2. Temporomandibular Joint Dysfunction Flashcards
Vascular supply of TMJ
Branches of the superficial temporal, maxillary, and masseteric arteries
Nerve supply of TMJ
Branches of the auriculotemporal with contributions from the masseteric and posterior deep temporal nerve
Define myofascial pain dysfunction (MPD)
Non-articular TMJ disorder that manifests itself as dull regional masticatory myalgia that worsens with function and can lead to a decreased range of motion. It can involve the muscles of mastication and any combination of the supramandibular and inframandibular muscle groups (most common TMJ disorder).
Etiology of myofascial pain dysfunction
Parafunctional habits
Life stressors
Apertognathia and/or overjet greater than 6mm
Lack of posterior dentition leading to muscle hyperactivity
Types of degenerative joint disease (2)
Non-inflammatory degenerative joint disease (osteoarthritis)
Inflammatory arthritis (RA, JRA, psoriatic arthritis, gout, pseudogout, ankylosing spondylitis, reactive arthritis)
What is internal derangement of the TMJ?
Disorder of the TMJ in which the articular disk is in an abnormal position as it relates to the condyle and fossa when the teeth are in occlusion. Malposition of the disk may lead to pain, instability, decreased ROM, and abnormal mobility of the mandible
Etiology of TMJ internal derangement
Trauma, joint laxity, parafunctional habits, altered joint lubrication system, anchored disk phenomenon (disk adhesion to articular fossa), MPD
How is internal derangement diagnosed?
Decreased MIO, deviation, deflection, palpable clicks (reciprocal), and crepitus. Patients often have pain in preauricular region as opposed to side of face.
MRI (T1, T2). Disk displaced often in anteromedial vector. Osseous changes and abnormal contours of the disk.
What is the Wilkes classification?
Classifies degree of internal derangement
Stage I: painless clicking, no pain or locking. ADD. Normal disk displaced AM.
Stage II: occasional painful clicking, intermittent locking. ADDwR. Mild disk deformity. No osseous changes.
Stage III: frequent painful clicking with severe limitation in ROM. Joint tenderness. ADDw/oR. Moderate disk deformity, no osseous changes. Possible adhesions.
Stage IV: restricted ROM, chronic pain, creptius. ADDw/oR. Marked disk deformity, osseous changes. Disk perforated.
Stage V: joint pain, crepitus. Disk displaced. Marked disk deformity, severe osseous changes. Perforated disk. Severe osseous changes of condyle and fossa.
What is ankylosis of the TMJ?
True ankylosis is 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, RA, psoriatic arthritis, prolonged immobilization, and previous TMJ or orthognathic surgery.
What are two common accepted classifications of TMJ ankylosis?
Topazian (1984): 1. only condyle; 2. extends to sigmoid notch; 3. entire condyle, sigmoid notch and coronoid.
Sawhney (1986): 1. flattened condylar head with close approximation to joint space; 2. flattened condyle, bony fusion on outer aspect of articular surface; 3. bony block bridging ramus and zygomatic arch; 4. wider bony block completely replaces architecture of the joint.
What is the KABAN protocol?
Seven step protocol for treatment of TMJ ankylosis in pediatric patients:
1. aggressive resection of fibrous or bony ankylotic mass
2. coronoidectomy on affected side and measure MIO intraoperatively
3. coronoidectomy on contralateral side if you cannot achieve MIO >35mm
4. lining TMJ with temporalis myofascial flap or native disk
5. reconstruction of ramus-condyle unit with DO or CCG
6. early mobilization of the jaw
7. aggressive physiotherapy
How is fibrous ankylosis treated surgically?
More conservatively than bony ankylosis. Lysis of adhesions and fibrosis, diskectomy.
What can be adjunctive treatment to surgical treatment of ankylosis?
Aggressive PT. Frequent follow-up. Consider radiation therapy (20Gy in 10 fractions) to prevent recurrence and consider when using autogenous grafting as recurrence is higher.
When is a costochondral graft used?
CCG used in growing child. Ease of adaptation and remodeling, low morbidity, low rate of infection, low cost.
Harvest ribs 4-7 (direct cartilagenous connection to sternum. 6 most commonly harvested (inframammary crease, avascular plane). Right rib so not confused with cardiogenic pain. Some advocate rib from contralateral side for appropriate curvature.
Describe rib harvest technique.
-Incision inframammary crease (5cm)
- Dissection through subq tissue, fascia, plane b/t pectoralis major and rectus abdominis.
- Two fingers to straddle fifth and sixth intercostal space. Incision through periosteum. Dissect around rib subperiosteally.
- Sharp blade to make cartilaginous incision. No more than 3cm in children to avoid overgrowth of ridge and to prevent separation of cartilaginous cap.
- Pull rib laterally and section. Check for pleural tears with saline/valsalva.
- Close periosteal sleeve. Close fascia. Postop CXR.
T1 MRI
Fat bright (white)
Better for anatomy eval
Marrow fat in condyle will have high signal intensity
Gyri of brain do not show white banding. Orbits gray.
Disk and cortical bone black due to low proton density (same with T2).
T2 MRI
Water is bright and fat is dark
Brain gray.
Better to look for effusions and pathology.
Bone marrow less bright (condyle looks gray)
Disk and cortical bone black due to low proton density (same with T1)
Bright signal from gyri of brain.
OLD CARTS acronym
O: onset
L: location
D: duration
C: character
A: aggravating/associated symptoms
R: relieving
T: timing
S: severity
Arthrocentesis indications
For acute closed lock, previous surgery with continued discomfort, TMJ arthralgia, Wilkes classification 1, 2, 3.
Arthrocentesis contraindications
Ankylosis, overlying skin infection, inability to appreciate regional anatomy.
Describe technique for arthrocentesis
-Draw canthal tragal line (Holmlund-Hellsing line)
-First point 10mm ahead of line and 2mm below (deepest point of glenoid fossa)
-Second point 20mm ahead and 10mm below (height of articular eminence)
-Prep skin
-Local w/out epi
-Insufflate joint space with 27-gauge needle with LR
- 18-gauge at 45 degree angle anteriorly to reach zygomatic arch and walk into superior joint space
- Posterior port in similar manner with 18-gauge
- Irrigate with at least 100cc
- Remove anterior port. Inject 40mg/mL Kenalog
- Manipulate joint under anesthesia, check opening
- Aggressive ROM exercises, NSAIDs, splints
When is disk repositioning procedure indicated?
Surgical procedure to manually reposition disk into premorbid position. Indications are failure of conservative therapy, Wilkes 2-5.
Describe disk reposition technique
Incision preauricular crease, skin, subq
- Attention to superior portion. Dissect through temporoparietal fascia to temporalis fascia (glistening white).
- Temporal branch of facial nerve runs within TP fascia 8-35mm (avg 20mm) from bony anterior extent of EAM.
- Palpate zygomatic arch, incise through periostium and dissect subperiosteally until you appreciate joint capsule
- Insufflate joint with local. Make incision into joint capsule to enter superior joint space.
- Mobilize disk, assess for perforations (repair if small, remove disk if large).
- Disk can be plicated in posterolateral vector to disk capsule or temporalis fascia with non-resorbable suture or Mitek anchor.
- Close in layers
TMJ TJR indications
Failed previous TMD surgeries
Severe arthritic joint
Loss of vertical mandibular height and occlusal relationship
Pathology
Ankylosis- either bony or fibrotic
Condylar agenesis
Surgical technique for TMJ TJR
Preauricular approach to joint capsule.
- incision preauricular crease through skin, subq
-superior portion of incision- through TP fascia to temporalis fascia (glistening white). Temporal branch of facial nerve runs within TP fascia 8-35mm from bony anterior extent of EAM (avg 20mm).
-Palpate zygomatic arch, incise through periosteium. Dissect subperiosteally to joint capsule. Insufflate with LA.
- Incision in periosteum of lateral aspect of condylar head in T-shape fashion to expose lateral aspect of condyle. Expose anterior and posterior regions of condylar neck. Pack site
Submandibular approach
- 2cm below inferior aspect of mandible. Inject vasoconstrictor.
-6cm incision through skin, subq to platysma
-Undermine
-Sharp dissection through platysma to superficial layer of deep cervical fascia. Disect through with nerve stimulator to test for marginal mandibular nerve.
- Dissect out facial artery and vein. Isolate and clamp/tie vessels.
- Divide pterygomasseteric sling.
Condylar resection
- Condyle retractors, resect exposed condyle (15mm clearance for condyle and fossa.)
Fossa preparation (for TMJ concepts reproduce any contouring noted on model.
- Secure fossa component (only 2 screws to start)
Condyle component
- Place in MMF
- Place condyle prosthesis, 2 screws
Final screw securement
Ensure ROM 32-35mm
Irrigate and close in layers
Myofascial pain dysfunction potential treatment
- Treatment to address etiology (stress, anxiety, bruxism, clenching, malocclusion, parafunctional oral habits, internal derangement of TMJ, rheumatologic diseases, fibromyalgia, and vasculitis)
Conservative therapy: stress management, occlusal splint therapy, PT, heat, NSAIDs, muscle relaxants, anxiolytics.
Orthodontic therapy
Trigger point injections (local w/ or w/o steroid directly into tender areas of muscles).
Botulinum toxin to reduce muscle activity.
Mahan’s test
Biting on a tongue depressor on one side that elicits pain in contralateral TMJ is positive test that suggests intracapsular pathology.
If ipsilateral pain, muscular etiology
