Temporomandibular Joint
-Surgical Anatomy and
Approaches
INDIAN DENTAL ACADEMY
Leader in continuing dental education
www.i...
TEMPOROMANDIBULAR JOINT
Unique features
•
•

Covered with fibrocartilage

•

•

Simultaneous movements

Presence of teeth
...
Evolution

Agnatha

Gnathostomes

Osteichthyes

Amphibians
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Reptiles

Mammals

Mammals like reptiles
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Prenatal development

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Post natal development
Condyle


Mediolateral width
• 9.6mm at birth
• 12.4mm at deciduous point
• 15mm in permanent dent...
Glenoid fossa


3 times more deeper in adult than infant.



Cartilage slowly replaced by fibrous tissue with age.

Arti...
Age changes in Mandible

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ANATOMY &
BIOMECHANICS OF THE
TEMPOROMANDIBULAR
JOINT
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TMJ

BONY COMPONENTS

SOFT-TISSUE
COMPONENTS
1. Articular disk
2. Joint capsule
3. Ligaments

1. Glenoid fossa
2. Condylar...
BONY COMPONENTS

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CONDYLAR HEAD


Oval – mediolaterally – ‘Rugby ball’



15-20 mm long (M-L); 8-10 mm wide (A-P); 8-120 mm thick



Medi...
ARTICULAR EMINENCE
•

Sigmoid shape, Anterior & posterior slopes

•

Saddle – shaped in coronal section – concave
mediolat...
JOINT CAPSULE / CAPSULAR
LIGAMENT


Fibrous, non-elastic membrane
surrounding the TMJ

Functions:


Seals joint space

...
Articular Disc

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Attachments of articular disk –

1. Anteriorly – Joint capsule,
Lateral pterygoid muscle fibres –
‘Sphenomeniscus’ fibres
...
Discal ligaments

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Retrodiscal tissue


loose connective tissue



Between bilaminar
zone of disc



SRL – Meniscotemporal frenum



IRL ...
SYNOVIAL MEMBRANE


Lines inner surface of capsule – villi



Functions:

1.

Medium for metabolic exchange to avascular...


Lubrication by 2 mechanisms –

1.

BOUNDARY LUBRICATION
- primary mechanism
- moving joint
- synovial fluid forced from...
LIGAMENTS


Non-elastic collagenous structures - restricts and limits
movements a joint



Maintains – joint spaces, wit...
COLLATERAL / DISCAL
LIGAMENT
Functions:
1.

Restricts movement of disc
away from condyle

2.

Hinge movement between
condy...
TEMPOROMANDIBULAR /
LATERAL LIGAMENT


FUNCTIONAL LIGAMENT



Fan-shaped reinforcement of
lateral wall of capsule



2 ...


Horizontal part –
lateral pole of condyle & lateral margin of disk
•
•
•

limits posterior movement of condyle & disc
p...
Accessory Ligaments


Sphenomandibular L
igament – no role
• Remnants of Meckel’ s cartilage
• Important landmark during ...
MUSCLES INVOLVED
IN JAW-MOVEMENTS

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Classification:
1.

Jaw-closing group –
1. Temporalis
2. Masseter
3. Medial pterygoid

2.

Jaw-opening group –
1. Lateral ...


TEMPORALIS



Three parts
• Anterior part – almost vertical –
elevation
• Middle part – oblique – elevate
& retrude
• ...


MASSETER
• Origin
 superficial –
• Ant 2/3rd of zygomatic
arch
 Middle layer• ant 2/3rd of deep surface
and post 1/3r...
MEDIAL PTERYGOID:
OriginSuferficial – tuberosity of maxilla and
adjoining bone
deep – medial surface of lat pterygoid
p...


LATERAL PTERYGOID:



Origin• Upper head- Crest of greater wing
of sphenoid.
• Lower head- lat surface of lateral
pter...
SUPRAHYOID MUSCLES:
Digastrics
Mylohyoid
 Stylohyoid

FUNCTIONS
Jaw opening & swallowing
 Pull mandible downward & hy...
BIOMECHANICS OF
TMJ

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At Rest


Occlusion - physiological rest position



Tonus of elevators – maintain constant contact



Intra articular ...
1. INFERIOR JOINT CAVITY




Tightly bound – discal ligaments
Condyle + disc
Rotational / Hinge

2. SUPERIOR JOINT CAVI...
Jaw Movements

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TMJ Relations
Superficial relations


Skin, superficial fascia and branches of the facial
nerve



Auriculo-temporal ner...
Inferior relations


Parotid gland



Lower head of the lateral pterygoid.



Venous channels.



Branches from the pt...
Posterior relations


Auriculo-temporal nerve



Superficial temporal artery.



Parotid gland



Styloid process

Med...
Distances of important structures medial to TMJ.
Structures
from
zygomatic
arch

Mean
mediolateral

Mean
anteroposte
rior
...
IMPORTANT STRUCTURES
Auriculotemporal nerve


Runs from deep to superficial
layers as it reaches
preauricular region.


...
Maxillary artery


Beneath – condylar neck.



Immediate posteromedial relation.



Subperiosteal guard.



Endangered...
Facial nerve

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Mandibular and cervical branch

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Approaches



Many approaches have been proposed.
Can be grouped as follows
•
•
•
•
•
•
•
•

Pre-auricular
Endaural
Post...


Ideal approach characteristics.
• Be based on sound anatomical principles. Have clear
anatomical landmarks.
• Be design...
www.indiandentalacademy.com
Pre-auricular


Started by Risdon in 1934

www.indiandentalacademy.com
www.indiandentalacademy.com
•Popularized by Blair (1936) –
inverted L shape.
•Dingman used Blairs
modification - obtuse angulated
vertical incision.
V...


1979 extensive study by Alkayat and Bramley – the first
modified preauricular incision

www.indiandentalacademy.com
www.indiandentalacademy.com
Indications


When maximum exposure is required.



When lateral and anterior exposure is desired.

Advantage:


There ...
Disadvantages:
 Scarring present.
 Threat of damage to facial nerve
branches.
 Sensory loss over post-auricular skin.
...
Endaural approach







Introduced by Shanbaugh – middle ear surgeries.
Lemperts – use for TMJ.
Different from Dingma...
Surgical approach
I-part



•

Anterior endaural incision in superior meatal
wall (depth-bony cartilagenous junction).

•...
Indications:


When lateral and posterior exposure is required.



To avoid scarring.

Advantages:


Excellent lateral ...
Post-auricular approach


Introduced by Bockenheimer (1920)



Modified by Axhausen.

www.indiandentalacademy.com
www.indiandentalacademy.com
Indications:
 When lateral and posterior exposure is required.
 Normal scar formation in the patient's history.
 Health...
Advantages:
 Excellent accessibility especially
posterior and lateral.
 Reduction in facial nerve damage.
 No excessive...
Risdon’s approach (Submandibular)


Incision about finger breadth
below angle of mandible
parallel to lower border.



L...
www.indiandentalacademy.com
Indications


Usually for subcondylar procedure



Severe bony ankylosis



Direct condylar fracture fixation



Costo...
Retromandibular approach


Developed by E.C. Hinds and W.J. Girotin (1967)

www.indiandentalacademy.com
www.indiandentalacademy.com
Indications
 For condylar neck fractures
 Condylotomy
 Vertical ramus osteotomies
Advantages:
 Less chances of damage ...
Rhitidectomy approach


A variant of retromandibular approach.

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Indications


Esthetic is a concerned and extensive exposure
is required.

Advantages


Less conspicuous facial carve

...
Bicoronal flap


Incision following hair line about
4cm behind it.



Depth – till subgleal loose tissue



Inferior ex...
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Indication
 Bilateral exposure
 Extensive exposure required
Advantages
 Good exposure
 Easy to get the facial phase
 ...
Intra-oral approach


Vertical incision in the retromolar region along the ascending
ramus.



Expose the entire medial ...
Indications
 Oblique subcondylar osteotomy
 Open condylotomy (asymmetry)
Advantages
 No risk to facial and auricular te...
Arthroscopic approach




Arthroscopy of human TMJ
was first described Ohnishi
(1975).
3 primary approaches
•
•
•



La...


2 points are marked on tragocanthal line
• 10mm and 15mm anterior to tragus



18 or 19 gauge needle is passed in the ...
Indications
 Joint arthritis
 For diagnostic purpose
 Hyperextensibility
Advantages
 Closed procedure
 No scar
Disadv...
Conclusion

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References

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Thank you…
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Tmj surgical anatomy and approaches (nx power lite) /certified fixed orthodontic courses by Indian dental academy

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Tmj surgical anatomy and approaches (nx power lite) /certified fixed orthodontic courses by Indian dental academy

  1. 1. Temporomandibular Joint -Surgical Anatomy and Approaches INDIAN DENTAL ACADEMY Leader in continuing dental education www.indiandentalacademy.com www.indiandentalacademy.com
  2. 2. TEMPOROMANDIBULAR JOINT Unique features • • Covered with fibrocartilage • • Simultaneous movements Presence of teeth Bicondylar, ginglymoarthroidal, compound, complex, secondary, synovial joint. www.indiandentalacademy.com
  3. 3. Evolution Agnatha Gnathostomes Osteichthyes Amphibians www.indiandentalacademy.com
  4. 4. Reptiles Mammals Mammals like reptiles www.indiandentalacademy.com
  5. 5. Prenatal development www.indiandentalacademy.com
  6. 6. Post natal development Condyle  Mediolateral width • 9.6mm at birth • 12.4mm at deciduous point • 15mm in permanent dentition  Anteroposterior • Faster than mediolateral growth • 6.5mm - from eruption to completion of deciduous teeth. • 7.3mm - adult size www.indiandentalacademy.com
  7. 7. Glenoid fossa  3 times more deeper in adult than infant.  Cartilage slowly replaced by fibrous tissue with age. Articular eminence :  Rudimentary at birth  Growth increases after eruption of permanent incisors www.indiandentalacademy.com
  8. 8. Age changes in Mandible www.indiandentalacademy.com
  9. 9. ANATOMY & BIOMECHANICS OF THE TEMPOROMANDIBULAR JOINT www.indiandentalacademy.com
  10. 10. TMJ BONY COMPONENTS SOFT-TISSUE COMPONENTS 1. Articular disk 2. Joint capsule 3. Ligaments 1. Glenoid fossa 2. Condylar head 3. Articular eminence  MUSCLES 1. Muscles of mastication 2. Muscles attached to the joint 3. Muscles of facial expression 4. Muscles of the neck www.indiandentalacademy.com
  11. 11. BONY COMPONENTS www.indiandentalacademy.com
  12. 12. CONDYLAR HEAD  Oval – mediolaterally – ‘Rugby ball’  15-20 mm long (M-L); 8-10 mm wide (A-P); 8-120 mm thick  Medial pole > lateral pole  Posterior surface > anterior surface  Articulating surface – Fibrous tissue  140o with line connecting EAM on both sides  Axes – meet anterior to foramen magnum www.indiandentalacademy.com
  13. 13. ARTICULAR EMINENCE • Sigmoid shape, Anterior & posterior slopes • Saddle – shaped in coronal section – concave mediolaterally – path of condyle • With disc, guides mandibular movement during jaw opening • Has 3 layers − Fibrocartilagenous layer (gradually diminishes with age but persists) − Undifferentiated connective tissue − Fibrous connective tissue www.indiandentalacademy.com
  14. 14. JOINT CAPSULE / CAPSULAR LIGAMENT  Fibrous, non-elastic membrane surrounding the TMJ Functions:  Seals joint space  Provides passive stability  Active stability - proprioceptive nerve-endings in capsule www.indiandentalacademy.com
  15. 15. Articular Disc www.indiandentalacademy.com
  16. 16. Attachments of articular disk – 1. Anteriorly – Joint capsule, Lateral pterygoid muscle fibres – ‘Sphenomeniscus’ fibres - stabilize disk during mastication & deglutition 2. Posteriorly disc attached Retrodiscal tissue www.indiandentalacademy.com
  17. 17. Discal ligaments www.indiandentalacademy.com
  18. 18. Retrodiscal tissue  loose connective tissue  Between bilaminar zone of disc  SRL – Meniscotemporal frenum  IRL – Meniscomandibular frenum  Rich blood supply & nerve supply, Compressible www.indiandentalacademy.com
  19. 19. SYNOVIAL MEMBRANE  Lines inner surface of capsule – villi  Functions: 1. Medium for metabolic exchange to avascular articulating surfaces 2. Lubricant – minimizes friction www.indiandentalacademy.com
  20. 20.  Lubrication by 2 mechanisms – 1. BOUNDARY LUBRICATION - primary mechanism - moving joint - synovial fluid forced from one area of cavity to another 2. WEEPING LUBRICATION: - Compressed but not moving joint - synovial fluid forced in & out of articular surfaces by compression - prolonged loading will exhaust fluid - mechanism of www.indiandentalacademy.com metabolic exchange
  21. 21. LIGAMENTS  Non-elastic collagenous structures - restricts and limits movements a joint  Maintains – joint spaces, without causing tissue damage  True ligaments: 1. COLLATERAL / DISCAL LIGAMENTS 2. CAPSULAR LIGAMENT 3. TEMPOROMANDIBULAR / LATERAL LIGAMENT  Accessory ligaments: 1. SPHENOMANDIBULAR LIGAMENT www.indiandentalacademy.com 2. STYLOMANDIBULAR LIGAMENT
  22. 22. COLLATERAL / DISCAL LIGAMENT Functions: 1. Restricts movement of disc away from condyle 2. Hinge movement between condyle & disc 3. Disc moves passively with condyle www.indiandentalacademy.com
  23. 23. TEMPOROMANDIBULAR / LATERAL LIGAMENT  FUNCTIONAL LIGAMENT  Fan-shaped reinforcement of lateral wall of capsule  2 parts 1. Outer oblique – outer surface of condylar neck resists excessive dropping of condyle limits extent of mouth opening www.indiandentalacademy.com
  24. 24.  Horizontal part – lateral pole of condyle & lateral margin of disk • • • limits posterior movement of condyle & disc protects RDT from trauma protects lateral pterygoid from over lengthening or extension Functions:  Prevents lateral (same side) & medial (contralateral) dislocation www.indiandentalacademy.com
  25. 25. Accessory Ligaments  Sphenomandibular L igament – no role • Remnants of Meckel’ s cartilage • Important landmark during surgery  Stylomandibular L igament – limits excessive protrusive movements  Retinacular ligament www.indiandentalacademy.com
  26. 26. MUSCLES INVOLVED IN JAW-MOVEMENTS www.indiandentalacademy.com
  27. 27. Classification: 1. Jaw-closing group – 1. Temporalis 2. Masseter 3. Medial pterygoid 2. Jaw-opening group – 1. Lateral Pterygoid 2. Suprahyoid muscles 3. Infrahyoid muscles www.indiandentalacademy.com
  28. 28.  TEMPORALIS  Three parts • Anterior part – almost vertical – elevation • Middle part – oblique – elevate & retrude • Posterior portion – almost horizontal - retrusion & joint loading shared with pterygo massetric sling www.indiandentalacademy.com
  29. 29.  MASSETER • Origin  superficial – • Ant 2/3rd of zygomatic arch  Middle layer• ant 2/3rd of deep surface and post 1/3rd of lower border of Z arch  Deep layer• Deep surface of Z arch • Insertion  Angle of mandible and ramus  Lower part of lat surface of ramus  Middle & deep fibers – middle and upper part of ramus www.indiandentalacademy.com
  30. 30. MEDIAL PTERYGOID: OriginSuferficial – tuberosity of maxilla and adjoining bone deep – medial surface of lat pterygoid plate Insertion roughened medial surface of angle of mandible Functions Elevation  Protrusion  Unilateral – Mediotrusive  With masseter – muscular sling to support angle of mandible www.indiandentalacademy.com
  31. 31.  LATERAL PTERYGOID:  Origin• Upper head- Crest of greater wing of sphenoid. • Lower head- lat surface of lateral pterygoid plate.  Insertion• Pterygoid fovea • Ant margin of articular disc & capsule www.indiandentalacademy.com
  32. 32. SUPRAHYOID MUSCLES: Digastrics Mylohyoid  Stylohyoid FUNCTIONS Jaw opening & swallowing  Pull mandible downward & hyoid backward www.indiandentalacademy.com
  33. 33. BIOMECHANICS OF TMJ www.indiandentalacademy.com
  34. 34. At Rest  Occlusion - physiological rest position  Tonus of elevators – maintain constant contact  Intra articular pressure www.indiandentalacademy.com
  35. 35. 1. INFERIOR JOINT CAVITY    Tightly bound – discal ligaments Condyle + disc Rotational / Hinge 2. SUPERIOR JOINT CAVITY  Disc not tightly attached to fossa  Translatory / sliding movements www.indiandentalacademy.com
  36. 36. Jaw Movements www.indiandentalacademy.com
  37. 37. www.indiandentalacademy.com
  38. 38. TMJ Relations Superficial relations  Skin, superficial fascia and branches of the facial nerve  Auriculo-temporal nerve  Superficial temporal artery  Glenoid lobe of the parotid gland Superior relations  Temporal lobe of brain  Tympanic cavity  Chorda tympani and anterior ligament to malleus www.indiandentalacademy.com
  39. 39. Inferior relations  Parotid gland  Lower head of the lateral pterygoid.  Venous channels.  Branches from the pterygoid venous plexus Anterior relations  The lateral pterygoid.  The masseteric and deep temporal nerves www.indiandentalacademy.com
  40. 40. Posterior relations  Auriculo-temporal nerve  Superficial temporal artery.  Parotid gland  Styloid process Medial relations  squamo-tympanic fissure, chorda tympani nerve  spine of the sphenoid, sphenomandibular ligament.  middle meningeal artery, carotid sheath.  auriculo-temporal nerve, mandibular nerve.  middle, inner ear, auditor tube. www.indiandentalacademy.com
  41. 41. Distances of important structures medial to TMJ. Structures from zygomatic arch Mean mediolateral Mean anteroposte rior Middle meningeal artery 31mm 2.4mm Carotid artery 37mm -6.5mm Internal jugular vein 38.3mm -8.7mm Mandibular nerve (from GF) 18.7mm 9.2mm Nojan et al [OOO 1999; 88: 674-8]. www.indiandentalacademy.com
  42. 42. IMPORTANT STRUCTURES Auriculotemporal nerve  Runs from deep to superficial layers as it reaches preauricular region.  Inevitable damage – preauricular approach. Superficial temporal artery  Deep to parotid.  Posterior to neck of condyle and crosses zygomatic process  Runs in superficial fascia www.indiandentalacademy.com
  43. 43. Maxillary artery  Beneath – condylar neck.  Immediate posteromedial relation.  Subperiosteal guard.  Endangered in condylotomy and resection of bony ankylosis. www.indiandentalacademy.com
  44. 44. Facial nerve www.indiandentalacademy.com
  45. 45. www.indiandentalacademy.com
  46. 46. Mandibular and cervical branch www.indiandentalacademy.com
  47. 47. Approaches   Many approaches have been proposed. Can be grouped as follows • • • • • • • • Pre-auricular Endaural Post auricular Submandibular Intra-oral Closed condylotomy Rhytidectomy incision Horizontal incision along the lower border of the malar arch • Through soft tissue lacerations or scars. www.indiandentalacademy.com
  48. 48.  Ideal approach characteristics. • Be based on sound anatomical principles. Have clear anatomical landmarks. • Be designed to give protection to both the facial and the auriculo-temporal nerves, and to the external auditory canal. • Provide a relatively bloodless field. • Provide excellent visibility of the lesional site without flap tension. • Be rapidly and confidently executed. • Be uncomplicated in its repair. • Give a good cosmetic result with minimal functional sequelae. www.indiandentalacademy.com
  49. 49. www.indiandentalacademy.com
  50. 50. Pre-auricular  Started by Risdon in 1934 www.indiandentalacademy.com
  51. 51. www.indiandentalacademy.com
  52. 52. •Popularized by Blair (1936) – inverted L shape. •Dingman used Blairs modification - obtuse angulated vertical incision. Vertical component – anterior to tragus. Superior leg – obliquely anterior to pinna. www.indiandentalacademy.com
  53. 53.  1979 extensive study by Alkayat and Bramley – the first modified preauricular incision www.indiandentalacademy.com
  54. 54. www.indiandentalacademy.com
  55. 55. Indications  When maximum exposure is required.  When lateral and anterior exposure is desired. Advantage:  There is minimal bleeding and less sensory loss. • Spares the main branches of vessels and nerves.  Fascial planes are easily identified.  There is excellent visibility.  The potential complications of muscle herniation and fibrosis are avoided. • The muscle is never exposed. www.indiandentalacademy.com
  56. 56. Disadvantages:  Scarring present.  Threat of damage to facial nerve branches.  Sensory loss over post-auricular skin.  Frey syndrome.  Damage to superficial temporal artery. www.indiandentalacademy.com
  57. 57. Endaural approach     Introduced by Shanbaugh – middle ear surgeries. Lemperts – use for TMJ. Different from Dingman that it involved external auditory meatus to a greater depth. Davidson modification – superior preauricular component. www.indiandentalacademy.com
  58. 58. Surgical approach I-part  • Anterior endaural incision in superior meatal wall (depth-bony cartilagenous junction). • Then outward incision for 3-5mm at conchal cartilage. II-part  • Extends from superior extent endaural incision directly upwards to a point about halfway between meatus and upper edge of the auricle. III-part  • Continuous superiorly in the inter cartilagenous cleft and becomes the facial www.indiandentalacademy.com
  59. 59. Indications:  When lateral and posterior exposure is required.  To avoid scarring. Advantages:  Excellent lateral and posterior exposure.  Scar exposure is less. Disadvantage:  Limited anterior visibility.  Demands greater skills.  Tragal cartilage degeneration. www.indiandentalacademy.com
  60. 60. Post-auricular approach  Introduced by Bockenheimer (1920)  Modified by Axhausen. www.indiandentalacademy.com
  61. 61. www.indiandentalacademy.com
  62. 62. Indications:  When lateral and posterior exposure is required.  Normal scar formation in the patient's history.  Healthy ear apparatus and absence of aural sepsis.  Normal width of the external auditory canal.  Absence of infection or inflammation of the joint structures.  General health of the patient does not restrict length of operating period. www.indiandentalacademy.com
  63. 63. Advantages:  Excellent accessibility especially posterior and lateral.  Reduction in facial nerve damage.  No excessive bleeding. Disadvantages:  Limited anterior accessibility.  Perforation of cartilaginous external auditory meatus.  External auditory canal stenosis.  Infections. www.indiandentalacademy.com
  64. 64. Risdon’s approach (Submandibular)  Incision about finger breadth below angle of mandible parallel to lower border.  Lies between cervical branches of facial nerve, lower boundary of bony EAM at least 3cm inferior. www.indiandentalacademy.com
  65. 65. www.indiandentalacademy.com
  66. 66. Indications  Usually for subcondylar procedure  Severe bony ankylosis  Direct condylar fracture fixation  Costochondral grafting Advantages:  Less chances of facial nerve damage Disadvantages:  Inadequate accessibility  Increased reflection and traction of tissue  Temporary parasthesia may be present www.indiandentalacademy.com
  67. 67. Retromandibular approach  Developed by E.C. Hinds and W.J. Girotin (1967) www.indiandentalacademy.com
  68. 68. www.indiandentalacademy.com
  69. 69. Indications  For condylar neck fractures  Condylotomy  Vertical ramus osteotomies Advantages:  Less chances of damage to facial nerve Disadvantages:  Reduced accessibility  Parasthesia of facial nerve  Damage to retromandibular vessels www.indiandentalacademy.com
  70. 70. Rhitidectomy approach  A variant of retromandibular approach. www.indiandentalacademy.com
  71. 71. Indications  Esthetic is a concerned and extensive exposure is required. Advantages  Less conspicuous facial carve  Good exposure Disadvantage  Added time required www.indiandentalacademy.com
  72. 72. Bicoronal flap  Incision following hair line about 4cm behind it.  Depth – till subgleal loose tissue  Inferior extent – continue as preauricular  Blunt dissection to reflect the flap till 2cm above the infraorbital rim and superior temporal line.  Pericranium is incised about 3-4cm superior to orbital rim,  Incision of Alkayat and Bramley www.indiandentalacademy.com continued
  73. 73. www.indiandentalacademy.com
  74. 74. Indication  Bilateral exposure  Extensive exposure required Advantages  Good exposure  Easy to get the facial phase  Reduced risk of damage to facial nerve branches  Hidden scar Disadvantages  Bleeding in initial phase  Extensive dissection required  Not esthetic in completely bald patients www.indiandentalacademy.com
  75. 75. Intra-oral approach  Vertical incision in the retromolar region along the ascending ramus.  Expose the entire medial surface of the ramus protecting the lingual nerve and inferior dental bundle with a retractor.  The condylar notch is visualize.  Elevation of temporal attachment might be necessary.  Winstanely’s used a long, vertical incision from the tip of the coronoid process to the depth of the buccal sulcus.  Sear….. advocates lateral and medial exposure for condylectomy. www.indiandentalacademy.com
  76. 76. Indications  Oblique subcondylar osteotomy  Open condylotomy (asymmetry) Advantages  No risk to facial and auricular temporal nerves  No scar Disadvantages  Limited accessibility  Risk of damage to lingual nerve, Inferior alveolar bundle and maxillary artery. www.indiandentalacademy.com
  77. 77. Arthroscopic approach   Arthroscopy of human TMJ was first described Ohnishi (1975). 3 primary approaches • • •  Lateral posterior (most safe) Lateral anterior Endaural Landmarks • Condyle, zygomatic arch, superficial temporal artery and posterior aspect of mandible. www.indiandentalacademy.com
  78. 78.  2 points are marked on tragocanthal line • 10mm and 15mm anterior to tragus  18 or 19 gauge needle is passed in the upper joint cavity from point A through posterior approach inclining 30° anterior and superior direction.  For the inferior joint cavity needle and cannula are passed at the same point and directed inferiorly and posteriorly at 45° rather than anteroinferiorly www.indiandentalacademy.com
  79. 79. Indications  Joint arthritis  For diagnostic purpose  Hyperextensibility Advantages  Closed procedure  No scar Disadvantages  Risk of damage to the encountering structures  Massive bleeding  AV fistula formation  Intracranial entry www.indiandentalacademy.com
  80. 80. Conclusion www.indiandentalacademy.com
  81. 81. References www.indiandentalacademy.com
  82. 82. Thank you… www.indiandentalacademy.com

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