Humphry- 1st to do mandibular condylectomy for TMJ ankylosis , 1864
Esmarch- pseudo-arthrosis, 1855
Murphy-1914, interpositioning of flap of fat and temporal fascia to maintain pseudoarthrosis.
Pickerill- 1942, cartilage graft for TMJ reconstruction
Stuteville- established- condyle as growth center of mandible.
Ankylosis def.- stiffness of joint as a result of disease process with fibrous or bon fusion across the joint.
TMJ ankylosis- condylar head fuses with glenoid fossa
Type of joint- Diarthodial, Ginglymus (hinge), synovial joint
Movement- rotational and translatory
Articulation- mandibular condyle with squamous portion of temporal bone (glenoid fossa)
Blood supply of mandible- inferior alveolar artery and muscle and gingival attachments.
Glenoid fossa –
Anterior articular surface formed by inferior aspect of temporal squama.
Surface – smooth, oval & deeply hollowed out.
Roof of glenoid fossa forms the partition of middle cranial fossa and TMJ.
Fossa is lined by fibrocartilage.
Posterior wall of glenoid fossa – formed by squamo-tympanic fissure – separates it from tympanic plate.
Glenoid fossa is the cranial component of TMJ.
Its limit –
Anteriorly – articular eminence or tubercle.
Posteriorly – a small conical postglenoid tubercle.
(Articular eminence – a small prominence on ZA
Postglenoid tubercle – separates articular surface of fossa laterally from the tympanic plate – tympanic plate separates TMJ from bony part of EAM.)
TMJ articular surface-
Lined with fibrocartilage (avascular fibrous tissue with cartilage)
(TMJ is a synovial joint, but has fibrocartilage lining, while other synovial joint has hyaline cartilage as lining)
Articular disk or meniscus-
It separates TMJ into two spaces-
Upper joint- 1ml volume– extends from glenoid fossa to articular eminence.
Lower joint- 0.5ml volume– begins above the insertion of the lateral pterygoid and then spreads out over the condyle.
Articular disk has two bands for attachments-
Anterior band – is thick and narrow- attaches –
Superiorly –to articular eminence and superior belly of lateral pterygoid
Inferiorly – to condyle (though synovial membrane) along attachment of lateral pterygoid.
Posterior band- it is wide and thick – a Bilamellar structure- highly innervated and vascular.
Upper layer- attaches to – tympanic plates of temporal bone
Lower layer- attaches to – posterior meniscus to neck of condyle.
A third intermediate zone is also described – its thinnest part – gives meniscus flexibility and ability to alter shape under pressure.
Histologically – Disc is meshwork of firmly woven avascular fibrous connective tissue. It is non-innervated.
Joint range of motion
Main shock absorber
Has very little potential for repair after insult
Movements in joint-[HITS]
Hinge movement- Inferior joint space
Translational movement- Superior joint space
Shape- elliptical/oval (broad laterally and narrow medially)
Size- 20mm- medial to lateral (13-25mm)
10mm- AP diameter (6-16mm)
Two condyles of a patient can be asymmetrical.
Surface is mostly convex superiorly (58%) – but can be flat, pointed, angular, round, bulbous.
Articular surface is covered with dense fibrous connective tissue.
This is thickest – anteriorly and superior surface.
The hyaline cartilage is the head of condyle is the growth center of the condylar process.
TMJ capsule –
Thin, Funnel-shaped, Blends with periosteum of mandibular neck
Anteriorly – to anterior border of articular eminence.
Posteriorly – to lip of squamotympanic fissure & anterior surface of postglenoid process.
To the circumference of the cranial articulating surface
To neck of condyle both lateral and medial side.
Capsule is fibrous having a synovial lining on inside.
(Fibrous capsule- attaches to – Zygomatic arch -above & Condyle- below)
Capsule is reinforced- medially and laterally by temporomandibular ligaments.
Lateral or temporomandibular ligament –
Extends downwards and backwards – from articular eminence to external and posterior side of condylar neck.
Its posterior fibers unites with capsular fibers.
Made of collagenous fibers – have poor ability to stretch à hence maintains integrity and limits movement of TMJ à called ‘check-rein’ ligament
Prevents – Anterior excursion of jaw & Posterior dislocation.
Accessory ligament –
Makes no contribution to joint activity.
These are –
Sphenomandibular ligament –
Arising from sphenoid spine and pterygoid fissure
Runs downward and medial to the TMJ
Gets inserted on lingula of mandible.
Its remnant of Meckel’s cartilage
It’s an important landmark – internal maxillary artery and auricotemporal nerve lies b/w it and mandibular neck.
Stylomandibular ligament –
Dense thick band of deep cervical fascia.
Runs from styloid process to mandibular angle.
Blood supply of TMJ-
Superficial temporal vessels and massetric artery branches through sigmoid notch of mandible.
Nerve supply of TMJ –
CN V3 branches –
Largest branch – auricotemporal n – supplies the posterior, medial, lateral part of the joint
Branch of posterior deep temporal nerve – supplies anterior part of joint.
Outer aspect of zygomatic arch (ZA) to middle meningeal artery – 31mm
MMA to height of glenoid fossa (HGF) – 2.4mm
ZA to carotid artery – 37.5 mm
ZA to IJV – 38.3 mm
Outer aspect of ZA to CN V3 – 35mm
HGF to CN V3 – 9.2mm
Excessive bleeding during TMJ resection – MC related to IMA (internal maxillary artery)
Anterior tympanic artery is intimately related to retroauricular region- supplies posterior part of TMJ.
Retrodiscal venous plexus (pterygoid venous plexus) – venous space in retromandibular space.
Mandible movements and muscles:
Protusion or elevation-
Lateral pterygoid- superior portion in elevation
Depressor or retractor-
Anterior belly of diagastric – main
Lateral pterygoid – inferior portion in depression
Masseter – elevation and protrusion
Medial pterygoid – protrusion and elevation. U/L movement – mediotrusion
Anterior fibers – elevation
Middle fibers – elevation and retrusion
Posterior fibers – retrusion
Inferior portion- attaches to neck of condyle à produces movement of the joint – mouth opening and protrusion
Superior portion- attaches to fibrous capsule and meniscus of TMJà stabilizes meniscus during movement of mandible.
At rest condyle articulates with intermediate zone of disc.
Mouth opening – condyle disc complex translates down the articular eminence and then disc rotates posteriorly on condyle.
Superior retrodiscal tissue – limits the forward sliding of disc.
Mouth opening is initiated by – superior head of lateral pterygoid.
Mouth closure – each head glides back and hinges on its disc.
The initial 20-25° of mouth opening is pure Hinge movement. Beyond this condyle translates forwards and rest of the movement occur.
[Depression – Diagastric][Protrusion – Pterygoids][Elevator – Temple & mass – Tempolaris and Masseter][Superior lateral pterygoid- originates from Sphenoid greater wing]
TMJ and its characteristic features –
- Articular cartilage – covered by avascular fibrocartilage (not hyaline).
- Right and left movements are coupled through mandible
- Mandible is stabilized by three functionally linked articulation – 2 TMJs and the dentition. Problem in any of the three will affect mandible movement.
- Multiple muscle involved in movement – requires delicate neuromuscular balance
- TMJ is the only joint that has rigid endpoint of closure (as a consequence of teeth contacting).
- The joint function as a regional adaptive growth center for the growth and development of the mandible and middle third of face (in response to changes in the “functional matrix” of surrounding mastectomy muscle and other sift tissue).
|Type 1||Fibrous adhesion in or around the joint
Restricted condyle gliding
|Type 2||Formation of bony bridges between the condyle and glenoid fossa|
|Type 3||Condylar neck is ankylosed to the fossa completely|
CP Sawhney classification-
|Type 1||Fibrous adhesions all around the joint making any movement impossible
Condylar head- flattened or deformed lies closely approximated to the articular surface.
|Type 2||Bony fusion of the head to the outer edge of the articular surface either anteriorly or posteriorly but only to a small area
Condylar head- misshaped or flattened but was still distinguishable
Deeper to it the articular surface and the articular disk were undamaged
|Type 3||Bony block seen to bridge across the ramus of mandible and the zygomatic arch.
Condylar head displaced and atrophic lying free or fused
Upper articular surface and articular disk of the deeper aspect intact
|Type 4||Bony block wide and deep and extends between ramus and upper articular surface, completely replacing the architecture of joint|
Type 4 is the MC type.
El- Haki & Metwalli, 2002
A1- fibrous ankylosis with or without bony fusion
A2 – Bony fusion <50%
A3 – Bony fusion >50%
A4 – complete fusion
Consolidation and fibro-osseous restructuring of a hemarthosis.
Hemarthosis itself may have many cause.
Trauma results in ankylosis- 29-100% cases.
Condylar neck fracture is the MC cause.
Factors leading to ankylosis-
- Age-Younger age group
Higher osteogenic potential
Articular capsule not well developed- easier condylar displacement out of fossa- damage to disk
Anatomically different condyle in children—condyle neck is wide and condylar head has blunt anatomyàmore chances of comminuted fracture. More frequent medial displacement of condylar head – more chance of glenoid fossa fracture.
Prolonged period of self- immobilization
- Severity of trauma
- Site of fracture
- Intracapsular fracture à greater risk of ankylosis
- Condyle in children poorly tolerates crishing injury directed along its long axis—resulting in burst fracture- severe hemarthosis with multiple osteogenic fragments
- Duration of immobilization
- Articular disk
Torn or displaced meniscus – provide direct contact b/w a comminuted fracture and glenoid fossa- key factor in developing ankylosis.
Septic arthritis- organisms- Neisseria Gonococcus, staphylococcus, streptococcus, hemophilus.
Predisposing factors (for infection):
Blunt trauma, Previous joint disease, Burn wound to region, Systemic/autoimmune disease- RA, Reiter’s, alcohol abuse, hypogammaglobulinemia, Drugs- steroids, immunosuppressant, STDs
Contiguous – from middle ear
Direct- arthroscopy, arthrocentesis, injection in the area, acupuncture
Previous TMJ surgery-
Discoplasty, Dissectomy, High condylar shave procedure, Failed alloplastic material
Fibrous ankylosis- following prolonged MMF
Jacob’s disease- osteochondroma of the coronoid process à subsequent fusion to the base of the zygoma
Ankylosis can occur in non-articular site.
Forceps delivery- a trauma to TMJ.
Fusion of maxilla-mandible (extra-articular)
Trismus- is the functional characteristics. The cause of trismus can be many.
- Direct on mandible
- Indirect (secondary effect)
Maxilla (No place to grow because of hypoplastic mandible)
Shortened pterygo-masseteric sling
Shortened ligament attaching mandible to skull base
Hypertrophy of – tempolaris, coronoid process, suprahyoid muscle
Narrowing of oropharyngeal airways
Narrowing of space between mandibular angles
Facial deformity is severe if ankylosis occurs before 15yrs of age.
- Deviation of chin and mandible towards affected side
- U/L vertical deficiency (of ramus) on affected side
- Roundness and fullness of face on affected side,
- Flatness and elongation of face on opposite side.
- Concave mandible that ends up in well-defined “antegonial notch”
- Class II angle malocclusion on affected side + U/L posterior cross bite on affected side.
- Absent condylar movement on affected side
- Occlusion cant with deviation of maxilla and mandibular midline towards affected side.
- Retrognathic/micrognathic mandible (which is symmetrical)
- Neck chin angle (cervicomental angle) – reduced or almost completely absent.
- Bilateral well-defined antegonial notch
- Class II malocclusion
- Anterior open bite with protrusive upper incisors
- Oral opening ↓↓ (<5mm)
- Multiple dental caries
- Severe malocclusion crowding and impacted tooth
- Convex facial profile
- Short hypo-mental distance with tight suprahyoid musculature
- “Bird-face” deformity (Ande-Gump deformity)- Vogelgesicht
- Markedly elongated coronoid process
Obstructive sleep apnea can occur- due to oropharyngeal airways narrowing
Narrowing can occur in-
Cephalocaudal direction- due to shortening of mandibular rami
Transverse – reduced space b/w angle of mandible
Antero-posterior diameter- hypoplastic (↓ed) body.
Key difference b/w intra-articular vs extra-articular
Intra-articular- translational movement – ↓ed or absent
Extra-articular- translational movement- not as limited.
Rotational movement- affected in both
- History – of trauma or infection
- Clinical findings
Easy, quick, shows adjacent areas.
Blind area of OPG – angle (blinded by cervical shadow) & symphysis (pharyngeal shadow)
Presence of antegonial notch
Antegonial notch- develops- secondary to contraction of depressor muscle and their action against elevator muscles
Prominent and elongated cornoid process
Shallow sigmoid notch
Cephalometric studies– lateral and antero-paoterior. Required for aesthetic correction.
Very helpful. 3-4 mm cuts are obtained. Evaluates- medial extent of bone mass, Density of bone mass, Thickness of temporal bone
Typical appearance of ankylotic joint is – “mushroom- shaped”
CT scan can also- differentiate any extra-articular contribution to ankylosis.
Minimum 3 slides needed to diagnose
Allows measurements. Allows subtraction CT
Cone beam CT- CBCT-
Small area of CT. Low radiation dose. Smaller equipment. Small cuts are used 1-2mm.
Provides multiplanar and reformational and 3D images
Fibrous ankylosis- reduced joint space and hazy
- Complete obliteration of joint space
- Distorted TMJ anatomy
- Deformed condylar head
- Complete bony consolidation
- Elongation of coronoid process
Sequel of untreated ankylosis-
- Facial growth and development affected
- Speech impairment
- Nutritional impairment
- Poor oral hygiene – multiple caries and impacted tooth
- Respiratory distress
Aims and objective of surgery
- Restore mouth opening
- Restore joint function
- Allow for condylar growth
- Correct facial profile
- Relieve upper airway obstruction
- Prevent recurrence
Surgical strategies depend upon-
- Age of onset of ankylosis
- Extent of ankylosis
- U/L or B/L involvement
- Associated facial deformity
Various technique has been used- but, basically three strategies-
- )Condylectomy, 2). Gap arthroplasty, 3). Interpositional arthroplasty.
Incision- Behind the external ear in the crease near superior aspect of external pinna and extended to tip of mastoid.
Small exposure- poor access and poor exposure, Stenosis of EAM (external auditory meatus), Infection of external auditory canal, Chondritis, Paraethesia, Deformity of pinna
Endaural approach (Lamport)
Incision- short facial incision with extension into EAM
Begins just above zygomatic arch, extends downwards and backwards into intercartilaginous cleft b/w helix and tragus and then extends inwards along the roof of EAM for approx. 1cm.
Disadvantage- Limited access, Meatal stenosis, Chondritis
Incision- 1 cm below and parallel to lower border of mandible going slightly behind
Disadvantage-poor access to condylar head
Used for-approach to neck of condyle and ramus
Post-ramal (Hind) approach-
Indicated for surgery involving condylar neck and ramus
Incision- 1cm behind ramus, extends 1 cm below ear lobe to angle of mandible
Advantage- cosmesis, Excellent visibility and accessibility
Incise parotidomasseteric fascia –>Avoid injuring to facial vein and facial n.
Expose posterior border of ramus –>Incise pterygomasseteric sling (PMS) at the angle
Reflect masseter and parotid glands –> Condylar neck is now exposed.
After procedure PMS is re-approximated.
Preauricular (Dingman’s) approach –
Most basic and standard approach to TMJ
Described by Dingman in 1951
Incision – at the junction of the facial skin with the helix of the ear.
Incision from – helix to the upper border of the tragus.
Modifications of preauricular incision –
- Blair and Ivy – “Inverted hockey stick” incision ove the zygomatic arch.
- Thema – angulated vertical incision.
- Al-Kayat & Bramley, 1979 –
Preauricular approach with temporal extension over zygomatic arch considering the main branches of vessels and veins in vicinity.
Facial and main trunk – 1.5cm -2.8 cm below the lower border of EAM.
Temporal branch – 0.8cm – 3.5cm anterior to anterior border of EAM.
Popwich and Crane modification of Al-Kayat & Bramley –
Incision is longer and wider than conventional.
Skin incision is “question mark”. Begins about pinnas length away from ear.
Curves, backwards and downwards well posterior to main branch of temporal vessel. Till it meets upper attachment of ear.
Rest of incision is same.
Decreased facial nerve palsy.
Provision of donor site for temporal fascia
Decreased hemorrhage (avascular plane of dissection)
Improved visibility and easier identification of facial planes.
Reduction and post-op edema and discomfort.
Reduction in operative time.
Avoidance of auricotemporal nerve aneasthesia or paraethesia.
Coronal approach –
Hemicoronoal (U/L incision)
Bicoronal (B/L incision)
Incisions particularly useful for TMJ ankylosis surgery –
1). Dingman’s and its modification, 2). Risdon, 3). Combined approach – Dingman + Risdon, preauricular + coronal (Poswillo, 1974)
Internationally accepted protocols –
Kaban, Perrot, Fischer, 1990
- Early surgical intervention
- Aggressive resection of bony or fibrous ankylotic segment – gap of at least 1-1.5cm should be created
- Ipsilateral coronoidectomy and tempolaris myotomy –
- Coronoid process cut from the level of sigmoid notch till the anterior border or ramus
- Tempolaris muscle attachment are severed by carrying out tempolaris myotomy à check intraoral opening – if >35mm à no need for C/L procedure. If opening <35mm àthen C/L coronoidectomy and tempolaris myotomy (this can be done by intraoral incision).
- Lining of glenoid fossa region with tempolaris
- Reconstruction of ramus with costochondral graft.
- Early mobilization and aggressive physiotherapy for at least 6months period post-op.
- Regular long term follow up
- Cosmetic surgery later on when patient grows.
Coronoidectomy – Important to excise rather than just release à otherwise reankylosis will occur.
Temporalis myofascial flap for Lining of glenoid fossa – based on middle and deep temporal arteries. This flap is a versatile flap for glenoid fossa lining because of –
- Robust blood supply
- Proximity to TMJ
ability to alter arc of rotation by basing the flap inferiorly or posteriorly
- Vague simulation of disc.
El- Sheikh, 1999- Cardinal principles –
- Radical resection of ankylosed mass via wide surgical exposure
- Release of pterygo-masseteric muscle sling with resection of condylar process
- Restoration of vertical ramal height and condylar head by a costochondral graft
- Simultaneous correction of jaw bone deformities at the same time as release of ankylosis
- Careful selection of patient – who can comply for at least 1 year of follow up.
MC cause of reankylosis –Incomplete removal of the bony or fibrous mass (esp. from medial aspect of joint).
- Gap Arthroplasty (GA) –
First described by Abbe, 1880. Recurrence – 14-100%. Minimum extent of width of bone resection – At least 1cm. The procedure causes – gleno-mandibular dysjunction
Laser & arthroscopy –
Ho:YAG laser can be used to debride fibrous ankylosis through arthroscopy creating a pseudo-arthrosis below the mass.
Described by Salins.
Made subcondylar fracture below the ankylosed mass à through post-op physiotherapy creates a pseudo-arthrosis – resulting in mouth opening.
It does not resects the ankylosed mass.
- Interpositioning arthroplasty (IA) –
Various grafts has been used for lining the joint after resection of ankylotic mass.
Glovine, 1898- first used the tempolaris myofascial flap (TMF) for orbital reconstruction.
Topazian, 1966 – compared GA and IA in favor of IA.
Other autogenous interposition grafts –
Dermal graft, Masseter muscle graft, Auricular cartilage, Fascia lata, FTG
Alloplastic material –
Proplast/Teflon, Polyethylene, Christensen metallic fossa implant, Silastic sheets, Acrylic marbles
Modification of TMF –
Feinberg & Larsen – described full thickness, pedicled, tempolaris muscle-pericranial flap that includes periosteum along with muscle.
Pogrel Kaban – flap includes fascia alone or with muscle and is inferiorly rotated over the arch into the joint space.
Omura & Fujito – Folded the flap over itself making fascia face both condylar surface and glenoid fossa and thus reducing the functional friction.
Routes of placing TMF –
- Tunnel under zygomatic arch (ZA)
- Osteomatize the ZA
- Thinning of ZA & pass under it
- Over the ZA
CCG (costochondral graft)–
Harvested either from 5th, 6th rib.
Costochondral junction of rib is chosen along with some length of rib.
Length of total graft will depend on the height of ramus to be restored.
A minimum of 1.5cm of costochondral junction should be included in the graft.
Fixation to lateral aspect of ramus with screws or interosseous wire.
Reconstruction of resected joint –
- Reestablish joint function
- Reestablish vertical height of the ramus and occlusion
- Provide growth potential in children
Autogenous grafting –
Costochondral graft (CCG) –
First described by Gillies- 1920
Ware & Brown – promoted its use as potential growth center for the mandibular joint.
CCG is forerunner in autogenous graft choice –
Easily adaptable to the site. Remodels over time. Less donor site morbidity
Infection are rare. Harvested rib generally regenerates.
Anatomical similarity to the mandible condyle. Regenerative and growth potential both at host & donor site. Ease in training and adapting the graft.
The cost & time for preparation are considerable
Unpredictable growth pattern – progressive dental midline shift, occlusion changes, chin deviation, enlargement of the graft itself.
CCG should be at least 0.5cm to 2cm to diminish the chance of all graft converting to bone.
A minimum gap of 0.5cm to 1cm should be there b/w graft and glenoid fossa so that free movement is possible.
Other autogenous materials –
Metatarsal, Sternoclavicular joint, Fibula, Iliac crest, Ankylotic mass itself after contouring, Free vascularized whole joint transplant to 2nd toe, Preserved costal cartilage
Alloplastic materials –
Ability to begin physiotherapy almost immediately after the surgery.
Avoidance of second surgical site
Ability to mimic normal anatomy
Rationale to use alloplastic Vs autograft –
Placing an autogenous tissue into an area where reactive or hypertrophic bone already formed once is not a good idea.
Previously operated joints has compromised vascular bed that will not take up autogenous tissue predictably
Relatively contraindication for allograft use –
- Uncontrolled systemic disease eg. DM
- Active infection at implant site
- Allergy to implant material
- Cost of device
- Material wear & tear
- Questionable long term stability
- Lack of growth potential
Total joint prosthesis –
CAD-CAM design are useful.
McCarthy first used distraction technique for mandibular lengthening in microsomia. Papageorge & Apostolicis then used this for TMJ ankylosis
Distractor placed along – ascending ramus and inferior border. A reverse corticotomy performed through sigmoid notch.
Simultaneous arthroplasty is done.
During anesthesia –
Difficult intubation and risk a/w it.
During surgery –
- Hemorrhage – sources –
- Superficial temporal vessels
- Transverse facial a
- Inferior alveolar vessels
- Internal maxillary vessels
- Pterygoid plexus of vein
- Damage to EAM
- Damage to Zygomatic and temporal branch of facial nerve
- Damage to Glenoid fossa à leading to perforation of middle cranial fossa
- Damage to auricotemporal nerve
- Damage to parotid gland
- Damage to teeth during jaw opening with stretcher
- Open bite
- Unpredictable growth of costochondral graft
- Fracture of graft at costochondral junction à remove cartilage and reshaping the bony part.
Frey’s syndrome –
Pain in auricotemporal region. Gustatory swaeting and occasional erythema. Flushing on the affected side.
Topical agents – Antiperspirants – only for mild symptoms. Anticholinergic – topical glycopyrrolate
Radiation therapy – Dose of 50Gy is used. For very symptomatic patient when other forms of treatment fails.
Surgical procedure –
Skin incision – for localized and small areas
Auricotemporal nerve resection. Tympanic neurectomy. Botulinum toxin A injection
Recurrence of ankylosis –
- Inadequate gap b/w the fragments
- Missing on medial condylar stump and leaving it behind
- Fracture of costochondral graft
- Loosening of costochondral graft due to inadequate fixation
- Inadequate coverage of glenoid fossa
- Inadequate post-operative physiotherapy
Two most dreaded complications of TMJ surgery –
- Perforation into middle cranial fossa
- Severe bleeding from the medial infra-temporal fossa
Dural exposure through glenoid fossa à if Dural tear present à neurosurgical consult
Internal maxillary artery tear à Embolization.
Steps of surgery –
Safe and secure airways or tracheostomy under GA
Gap arthroplasty – with 1.5 – 2.0 cm gap
Tempolaris fascia flap – interposition in the gap
Costochondral graft placed through Risdon’s incision. CCG fixed with two 2mm diameter and 8-10mm length screw.
I/L or C/L coronoidectomy or both if intraoral mouth opening <35mm
Extended sliding genioplasty to correct retruded chin
For GA. For Tracheostomy. For CCG
Incision – Skin – as planned (preauricular with hemicoronal extension)
S/C tissue –> incision stops at level of tempolaris fascia
Blunt stripping with back of scalpel sweeping forward, inferiorly up to inferior point of helical attachment.
Root of zygomatic arch palpated – on which a vertical incision is placed down to the bone. Upper limit of incision is carried up to 2 cm above ZA angulated forward at 45°.
Periosteal dissector is used to tunnel the periosteum over the ZA and anteriorly retracted -> exposing the ankylotic mass.
Periosteum over the ramus is bluntly divided to expose the ankylosed mass up to the anterior border of ramus and coronoid if present separately.
Deeper dissection should not be extended below the inferior limit of the bony EAM (to prevent injury to facial nerve).
Ankylotic mass dissected with a cutting burr.
Initially – inferior cut is placed and completed with an osteotome.
Superior cut usually follows cleavage b/w the supposed glenoid fossa and condyle or a horizontal cut.
In dense ankylosis- 1.5 cm osteotomies are performed in layers to avoid arteriovenous anatomy medial to mandible.
Bleeding at this level is due to –
1). Inferior alveolar vessel, 2). Pterygoid plexus, 3). Middle meningeal vessels
And rarely from internal maxillary a. Pressure and cautery will control bleeding.
Mandible is now opened to achieve 35-40 mm mouth opening –> if not achieved –>C/L coronoidectomy
Coronoid, if identified, separately, is usually hypertrophied and is excised through same incision.
Temporoparietal flap – 2 cm in width, dissected about 6 cm superior to ZA. This flap is freed up to 1 cm from ZA (5 x 2 cm flap) and tucked into gap arthroplasty (sutured to remnant of pterygoid muscle or to medial of ramus).
Harvest of CCG –
5th or 6th rib. Subperiosteal elevation. 4cm of rib with 5mm of cartilaginous cap.
Chest wound closed in layers. Harvested graft placed lateral to ramus of mandible through Risdon incision.
CCG is secured with two 2mm screws of 8-10mm length.
Advancement genioplasty –
Extended genioplasty is done making bone cut inferior to the mental nerve on either side.
Osteotomy is completed using 2mm burr. Osteomized chin is pulled forward and overlapped on body of mandible anteriorly
Total joint replacement technique –
CAD-CAM generated custom made TMJ condyle and fossa prosthesis.
Endaural (Lamport’s) with hockey stick extension.
Ankylotic mass is exposed.
A Steiger burr is used to perform gap arthroplasty & a condylectomy and ankylotic mass removed.
A sialistic block is then contoured and placed in the gap as a temporary spacer.
IMF is done. Pt is discharged.
CT scan done –> CT scan sent to company for manufacturing prosthesis – after CT, IMF can be removed.
2nd stage of surgery –
IMF given – Gap arthroplasty exposed à sialistic spacer removed à I/L coronoidectomy done à prosthesis fitted & fixed (with 2mm screw) à IMF released.
Additional procedure if desired range of motion not achieved à C/L coronoidectomy à B/L masseteric myotomy.
F/b post-op radiation –> 10Gy in 5 fraction.
TMJ disorders –
Intra-articular or intrinsic
Extra-articular or extrinsic
Extrinsic factors –
Masticatory muscle disorder –
Protective muscle splinting
MPD (masticatory muscle spasm) syndrome
Extrinsic trauma –
Fracture, Traumatic arthritis, Myositis, myospasm, Tendonitis, Myofibrotic contracture
Causes of trismus –
- Infection –
- Acute – odontogenic, or
- Around the joint
- Chronic – tubercular osteomyelitis of ramus/body
- Acute – odontogenic, or
- Trauma –
- Fracture ZA – impinging on coronoid
- Fracture mandible – pain and tenderness or muscel spasm
- Inflammation – myositis or muscular atrphy
- Myositis ossificans
- Neurological disorder – epilepsy, brain tumor, bulbar paralysis
- Psychosomatic trismus
- Drug induced – strychnine
- Mechanical blockage – elongation, exostosis, osteoma, osteochondroma
- Extrarticular fibrosis
- Iatrogenic – hematoma in medial pterygoid (following needle puncture) à leading to fibrosis
Intrinsic factors –
- Trauma – dislocation, subluxation, intracapsular fracture, extracapsular fracture, hemarthrosis
- Internal disc displacement
- Arthritis – OA, RA, JRA, infectious arthritis
- Developmental defects –
- Agenesis/ aplasia of condyle – B/L or U/L
- Hyperplasia/hypoplasia of condyle
- Bifid condyle
Dislocation, Subluxation, hypermobility of TMJ –
Excursion of condylar head –> normally just under the apices of articular eminence (in some individuals till anterior slope of articular eminence) –> beyond this point is abnormal.
Mandibular dislocation is uncommon in comparison to other joints in body.
Dislocation can be –
Unilateral or Bilateral
Acute (Luxation) or Chronic recurrent (habitual) – subluxation or Long standing
Acute dislocation –
Extrinsic or iatrogenic
Intrinsic or self-inducing forces
Extrinsic or iatrogenic causes –
Blow to chin (while mouth open)
Injudicious use of mouth gag during anesthesia
Excessive pressure on mandible
Intrinsic or self-inducing forces –
Excessive yawning, Vomiting
Singing/blowing wind instruments/laughing loudly
Excessive opening during eating
Predisposing factors –
- Laxity of ligaments, capsule
- Abnormal skeletal form
- Previous injuries
- Ehler-Danlos Syndrome
Clinical factors –
Difficulty mastication and swallowing. Profuse drooling of saliva
Deviation of chin to opposite side
Lateral cross and open bite on C/L side
Inability to close mouth. Pain, excessive salivation, difficulty speaking
Protruding chin. Anterior open bite
Assurance. Pain killers. Sedatives.
Pressure and massage of area.
Manipulation – downward force–> and then backward force.
Patient kept on semisolid diet
Long standing dislocation – when dislocation longer than one month.
Chronic recurrent or habitual dislocation or subluxation –
Triad of –
Ligamentous and capsular flaccidity
IMF for 3-4 weeks
Sclerosing agents in joint space –> fibrosis
Surgical options –
- Capsule tightening procedure
- Creation of mechanical obstacle or block
- Creation of new muscle balance
- Removal of mechanical obstacle
- LeClerck’ procedure – ZA fractured to create eminence
- Glenotemporal osteotomy – eminence augmentation
Capsule tightening procedure –
- Capsulorrhaphy – shortening the capsule and resuture
- Placement of vertical incision – in the capsule and drawing it tight by overlapping the edge and suturing
- Reinforcement of the joint capsule – by turning down a strip of temporal fascia and suturing to capsule
Creation of mechanical obstacle –
- Eminence osteotomy and turning down in front of condylar head – Lindermann
- Mayor- eminence grafting – Bone grafting (taken from zygoma) over the eminence to increase the size and height.
- Silastic block or Vitallium mesh implant to add to height of eminence
- Dautry – zzygomatic arch osteotomy and depressing it in front og condylar head to prevent abnormal forward translation
- Findlay – “L-shpaed” pins anchored in the zygomatic process of temporal bone and projecting it anterior to condyle.
- Creation of mechanical obstacle – has certain disadvantage – not used frequently.
Direct restrain of condyle – Questionable results
- Tempolaris fascia turned down and sutured to lateral surface of articular capsule.
- Piece of fascia lata – threaded through hole in the ZA and then second hole in condyle and then tighten it until half of pre-operative opening existed.
Creation of new muscle balance –
- After making vertical intraoral incision –
Tempolaris fascia and periosteum divided – from the tip of coronoid to retromolar area.
At and below the coronoid tip – masseter muscle is also partly elevated from the lateral surface of ramus.
Wound then closed horizontally –> fibrosis –> restricts oral opening.
- Medial pterygoid myotomy procedure
Removal of mechanical obstacle –
- Removal of torn meniscus or meniscectomy – became popular à but lots of side effects.
- High condylectomy –
- Excision of the superior portion of condylar head above the attachment of the lateral pterygoid.
- This shortened head has now less chance of locking
- Eminectomy –
- Myrhang, 1951
- Eminectomy allows condylar head to move freely forward and backwards.
- Recurrent episodes of dislocation
- Chronic hypermobility a/e severe pain
- Irreversible TMJ pain a/w clicking or grating
Simple to perform. Can be performed under local anaethesia.
Joint cavity not opened – avoids injury to meniscus and capsule
Skin incision – small horizontal incision over the ZA in the region of articular eminence in front of tragus.
Articular eminence is located ⁓1.5 cm anterior to EAM.
Eminence is then exposed with T-incision, the horizontal portion being over and parallel to ZA and vertical portion extending to the apex of the eminence.
Periosteum reflected to expose entire lateral portion of the eminence.
Series of burr hole then created at the base of eminence in a line parallel to ZA
Burr is directed downwards @ 10° to horizontal plane.
These burrs are then connected with fissure burr.
Eminence is then sectioned and separated.
Base is then smoothened.
(Foramen spinosum is just mesial to articular eminence. It contains MMA (middle meningeal artery) – may be source of major hemorrhage after eminectomy).
Area is thoroughly irrigated – wound closed in layers.
Pressure bandage given for 48-72 hrs.