TMJ Anatomy powerpoint, tmd, maxillofacial surgery, oral surgery, dentistry

1. Temporomandibular Joint

2. Temporomandibular Dysfunction
Chief Complaint
Signs and symptoms
Pain
TMJ
Muscles
Headache or earache
Altered jaw mechanics
Limited range of motion
Joint noise
Clicking
Crepitus
History of Present Illness
Onset
Duration
Extenuating circumstances
Clinical Examination
Myofascial palpation
MIO and symmetry
Excursion and protrusion
Occlusion
Palpation and auscultation of joint

3. TMJ Anatomy
Ginglymoarthroidal joint
- Ginglymoid: hinge movement
- Rotation of condyle on disk in
inferior joint space
- Multiple axis translation between
condyle-disk complex and
temporal bone
- Load bearing condyles function as
fulcrum point for class III lever
- Functional unit requires response
in contralateral joint with every
movement on ipsilateral side
- Compound synovial joint

4. TMJ Anatomy
Glenoid fossa
- Concave structure lined with thin layer of
fibrocartilage (absence of loading)
- Petrotympanic fissure posterior boundary
Attachment of capsule limits boundary of posterior
superior recess of joint cavity
Chorda tympani nerve courses in medial aspect of
fissure
- Temporal bone (1 – 2 mm thick) separates
middle cranial fossa from TMJ
- Spine of sphenoid, sphenomandibular
ligament and middle meningeal artery
(foramen spinosum) positioned medially

5. TMJ Anatomy
Articular eminence
- Prominent convexity covered with dense,
compact connective tissue
- Subjected to loading during function
- Anterior bilaminar
zone inserts on
ascending slope
of eminence
- Limitation of anterior
superior recess
of joint

6. TMJ Anatomy
Condyle
- Broad mediolaterally twice that of
anteroposterior dimension
- Condylar axis along tubercles runs in
posteromedial direction forming obtuse
angle
- Articular surface
covered with thick
layer of
fibrocartilage
- Remodeling with
excessive loading

7. Articular Disk
- Biconcave avascular fibrocartilage (collagen)
- Posterior, intermediate and anterior bands
- Divides joint into two compartments allowing
complex movements of rotation and
translation
- Functions in load adaptation and fluid
distribution
- Attachments:
Medial and Lateral: condylar poles
Anterior: capsule and superior head of lateral
pterygoid
Posterior: bilaminar zone (retrodiskal tissue)

8. TMJ Anatomy
Joint Spaces
- Superior joint space
Translation between condyle-disk complex
and articular eminence
Volume: 1.2 cc
- Inferior joint space
Rotation of condyle
on disk
Volume: 0.9 cc

9. TMJ Anatomy
Facial nerve
- Temporal branch
crosses zygomatic
arch: mean 2.0
cm (0.8 – 3.5 cm)
anterior to
concavity of EAM
- Bifurcation of facial
trunk 1.5 – 2.8 cm
inferior to bony
external auditory
canal
-

11. TMJ Imaging
Arthrography
- Position, shape and integrity of disk - Therapeutic dilation
- Accurate in demonstrating displacement - Extinct?

12. TMJ Imaging
CT scan
- Indicated in complex trauma or
advanced joint pathology
- Depicts osseous structures with
poor disk visualization
- Direct sagittal imaging
- Reformat in different planes
and 3D reconstruction

13. TMJ Imaging
- Direct multiplanar examination
of structures
- Delineation of disk morphology
and position
- Evaluation of joint inflammation
and effusion
- Non-invasive, no ionizing
radiation
- Titanium plates and dental
implants not prohibitive
Magnetic Resonance Imaging

14. TMJ ImagingT1 – weighted images
- 300 – 600 msec
- Morphology (contours,
displacement,
deformity)
- Fat highlighted
- Bone: cortex – black
T2 – weighted images
- 2000 msec
- Pathology (effusions,
avascular necrosis, etc.)
- Water highlighted

15. TMJ Imaging
Disk displacement (arrows) in sagittal and coronal
planes illustrated by MRI

16. TMJ Pathophysiology
Etiology of TMJ disorders
multifactorial
Direct mechanical injury
- Excessive load can lead to physical disruption of
molecules generating free radicals
- Free radical damaging to tissue
- Superoxide anion implicated in degradation of
hyaluronic acid
Osteoarthritis
- Result of chrondrocyte controlled anabolic and
catabolic processes
- Progressive degradation of matrix with accumulation
of inflammatory factors
- Initial morphologic changes are subclinical

17. TMJ Pathophysiology
Osteoarthritis
Early Stage
- Characterized by increased degradation
exceeding synthesis
- Increased metabolic activity in chondrocytes
with disorganized proliferation
Clinical features
Pain
Limitation of opening
Arthroscopic findings
Edematous articular cartilage
Superficial fibrillation
Synovitis
Adhesions

18. TMJ Pathophysiology
Osteoarthritis
Intermediate Stage
- Increased degradation exceeds limited
synthesis
- Progressive degradation and loss of structure
Clinical features
Pain
Limitation of opening
Joint noise
Arthroscopic findings
Advanced fibrillation
Thinning of articular cartilage
Disk displacement
Joint stenosis

19. TMJ Pathophysiology
Osteoarthritis
Late Stage
- Degradation of articular surfaces
Arthroscopic findings
Severe fibrillation
Denudation
Villonodular synovitis
Disk displacement
Disk degeneration or perforation
Joint stenosis
Clinical features
Pain
Limitation of joint movement
Crepitance
Residual Osteoarthritis may
have decreased symptoms and
improved motion

20. TMJ Disorders

21. Conservative Management
Splint Therapy
- Nonsurgical phase III
- Maintenance of occlusal scheme
with flat plane acrylic
splint to decrease
parafunctional habits and
load
- Stabilize TMJ, redistributing
occlusal forces,
protecting dentition,
decreasing bruxism and
reducing pain

22. Undisputed applications for TMJ
Surgery
• Ankylosis
• Growth disorders
• Recurrent subluxation
• Infections
• Neoplasms
• These make up the minority of TMJ cases

23. Relative Indications for TMJ
Surgery
• TMD is refractory to appropriate non-surgical
therapies
• TMJ is the source of pain and/or dysfunction that
results ina significant impairment to the patient
in day to day acitivity
– Pain localized to the TMJ
– Pain on loading of the TMJ
– Pain on movement in the TMJ
– Mechainical interferences in the TMJ

24. Surgical Procedures for
Temporomandibular disorders
• Arthrocentesis and lavage
• Arthroscopy
• Arthrotomy
• Modified condylotomy
• Adjunctive procedures for TMJ
– Botox
– Coronoidectomy

25. Arthrocentesis
- Minimally invasive, simplest TMJ intervention
follows conservative management
- Local vs. conscious sedation
- Lavage, lysis, manipulation, injection of meds

26. Arthrocentesis
Benefits
- Reduction of joint
friction, release of
fine adhesions, re-
establish range of
motion
- Evacuation of debris,
chemical mediators
of pain and
inflammation
- Therapeutic, low
morbidity, cost
effective
Indications
-Localized joint pain,
acute limitation of motion
(interincisal and
excursion), inflammatory
conditions
- Limited improvement
with medical
management

27. Arthrocentesis Technique
- Auriculotemporal nerve block
- Needle positioned at 10-2 point
anterior to tragus
- Identify arch and periosteum
- Superior joint space confirmed
with vacuum after insufflation,
return of joint fluid, mandible
motion
- Additional port placed
immediately anterior
- Lavage joint with 100-200 cc
- Steroid and anesthetic infiltrated

28. Arthrocentesis Results
- Significant reduction in pain and increased
opening in >70% of patients
- Nitzan, et al: 91.8% success rate in treatment
of severe, limited range of motion (1991)
- Hosaka, et al: “Outcome of Arthrocentesis for
TMJ with Closed Lock at 3-year follow
up.”
70% success rate at 3 months and 78.9% at 3 years
- Goudot, et al: 79% improvement in pain;
arthroscopy 52% (2000)
Functional improvement more significant with
arthroscopy (9.6 ± 5.8mm) vs. 4.3 ± 4.4mm

29. Arthroscopy
- TMJ arthroscopy first
reported in literature
(Ohnishi, 1975)
- Arthroscopic anatomy,
diagnosis and treatment of
locking TMJ (Murakami,
1984)
- Holmlund and Hellsing
describe identifiable and
repeatable puncture sites
(1985)
- McCain and Sanders
pioneers in arthroscopic
Historical Perspective

30. Arthroscopy Technique
Preoperative Preparation
- General anesthesia - nasotracheal intubation
- Exam under anesthesia (palpation)
- Elimination of muscle influence permits
evaluation of joint function
- Bacitracin impregnated
cotton pellet
placed in external
auditory meatus
- Prep and sterile Quinn
drape

31. Arthroscopy Technique
Superior Joint Space Insufflation
- 18-gauge needle positioned at 10-2 point
anterosuperiorly paralleling ear canal
- Contact lateral rim of glenoid fossa, needle guided
around rim inferiorly, medial insertion to enter joint
space
- Balloon joint space with ≈ 3-5 cc normal saline; aids
trocar placement (plunger rebound indicates
correct position
and adequate insufflation)

32. Arthroscopy Technique
Trocar placement
- Cannula and trocar positioned with anterior and
superior vector on lateral zygomatic arch in region
of posterior slope of articular eminence
- Tip advanced to bone edge, periosteum scored and
inferiorly directed for incising capsule
- Stepping off bone ledge rotating through capsule and
advancing into superior joint space
- Puncture into posterior recess
entering joint in single pass
(multiple lacerations increase
postoperative inflammation and
morbidity)

33. Arthroscopy Technique

34. Arthroscopy Technique
- Arthroscope advanced through lateral recess to
visualize anterior aspect of articular eminence,
anterior disk and anterodiskal tissue
- Access to anterior recess provides visualization for
placement of second working port

35. Arthroscopy Technique
Triangulation
Working port placed after stab incision
at 25-10 point (minimum of 15 mm
separation between ports)
Second portal in eminence region placed
under direct visualization allows
instrumentation of joint contents

36. Arthroscopy Technique
Instrumentation
- Blunt trocar, radiofrequency
probe, motorized shaver,
and/or laser utilized
- Treatment of adhesions,
pathology, internal derangements
and removal of tissues
- Depth roughly 20 – 25 mm from
skin to center of joint
- Lavage of joint with irrigation
expands joint space, allows
visualization during
instrumentation and flushes
irritants (inflammatory and pain
mediators)

37. Arthroscopic Anatomy
Medial synovial drape
- First area examined with
classic gray-white
translucent lining
- Vertically running stria
provide orientation
- Vascular proliferation
during inflammatory
states

38. Arthroscopic Anatomy
Pterygoid shadow
- Purple hue related to presence of pterygoid
muscle beneath thin synovial lining
- Medial trough leads from medial synovial
drape anteriorly to pterygoid shadow
- Marked erythema in pathologic states

39. Arthroscopic Anatomy
Retrodiskal synovium
- Taut tissue when condyle in normal position
and bunched with condylar seating
- Oblique protuberance (fibroelastic band)
evident when condyle translated anteriorly
- Hypervascularity and
synovial redundancy
apparent during
inflammatory states
- Lateral recess difficult to
inspect secondary to
angle of trocar
placement

40. Arthroscopic Anatomy
Glenoid fossa and posterior slope of
eminence- Arthroscope positioned
immediately inside of
capsule
- Fibrocartilage distinctly
white and reflective
- Striations in fibrocartilage on
posterior slope diminish
on thin layer covering
glenoid fossa
- Iatrogenic trauma to
fibrocartilage may result in
degenerative erosions

41. Arthroscopic Anatomy
Articular Disk
- Smooth surface with no
dimpling or vascularity
- Retrodiskal flexure at
junction of synovium
and posterior band
- Manipulation of mandible to
evaluate position and
function of disk
- Redundant tissue often evident
with displacement

42. Arthroscopic Anatomy
Intermediate zone
- Space between posterior slope of eminence
and articular disk
- Normal anatomy described as white
fibrocartilage on smooth white disk contour
- Condylar position and
displacement of disk
alter zone
- Maneuvering through
intermediate zone allows
visualization of
anterior recess

43. Arthroscopic Anatomy
Anterior recess

44. Arthroscopic Maneuvers
Lysis and Lavage
- Most conservative form and gold standard of
arthroscopy
- Adhesions released with blunt probes or
instrumentation (radiofrequency or laser)
- Confirm disk mobilization depressing
retrodiskal tissues and manipulation of
mandible

45. Arthroscopic Maneuvers

46. Arthroscopic Maneuvers
Releasing Procedures

47. Arthroscopic Maneuvers
radiofrequency
fibrillations
Ablation
laser

48. Arthroscopic Maneuvers
synovitis
disk removal
synovitis
Laser aiming beam

49. Condylotomy
• Condylar sag aids range of
motion and internal
derangement
• Complications include
malocclusion and sensory
disturbances

50. Arthrotomy – Total Joint
Reconstruction

51. Arthrotomy – Total Joint Reconstruction

52. Adjunctive Measures
Distraction
Osteogenesis
Condyle recreated post-
condylectomy or
prosthetic joint failure

53. AURICULAR CARTILAGE
• Witsenburg 1984, Matukas 1990, Kent
and Widner 1990
• Somewhat operative technique
dependent
• Stabilization varies
• Early complication minimal
• Fun procedure - otoplasty effect

56. DISC REMOVAL WITH AUTOLOGOUS
TEMPORALIS MUSCLE/FASCIA FLAP:
INDICATIONS
• Disc replacement where significant vertical
dimension (up to 4-5mm) of the condyle has
been lost and lateral pterygoid function of the
mandibular condyle has not been
compromised
• Patient refuses a graft from an additional
donor site

63. DERMIS GRAFTS
Clinical-Georgiade 1957, Zetz and Irby
1984, Meyer 1988
• Disc repair
• Disc replacement
• Ankylosis cases - thickness of dermis
depends on gap
• With costochondral grafting

64. • Resembles a disc when used as a
patch in perforations
• Reported superior ability to
withstand joint loading compared to
other tissues
DERMIS GRAFT

65. De-epithelializing prior to dermis harvest

66. Dermis in monkey - Tucker

69. FOSSA - ARCH - EMINENCE
RECONSTRUCTION
• Large fossa perforation and thinning -
cranial, rib
• Large fossa perforation with arch loss
- iliac crest, cranial
• May be done with partial/total joint
procedures

73. INDICATIONS
• Condylar height loss greater than 7-8 mm
• Loss of lateral pterygoid muscle
• Trauma
• Multiple joint surgery
• Advanced rheumatoid-disease and DJD
• Ankylosis
• Hypoplasia

75. 15
Yr
Post
op

77. TECHMEDICA - TMJ
CONCEPTS
• Custom CAD/CAM design based on CT,
computer generated plastic model, and
surgeon imput