TMJ Flashcards

Question

What are intra-articular causes of hypomobility (true ankylosis)?

Answer 1

Intra-articular fusion within the joint space resulting in hypomobility. -Can be bony, fibrous or fibro-osseous -Can be complete vs incomplete -Can be caused by trauma, infection, otitis media, rheumatoid arthritis, psoriatic arthritis, prolonged immobilization, previous TMJ or orthognathic surgery.

Answer 2

Two systems. Sawhney and Topazian. Sawhney -Type 1: Flattened condylar head with close approximation to joint space -Type 2: Flattened condyle close to glenoid fossa, bony fusion on outer aspect of articular surface, no fusion of medial joint space -Type 3: Bony block bridging the mandibular ramus and zygomatic arch -Type 4: Wider bony block bridges the mandibular ramus and zygomatic arch, completely replacing the architecture of the joint Topazian -Stage 1: Only condyle involved -Stage 2: Extends to sigmoid notch -Stage 3: Entire condyle, sigmoid notch and coronoid

Answer 3

-Clinical exam: Decreased MIO, inability to appreciate translation of condylar head -Panorex: Can see radiodense mass overall bony morphology, coronoid hypertrophy -CT with contrast: Defines the extent of the heterotopic bone/ankylotic mass. Delineates relationship of mass to vital structures. May aid in fabrication of custom TMJ prosthesis in setting of immediate reconstruction

Answer 4

-Requires excision of the mass w/ reconstruction -Goal of MIO is 35 mm or greater -Recon typically with a custom joint, other options include costochondral graft or fibular free flap

Answer 5

-Aggressive resection of the fibrous and or bony ankylotic mass -Coronoidectomy on the affected side and measure MIO intra-op -Coronoidectomy on contralateral side to achieve MIO >35 mm -Lining of the TMJ with a temporalis myofascial flap or the native disc if salvageable -Recon of the ramus condyle unit with either distraction osteogenesis (activate 2-4 days. takes advantage of fibrocartilaginous cap for distracting) or costochondral graft with rigid fixation and MMF x10 days -Early mobilization of the jaw (day of surgery for DO, 10 days for costochondral graft -Aggressive physiotherapy

Answer 6

Can be treated more conservatively -Lysis of adhesions and fibrosis -Diskectomy

Answer 7

-Aggressive Physical therapy most important -Frequent follow-up -Consider radiation therapy 20 Gray in 10 fractions (prevent recurrence and helpful in autogenous grafting when the risk of recurrence is higher)

Answer 8

Children: 7-10 cm Adult: 12-17 cm From lateral edge of latissimus dorsi and costochondral junction

Answer 9

-RIbs 4-7 -Direct cartilaginous connection to the sternum -Rib 6 is most common. Incision falls in the inframammary crease

Answer 10

Avascular plane between the fusion of the rectus and pectoralis major

Answer 11

-Common to take right rib (least likely to be confused with cardiogenic pain -Some advocate for contralateral side of the defect to allow appropriate curvature of the harvested rib

Answer 12

-Sharp 5cm incision made in the inframammary crease -Dissection carried through Subcutaneous tissue, fascia and a plane between the pectoralis major and rectus abdominis -Two fingers are use to straddle the fifth and sixth intercostal space to prevent slipping of the instruments. A sharp incision is cut through the periosteum down to the outer cortex of the rib -Periosteal elevator used to dissect in a subperiosteal plane around the rib -Sharp blade used to make the cartilaginous incision. Important to only harvest 1-3cm to avoid overgrowth of the rib and prevent separation of the cartilaginous cap -Rib pulled laterally and protected rib cutter used to section the length of the rib -Check for pleural tears (Fill cavity with saline and have anesthesia valsalva) -Periosteal sleeve closed with 3/0 polyglactin -Fascia between rectus and pec major closed with 3/0 resorbable suture, followed by subcutaneous tissue and finally skin -Post-op CXR ordered to r/o penumo/hemo thorax -Normal activity POD #7, no strenuous activity until 6 weeks post-op

Answer 13

-Drill a hole through the rib and tie a non-resorbable suture to secure the cap -Or harvest a new rib (2 above so there is no cosmetic defect)

Answer 14

-Occurs when air is trapped between the visceral and parietal pleural cavity and there is a one-way valve allowing air to enter but not escape -100% oxygen -10% or less in size can be left to reabsorb with serial xrays, if doesn't resolve in 1 week do a tube thoracostomy -If immediate pressure release is required, complete needle decompression by placing an IV catheter at the 2nd intercostal space along the mid-clavicular line (listen for rush of air) -Tube thoracostomy: requires a 2-3 cm incision at 5th intercostal space, just above the 6th rib. Local infiltrated. Proximal end of a thoracotomy tube is clamped and advanced over the 6th rib (avoid neurovascular bundle). Tube placed on water-sealed suction drainage

Answer 15

-Air bubbles appreciated during valsalva maneuver -Suction catheter is placed into the wound and a purse string suture through the tear -The suction catheter is removed under suction while tightening the purse string simultaneously

Answer 16

-Happens with hypermobility/dislocation -Inability for patient to close from MIO -Condylar head anterior to articular eminence

Answer 17

-Excessive yawning -Excessive/prolonged opening (dental appt) -Seizure disorder -Intubation -Tardive dyskinesia -Phenothiazine treatment -Connective tissue disorders (Ehlers danlos, Marfans)

Answer 18

-Reduction by bimanual mandibular manipulation in a downward and posterior vector (consider sedation) -Wrap the head with a Barton bandage to limit jaw movements for 1 weeks (allows stretched tissues to heal)

Answer 19

-Noninvasive measures include intra-articular injections of a sclerosing agent (alcohol or autogenous blood) in the superior joint space -Botox used in the lateral pterygoid -LeClerc/Dautrey procedures (Zygomatic arch osteotomies), eminectomy, lengthening the articular eminence with a bone graft (calvarium, symphysis, ramus)

Answer 20

-Order with T1 and T2 weighted images -3 mm serial cuts in coronal, sagittal, and axial views for both open and closed mouths

Answer 21

-Junction of the posterior band and the posterior attachment at the 12 O' Clock position in a closed mouth

Answer 22

-Fat appears bright and will appear white -Better for anatomy evaluation -Marrow fat in condyle will have a high T1 signal intensity -Can tell if an image is T1 is if condyle is white, the gyri of the brain DO NOT show white banding, or the orbits appear grey -Disk and cortical bone are black in both T1 and T2 -If there is avascular necrosis, T1 marrow will be black and T2 will be bright due to necrosis

Answer 23

-Water is bright and fat is dark -Brain appears grey w/ white branding -Better to look for effusions and pathology -Bone marrow is less bright (condyle grey)

Answer 24

CC: Ask patient to expound on the chief complaint. HPI (Use OLD CARTS) -Onset -Location -Duration -Character (characterize pain) -Aggravating/associated symptoms) -Relieving -Timing -Severity

Answer 25

-Inspection: Look for gross asymmetry of the face, signs of occlusal trauma, loss of posterior teeth -Palpate: Palpate muscles of mastication, cervical musculature, preauricular region -Assess mandibular gait: MIO, excursive movements, protrusive movements, deflection, deviation

Answer 26

Place a tongue blade on canine -If there is ipsilateral preauricular pain, then there is an internal deranagement of the ipsilateral joint

Answer 27

-Condyles in fossa? -Degenerative changes to condylar head? -Loss of joint spacing? -Subcortical cysts? -Chondromatosis (joint mice)? -Subchondral eburnations (sclerosis)? -Osteophytes? -Radiodense changes or coronoid hypertrophy indicative of ankylosis -Condylar hyperplasia, hypoplasia or agenesis -Look at surroundings: 3rd molars, fractures, caries, perio, sinus pathology

Answer 28

-Get T1, T2 weighted, open and closed mouth views -Assess disk position, disk integrity, condition of condyles -T1 better detail of joint anatomy, T2 useful for inflammatory changes and effusions -T1 fat bright, T2 water bright -Brain in T2 has bright gyri and periorbital tissues

Answer 29

-Plain film to visualize TMJ with contrast -Good to visualize the position of the disk and assess for perforations

Answer 30

-Look for ankylotic masses, neoplasms, mechanical obstruction, infectious causes of trismus -Contrast helps to delineate the proximity of blood vessels to an ankylotic mass or a collection of an infection

Answer 31

-Acute closed lock -Previous surgery with continued discomfort -TMJ arthralgia -Wilkes classification 1, 2, and 3

Answer 32

-Ankylosis -Overlying skin infection -Inability to appreciate the regional anatomy (obese patient)

Answer 33

-Draw out the canthal-tragal line (Holmlund-Hellsing line) -First point 10 mm ahead of line and 2 mm below. Corresponds with glenoid fossa -Second point 20 mm ahead of line and 10 mm below. Corresponds with height of the articular eminence -Prep skin with antiseptic solution -Use local anesthetic w/o epi to anesthetize area -Manipulate the jaw to open the joint space -Insufflate superiro disk space with 27-gauge needle with LR -Use an 18 gauge needle (45 degrees), superior and anteriorly to reach lateral aspect of zygomatic arch, walk needle off the bone and enter the superior joint space (anterior port). Average 25 mm deep to skin, 3 cc volume in space -Place posterior port in similar manner with 18 gauge needle -Irrigate with LR (at least 100 mL). Lavaging the joint can break up adhesions and allow the disk to recapture into its premorbid position. This also irrigated out inflammatory mediators -Remove anterior port and inject (Kenalog 40 mg/mL with 0.5% bupivacaine 0.5% with 1:200k epi) -Manipulate joint under anesthesia and check opening under sedation -Post-op management includes aggressive ROM exercises, NSAIDs, splints

Answer 34

-Surgical procedure to manually reposition the disk into its premorbid position -Indications are failure of conservative therapy, Wilkes 2-5

Answer 35

-Ear pack, local anesthesia -Incision marks in the preauricular crease -Incision made through skin and subcutaneous tissue for the entire length -Attention is directed in the superior portion of the incision. Dissect through temporoparietal fascia and auricularis anterior muscle down to the temporalis fascia (glistening white) -The temporal branch of the facial nerves runs within the TP fascia anywhere from 8-35 mm (average 20 mm) from the bony extent of the external auditory meatus -The remaining intervening tissue are dissected down to the level of the temporalis fascia using a nerve monitor/stimulator to avoid the course of the nerve -Palpate zygomatic arch, incise through the attached periosteum. Dissect subperiosteally until you appreciate the joint capsule -Insufflate the joint with LA, make an incision into the joint capsule to enter superior joint space -Mobilize the disk -Assess for perforations (can repair small perforations vs remove disk) -Disk can be plicated in a posterolateral vector to the disc capsule or temporalis fascia with a non-resorbable suture or Mitek anchor -Layered closure

Answer 36

-Infection of the external auditory canal -Pt complains of pain on movement and pressure of the ear -Otoscopy will reveal edematous EAC with possible discharge -Treatment with topical floroquinolone (cover pseudomonas)

Answer 37

-Inflammation of the middle ear structures -Patient complain of ear pain, difficulty hearing, and fever -Otoscopy shows full or bulging tympanic membrane or purulence -Treat with amoxicillin -Consider ENT for myringotomy tubes

Answer 38

-If you are able to visualize the fragment, and having arthroscopic training, attempt removal arthroscopically -If you can't visualize, obtain radiographs in multiple planes for ID -Convert to an open approach for removal

Answer 39

-Otoscopy to examine for TM rupture or hemotympanum -Consult ENT for intra-op examination if noted -If EAC is damaged, place an antibiotic impregnated sponge dressing, suture to maintain opening of EAC -Consider antibiotic-hydrocortisone suspension x14 days -Monitor for granulation tissue and remove as needed

Answer 40

-Fossa is only 0.9 mm thick -If large perforation is noted, obtain an intra-op NSGY consult -If CSF leak suspected post-op, obtain CT scan/MRI (with NSGY consult) -Pt placed on bedrest with HOB greater than 30 degrees -Place on cotrimoxazole (bactericidal and enters CSF) -Most small leaks spontaneously heal within 1 week

Answer 41

-Range 8-35 mm average 20 mm from bony external auditory canal -Innervates frontalis, orbicularis and currugator supercilli muscles -Most resolve in 3-6 months -Start with observation -Treatment for symptomatic patients -Ophthalmology consultation -Lubrication and taping of the eye at night (prevent keratoconjunctivitis) -Physical therapy with electrical stimulation (maintain muscle tone while healing) -Gold weight implants can be placed in upper eyelid for permanent defects

Answer 42

-Gustatory sweating, flushing, and warmth over temporal/pre-auricular areas -Occurs when auriculotemporal nerve is damaged (mostly during arthroscopy) -Usually temporary and resolves within 6 months -Can evaluate with Minor test (solution of iodine, castor oil and alcohol applied to both preauricular regions, gustatory sweating is elicited by having patient chew on lemon drop. Positive test is when yellow mixture turns blue) -Case reports have shown 16-80 IU of botulism A subcutaneous injection resulted in resolution within 1 week -Application of scopolamine (anticholinergic properties) -Surgical transection of innervation

Answer 43

-Concern for bleeding of the internal maxillary artery and branches -IMAX runs 3 mm medial from the mid-sigmoid notch and 20 mm below the condylar head -ALso concern for damage to masseteric artery when cut through sigmoid notch

Answer 44

-Retrodiscal tissue -Lateral pterygoid muscle -Middle meningeal artery (31 mm medial to the zygomatic arch and 2.4 mm anterior to the height of the glenoid fossa

Answer 45

-First step is visualization -Atempt to identify any vessels for cauterization or ligation -If unable to identify, apply firm pressure with moistened gauze, packed tightly in wound -Try thrombin soaked gauze, flowable hemostatic agents, collagen sponges. Hold pressure for at least 5 minutes -Interventional radiology for embolization is warranted if bleeding not controlled by local hemostatic measures -Some advocate for carotid artery cut down, some question due to collateral circulation

Answer 46

-5 cm incision 2 cm below inferior border of the mandible over the SCM -SCM retracted posterior and with blunt dissection parallel to the vessels identify the carotid sheath -Enter sheath carefully -Retract internal jugular vein posteriorly to reveal common carotid -Hypoglossal nerve crosses the arteries above bifurcation, identify and protect -Ligation should occur above the facial branch (third anterior branch) -This reduces blood flow by 73%

Answer 47

-Failed previous TMD surgeries -Severe arthritic joint -Loss of vertical mandibular height and occlusion -Pathology -Ankylosis (bony and fibrotic) -Condylar agenesis

Answer 48

-Biomet stock TMJ (multiple sizes) -TMJ concepts custom

Answer 49

-Chronium cobalt alloy for condylar component -Ultra-high molecular weight polyethylene for fossa component -If unilateral, pseudotranslation possible due to push of contralateral TMJ -Sizes of chronium cobalt (condylar component) are 45, 50 or 55 mm with standard, narrow or offset styles -Chromium cobalt may contain nickel, be aware if allergy

Answer 50

-Pure titanium for condylar component -Pure titanium with ultra high molecular weight polyethylene for the fossa component

Answer 51

-Place pt in MMF Preauricular approach: -Standard preauricular approach to joint capsule -Make an incision in periosteum of lateral aspect of condylar head in a T shape fashion. Expose the lateral aspect of the condyle -Dissect subperiosteally to expose the anterior and posterior regions of the condylar neck -Pack site and direct attention to submandibular approach Submandibular approach -2cm below inferior aspect of mandible -Inject vasoconstrictor -6 cm incision -Dissect skin and subcutaneous tissue to platysma -Undermine skin -Sharp dissection through platysma exposing the superficial layer of the deep cervical fascia. Dissect through this layer with nerve stimulator to protect marginal mandibular nerve (Within or deep to the fascia) -ID and clamp facial artery/vein -Divide pterygomasseteric sling along inferior border of mandible Condylar resection -Condyle retractors placed to isolate the neck of the condyle -Resect exposed condyle (minimum of 15 mm for clearance of condyle/fossa component) -Inadequate removal may lead to impingement of ramus remnant on fossa prosthesis with MMF Fossa Preparation -Reduce fossa noted on pre-op model to accommodate prosthesis -Secure fossa with instrument from TMJ concepts, secure two screws Condyle component -Place in MMF -Secure 2 screws Final screw securement -Cover wounds, enter mouth and remove MMF -Ensure ROM (may need coronoidectomy) and occlusion -Secure rest of screws (4 total in fossa, 6 in ramus) -Irrigate and close -Consider fat graft around fossa to prevent ankylosis

Answer 52

-Post-op radiographs to confirm position and alignment -Post-op exercises and soft diet -Consider PT for 4-6 weeks

Answer 53

-At least 400 mL of LR -Adequate in reducing inflammatory markers of the TMJ (IL-6, bradykinin) -LR is a crystalloid solution containing CaCl, KCL, Sodium lactate. It is close to human serum make-up and well tolerated

Answer 54

-Mimics glycosaminoglycan made by synovial cells -It is viscous, high molecular weight that lubricates and protects articulating surfaces

Answer 55

-Goal is to increase joint space and unload the disk to relieve pain (allows condylar sag) -Procedure is to access like an IVRO with medial pterygoid muscle release to allow for condylar sag -Posterior cut 6-8 mm from posterior border and 10 mm from sigmoid notch -Goal is to achieve 3-4 mm of condylar sag (looking at inferior border and tip of proximal segment)

Answer 56

-Post-op orthopantogram -7 days of IMF (unilateral), 14-21 days of IMF (bilateral) -Elastics and physical therapy -Remove arch bars in 7 weeks