to be recorded • www.indiandentalacademy.com
    27. 27. www.indiandentalacademy.com
    28. 28. • Electrode hand set • Hand dynamometer • Disposable electrodes Emg accessories www.indiandentalacademy.com
    29. 29. www.indiandentalacademy.com
    30. 30. Emg recording technique • A needle electrode is inserted through skin into muscle. • Recordings -while muscle is at rest – contraction • . displayed as electrical waves on the cathode ray oscilloscope • At same time activity is reproduced as sound over a speaker • the pressure ,size,shape of wave form- action potential-producedwww.indiandentalacademy.com
    31. 31. www.indiandentalacademy.com
    32. 32. www.indiandentalacademy.com
    33. 33. • EMG-raw signal-voltage difference in electrical potential measured b/n record electrodes • Origin-electrical activity –tissues • Important guideline – • Confirm needle position • Emg alone cannot confirm-antagonistic muscle-synergistically www.indiandentalacademy.com
    34. 34. Nerve Muscle Tendon Raw EMG Signal Electrode Electrode Tendon Skin www.indiandentalacademy.com
    35. 35. www.indiandentalacademy.com
    36. 36. • After care • Minor pain &bleeding • Muscle-tender • Risks • no significant risks-needle insertion • Normal results • some brief action • increased in nerve diseases • reduced in long standing muscle disorders • Abnormal results • electrical activity at rest • nerve lesions • myotonia/inflammatory myopathies www.indiandentalacademy.com
    37. 37. EMG in orthodontics • History • 1 st effort apply emg by robert e moyers • observed normal relations of teeth to each other in same jaw and with those of opposite jaw influenced by muscular balance • Muscles relevant –mandibular elevators • masseter, temporalis, medial pterygoid • mandibular depressor • lateral pterygoid • Genioglossus –role in facial morphology • Mentalis orbicularis -importantwww.indiandentalacademy.com
    38. 38. Allen Brodie-if we could learn to control the musculature through critical period of growth, we might be able to expect that in at least a proportion of patients,there would be spontaneous unfolding of development ,that we thought previously must be managed with orthodontic force www.indiandentalacademy.com
    39. 39. EMG its application-orthodontics • Diagnosis-habits-tongue thrusting • lip &cheek activity,sucking habits • swallowing • palsy • Malocclusions-class1 • class2 • class3 • Treatment aspects- myofunctional appliances • activator • twin block • orthognathic surgery • Retention and relapse • Cleft and palate • www.indiandentalacademy.com
    40. 40. EMG activity in class 2 malocclusion patients • Graber –in contrast to cl 1, cl 2 patients-abnormal muscle activity,especially,cl 2div 1 • In cl 2div 2-compensatory muscle activity- posterior fiber –temporalis&masseter • He also added-in cl 3 and cl 2div1maloclussion- problem is –dominant bone dysplasia with adaptive muscle function and tooth irregularity reflecting a severe basal dysplasia www.indiandentalacademy.com
    41. 41. Pancherz analyzed-emg activity in masticatory muscles –cl 2div1 and normal occlusion-maximal biting in centric occlusion and chewing • Maximal biting in centric occlusion • Cl 2-less emg in masseter and temporal than control • Reduction more in masseter • During chewing • Cl 2 – less emg in masseter than controls • Temporalis no difference www.indiandentalacademy.com
    42. 42. High positive-b/n emg activity –maximal biting and chewing for both muscles of 2 groups Impaired muscle activity in cl2 –a diverging dentofacial morphology and unstable occlusal contact conditions Moyers –emg in children with cl2 div1- dysfunction of temporal in habitual occlusion and rest –may be etiological factor-post normal occlusion www.indiandentalacademy.com
    43. 43. www.indiandentalacademy.com
    44. 44. Emg –on cl 3 • It is believed-correction of anterior cross bite-cl3- increased emg –of masseter and temporalis/bilateral improvement of both • Study-deguchi and iwahara-chin cup • reduced masseter activity with no improvement of bilateral co-ordination of both • Reported-integrated emg activity-in cl3 reduced than in normal occlusion • www.indiandentalacademy.com
    45. 45. Emg –on functional appliance therapy • Neuromuscular reaction seen in patients wearing appliance on full time-as ‘pterygoid response;by james.mc namara.jr- begins after few months • During 1 few hrs –no change • Distinct change in muscle activity-few days/weeks- www.indiandentalacademy.com
    46. 46. • Decrease –post temporalis • increase-masseter • significant increase-function- lateral pterygoid • As expt-progressed pterygoid response decreased gradually-pr -appliance level • Results –treatment with oral shields caused a decrease in oro-facial activity during oral function www.indiandentalacademy.com
    47. 47. Lacouture,et,al-action of 3 types functional appliance on activity of masticatory muscles • Used-herbst,twin block,frankel appliance • Study done to ‘lateral pterygoid ‘hypothesis- functional and postural activity of sup and inf heads of lateral pterygoid- increases-appliance placement • Emg activity-decreased- placement of appliance more –lateral pterygoid • Study-did not support hypothesis www.indiandentalacademy.com
    48. 48. • Sessle bj,wood side dg.-univer toronto,canada • Studied –functional appliance-change in postural emg activity of muscle • Showed –decrease in postural activity of sup inf heads of pterygoid,sup masseter and ant digastric-more- lateral pterygoid www.indiandentalacademy.com
    49. 49. www.indiandentalacademy.com
    50. 50. Emg activity-swallowing • Showed characteristic differences-normal and abnormal swallowing • In mature swallow- • During teeth apart swallow- • Winders-study force exerted on dentition by perioral and lingual musculature-swallowing • Concluded –during swallowing buccal and labial musculature do not contract • In tongue thrust swallowing-tongue muscle hypertrophies-,emg activity increases • Emg activity-returns to normal after correction www.indiandentalacademy.com
    51. 51. www.indiandentalacademy.com
    52. 52. Emg in cerebral palsy • Useful in children with cerebral palsy patients • Paralysis/hyper kinetic activity of muscle associated with stomatognathic system www.indiandentalacademy.com
    53. 53. Effect of pain –orthodontic treatment • Effect from archwire jaw muscle is unclear • Goldrich et al evaluated effect-on masseter emg activity • emg activity during function reduced- significantly after treatment started • Shows that orthodontic pain on teeth tend to reduce muscle activity during function www.indiandentalacademy.com
    54. 54. • Negan –assessed muscle pain and emg activity before and after treatment with orthopedic retraction head gear • 800 gm force and 75% of force transmitted to tmj via mandible • No significant increase in muscle activity/muscle pain associated with orthopedic treatment www.indiandentalacademy.com
    55. 55. Emg activity in cleft lip and palate patients • Li et al evaluated- muscle activity in operated unilateral cleft lip and palate • Activity –masseter • higher activation in rest position • Lower potential function • Activity –temporalis • Higher activation • Lower potential of action www.indiandentalacademy.com
    56. 56. • In harmonious activity masticatory muscles during mandibular border movement • Higher asymmetry index of masseter and temporalis www.indiandentalacademy.com
    57. 57. Emg on buccinator activity • In cl 2 div 1 buccinator contracts excessively and hyper active mentalis muscle • Post fibers of temporalis exerts a greater influence in cl2 div 1 than normal • Emg identifies this abnormality www.indiandentalacademy.com
    58. 58. Influence of activator on emg activity of mandibular elevator • Mirallis r burger faculty of medicine-univ of chile • Emg activity record-15 children-cl 2 div1 • Records-anterior temporal and masseter with or without activator in postural rest position during saliva swallowing and maximal clenching • Saliva swallowing-both muscle increased with activator – • Negative correlations-age of children-change of masseter www.indiandentalacademy.com
    59. 59. Muscle response-twin block • Aggarwal p –aims .delhi • Significant increase in activity of masseter and temporalis • Enhanced stretch reflex of activator muscle • Main force-twin block appears through increased active tension in stretched muscle and from initiation of myotactic reflex activity • Importance of full time wear of appliance www.indiandentalacademy.com
    60. 60. Emg study on mand movement – unilateral cleft lip and palate patients- • Saksmoto t ohtsuakak dept of ortho tokoyo japan • Investigate masticatory muscle function • Improvement in masticatory muscle and jaw reflexes after ortho treatment • Influence plastic surgery- causes maxillary retrusion- results skeletal malocclusion • Ortho treatment-designed to compensate malocclusion www.indiandentalacademy.com
    61. 61. Emg – Herbst appliance • Dept of ortho tokoyo medical and dental univ japan • Examine functional muscular adaptation to changes in saggital jaw relation by emg • Activity of lateral pterygoid-increased after wearing appliance –remarkably reduced after 4to 6 hrs These findings indicate multifactorial effect of adaptation of muscle function • Concluded that functional adaptation were not dependent only on only on intensity andwww.indiandentalacademy.com
    62. 62. Emg on post orthodontic stability • J adwt ortodontic orthognathic surgery 2002.17[4]307-13 • To prevent relapse after ortho treat- retention is often considered indispensable • To quantify influence of masticatory muscle on post treatment relapse study was done • Result-emg assessment help in detection of patients who might need a post orthodontic retention www.indiandentalacademy.com
    63. 63. Muscular equilibrium and orthognathic surgery • Evaluate modifications of muscular activity b/n pre surgical and during year after surgery • Decrease in lower facial height-appears to indicate that at rest masseter activity tends to normalize ,temporal increases • Maximal contraction –reduced temporal and masseter activity • Increase in vertical dimension causes a change in muscular tonus depending on associated osteotomy www.indiandentalacademy.com
    64. 64. • Existence of significant modification after surgery often reveals a craniomandibular dysfunction • Emg activity during treatment enables a perfect re –evaluation of these major vertical discrepancies www.indiandentalacademy.com
    65. 65. Surface emg on TMJ • More specifically delineate and define hypertronic musculature in the compromised TMJ patients • Series of test necessary – differentiate diagnosis b/n intra capsular and extra capsular • Surface electrodes • Summary-several studies conducted shows unequivocal evidence to support use of emg for diagnosis of tmj disorders-robert jankelson www.indiandentalacademy.com
    66. 66. www.indiandentalacademy.com
    67. 67. Emg on lip and cheek activity in sucking habits • Ahlgeren –study on lip and cheek activity in sucking habits • Profound lip[perioral] activity-thumb and dummy sucking • Cheek;buccinator] –less evident • Lip and cheek activity –more during dummy sucking than thumb sucking • Activity at rest in perioral muscle-pronounced among thumb sucking • Lip and cheek activity was Less among control group-both at rest and during suckingwww.indiandentalacademy.com
    68. 68. conclusion • Role of musculature in malocclusion is very important • Facial muscles have various functions that are equally important • An emg studies have shown ,even at postural rest position muscles are apparently at function,maintaining a status quo soft tissue and bony elements • Premature occlusal contacts and compensatory muscle activity during active function produces a departure from normal such activities can change bony morphology accentuating the malocclusion www.indiandentalacademy.com
    69. 69. • Emg helps to identify impaired muscle activity in malocclusion patients compared to normal and also muscle activity during various treatment periods and helps to overcome these abnormalities www.indiandentalacademy.com
    70. 70. References • A text book of clinical neuro physilogy by U K mishra • Electromyography and its applications in orthodontics by meenaskhi iyer and ashima valiathan • Am J orthod Dentofacial Orthop 1988 Aug 94 [2] 97-103 • Kokubyo gakki zassgi 1996 mar 63 [1] 18-30 • Dr.joseph f .smith medical library • Am J Orthod dentofacialOrthopedic 1990 sep 98 [3] 222-30 www.indiandentalacademy.com
    71. 71. • Int j adult orthodon orthognathic surg 2002 17[4] 307-13 • Orth fr 2000 jan 71 [1] 37-48 • Am j ortho dentofacial orth 1988 aug 94[2] 97-103am j orthod dentofacial orthp 200 apr 117[4]25a • Medical encyclopedia www.indiandentalacademy.com
    72. 72. ThankThank youyou www.indiandentalacademy.com For more details please visit www.indiandentalacademy.com

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