Surgical anatomy of TMJ

This seminar explains about the development, relations, ligaments, various attachments, vascular and nervous supply and various surgical approaches and its modifications to TMJ

1. SURGICAL ANATOMY OF TMJ Dr. VIJAYA LAKSHMI.G I MDS Dept. of OMFS

2. CONTENTS- INTRODUCTION DEVELOPMENT OF TMJ PECULIAR FEATURES ARTICULATORY SYSTEM COMPONENTS - Articular Eminence - Glenoid Fossa - Condyle - Articular Disc - Ligaments - Muscular Components

3. Vascular supply Nerve innervation Relations of the TMJ Age changes in TMJ Structures injured during surgery Associated surgical anatomy Surgical approaches to TMJ and their modifications Complications C onclusion References

4. INTRODUCTION - Ginglymoarthrodial joint ginglymus : hinge joint arthrodia : gliding motion Craniomandibular joint Complex joint

5. DEVELOPMENT - Early TMJ develops from the 1 st branchial arch mesenchyme Early embryonic joint: Between malleus and incus (from 1 st branchial arch) Primary TMJ till 16 weeks of IUL Uniaxial hinge joint capable of no lateral motion.

6. End of 7-11 weeks: 2 TMJ begins to develop . 9th week– a condensation of mesenchyme appears surrounding the upper posterior surface of rudimentary ramus ( joint capsule develops from the condensed mesenchyme) 10-12 weeks of IUL, both blastema grows towards each other 10th week- two clefts - forming the two joint cavities -intervening articular disc Upper compartment starts to appear: 11 1/2 weeks

7. The TMJ develops from 2 blastemas: a) temporal blastemas arise from the otic capsule b)The condylar blastema arises from the secondary cartilage of the mandible

8. Intra articular disc: well defined by 16 th week of IUL At birth: mandibular fossa : - flat (no articular eminence) - prominent after eruption of 1 dentition Developing disc- highly cellular & vascular. (vessels disappear by 3 years of age) Attachments of fetal disc: rich in elastic fibers. Joint components mature by 14 th week of IUL

9. Fetal disc: - nerve fibers & blood vessels in periphery. - disappear but remain at the disc attachment after birth. - In center of condyle, cartilage develops. - Remains as 2 cartilage upto 27yrs of age Adaptive changes: C ondyle enlargement in adulthood (in response to overloading)

10. PECULARITY OF TMJ - Bilateral diarthrosis Articular surface covered by fibrous cartilage instead of hyaline cartilage It is the only bilateral joint that crosses the midline. Only joint in human body with rigid end point ,due to occlusion In contrast to other diarthroidal joints, TMJ is last to develop (i.e., in about 7th week of uterine life) TMJ develops from distinct blastema The effect of distraction on the temporomandibular joint Suzanne U. Stucki -McCormick

11. Regional adaptive growth center for growth & development of mandible & middle 3 rd of face Trauma Retrognathia SIGNIFICANCE OF TMJ -

12. ARTICULATORY SYSTEM - Upper articular surface: Articular tubercle Anterior part of the mandibular fossa Posterior non-articular part formed by tympanic plate

13. B) Lower articular surface: Head of mandible

14. COMPONENTS - ARTICULAR EMINENCE MANDIBULAR FOSSA CONDYLE ARTICULAR DISC LIGAMENTS MUSCULAR COMPONENT

15. E: Articular eminence Enp: entogolenoid process t: articular tubercle Gf: Glenoid fossa lb: lateral border of the mandibular fossa pep : preglenoid plane

16. GLENOID FOSSA- separates the joint from middle cranial fossa Lined by: dense avascular fibrocartilage Cross section: fossa & eminence form ‘Lazy S’ PA Sqamotympanic fissure separates it from tympanic plate, forms a posterior wall of glenoid fossa

17. Parts: Medial rim: lateral to : - spine of sphenoid & - foramen spinosum (middle meningeal artery) B) Lateral rim continues: - anteriorly into zygomatic tubercle (which can be felt under the skin ) - posteriorly into postglenoid tubercle

18. CLINICAL SIGNIFICANCE: Chorda tympani nerve appears at the medial end of petro tympanic fissure close to spine of sphenoid. Roof of fossa is thin (separates brain from joint) – avoid perforation of roof during surgery of roof. Melugin MB et al. 1997 55;11: 1342-1347 Glenoid fossa fracture and condylar penetration into the middle cranial fossa: Report of a case and review of the literature 

19. Important surgical landmark during dissection down to the joint from a preauricular approach. Posteromedially: contents of the middle ear, damaged by injudicious surgery

20. CONDYLE - Elliptical shape Long axis:15-33 to frontal plane 90 to body of mandible

21. It has a medial and lateral pole The medial pole is directed more posteriorly Thus, if the long axes of two condyles are extended medially, meet at approximately the basion on the anterior limit of foramen magnum, forming an angle that opens toward the front ranging from 145° to 160°

22. Anterior aspect Mediolateral length – 15-20mm Poster superior aspect Anteroposterior width- 8 to 10 mm

23. Mainly 4 shapes are seen- Convex-58% Flat- 25% Pointed-12% Round- 3% ( mainly in children)

24. ARTICULAR DISC- Biconcave (sagittal) fibrocartilagenous non-innervated (except around periphery) Avascular collagen flexible

25. Articular space: Upper compartment * Gliding movement B) Lower compartment * Hinge/Rotation * Gliding movement

26. 3 zones: Anterior band (2mm)- Narrow anteroposteriorly Posterior band: 3mm – Thickest and widest Intermediate zone: 1mm (thinnest) More posteriorly: bilaminar or retrodiscal region

27. Disc stabilized on condyle by: Disc edges fused with the part of the capsular ligament that tightly surrounds the lower joint compartment. Well-defined bands in the capsular ligament attach the disc to the medial and lateral poles of the condyle. - Thick anulus prevents the disc sliding off the condyle, provided that the condyle and disc are firmly lodged against the articular fossa

28. Anterior: - Confluent with capsule, fascia of lateral pterygoid (Superior head) Posterior: retrodiscal tissue

29. The TMJ disc displays viscoelastic material properties that are related to its ECM components. - TMJ disc is observed to be 100-1000 times stiffer under tension than compression . Compression- The compressive properties of the disc may be contributed by both GAG and collagen. Tension- The disc frequently experiences tensile forces during normal joint movements. At strains of 0-2%, the instantaneous elastic modulus of the healthy TMJ disc is 44 MPa , compared to 53 MPa for internally deranged tissue. MECHANICAL PROPERTIES -

30. JOINT IN POSITION- Primary proprioceptors (Golgi tendon organs) b) Encapsulated mechanoreceptors

31. Malleo mandibular ligament (Pinto’s ligament) - Most medial portion of disc is connected posteriorly to PINTO’s ligament vascular innervated fibro elastic

32. Function: Shock absorber (less friction & heat production) Designed to transmit forces generated through the condyle to the articular eminence Protection for bony components Promotes lubrication Stabilizes the condyle against the temporal articulation

33. VASCULAR KNEE- Above Posterosuperior aspect of condyle & anterior to bilaminar zone, disc is vascular. Anterior extensions of disk at its attachment to superior belly of lateral pterygoid is also vascular.

34. LIGAMENTS OF TMJ -

35. CAPSULE- Attached : Above to rim of glenoid fossa & articular eminence Below to periosteum of neck of condyle

36. ATTACHMENTS OF CAPSULE- Anterolaterally : articular tubercle Laterally : lateral rim of the mandibular fossa Posterolaterally : postglenoid process Posteriorly : posterior articular ridge Medially : medial margin of the temporal fossa Anteriorly : preglenoid plane

37. Relations: (Medially)- 1) Spine of Sphenoid 2) Sphenomandibular ligament 3) Middle meningeal artery (through Foramen Spinosum)

38. Lateral retraction of capsule allows access to upper joint space. FUNCTION: On the lateral part of the joint , capsule functionally limits the forward translation of the condyle. Medially and laterally- blends with the condylodiscal ligaments

39. Anteriorly, the capsule has an orifice through which the lateral pterygoid tendon passes This area of relative weakness in the capsular lining becomes a source of possible herniation of intra-articular tissues, may allow forward displacement of the disk

40. CLINICAL SIGNIFICANCE: Extension of a lateral capsular incision cause severe bleeding if not cautious.

41. During Preauricular incision ( expose lateral aspect of TMJ), protect temporal branch of facial nerve by having the dissecting plane under superficial layer of deep temporalis fascia until root of zygomatic arch is reached Reflect tissue close to periosteum & desend inferiorly to expose the entire lateral capsule Parotid is usually found between posterior capsule and postglenoid tubercle. Extends till it reaches lateral wall of pharynx. Enlargement of Parotid can impinge on posterior capsule of TMJ & cause pain during closure of mouth or during chewing movements

42. LATERAL/TM LIGAMENT- Main stabilizing ligament Thickened capsule Collagen fibers - Course: Down & back Attached above to articular eminence Below to outer & post side of neck of condyle Posterior fibers unite with capsule

43. Function: Limits protraction Inferior distraction Posterior movement of condyle Specific length & poor ability to stretch- maintains integrity & limits movement of TMJ (mainly anterior excursion & prevents posterior dislocation – CHECK LIGAMENT Slippage of condyle: medially prevented by Glenoid process laterally by TM ligament

44. COLLATERAL /DISCAL LIGAMENT- Attach medial & lateral borders of articular disc to the poles of the condyle. True ligament (collagen i.e. don’t stretch) Function: Restrict movement of disc away from condyle (allow disc to move passively with condyle as it glides anteriorly & posteriorly) Hinge movement

45. SPHENOMANDIBULAR LIGAMENT: Arises: from spine of sphenoid Inserted into: Lingula of mandible ACCESSORY LIGAMENTS -

46. RELATIONS- 1. Laterally- lateral pterygoid muscle 2. Posteriorly- auriculotemporal nerve 3. Anteriorly- maxillary artery 4. Inferiorly- the inferior alveolar nerve & vessels, a lobule of the parotid gland 5. Medially- medial pterygoid with the chorda tympani nerve and the wall of the pharynx with fat and the pharyngeal veins intervening

47. The ligament is pierced by the mylohyoid nerve and vessels This ligament is passive during jaw movements, maintaining relatively the same degree of tension during both opening and closing of the mouth

48. Internal Maxillary artery Auriculotemporal nerve lies between it & neck of mandible. Chorda tympani branch of facial nerve crosses the ligament at the upper end. Important landmark during surgery:

49. SIGNIFICANCE- a ) forms broad impermeable wall medial to mandibular foramen. During IANB ,it holds LA concentrated against the nerve and prevents fluid from dissipating into adjacent soft tissue. b) Loose areolar tissues present in it, during blunt dissection, help define the posterior limits of capsule. It can cause abundant venous hemorrhage.

50. 2) STYLOMANDIBULAR LIGAMENT- Thick deep cervical fascia Origin: Styloid process Insertion : Angle of mandible Function: Restrict movement of disc away from condyle Hinge movement

51. Sources: 1) from plasma by dialysis 2) secretion synoviocytes type A and B Upper compartment - 1.2 ml Lower compartment - 0.9 ml SYNOVIAL FLUID -

52. Composition: a) Hyaluronic acid - viscous b) Lubricin – (glycoprotein): lubricates reduces friction b/w articular surfaces of joint c) Mucin

53. SIGNIFICANCE- Synovial hyperplasia seen in Rheumatoid arthritis, causes severe pain Fluid exists under –ve intra-articular pressure ↑ in pressure: factor in pathogenesis of Osteoarthritis & cause pain

54. FUNCTION: Nutrition Phagocytosis Lubrication

55. MUSCLES AROUND TMJ -

56. Lateral pterygoid muscle attachments are of surgical significance, since it is not possible to remove the head of the condyle without sectioning the insertion Where reattachment does not take place, some joint function is lost and deviation of the jaw occurs when opening widely.

57. Limits rotation of condyle (20-25mm) Translation Beyond 25 mm

58. Lateral movements: Medial & Lateral pterygoid Hinge movement: Geniohyoid Anterior belly of Digastric Translatory : lateral pterygoid

59. Stable occlusion- Five requirements centric jaw relation immediate front teeth separation, proper cusp–fossa relationship, stable/even bite, and proper space (volume) inside the mouth. Instability : ↑ pressure on the joint damage & degeneration OCCLUSION - The Relationship Between Dental Occlusion/Temporomandibular Joint Status and General Body Health: Part 1. Dental Occlusion and TMJ Status Exert an Influence on General Body Health Hyung-Joo Moon, DDS, MSD, PhD,1 and Yong- Keun Lee, DDS, MSD, PhD1,2

60. VASCULAR SUPPLY -

61. Lateral aspect of capsule: Superficial temporal artery -Deep & posterior aspect of retrodiscal capsular part Branches of Internal Maxillary artery ( Deep auricular Posterior auricular, Massetric branches) The blood supply to TMJ is only superficial, no blood supply inside the capsule TMJ takes its nourishment from Synovial fluid

62. Venous plexus around capsule Maxillary vein Transverse facial vein Superficial temporal vein VENOUS DRAINAGE -

63. Auriculo temporal nerve – - posterior, - medial - lateral parts of the joint Massetric nerve Branch from posterior deep temporal nerve for anterior parts of joint NERVE SUPPLY -

64. Anteriorly- - Mandibular notch - Lateral pterygoid - Masseteric nerve and artery RELATIONS OF THE TMJ -

65. Posteriorly - Parotid gland - Superficial temporal vessels - Auriculotemporal nerve

66. Laterally- - Skin and fascia - Parotid gland - Temporal branches of facial nerve Medially- - Tympanic plate (separates from ICA) - Spine of sphenoid - Auriculotemporal & chorda tympani nerve - Middle meningeal artery - Maxillary artery

67. Superiorly– Middle cranial fossa M iddle meningeal vessels Inferiorly– Maxillary artery & vein

68. Condyle: More flattened Fibrous capsule : thicker Osteoporosis Thinning or absence of cartilaginous zone Articular Disc: Thinner Hyalinization AGE CHANGES IN TMJ -

69. DISEASES AFFECTING TMJ -

70. Dislocation – forward Reduction is prevented by spasm of elevators (Masseter, Temporalis, Medial Pterygoid) hold the dislocated jaw open with condyle in front of eminence. R x : operators thumbs pressing down on molars or alveoli, before the condyle can be guided back into the fossa.

71. Facial nerve Auriculotemporal nerve Bleeding from medial aspect of the condylar head * Lateral pterygoid * Internal maxillary artery STRUCTURES INJURED DURING TMJ SURGERY -

72. ASSOCIATED NEUROVASCULAR STRUCTURES - FACIAL NERVE- Distance from the lowest concavity of the external auditory canal to the bifurcation of the main trunk of the facial nerve- 1.5 to 2.8 cm Atlas of temporomandibular joint surgery – Peter D Quinn 2 nd ed

73. Atlas of temporomandibular joint surgery – Peter D Quinn 2 nd ed From the bifurcation of the facial nerve to the post-glenoid tubercle- 2.4 to 3.5

74. Atlas of temporomandibular joint surgery – Peter D Quinn 2 nd ed The distance from the most anterior concavity of the bony external auditory canal to the most posterior significant temporal branch of the facial nerve- 0.8-3.5 cm (mean 2 cm)

75. TEMPORAL BRANCH - Liebman et al in 1982 , described histologically that the layer in which it travels. They reported that it was locked in the fascial layer between temporalis fascia and subdermal fat superficially . Stuzin et al in 1988 , examined the temporal region by cadaver dissection and reported that it lay within the temporoparietal fascia and travels along undersurface of this fascial layer.

76. A straight trajectory A curved trajectory Temporal branches of Facial nerve Ishikawa Y: An anatomical study on the distribution of the temporal branch of the facial nerve.

77. Pitanguy, L, A. S. Ramos: The frontal branch of the facial nerve: The importance of its variation in face lifting . Middelton’s line Plast . Reconstr . Surg. 38 ( 1966) 352

78. The new guideline for preservation of the entire temporal branch is drawn with a dashed line. J.CRANIO-MAX- FAC.SURG.18(1990 ),287-292. An anatomical study of the distribution of temporal branch of facial nerve

79. J.CRANIO-MAX- FAC.SURG.18(1990),287-292. An anatomical study of the distribution of temporal branch of Facial Nerve

80. Dingman and Grab Ziarah and Atkinson MARGINAL MANDIBULAR NERVE -

81. SURGICAL ANATOMY OF MANDIBULAR DISTRIBUTION OF FACIAL NERVE. ZIARAH & ATKINSON, BJOS 1981;19,159-170 MARGINAL MANDIBULAR BRANCH

82. Superficial temporal artery Transverse facial artery Maxillary artery Atlas of human anatomy – Frank H Netter 6 th ed SUPERFICIAL TEMPORAL VESSELS

83. AURICULOTEMPORAL NERVE Arises from posterior part of mandibular division of CN V 89 Atlas of human anatomy – Frank H Netter 6 th ed Runs beneath lateral pterygoid muscle. Passes from medial surface of condyle & emerges on to the face behind the TMJ within the superior surface of the parotid gland. Ascends posterior to the superficial temporal vessels, passes over the posterior root of the zygoma, and divides into superficial temporal branches .

84. Superficial temporal vein Maxillary vein Retromandibular vein Anterior division Posterior division GRAY’S Anatomy, The anatomical basis of clinical practice – 41 st ed RETROMANDIBULAR VEIN

85. GREATER AURICULAR NERVE Largest ascending branch of the cervical plexus Greater auricular nerve arises from the second and third cervical rami, encircles the posterior border of sternocleidomastoid, perforates the deep fascia and ascends on the muscle beneath platysma On reaching the parotid gland, it divides into anterior and posterior branches

86. SURGICAL APPROACHES TO TMJ - Temporomandibular joint and its components frequently require exposure for a myriad of procedures.

87. Coronal section of the temporomandibular joint (TMJ) region. Dissection layers -

88. Concept given by Teisser & defined by Mitz and Peyronie in 1976. Continuous fibromuscular layer. Synonyms: In scalp– galea aponeurotica In temporal region – temporoparietal fascia, superficial temporal fascia or suprazygomatic SMAS Below zygomatic arch – parotideomasseteric fascia SMAS -

89. TYPES - Extra oral approaches Preauricular Endaural Postauricular Coronal Retromandibular Submandibular Rhytidectomy Intraoral approaches 1. Intraoral vestibular – - without endoscope - with endoscope

90. Accessibility to the joint Avoiding damage to vital neurovascular structures Aesthetic concerns on visibility of post op scars Technique sensitivity and surgeon’s experience In case of ankylosis, choice of interpositioning material. CHOICE OF INCISION

91. Surgical approaches to facial skeleton – Edward Ellis 2 nd ed PRE AURICULAR INCISION

92. Incision is outlined at the junction of facial skin and helix of the ear. Incision usually is 3-4 cm in length consist of 2 limbs- superior curved limb and inferior vertical limb anterior to tragus. Initial incision is made through skin and subcutaneous tissue.

93. Surgical approaches to facial skeleton – Edward Ellis 2 nd ed DISSECTION

94. Incision through the lateral attachment of the temporomandibular joint disk, entering the inferior joint space. A: Illustration showing use of sharp scissors to incise the lateral attachment of the disk. B: Photograph showing a scalpel used for the same purpose.

95. Suprafascial procedure Rowe NL: Surgery of the temporo-mandibular Joint. Proc R Soc Med 65:383, 1972 Subfascial procedure Al-Kayat A, Bramley P: A modified pre-auricular approach to the temporomandibular joint and malar arch. Br J Oral Surg 17:91, 19 Deep Subfascial Approach - Massimo Politi : J Oral Maxillofac Surg 62:1097-1102, 2004 Preauricular dissection techniques described in literature

96. Politi et al. Deep Subfascial Approach to the TMJ. J Oral Maxillofac Surg 2004

97. Blair’s Inverted Hockey Stick Dingman’s Incision Endaural Incision Popowich and Crane Incision Thoma’s Angulated Incisio n MODIFICATIONS OF PRE AURICULAR APPROACH

98. ALKAYAT AND BRAMLEY APPROACH Skin incision is question mark shaped A modified pre-auricular approach to the temporomandibular joint and malar arch British Journal of Oral Surgery 17 (1979-80), 91-103 Begins antero-superiorly within the hairline & curves backwards and downwards well posterior until it meets upper ear attachment Incision then follows ear attachment endauraly

99. Advantage s : less bleeding F ascial planes can be easily identified E xcellent visibility good cosmetic result 108 7-Mar- 17

100. Incision is started in the fold at the junction of anterior margin of helix Carried downwards to upper portion of tragus where it is contained inside the margin of tragus to anterior fold of lobule It again becomes visible at this point and is carried downwards to lower attachment of ear DINGMAN’S APPROACH

101. MODIFIED BLAIR INCISION

102. First described by Lempart as an approach to mastoid process for surgical improvement of otosclerosis , for approaching TMJ . ENDAURAL APPROACH

103. Incision begins well within the EAM at superior meatal wall The incision is carried carefully through the skin over the tragal cartilage at a 90- degree angle to the most convex part of the tragus itself. The incision is carried superiorly to the uppermost portion of the auricle and then extends in approximately a 45 degree angle into the temporal hairline for about 3 to 4 cm.

104. Incision is deepened to temporoparietal fascia continued inferiorly with knife in continuous contact with the tympanic plate. Sharp dissection is done along the perichondrium and the flap is raised en masse anteroinferiorly.

105. Comparison of standard preauricular and endaural surgical approaches Advantages: Most of the vital structures are in a superficial plane. Very good access to the joint and also the coronoid process. Excellent esthetic result with minimal post operative scar Disadvantage s : Esthetic compromise if tragal projection is lost Risk of possible perichondritis 7-Mr- 17

106. A modified endaural approach to the TMJ J ORAL MAXILLOFAC SURG 51:33-37,1993 Broad based flap with excellent blood supply Possibility of residual cartilaginous deformity is less Damage to CN VII is unlikely ADVANTAGES-

107. Descibed by Alexander & James Incision is placed in the grove between the helix and post auricular skin Pre-op considerations described by Walter and Geist : History of normal scar formation Healthy auditory system with no infection No TMJ infection POSTAURICULAR APPROACH

108. 3-5cm incision is made parallel & posterior to postauricular flexure Begins at superior aspect of external pinna and extended till the tip of mastoid process Dissection is done through posterior auricular muscle to the level of mastoid fascia The Post-Auricular approach for Gap A rthroplasty a Clinical Investigation Journal of Cranio - Maxillo -Facial Surgery 40(2012) 500-505

109. ADVANTAGES Predictability of anatomic exposure excellent surgical exposure of the bilaminar zone and the mandibular condyle posteriorly Cosmetic superiority Less risk of CN VII injury Dissection is more rapid DISADVANTAGES Not advised in patients susceptible to keloid Infection Meatal stenosis can occur Anterior exposure is limited

110. V ersatile surgical approach to the upper and middle regions of the facial skeleton, including the zygomatic arch and TMJ . CORONAL APPROACH OR BICORONAL/HEMICORONAL OR BITEMPORAL APPROACH

111. 7-Mar- 17 57 LAYERS OF THE SCALP BELOW THE SUPERIOR TEMPORAL LINE

112. 7-Mar- 17 58 Incision placement for patients with male pattern hair recession. The incision is stepped posteriorly just above the attachment of the helix of the ear Incision placement for most female patients. The incision is kept approximately 4 cm behind the hairline

113. The incision is through the skin, subcutaneous tissue, and galea revealing the subgaleal plane of loose areolar connective tissue overlying the pericranium.

114. 124 7-Mar- 17

115. The skin incision below the superior temporal line should extend to the depth of the glistening superficial layer of the temporalis fascia, into the subgaleal plane, continuous with the dissection above the superior temporal line.

116. 7-Mar- 17 63 Along the lateral aspect of the skull, the glistening white temporalis fascia becomes visible where it blends with the pericranium at the superior temporal line . The plane of dissection is just superficial to this thick fascial sheet

117. Near the ear, the flap is dissected inferiorly to the root of the zygomatic arch by incising superficial layer of temporalis fascia The lateral portion of the flap is dissected inferiorly atop the temporalis fascia

118. Exposure of the Temporomandibular Joint : Access to the TMJ region is gained by dissecting below the zygomatic arch anterior to tragal cartilage. Masseter is detached from the zygomatic arch exposing the sigmoid notch and TMJ capsule. Capsule is then incised exposing the TMJ.

119. CLOSURE : done in layers Closure of TMJ capsule is done followed by closure of temporalis fascia . Superficial layer of the temporalis fascia, which is incised during the approach, is sutured approximately 1 cm superior to the superior edge of the incised fascia. Galea is closed as a distinct layer. Scalp incision is closed.

120. The principal difference involves the position of the skin incision placed behind the ear. use of a zigzag incision instead of a straight incision within the hairline. A dvantage : further camouflage of the scar MODIFICATION OF CORONAL INCISION

121. 7-Mar- 17 68 SUBMANDIBULAR OR RISDON’S APPROACH

122. 69

123. Associated anatomic structures

124. D issection is performed through the fascia at the level of the initial skin incision, followed by dissection superiorly to the level of the periosteum of the mandible

125. The pterygomasseteric sling is sharply incised with a scalpel along the inferior border

126. Closure is done in multiple layers- Masseter and medial pterygoid muscles are sutured together Platysma is closed Subcutaneous tissues S kin   CLOSURE -

127. E xposes the entire ramus from behind the posterior border. RETROMANDIBULAR APPROACH OR HIND’S APPROACH

128. ADVANTAGES: close proximity to the condylar area DISA D V AN T A G ES: P assing through the parotid gland tissue, thus increasing the risk of facial nerve injury and salivary fistulae.

129. Important structures encountered

130. Main Landmarks should be visible- Ear Lower lip Corner of the mouth Incision- Begins 0.5 cm below the ear lobe and continues inferiorly 3-3.5 cm just behind the posterior border of the mandible

131. Blunt dissection

132. Sigmoid notch retractor. The curved flange at the end is inserted into the sigmoid notch, retracting the masseter muscle.

133. J ORAL MAXILLOFAC SURG 67:2418-2424, 2009 Transmasseter approach to condylar fractures by mini- retromandibular access

134. Smaller scar as access was limited to 2cm only. Plane of dissection was superficial to SMAS. Risk of Frey’s syndrome, sialocoele and salivary fistula can be eliminated. Surgical site is always perpendicular to fracture site. Integrity of joint is always maintained. 149 7-Mar- 17 ADVANTAGES-

135. Novel Retro mandibular Sub- parotideomasseteric Fascial approach for placement of a TMJ prosthesis

136. Also called as facelift approach. Variant of retromandibular, transmasseteric -anteroparotid approach 92 7-Mar- 17 RHYTIDECTOMY

137. When using the rhytidectomy approach, the structures that should be visible in the field include – the corner of the eye, the corner of the mouth, and the lower lip anteriorly, the entire ear and descending hairline, and 2 to 3 cm of hair superior to the posterior hairline, posteriorly the temporal area must also be completely exposed superiorly LANDMARKS FOR DRAPING

138. The incision begins approximately 1.5 to 2 cm superior to the zygomatic arch just posterior to the anterior extent of the hairline. The incision then curves posteriorly and inferiorly, blending into a preauricular incision in the natural crease anterior to the pinna. The incision continues under the earlobe and approximately 3 mm onto the posterior surface of the auricle instead of continuing in the mastoid–ear skin crease. It curves posteriorly toward the hairline and then runs along the hairline, or just inside it, for a few centimeters.

139. Closure

140. TRANSORAL/ INTRAORAL APPROACH

141. Mandibular Vestibular Approach Advantages- -Ability to constantly assess the dental occlusion during surgery. - Greatest benefit- hidden intraoral scar. -approach is also relatively rapid and simple Disadvantages- Access is limited in the lower border of the mandible at the angle and parts of the ramus. Complications are few but include mental nerve damage and lip malposition , both of which are minimized with the use of proper technique.

142. Gap arthroplasty for temporomandibular joint ankyloses by trans oral approach: A case series Int. J. Oral Maxillofac Surg

143. AD VANTAGES : better visibility access to high level fracture using transbuccal trocar. 101 7-Mar- 17 ENDOSCOPE THROUGH INTRAORAL INCISION

144. Once the capsule has been identified, access to the articular surfaces (superior and inferior joint spaces) can be obtained by a great variety of incisions. CAPSULAR INCISIONS

145. The lateral ligament, capsule, and periosteum are reflected inferiorly en masse . Discal or posterior attachment are dissected sharply with scissors to the level of the condylar neck . Horizontal incision over the lateral rim of the glenoid fossa

146. The posterior attachment and disc attachments are then severed sharply at the lateral pole of the condyle from within the developed flap. These tissues are then reflected superiorly from the head of condyle to expose inferior joint space

147. The superior joint space is punctured at the level of discocapsular sulcus. A dissection is then carried inferiorly removing the attachment of the capsule to the disc and exposing the inferior joint space. Horizontal incision below the lateral rim of the glenoid fossa

148. Horizontal incisions above and below the disc

149. T- Shaped Incision

150. Poor facial scar Infection Wound dehiscence Facial nerve palsy Perichondritis Sialocoele Frey’s syndrome COMPLCATIONS

151. POOR FACIAL SCAR

152. FACIAL NERVE PARALYSIS Eyes closed with minimum effort At rest Eyebrows raised Eyes tightly closed Rowe’s incision Maximum mouth opening

153. According to House‑ Brackmann grading system, at 24 h, 78.9% patients had different grades of facial nerve injury, which gradually improved and came to normal limits within 1‑3 months post‑operatively. Conclusion- The degree of temporary nerve injury could be either due to the heavy retraction causing compression and or stretching of nerve fiber resulting in neuropraxia .

154. SYMPTOMS: P ain over auricle and deep in ear canal, edema, erythema, induration PERICHONDRITIS

155. MANAGEMENT: Conservative: mildest form is treated by using oral and topical antibiotics. Hematoma of the auricle should be drained properly If there is any sign of pus drainage – C/S followed by broad spectrum IV antibiotics. In resistant cases, continuous drainage and irrigation with antibiotics and steroids solution. In severe cases, aggressive excision of the necrosed cartilage involving overlying subcutaneous tissues and skin should be done.

156. Sialocoeles result in the accumulation of saliva in glandular/periglandular or subcutaneous tissues. When the accumulated saliva drain through the skin it is termed as salivary fistula . SIALOCOELE/ SALIVARY FISTULA

157. 1 . Small sialocoeles have said to resolve spontaneously by scar formation which seals the salivary flow. 2 . Non surgical management : repeated aspirations compression dressings administration of anticholinergic and antisialogogues 114 7-Mar- 17 MANAGEMENT:

158. Surgical management: These procedures direct the salivary flow into the mouth or Depresses the salivary secretion Creating a tract intraorally Duct ligation Sectioning of auriculotemporal nerve Surgical excision of fistulous tract

159. Parotid fistula from transparotid approach for mandibular subcondylar fracture reduction S. M. Balaji

160. J Oral Maxillolac Surg49:680-682. 1991 N amed after Dr. Lucia Frey Frey’s syndrome or gustatory sweating and flushing is characterized by sweating and flushing of the facial skin during meals. The area involved is on the lateral aspect of the face and upper neck, usually around the parotid region. FREY’S SYNDROME

161. Minor starch iodine test The distribution of the greater auricular nerve and ATN was painted with a solution containing 3 g iodine, 20 g castor oil, and 200 mL of absolute alcohol. When dry, the area was lightly dusted with cornstarch. Given lemon drops to chew for 4 minutes to induce a salivary response. A positive test occurs when sweat dissolves the starch powder and it reacts with the iodine to produce dark blue spots that may become confluent .

162. (A) Gustatory sweating observed over the left preauricular region. (B) A positive Minor’s test over the left preauricular region

163. Techniques to evaluate - Blotting paper method Iodine sublimated paper H istogram Treatment : external radiotherapy local or systemic application of anticholinergic drugs Laage-Hellman was the first to apply scopolamine (3% cream) for the treatment of gustatory sweating. interposition of a subcutaneous barrier injection of botulinum toxin in the involved skin

164. Section of some portion of the efferent neural arc - Hemenway [62] in 1960 suggested interrupting the efferent neuronal pathway at the level of the middle ear, by sectioning the tympanic nerve of Jacobson. The first such procedure for gustatory sweating was carried out by Golding-Wood , who named it “tympanic neurectomy "

165. Surgical Interposition the use of a barrier between the facial skin and the parotid bed. Botulinum Toxin The injection of botulinum A toxin in the skin involved by gustatory sweating was recently proposed by Drobik and Laskawi. It acts by blocking the exocytosis mechanism of the presynaptic terminal, thereby inhibiting release of acetylcholine.

166. CONCLUSION- Both the macroscopic and microscopic structures of the TMJ joint are intimately related with the overall functions of the joint. Our understanding of the biochemical properties and the structure-function relationships of the TMJ tissue components can help illuminate pathophysiology of TMJ disorders, aid in clinical diagnosis and treatments, and inform the design and development of replacement tissues.

167. GREY`S ANATOMY (40TH EDITION) SICHER & DUBRUL`S ORAL ANATOMY (8TH EDITION) SURGICAL APPROACHES TO FACIAL SKELETON BY EDWARD ELLIS III ANATOMY OF HEAD & NECK BY B.D CHAURSIA TEXTOOK OF ORAL & MAXILLOFACIAL SURGERY BY NEELIMA MALIK MANAGEMENT OF TMJ DISORDERS AND OCCLUSION BY JEFFREY P. OKESON REFERENCES -

168. Thank you…