Temporomansibular joint disorders notes for UG AND PG dental students.
TMJ DISORDERS NOTES
CLASSIFICATION OF THE TMJ DISORDERS:-
1.
DISORDERS
OF THE TMJ:-
a.
DEVIATION
IN FORM:-
i. ARTICULAR SURFACE DEFECTS
ii. DISC THINNING AND PERFORATION
iii. ADHEREHCE AND ADHESIONS
iv. DISC DISPLACMENT
v. DISC DISPLACMENT WITH REDUCTION
vi. DISC DISPLACMENT WITHOUT
REDUCTION
b.
DISPLACMENT
OF DISC – CONDYLE COMPLEX:-
i. HYPERMOBILITY
ii. DISLOCATION
c.
INFLAMMATORY
CONDITIONS:-
i. CAPSULITIS & SYNOVITIS
ii. RETRODISCITIS
d.
DEGENERATIVE
DISORDERS:-
i. OSTEOARTHRITIS
ii. OSTEOARTHROSIS
iii. JUVENILE IDIOPATHIC ARTHRITIS
iv. POLYARTHRITIDES
e.
ANKYLOSIS:-
2.
MASTICATORY
MUSCLE DISORDER:-
a.
ACUTE
CONDITIONS:-
i. REFLEX MUSCLE SPLINTING
ii. MYOSITIS
iii. MUSCLE SPASM
b.
CHRONIC
CONDITIONS:-
i. MYOFACIAL PAIN
ii. HYPERTROPHY
iii. FIBROMYALGIA
3.
CONGENITAL
, DEVELOPMENT AND ACQUIRED DISORDERSOF CONDYLAR PROCESS:-
a.
CONGENITAL
AND DEVELOPMENTAL DISORDERS:-
i. CONDYLAR HYPERPLASIA
ii. CONDYLAR HYPOPLASIA
iii. APLASIA
b.
ACQUIRED
DISORDERS:-
i. NEOPLASMS
ii. FRACTURES
PAIN IN DISC INTERFERENCE DISORDERS:-
·
Pain
in these disorders is mainly from the nociceptors present in the soft tissue
surrounding the joint . i.e. in the retrodicsal tissue, the discal ligaments,
capsular ligaments.
·
Stimulation
of nociceptors occur on compression of these tissues, as a result there will be
a reflex decrease in the movements of associated muscles, i.e decreased
mandibular movements.
·
With
long standing chronic pain the associated muscles go into protective
co-contraction , resulting in decreased muscle movements.
DYSFUNCTION IN DISC INTERFACE DISORDERS:-
·
It
is disruption of normal condyle- disc movements with the production of joint
sounds, or locking of jaw.
·
Joint
sounds:-
o
Click:-
joint sound produced during a single event of short duration.
o
Pop:-
sound little louder than click.
o
Crepitations:-
multiple, rough, gravel like sounds described as grating and complicated.
DISORDERS ASSOCIATED WITH DEVIATION/ ALTERATION IN THE FORM OF ARTICULAR SURFACES:-
·
The
changes can be viewed at condylar fossa and mandibular fossa. They mainly
include condylar head flattening , flattening of glenoid fossa or bony irregularities
over the condylar head , thinning of articular disc borders and perforations
are common changes associated with change in form of disc.
·
Clinical
features:-
o
Usually
asymptomatic,
o
Over
a period of time patient is accustomned to new pattern of opening, so that pain
during movements can be avoided.
o
Occasionally
a click is evident during opening and closing. This click is evident at the
same point during opening and closing movements.-------- characterstic feature. But in other cases like in disc displacement
, the opening click is evident after 20mm of mouth opening and the closing
click is felt just short of occlusion of teeth.
·
Treatment:-
o
Instructing
the patient to develop a path of mandibular movement that avoids the
interference and to chew on the affected side to minimize the intra-articular
pressure on ipsilateral joint.
ARTICULAR DEFECTS:-
·
Disk
thinning and perforation:-
o
Commonly
seen in elderly people due to the disc wear . Other causes include excessive
load from para functional habits such as bruxism, clenching & trauma.
o
The
thinnest intermediate portion of the disc may show circular hole with irregular
or fragmented border exposing the articular surface of the joint.
·
Clinical
features:-
o
Crepitus
and grating sounds on auscultation of tmj.
o
In
the initial stages, only pain will be the major manifestation.
o
As
perforation of disc occurs , alteration in occlusion occurs.
o
Cholitgul
W et al (1990) evaluated 15 patients diagnosed with disc perforation on
arthrography:-
§ 11 patients reported apin
§ 9 patients show deviation of
mandible at maximum mouth opening towards the effected side .
§ All the patients showed clicking
and crepitations.
§ Muscles of the effected side
were tender on palpation.
§ Most disc perforation are
located in the posterior attachments in most joints.
§ Anterior disc displacement
without reduction found in all the members.
·
Radiographic
examination:-
o
MRI
and arthrography for evaluating disc changes.
o
Ct
and traditional imaging for evaluating degenerative changes.
ADHERENCE AND ADHESIONS:-
·
Adherence
means transient adhesion of the articular disc and glenoid fossa(superior joint
space) or articular disc and condylar head(inferior joint space).
·
Prolonged
state of adherence may lead to adhesion. The main cause of adhesion:-
o
Long
periods of static loading of the joint like in bruxism during sleep.
o
Trauma
causing heamarthrosis in the joint.
o
Surgery.
·
Normally
during compressioin weeping lubrication will be exhausted and boundary
lubrication will come into action. But during prolonged periods of static load,
even boundary lubrication is not sufficient resulting in adherence.
·
Clinical
features:-
o
Stiff
jaw
o
Dull
aching pain,
o
Limited
mouth opening characteristically corrects following a single click, when the
patient tries to open his mouth fully.
o
In
adhesion due to elongation of collateral discal ligament and and anterior
capsular ligament , the articular disc is placed posterior to condyle during
translator motion.---posterior disc displacement.
o
Disc
– superior joint space adhesion:- only
rotator movement of the condyle is permitted, i.e patient can open only upto 25
mm.
o
Disc—inferior
joint space adhesion:- only translator movements of the condyle are permitted ,
i.e pt can open mouth to full extent , but experiences a jerk , or limitation
when trying to open mouth to full extent.
DISC DISPLACEMENT:-
·
It
is also called internal derangement.
·
2
types:- disc displacement with reduction and disc displacement without
reduction.
·
Anterior
disc displacement
:-
o
Common.
o
Occurs
when there is:-
§ elongation of disc attachments
§ Deformation / thinning of
posterior border of disc causing the disc to be displaced anteriorly.
o
In
normal conditions the posterior band of disc ends at the apex of condyle, but in
anterior disc displacement the posterior band of disc terminates a head of the
condyle.
·
Causes
of disc displacement:-
o
Trauma
o
Clenching
and biting on hard substances.
·
Disc
displacement with reduction:-
o
While
opening the mouth there will be anterior or anteromedial displacement of disc.
o
While
closing the disc returns to its normal position relative to condyle.
o
Clinical
features:-
§ Clicking sounds during
mandibular opening and closing
§ Opening slick heard during
translator phase of mandibular opening .
§ Closing click heard as the disc again becomes displaced .
§ Mandible deviated to effected
side.
§ Joint tenderness and limited
opening due to muscle splinting.
· Disc displacement without reduction:-
o
The
condyle is unable to pass under the displaced disc at any stage of its
movement.
o
Causes:-
§ Thickening of the posterior band
of the disc
§ Change in the shape of the disc
from biconcave to biconvex.
§ Decrease in tension in posterior
attachment.
o
Clinical
features:-
§ Trapping of disc infront of
condyle.
§ Limitation of the condylar
trasition resulting in closed lock.
§ Inflammation of articular
capsule, discal ligaments and posterior attachments.
§ Severe limitation in mouth
opening – max 25-30mm.
§ Limitation of protrusive
movement
§ Mandible deviated to effected
side while opening.
§ Joint crepitus observed.
·
HYPERMOBILITY
AND DISLOCATION (DISPLACMENT OF DISC- CONDYLE COMPLEX):-
o HYPERMOBILITY/ SUBLUXATION/ PARTIAL DISC DISLOCATION:-
In the terminal phase of translator
cycle , the condyle moves past the articular eminence and suddenly moves
forward to facilitate a wide mouth opening called as hypermobility / partial
disc dislocation. This may occur due to joint laxity that may be seen in:-
§ Ehler-Danlos syndrome,
§ prolonged
and excessive mouth opening during dental procedures,
§ excessive yawning,
§ during endotracheal intubation.
o
Clinical
features:-
§ This sudden forward movement
seen here can be felt as a “thud sound”, which is painless. But in chronic
conditions it becomes painful.
§ Hypermobility can be
distinguished form anterior disc displacement :-
·
Click
is associated only while opening and is absent during closing.
o DISLOCATION (OPEN LOCK):-
Dislocation is iability to close
the mouth with or without pain. Subluxation is a self reducable condition, but
dislocation is not.
o
when
the mouth is open in normal patients the articular eminence stops further
anterior movement of the condyle. But when there is laxity in the joint , the
condyle may move anterior to the articular eminence , which cannot be reduced
by the patient himself. This condition is called dislocation.
o
Anterior
dislocation is the most common.
o
Predisposing
factors:-
§ Muscle fatigue
§ Muscle spasm
§ Defect in the bony surface like
shallow articular eminence
§ Laxity of capsular ligament
§ Patients with collagen synthesis
disorders like Ehlers- Danlos syndrome, Marfan’s syndrome.
o
Clinical
features:-
§ Inability to close the mouth
after wide opening. This is mainly due to the spasm of the masticatory muscles.
§ Typical facial expression
(elongated face) with anxiety is evident in the pt’s face.
§ Bilateral dislocation is more
common than unilateral.
§ In unilateral dislocation chin
is dislocated to contra lateral side.
§ Palpation in preauricular fossa
:-
·
Empty
joint space
·
Condyle
placed anterior to joint space.
o
Types
of dislocation:-
§ Heslop 1956:-
·
Anterior
dislocation:- condyle moves anterior to articular eminence. Most common.
§ Morris and Hutton 1957:-
·
Anterio-lateral
varient
§ Helmy 1957:-
·
Posterior
variant:- head of the condyle displaced posterior to its usual position
.commonly seen incases of :-
o
Fracture
of base of skull
o
Fracture
of anterior wall of bony meatus.
§ Allen and Young 1969:-
·
Lateral
dislocation:- sub classiefied as:-
o
Type
1:- lateral subluxation
o
Type
2:- complete lateral dislocation, where condyle is forced laterally and
superiorly to the temporal fossa.
·
Commonly
seen in :-
o
Fractures
of body of mandible at symphysis.
§ Zecha 1977:-
·
Superior
dislocation:-
o
Dislocation
of condyle into middle cranial fossa and associated with fracture of glenoid
fossa. This mainly occurs due to the small round shape of the condye.
INFLAMMATORY JOINT DISORDER:-
·
Synovitis
or Capsulitis:-
o
Synovitis
refers to inflammation of synovial tissues.
o
Capsulitis refers to inflammation of capsular ligament .
o
Causes:-
§ Trauma
§ Opening of mouth excessively
§ Chronic condylar displacement in
posterior direction
§ Direct spread of inflammatory
products from the surrounding structures.
o
Clinical
features:-
§ Continuous pain exerbates during
the entire period of function.
§ Limitations in the jaw movement
§ Malocclusion in the posterior
teeth due to inferior displacement of the condyle resulting from edema.
· Retrodiscitis:-
o
Inflammation
of the retrodiscal tissue due to trauma which indirectly causes condylar head
to impinge upon retrodiscal tissue. This may further lead to chronic disc
displacements and dislocation.
o
Clinical
features:-
§ Forward and downward placement
of the condyle, producing a same sided malocclusion of the posterior teeth and
heavy contact in the anterior teeth of the opposite side.
§ Continuous pain in the TMJ
region which exerbates upon clenching.
o
Treatment:-
§ Patient is adviced to chew on
the effected side as this will relieve ocllusal load on the affected side
thereby hastens the healing process.
DEGENERATIVE JOINT DISORDERS:-
· OSTEOARTHROSIS:-
o
Osteoarthrosis
is a painless, non inflammatory
degenerative disorder affecting articular tissues and subchondral bone.
o
Excessive
load on TMJ may produce degeneration of fibrous articular tissue covering the
condyle.It occurs secondary to displacement of disk.
o
Clinical
features:-
§ Restricted movement of the
mandible
§ Mandible difflected towards the
effected side while opening.
§ Crepitus sounds during opening
and closing revealed during auscultation.
§ Prolonged periods of
osteoarthrosis may produce multiple cystic areas in medullary region of the
condyle, which finally lead to formation of erosive areas on condyle changing
the morphology of the condyle.
§ Some authors consider it as a
resolved phase of osteoarthritis.
o
Management:-
§ Correction of occlusal
irregularities to prevent tmj overloading.
· OSTEOARTHRITIS:-
o
Osteoarthritis
is a painful inflammatory disorder secondary to TMJ synovial inflammation.
o
Commonly
seen in elderly women. Gradual in onset, and is a self limiting , i.e. symptoms
subside over a period of time, and TMJ movement s revert back to mormal.
o
Clinical
features;-
§ In early stages:-
·
Pain
exerbates upon function and relieved by rest.
§ In later stages:-
·
Pain
present even at rest.
§ Stiff TMJ early in the morning.
§ Exerbated pain during cold
climatic conditions.
§ Limited range of movement.
§ Deviation of the mandible to the
affected side.
§ Anterior open bite
§ Crepitus, myositis, masticatory
muscle spasm.
o
Radiographic
features:-
§ Reduction in the space of the
joint / total lack of space
§ Flattened condylar head
§ Erosion on the articular surface
§ Subchondral sclerosis and
osteophytes.
§ Joint mice/ loose bodies:-
·
Osteophytes
beakoff and lie in joint space. MRI examination and arthrography can notice
these bodies as joint mice/ loose bodies.
§ Ely cyst:-
·
Subchondral
bony cyst in the condyle. They represent areas of degeneration containing
fibrous tissue and osteoid.
§ Erosion of the posterior slope
of the articular eminence and enlargement of glenoid fossa.
· JUVINILE IDIOPATHIC ARTHRITIS:-
o
Chronic
inflammatory systemic disease typically stating before 16 years of age. An
immunoinflammatory pathogensis is considered as etiology.
o
One
or more joints may be effected.
o
3
subtypes classified stating fron the
onset to first 6 months:-
§ Oligoarticular:- 4 or few joints
involved.
§ Poly articular :-five or more
joints involved.
§ Systemic:- presence of arthritis
and severe systemic involvement.
o
Clinical
features:-
§ Peripheral arthritis
§ Chronic synovitis
§ Arthralgia
§ Impaired joint mobility
§ Pain and joint sounds during
function
§ Micrognathia, retrognathia,
facial asymmetry and anterior open bite
§ Fever, rheumatoid rash, cardiac
disease, chronic uveitis.
· POLYARTHRITIDES:-
o
A
group of disorders characterized by inflammation of articular surfaces of the
joint.
o
It
is almost similar to osteoarthritis:-
§ Degenerative changes in
articular cartilage and underlying bone.
§ Inflammation of capsule and
synovial tissue.
o
Clinical
features:-
§ Tenderness on TMJ palpation.
§ Swelling and erythema in TMJ
region.
§ Limited function of mandible.
§ ** crepitus** characterstic finding
§ Symptoms may aggrevate upon para
functional habits.
o
Radiographic
examination:-
§ Surface changes in glenoid fossa
and flattening of the articular eminence.
· TRAUMATIC ARTHRITIS:-
o
Trauma
can be the etiological factor leading to articular surface changes.
o
Restricted
mouth opening and pain.
o
A
soft end feel evident on palpation.
· INFECTIOUS ARTHRITIS/ SEPTIC ARTHRITIS:-
o
Seen
in patients with previously existing joint diseases or with underlying systemic
illness
o
Causes:-.
§ Commonly seen in individuals on
longterm immunosuppressive drugs and corticosteroids.
§ Sterile articular surfaces get
infected secondary to blood borne bacterial infections or extensions of the
infections from adjoining sites such as molar teeth , middle ear, and parotid
gland.
o
Symptoms:-
§ Constant pain in tmj region
which aggrevates with function.
§ Swelling, tenderness and raise
in local temperature.
§ Limitation of mouth opening
§ Deviation of jaw to the effected
side.
§ Tender cervical lymphadenopathy
on the effected side.
o
Diagnosis:-
§ Synovial fluid examinationa ,
and blood studies
§ Common organism present in
infectious arthritis arising from sterile joint inclue gonococcal species.
§ Common organism present in
infectious arthritis arising from arthritis may include staphylococcus.
o
Complications:-
§ Brain abscess
§ Ankylosis and osteomyelitis of
temporal bone.
§ Ankylosis and facial asymmetry
are common complications in children.
· RHEUMATOID ARTHRITIS;-
o
Chronic
inflammatory autoimmune disorder which may involve many of the diarthroidal
joints (usually in symmetrical fashion) in the body characterized by persistent
synovitis.
o
Onset
age- 25 – 55 years
o
More
common in women.
o
Pathogenisis:-
§ Inflammation of the synovial
membrane extends into the surrounding connective tissue and articular surfaces
which then becomes thickened and tender.
§ The cells of the synovial
membrane express enzymes that cause destruction of articular surface eventually
leading to fibrous ankylosis.
§ Histologically there will be
reactive macrophage laden fibroblastic proliferation from the synovium that
exends to the joint surface which is called PANNUS.
o
Clinical
features:-
§ Pain, joint stiffness, limited
mouth opening, joint sounds, open bite.
§ TMJ involvement in RA cases is
almost 4.7% to 88%.
o
Diagnosis:- AMERICAN RHEUMATOID ASSOCIATION (1987) ;
(patient must have any 3-4 symptoms for a minimum period of 6 months)
§ Morning stiffness more than one
hour.
§ Arthritis in 3 or more joints
§ Arthritis in hands
§ Symmetrical arthritis
§ Rheumatoid nodes
§ Presence of rheumatic factor
§ Radiographic alterations
o
Laboratory
investigations:-
§ Rheumatoid factor estimation
§ ESR
§ C- reactive protein’
§ Thrombocyte count
§ Plasma tumor necrosis factor α
o
Radiographic
features:-
§ Generalized decreased
density of bone
§ Severe erosion of the
condylar head (occasionally only the neck of the condyle may be remaining)
§ Subchondral sclerosis
§ Flattening of the condylar head
§ Subchondral cysts
§ Osteophytes formation
§ Pencil shaped condyle in some
cases due to erosion of anterior and posterior condylar surfaces.
o
Modified
TMJ grading system based on degree of destruction of condyle:-
§ Grade0:- (normal) well defined
corticated outline of the condyle
§ Grade 1:- (mild) presence of
cortical destruction and irregular margins of the condyle
§ Grade 2 :- (moderate) bony
destruction or erosion of the condyle or evident flattening of the condyle with
deviation from normal joint morphology.
§ Grade 3:- (severe) complete or
almost complete destruction of the condyle.
· PSORIATIC ARTHRITIS:-
o
Psoriatic
arthritis present in 5-7% of psoriatic patients.
o
Diagnosis
is made by the presence of erosive polyarthritis with negative rheumatoid
factor. Psoriatic skin lesions are seen long before TMJ is effected.
o
Commonly
effects fingers, spine along with TMJ. Common presentation of pitting of nails
is present.
o
Clinical
features:-
§ RA is bilateral, but psoriatic
arthritis is unilateral.
§ Pain over TMJ , limited
mandibular movement, deviation of mandible to the effected side.
§ Radiographically similar changes
like RA, in some cases more extensive presentation.
· HYPERURECEMIA:-
o
It
is a true crystal deposition disease.
o
It
is the pathological respose of periarticular tissue to the presence of
Monosodium Urate Monohydrate crystals.
o
Gout
commonly effects the 1st metatarsophalangeal joint,and other joints
like ankle, knee, wrist, elbow and TMJ.
o
Clinical
features:-
§ Crystal deposition in tissues
adjacent to TMJ.
§ Presence of Mono sodium urate
crystals in synovial fluid aspirate.
· TMJ ANKYLOSIS:-
o
Ankylosis
is an intraarticular condition where there is fusion between the bony surface
of the joint , the condyle and the glenoid fossa.
o
Ankylosis
in greek terminology:- stiffening of the joint as a result of disease process.
o
It
may be of osseous type, fibro-osseous type, cartilaginous type.
o
Pseudo
ankylosis is hypomobilty of the joint due to coronoid hyperplasia, fibrous
adhesion between coronoid process and maxillary tuberosity. In these cases
pathology is extra articular., but in ankylosis the pathology is intra
articular.
o
Causes:-
§ Condylar injuries sustained
before 10 years of age. Common in children.
§ Condylar cortical bone is thin
in children with broad condylar neck with thick subarticular interconnecting
vascular plexus.
§ Intraarticular fracture leads
to heamarthrosis and comminution of
condylar head.. this type of fracture is called mushroom fracture.
§ It results in formation of
fibroosseous mass with high osteogenic environment.
§ Immobility after trauma may also
cause consolidation and ankylosis formation.
§ Forceps delivary
§ Local infections like otitis
media, mastoiditis, osteomyelitis of temporal bone , parotid abscess.
§ Systemic conditions like
tuberculosis, meningitis, rubella , varicella, scarlet fever, ankylosing
spondylitis through heamatogenous soread.
§ Common organisms to cause septic
arthritis:-
o
Staphylococcus,
streptococcus, hemophilus, neisseria gonorrhea.
o
All
these organisms spread through heamatogenous spread due to high vascularity of
the synovium.
·
Juvenile
RA (stills disease) and osteoarthritis may lead to ankylosis.
·
Osteoma,
sarcoma and chondroma may lead to degenerative
and destructive changes in the disc leading to ankylosis in regenerative
process.
§ Laskin 1978 propsed etiologies:-
·
Young
patients have high osteogenic potential and underdeveloped articular capsule
resulting in easy condylar displacement and disk damage.
·
Prolonged
self imposed immobilization of the mandible posttraumatically by children.
·
Intracapsular
fracture are more common in children due to broad condylar neck.
·
Direct
contact of the condyle to the glenoid fossa due to displacement or torn
meniscus may lead to ankylosis.
·
Total
immobility between articular surfaces may lead to bony fusion, slight movement
may lead to fibrous fusion.
o
Classification
of ankylosis:-
§ Based on tissues involved:-
·
True - pseudo ankylosis
·
Extra - intra articular
·
Fibrous-
bony – fibro osseous
·
Unilateral
– bilateral
·
Partial
and complete
§ Topazian 1966:-
·
Type
1:- fibrous adhesion --- restricted condylar gliding
·
Thpe
II :- bony bridge between condyle and glenoid fossa
·
Type
III:- ankylosis of condylar neck to fossa completely
§ Sawhney 1986:-
·
Type
I:-
o
Flatenning
of the condyle
o
Little
joint space
o
Minimal
bony fusion, but extensive fibrous adhesion
o
Some
movement is possible
o
Commonly
seen in crushing type of condylar injury
·
Type
II:-
o
Bony
fusion on the outer edge of the articular surface, but no fusion in deeper
aspects.
o
Seen
in crushing type of injuries
·
Type
III:-
o
A
bridge of bone exists between ramus and zygomatic arch.
o
A
medially displaced atrophic , but still functional condyle will be present.
o
Intact
positions of upper articular surface and articular disc in deeper portions.
o
Commonly
seen in displaced condyles due to fracture.
·
Type
IV :-
o
Total
TMJ obliteration between ramus and skull by large bone mass.
o
Clinical
features :-
§ Unilateral ankylosis:-
·
Facial
features:-
o
Facial
asymmetry
o
Receded
chin, hypoplastic mandible
o
Deviation
of chin and mandible to the effected side
o
Unilateral
vertical deficiency on effected side
o
Roundness
and fullness on effected side
o
Loss
of bilateral symmetrical divergence from mental region to angle of mandible.
o
Well
defined antegonial notch.
o
Markedly
elongated coronoid process.
·
Intra
oral features:-
o
Deviation
of midlines of maxilla and mandible to the effected side.
o
Class
II malocclusion on effected side
o
Unilateral
cross bite in opposite side
o
Restricted
mouth opening
§ Bilateral ankylosis:-
·
Facial
features:-
o
Retrognathic
mandible, micrognathia
o
Microgenia/
small chin
o
Bird
face deformity / andy gump facies
o
Convex
profile
o
Cervicomental
angle reduced/ absent
·
Intra
oral features:-
o
Mouth
opening < 5mm to nil
o
Commonly
Class II malcosslucion
o
Incompetent
lips, proclined lower anteriors
o
Anterior
open bite
o
Severe
crowing, anteriorly place upper and lower maxillary and mandibular teeth.
§ Intra articular ankylosis:-
·
Both
rotatory and translator movements are restricted
§ Extra articular ankylosis:-
·
Most
of times rotator movement is only restricted.
o
Radiographic
appearance:-
§ In fibrous ankylosis:-
·
joint appears normal, irregular articulating
surfaces.
·
Joint
space markedly decreased.
§ In bony ankylosis:-
·
Joint
space obliterated
·
Deepening
of antegonial notch
·
Compensatory
elongation of coronoid process on the effected side.
o
Management;-
o
Goals
of mangment:-
§ Restoration of mouth opening,
joint function
§ Facilitation of condylar growth
§ Correction of facial profile
o
Surgical
correction of ankylosis
§ Condylectomy
§ Gap arthroplasty
§ Coronoidectomy
§ Interpositional arthroplasty
with autogenous and allogenous grafts
§ Orthognathic surgery
MASTICATORY MUSCLE DISORDERS:-
· ACUTE DISORDERS:-
o
REFLEX
MUSCLE SPLINTING / PROACTIVE CO-CONTRACTION:-
§ It is CNS response to actual
tissue injury/ a threat of injury, so that the tissue muscle activity is
modified to protect from insult.
§ Causes:-
·
High
points in FPD, CD
·
Biting
on hard substances
§ Clinical features:-
·
Muscle
weakness following tissue injury
·
Pain
only during function
·
Limited
mouth opening which can improve when the patient attempts to open gently
·
Effected
muscle may feel tight or stretched on palpation.
§ Management:-
·
Removal
of cause
·
Resting
the muscle
·
Moist
heat fermentation
·
Muscle
relaxants for a short period of time.
o
MYOSITIS:-
§ Inflammation of a muscle due to
a local response.
§ Causes:-
·
Trauma
·
Muscular
strain
·
Oro
dental infections
·
Longstanding
severe and neglected muscle splinting and myospasm.
§ Clinical features:-
·
Painful
muscle associated with swelling
·
Pain
exerbates on function
·
Muscular
dysfunction
§ Untreated myositis lead to
myofibrotic contracture.
o
MYOSPASM:-
§ Myospasm of muscles of
mastication are uncommon.
§ It is a CNS induced tonic
contraction
§ here all the motor units of the
effected muscle may contract resulting in shortening of the muscle length
leading to acute spasm.
§ Causes;-
·
Muscle
fatigue
·
Alteration
in local electrolyte balance
·
Deep
pain
·
Usage
of tranquilizers.
§ Clinical features:-
·
Limited
mouth opening
·
Dull
and continuous pain with occasional periods of acute pain.
·
Pain
referred to face, temple, and ear
·
Malocclusion
§ Management:-
·
Analgesics
·
Moist
heat fermentation
·
Local
anesthetic without vasoconstrictor.
·
Occlusal
bite gaurds
· CHRONIC DISORDERS:-
o
MYOFACIAL
PAIN:-
§ Costen - 1934:-
·
First
describe TMJ pain dysfunction syndrome which included facial and head pain and TMJ
dysfunction.
§ Laskin – 1969:-
·
Coined
the term myofacial pain dysfunction syndrome.
§ Myofacial pain can arise from
anywhere in the skeletal muscles such as head, neck, lower back, shoulders.
§ Pathogensis:-
·
Earlier
thought to arise from TRP . TPR are minute sensitive areas in a muscle that
spontaneously or upon compression cause pain to a distant region , known as
Referred Pain zone.
·
Recent
studies revealed pain from taut bands with TRP or tender spots. Taut bands are
group of muscle fibres that are hard and tender on palpation. Tender spots are
specific sites of localized pain. The muscles will be in spasm with increased tension and decreased
flexibility.
·
Etiological
factors cause release of Acetyle choline at motor endplates , leading to
sustained muscle contraction. As a result local ischemia may occur . it causes
release of vascular and neuroactive substances leading to the production of
muscle pain.
·
Muscle
pain inturn causes release of Acetyl
choline, which further increases pain and muscle spasm.
·
Prolonged
periods of this condition may lead to muscle fibrosis.
§ Etiology:-
·
Acute
muscular injury as a result of macro trauma.
·
Sudden
wide mouth opening
·
Injuries
due to bad posture causing sustained state of muscle contraction
·
Bruxism
§ Clinical features:-
·
Unilateral
dull pain in the ear or preauricular region that is worse on aweking.
·
Tenderness
in muscle of mastication.
·
Limitation
and deviation of mandible.
·
Primary
features:-
o
Pain
in one or more muscles of mastication.
o
Tenderness
of muscle on palpation.
o
Referred
pain in other orofacial areas.
o
Acute
malocclusion.
·
Secondary
features:-
o
Restricted
range of movement, but can open to some extent upon assistence.
o
Increased
range of movements upon usage of vapocoolents.
o
Limited
function.
·
Other
findings:-
o
TMJ
pain
o
Joint
sounds
o
Inflammation
o
Hypertrophy
o
Myalgia
secondary to systemic disease.
§ Referral pattern in myofacial
pain:-
·
Medial
pterygoid:-
o
Pain
referred to posterior part of mouth, throat, TMJ
·
Lateral
pterygoid:-
o
Inferior
head refers pain to TMJ
o
Superior
head refers pain to Zygomatic area.
·
Masseter:-
o
Referd
pain to posterior mandible and maxillary
teeth, ear, TMJ.
·
Temporalis:-
o
Maxillary
teeth, and upper portion of face.
§ Management:-
·
Short
term aim targeted at removing taut bands (TB), TRP, tender spots(TS).
·
Longterm
aim targeted at achieving muscle flexibility and eliminating precipitating
factors.
·
Councelling
the patient about the nature of pain and discontinuing any parafunctional
habits.
·
Moist
heat application increases blood flow and vascularity, decreasing formation of
fibrosis and inflammation.
·
Trigger
point theraphy:-
o
Spray
and stretch technique:-refregerent spray such as ethyl alcohol or fluromethane
sprayed on stretched skin surface from a distance of 18 inches at an angle of
300 .
o
Local
injection technique:- 0.5% procaine without epinephrine can be injected into
trigger points.
·
Medication:-
o
NSAIDS,
skeletal muscle relaxants (methocarbomol).
o
Anxiety
patients adviced 2mg of carbamazepine thrice daily for 2 weeks.
·
Occlusal
splint:-
o
Helps
in maintaining harmonious relation between TMJ and muscles. Also helps in
resolution of micro trauma to muscle.
·
TENS
(transcutaneous electric nerve stimulation):_
o
TENS
temporarily activzates efferent nerves causing modification in pain. The
impulses generated have a duration of 2ms with an interval of 0.5 to 1.5 sec.
The operating voltage is 4 volts.
o
Rythemic
contractions produced by TENS in muscle increase blood supply, Electrical
stimulation inhibits pain transmission..
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