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Pooja kaloniya
48/2009
TEMPOROMANDIBULAR JOINT
THE TEMPOROMANDIBULAR JOINT IS ALSO KNOWN AS THE CRANIOMANDIBULAR JOINT or BILATERAL DIARTHROIDIAL.
IT IS THE ARTICULATION BETWEEN THE SQUAMOUS PART OF THE TEMPORAL BONE AND THE HEAD OF THE MANDIBULAR CONDYLE.
IT IS ALSO CONSIDERED AS COMPLEX JOINT BECAUSE IT INVOLVES TWO SEPARTE SYNOVIAL JOINT, IN WHICH THERE IS A PRESENCE OF INTRACAPSULAR DISC OR MENISCUS.
ANATOMY
THE TMJ ARTICULATION CONSIST OF:GLENOID FOSSAARTICULAR
EMINENCECONDLYESEPARATING DISCJOINT FIBROUS
CAPSULEEXTRACAPSULAR
LIGAMENTS
ARTICULATORY SYSTEMCOMPRISES OF
Temporomandibular joint
Masticatory and accessory muscles
Occlusion of teeth
The function is governed by sensory and motor branches of the third division of trigeminal nerve.
MANDIBULAR FOSSA(GLENOID) IT HAS AN ANTERIOR ARTICULAR AREA BY THE
INFERIOR ASPECT OF TEMPORAL SQUAMA. THE FOSSA IS LINED BY A DENSE AVASCULAR
FIBROCARTILAGE.
ARTICULAR EMINENCE IT SEPARATES THE ARTICULAR SURFACE OF THE
FOSSA LATERALLY FROM THE TYMPANIC PLATE. THE EMINENCE IS COVERED BY DENSE, COMPCT,
FIBROUS TISSUE THAT CONSISTS PRIMARILY OF COLLEGEN WITH AFEW FINE ELASTIC FIBERS
TMJ CAPSULE IT IS A THIN SLEEVE OF FIBROUS TISSUE INVESTING
THE JOINT COMPLETY IT IS A FUNNEL SHAPED CAPSULE,WHICH BLENDS
WITH THE PERIOSTEUM OF THE MANDIBULAR NECK AND ENVELOPS THE MENISCUS
IT REINFORCE THE TMJ CAPSULE IT EXTENDS DOWNWARD & BACKWARD FROM THE
ARTICULAR EMINENCE TO THE EXTERNAL AND POSTERIOR SIDE OF THE CONDYLAR NECK
ITS POSTERIOR FIBER ARE UNITED WITH THE CAPSULAR FIBERS
THIS LIGAMENT IS COMPOSED OF COLLAGENOUS FIBERS THAT HAVE SEPIFIC LENGTH AND POOR ABILITY TO STRETCH, HENCE IT MAINTAINS THE INTEGRITY AND LIMITS THE MOVEMENT OF TMJ
IT MAINLY LIMITS THE ANTERIOR EXCURSION OF THE JAW AS WELLAS PREVENTS POSTERIOR DISLOCATON , ALSO CALLED CHECK LIGAMENT.
TEMPOROMANDIBULAR LIGAMENTS
SPHENOMANDIBULAR LIGAMENT A FLAT BAND
ARISING FROM THE APHENOID SPINE AND PETROTYMPANIC FISSURE, RUNS DOWNWARDS AND MEDIAL TO THE TMJ
INTERNAL MAXILLARY ARTERY AND AURICULOTEMPORAL NERVE LIES B/W IT AND MANDIBULAR NECK
STYLOMANDIBULAR LIGAMENTIT IS DENCE THICK BAND OF THE DEEP CERVICIVAL FASIA EXTENDING FROM THE STYLOID PROCESS TO THE MANDIBULAR ANGLE.
THE MENISCUS DIVIDES THE TWO ARTICULAR SPACE INTO TWO COMPARTMENT LOWER OR INFERIOR COMPARTMENT- condylodiscal
complex b/w the condyle and the disc UPPER OR SUPERIOR COMPARTMENT – b/w disc and the
glenoid fossa.The disc is biconcave in the sagital section.The superior surface is concavoconvex to match the
anatomy of the glenoid fossa.The inferior surface is concave to fit over condylar headThe disc blends medially and laterally with the capsule,
which is attached to the medial and lateral poles of the condyle.
Anteriorly the disc is attached to the articular eminence above & to the articular margin of the condyle below.
Posteriorly disc is attached to the posterior wall of glenoid fossa
ARTIULAR DISC/ MENISCUS
The disc is a meshwork of firmly woven avascular fibrous connective tissue & it is also noninnervated with possible exceptions around its periphery.
These collagen fibers impart flexibility to the disc.
The disc is designed to transmit the forces generated through the condyle to the articular eminence.
It promotes lubrication energy absorption and joint range of motion. It acts as a main shock absorber enabling the articulating bones to move against each other with minimum friction and heat production.
Disc has Avery little potential for repair after inult.
Lateral aspect is supplied by superfical temporal branch of the external caroid artery.
Rich vascular supply to the deep and posterior aspect of retrodiscal capsular part by deep auricular, posterior auricular & masseteric branches of the internal maxillary artery
Vascular supply to the lateral pterygoid muscle also supplies to the head of the condyle by penetration of numerous nutrient foramina vessels
Blood supply
THE MANDIBULAR NERVE, THE THIRD DIVISION OF THE FIFTH CRANIAL NERVE INNERVATES THE JAW JOINTS:-The largest is the
auriculotemporal nerve which supplies the posterior, medial and lateral part of the joint
Masseteric nerveA branch from the
posterior deep temporal nerve, supply the anterior parts of the joint
Nerve supply
The movements of tmj are manifold. It is ginglimus diarthroidai type of joint, as it sis capable of rotating around more than one axis and is capable of translatory movement.
MUSCLE FUNCTION- The functions of the muscles of mastication in jaw movement are coordinated and balanced by normal muscle tone.
The muscle of mastication (medial and lateral pterigoid,masseter, buccinator, mylohyoid, temporalis & anterior belly of the digastric) are assisted by the suprahyoid and digastric muscle.
MOVEMENTS
JAW OPENING It is dominated by daigastric muscle contraction, which depress the body of the mandible. This action is assisted by the suprahyoid, sternohyoid and geniohyoid muscles.
JAW CLOSURE It is accomplished by the simultaneous contraction of the masseter, medial pterigoid muscles.
PROTRUSIVE MOVEMENT It requires equal simultaneous contracture of lateral and medial pterygoid muscle.
RETRUSION It is brought about by posterior fibers of temporalis muscles, assisted by middle and deep parts of the masseter, digastric and geniohyoid muscles.
LATERAL MOVEMENT These are carried out by unilateral contracture of medial and lateral pterygoid of each side acting alternatively.
TEMPOROMANDIBULAR JOINT DISORDERS CLASSIFICATION
Intra –articular origin or intrinsic disorderExtra –articular origin or extrinsic disorder
MASTICATORY MUSCLE DISORDERProtective muscle splintingMasticatory muscle inflamationMasticatory muscle spasm
PROBLEMS DAT RESULT FROM EXTRINSIC TRAUMATraumatic arthritisFractureInternal disc derangementTendonitisContracture of elevator muscle
DISORDER DUE TO EXTRINSIC FACTORS
TRAUMADislocation, subluxationHaemarthrosisIntracapsular fracture, extracapsular fracture
INTERNAL DISC DISPLACEMENTAnterior disc displacement with reductionAnterior disc displacement without reduction
ARTHRITISOsteoarthritisRheumatoid arthritisJuvenile rheumatoid arthritisInfectious arthritis
DISORDER DUE TO INTRINSIC FACTORS
DEVELOPMENTAL DEFECTSCondylar agenesis or aplasia-
unilateral/bilateral Bifid condyle Condylar hypoplasiaCondylar hyperplasia
ANKYLOSISNEOPLASM
Benign tumoursMalignant tumours
Surgical access to the tmj is an exacting procedure.
Tmj has got close proximity to the main trunk of the facial nerve with its branches in the temporal and
facial areas
It has also got close proximity to the auriculotemporal nerve and the abundant vascular
supply
SURGICAL APPROACHES TO MANDIBULAR
CONDYLE AND ITS NECK
ADVANTAGESUniform predictability of anatomic exposure &
avoidance of a salivary fistula.Negligible hemorrageNo distortion of anatomic landmarks
DISADVANTAGESInfection involving the external auditory canalParesthesis of the external pinnaSmall surgical exposure with poor access and
visibility
POSTAURICULAR APPROACH
POST/ RETRO AURICULAR
ADVANTAGESExcellent cosmesisExcellent lateral and posterior exposure with
intermediate anterior exposureDIADVANTAGES
Limited accessPossibility of meatal stenosis
ENDAURAL APPROACH
ADVANTAGESExcellent cosmesisExcellent visibility and accessibility
DISADVANTAGESClose proximity of the posterior facial vein and
trunk of the facial nerveProximity of the posterior border of the parotid
glandIdeal approach to the condyle neck and ramus
POSTRAMAL(HIND) APPROACH
ADVANTAGESInconspicuous location of the incisionStandard approach to the TMJ
DISADVANTAGESThe dissection follows a route through an area
which is rice in nerve and vascular supply.
BLAIR AND IVY INCISIONTHOMA;S ANGULATED INCISIONAL- KAYAT AND BRAMLEY
PREAURICULAR APPROACH
PREAURICULAR INCISION
Blair’s Inverted Hockey Stick
Incision
Thoma’s Angulated Incision
Dingman’s Incision
Popowich & Crane Incision
PREAURICULAR INCISION
ADVANTAGES OF POPWICH’S MODIFICATIONREDUCTION IN INCIDENCE OF
FACIAL NERVE PALSYDECEASED HAEMORRHAGEIMPROVED VISIBILITY GOOD COSMETIC RESULTSREDUCTION IN TOTAL OPERATION
TIMEAVOIDANCE OF
AURICULOTEMPORAL NERVE ANAESTHESIA
REDUCTION IN POSTOPERATIVE OEDEMA AND DISCOMFORT
POPOWICH INCISION
MANAGEMENT
ANKYLOSIS OF TMJ
It is a greek terminology meaning “STIFF JOINT”
The jaw function gets affected because of immobility of the joint.
Hypomobility to immobility of the joint can lead to inability to open the mouth from partial to complete.
Onset is usually seen before the age of 10 years.
WHAT IS ANKYLOSIS ?
FALSE ANKYLOSIS OR TRUE ANKYLOSISEXTRA –ARTICULAR OR INTRA –ARTICULAR FIBROUS OR BONYUNILATERAL OR BILATERALPARTIAL OR COMPLETE
CLASSIFICATION OF ANKYLOSIS
Trauma- At birth (with forceps)- Haemarthrosis- Blow to the chin (causing
haemarthrosis)- Condylar fracture- congenital
Infections and Inflammatory- Rheumatoid Arthritis- Septic arthritis- Otitis media- Mastoditis- Parotitis- Osteomyelitis- Osteoarthritis- Tonsillitis
Systemic disease- Small pox- Ankylosing spondylitis- Syphilis- Typhoid fever- Scarlet fever
Others- Malignancies- Post radiology- Post surgery- Prolonged trismus
Rare causes- Polyarthritis- measles
AETIOPATHOLOGY
TRAUMA
Extravasation of blood into the joint space
haemarthrosis
Calcificatiion and obliteration of the joint space
Intra-capsular ankylosis Extra-capsular ankylosis
PATHOPHYSIOLOGY
DIAGNOSIS
It depends more upon clinical examination, rather than the diagnostic test.
Restricted or nil oral opening is seen.Patient will complain of difficulty in mastication.Protrusive movements are not possible on the
involved side.Partial mobility or complete immobility of the
condyle is readily noticed.Pain is totally absentIn young patient a nature of facial deformity will
help to differentiate b/w unilateral and bilateral involvement
CLINICAL MANISFESTATIONS
IT VARY ACCORDING TO:Severity of ankylosisTime of onset of ankylosisDuration
EARLY JOINT INVOLVEMENT- less than 15 years: severe facial deformity and loss of function
LATER JOINT INVOLVEMENT- after the age of 15years: facial deformity marginal or nil but functional loss is severe.
Those patient in whom ankylosis develops after full growth completion have no facial deformity.
Obvious facial asymmetryDeviation of the mandible and chin on the affected sideThe chin is receded with hypoplastic mandible on the
affected sideThe appearance of the flatness and elongaltion on the
unaffected sideThe lower border of the mandible onthe affected side hass
a concavity that ends in a well- defined antegonial notchIn unilateral ankylosis some amount of oral opening may
be possible. Interincial opening will vary depending on whether it is fibrous or bony ankylosis
Cross bite may be seenClassic angles malocclusion on the affected side plus
unilateral posterior cross bite on the ipsilateral side seenCondylar movements are absent on the affected side
UNILATERAL ANKYLOSIS
Inability to open the mouth progresses by gradual decrease in interincisal opening. The mandible is symmetrical but micrognathic.The patient develops typical 'bird face' deformity with receding chin.
The neck chin angle may be reduced or almost completely absent
Antegonial notch is well defined bilaterallyClassii malocclusion can be noticedUpper incisors are often protrusive with anterior open
bite.Maxilla may be narrowOral opening will be less than 5mm or many times there is
nil oral openingMultiple carious teeth with bad periodontal health can be
seenSevere malocclusion, crowding can be seen and many
impacted teeth may be found on the x-rays.
BILATERAL ANKYLOSIS
History of trauma, infection, etc Clinical finding Radiographic finding- are important in arriving at a final
daignosis Orthopantomograph- will show both the joints picture
which can be compared in unilateral cases. Lateral oblique view- will give anteroposterior
dimension of the condylar mass. Elongation of coronoid process can be seen.
Cephalometric radiograph- is taken to evaluate the associated skeletal deformities
Posteroanterior radiograph- will reveal the medio lateral extent of the bony mass. It will also highlight the asymmetry in unilateral cases
CT scan- very helpful guide for surgery. Relation to the medial cranial fossa, the anteroposterior width, mediolateral depth can be assessed. Any presence of fractured condylar head on the medial aspect of ramus can be located
DIAGNOSIS
FIBROUS ANKYLOSISReduced JOINT SPACE AND HAZY
APPEARANCE CAN BE SEEN.But, still the normal anatomy of the head and
glenoid fossa can be appreciated.BONY ANKYLOSIS
Complete OBLITERATION OF JOINT SPACE NORMAL TMJ ANATOMY IS DISTORTED.
Deformed condylar head or complete bony consolidation replacing the joint space can be seen.
Elongation of the coronoid process onthe side of hypomobility will be seen.
RADIOGRAPHIC FINDINGS
Normal facial growth and development affected.
Speech impairment.Nutritional impairment.Respiratory distress, especially in bilateral
involvement with severe micrognathia.Malocclusion.Poor oral hygiene.Multiple carious and impacted teeth.
SEQELAE OF UNTREATED ANKYLOSIS
Release of ankylosed mass and creation of a gap to mobilize the joint
Creation of a functional jointTo improve patient's nutritionTo improve patient's oral hygieneTo carry out necessary dental treatmentTo reconstruct the joint and restore the
vertical height of the ramus.To prevent recurrence.To restore normal facial growth pattern.To improve esthetics and rehabilitate the
patient.
AIMS AND OBJECTIVE OF SURGERY
Early surgical interventionAggressive resection: a gap of atleast 1- 1.5cm
should be created. Special attention should be given to fusion on the medial of the ramus.
Ipsilateral coronoidectomy and tempralis myotomy: in most of these cases there is always association of elongated coronoid process. After carrying out gap arthoplasty. The coronoidectomy on the same side should be carried out either separately or in combination with the gap arthroplasy cut from the same etraoral incision.
The Internationally Accepted Protocol For The Management Of Tmj Ankylosis By Kaban, Perrot And Fisher In 1990
Lining of the glenoid fossa region with temporalis fascia
Reconstruction of the ramus with a costochondral graft.
Early mobilization and aggressive physiotherapy for the period of at least six months postoperatively
Regular long-term follow-upTo carry to cosmetic Surgery at the later date
when the growth of the patient is completedRelease of the jaw movements is quite
dramatic, upon competion of coronoid rather than release it and allow it to be pulled up superior process is removed, there is potential for reankylosis after reattachment.
Most surgical procedures can be done through a preauricular incision alone.
The popwich's incision is chosen for its obvious advantages
Whenever required additional submandibular incision can be used for fixation of the graft.
I : condylectomyII : gap arthroplastyIII : interpositional arthroplasty
SURGICAL TECHNIQUES
It is advocated in cases of fibrous ankylosis, where joint space is obliterted with deposition of fibrous bands , but there is not much deformity of the condylar head.
Radiologically and clinically after surgical exposure one can see the demarcation between the roof of the glenoid fossa and the head of the condyle.
The procedure can be done via preauricular incision
The unilateral condylectomy tends to cause devation of the mandibule towards the operated side on oral opening and if bilateral, anterior open bite will be caused as a result of the loss of the height in the vertical rami.
CONDYLECTOMY
Therefore. When the site of the fused joint is mobilized via condylectomy. Then after recontouring by arthroplasty, an alloplastic material can be used to maintain the joint space, satisfactory occlusion and joint movement.
In the extensive bony ankylosis, a broad,thick area of bone deposition obliterates the entire joint, sigmoid notch and coronoid process
Identification of the previous joint structure is impossible and mobilization at level of joint become difficult
In this operation the level of section is below that previous joint space
The section consist of two horizontal osteotomy cuts and removal of a bony wedge for creation of a gap between the roof of the glenoid fossa and ramus.
Minimum gap of 1cm is recommended to pervent reankylosis
GAP ARTHROPLASTY
It involves the creation of gap , but in addition a barrier is inserted between the cut bony surfaces to minimize the risk of recurrence and to maintain the vertical height of the ramus
INTERPOSITIONAL ARTHROPLASTY
Tamporalis fascia along with a varying thickness of temporalis muscle may be harvested as an axial flap based on the middle and deep temporal arteries and veins
The dependable blood supply, the proximity to the tmj and the ability to alter the arc of rotation by basing the flap inferiorly or posteriorly, makes this a versitile flap for lining the glenoid fossa.
It is used as an interpositional material after release of ankylosis of tmj.
LINING OF THE GLENOID FOSSA SIDE BY TEMPORALIS MYOFAICIAL FLAP
Basic 3 goals1. To replicate structurally normal joint
anatomy2. To provide functional articulation3. To establish an area , where adaptive growth
can occurs.
INTERPOSITION ARTHROPLASTY USING AUTOGENOUS COSTOCHONDRAL GRAFT
Costochondral graft is harvested through the infra-mammary incision
Either 5th, 6th, or 7th rib is harvested.Costochondral junction of rib is chosen along
with some amount of length of the rib.The length of the total graft will depend on the
height of ramus to be restoredMinimum of 1.5cm of costochondral junction
should be included in the graftThe graft should be fixed on the lateral aspect of
the rammus with the screws.A minimum gap of 0.5 - 1 cm should be kept
between the graft and the glenoid fossa side, so that free movement is possible without any friction
Increased operating timeAdditional surgical siteDonor site morbidityGraft over growthPossible potential for reankylosis
Disadvantages
DURING ANAESTHESIAAs the patient cannot open the mouth, awake
blind intubation has to be done, where patients cooperation is required, which is very difficult to obtain from younger group of patients
Because of small mandible and altered position of the larynx .intubation poses a problem
Aspiration of blood clot tooth or foreign body during extubation as throat cannot be packed prior to surgery
Danger of falling back of tongue and obstructing airway is always there after extubation
COMPLICATIONS DURING TMJ ANKYLOSIS SURGERY
DURING SURGERYHaemorrage due to damage to any of the
superficial temporal vessels, transverse facial artery, inferior alveolar vessel and internal maxillary vessels, pterygoid plexus of veins
Damage to external auditory meatusDamage to zygomatic and temporal branch of
facial nerveDamage to glenoid fossa and thus leading entry
into middle cranial fossaDamage to auriculotemporal nerveDamage to parotid glandDamage to the teeth during opening of the jaws
with jaw stretcherDURING POSTOPERATIVE FOLLOW-UP
InfectionOpen biteRecurrence of ankylosis
An inadequate gap created between the fragments
Missing on the medial condylar stump and leaving it behind
Fracture of the costochondral graftLoosening of the costochondral graft due to
inadequate fixation to the ramusInadequate coverage of the glenoid fossa surfaceInadequate postoperative physiotherapyHigher osteogenic potential and periosteal
osteogenic power may be responsible for high rate of recurrence in children
RECURRENCE OF TMJ ANKYLOSIS
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