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Relationship of tmj anatomy and pathology and related

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Dr. AJAY SRINIVAS

This document provides an overview of the temporomandibular joint (TMJ) anatomy and associated neuromuscular disorders. It begins with an introduction to the TMJ as a compound synovial joint, then describes the bony and soft tissue components of the TMJ. This includes the glenoid fossa, condylar head, articular eminence, articular disc, joint capsule, ligaments, innervation and blood supply. It also discusses the muscles of mastication - masseter, temporalis, lateral and medial pterygoid muscles. The document concludes with sections on TMJ imaging, disorders and the use of orthodontics in temporomandibular disorder treatment.

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TMJ ANATOMY AND ASSOCIATED NEUROMUSCULAR DISORDERS DR. AJAY SRINIVAS DEPT OF ORTHODONTICS PG STUDENT
CONTENTS • INTRODUCTION • CLASSIFICATION OF JOINTS • TMJ ANATOMY • MUSCLES OF MASTICATION • TMJ IMAGING • TMJ DISORDERS • USE OF ORTHODONTICS IN TMD TREATMENT • REFERENCES
INTRODUCTION TMJ IS A:  COMPOUND  BICONDYLAR  GINGLIMO-ARTHROID  ELIPSOIDAL  SYNOVIAL JOINT.
The TMJ influences the function, esthetics, & structural harmony of the teeth, dentition, face and thus a person in total.Therefore an understanding of the anatomy , physiology, biomechanics of the masticatory system is very much necessary.
Classification of Joints 3 TYPES: 1. FIBROUS: IMMOVABLE JOINT 2. CARTILAGENOUS JOINT : LIMITED MOVEMENT •PRIMARY •SECONDARY
• 3. SYNOVIAL JOINT: permits free movement between two bones; surrounded by capsule enclosing joint cavity filled with synovial fluid. Eg: TMJ
TMJ ANATOMY BONY COMPONENTS SOFT-TISSUE COMPONENTS 1. Glenoid fossa 1. Articular disk 2. Condylar head 2. Joint capsule 3. Articular eminence 3. Ligament
BONY COMPONENTS
GLENOID FOSSA The glenoid fossa is the depression in the temporal bone that articulates with the mandible. In the temporal bone, it is bounded, in front, by the articular tubercle; behind, by the tympanic part of the temporal bone, which separates it from the external acoustic meatus; it is divided into two parts by a narrow slit, the petrotympanic fissure (Glaserian fissure). It is also referred to as the mandibular fossa.
CONDYLAR HEAD • Oval – mediolaterally • 15-20 mm long (M-L); 8-10 mm wide (A-P); 8-12 mm thick • Medial pole is more prominent than lateral pole. • Articulating surface is convex anteroposteriorly & slightly convex mediolaterally. Anterior view Posterior view
Medial pole more prominent than lateral pole Articular surface of Posterior aspect > anterior aspect
• A line drawn through the centers of the poles of the condyles, usually extends medially & posteriorly towards the anterior border of the foramen magnum. 1450
ARTICULAR EMINENCE Its Sigmoid in shape and has Anterior & posterior slopes  Saddle – shaped in coronal section – concave mediolaterally  Along with articular disc, it guides mandibular movement during jaw opening
SOFT-TISSUE COMPONENTS
• Articular disc Seperating the 2 bones from direct articulation is the Articular disc. It serves as a non ossified bone that permits complex movements of the joint. - The disc is composed of dense fibrous connective tissue AB- anterior border PB- posterior border IZ- intermediate zone
Anterior view – the disc is slightly thicker medially than laterally. LP- lateral pole MP- medial pole
• The articular disc is attached to the capsular ligament ,not only anteriorly & posteriorly, but also medially & laterally; this attachment divides the joint into : a) the upper cavity [superior cavity] b) the lower cavity [inferior cavity]
• Specialized endothelial cells forms a synovial lining surrounding the internal surface of the cavities. • This lining along with a specialized synovial fringe located at the anterior border of the retrodiscal tissues, produce synovial fluid. Synovial Fluid – i) It provides metabolic requirements to the non-vascular articular surfaces of the joint. ii) provides lubrication during function,thus reducing friction.
• Lubrication – 2 types i) Boundary lubrication ii) Weeping lubrication • Boundary lubrication – -when the joint moves, the synovial fluid is forced from one area of the cavity to another. -prevents friction & is the primary mechanism of joint lubrication • Weeping lubrication – -due to the ability of the articular surfaces to absorb a small amount of fluid. -forces during function drive a small amount of fluid in & out of the articular tissues,this helps in metabolic exchange.
LIGAMENTS • They are Non-elastic collagenous structures which restrict and limit the movements of a joint . • They restrict the distance by which articulating bones can be separated from each other without causing tissue damage • According to definition– joint capsule is also a ligament • True ligaments: 1. COLLATERAL / DISCAL LIGAMENTS 2. CAPSULAR LIGAMENT 3. TEMPOROMANDIBULAR / LATERAL LIGAMENT • Accessory ligaments: 1. SPHENOMANDIBULAR LIGAMENT 2. STYLOMANDIBULAR LIGAMENT
• Collateral (discal ligaments) : - Attaches the medial & lateral borders of the articular disc to the poles of the condyles. - Divides the joint mediolaterally into the superior & inferior cavities. - True ligaments , do not stretch & restricts movement of the disc away from condyle. - They are Responsible for hinging movement of the TMJ. - They Have both vascular supply as well as neural innervation , providing movement information regarding joint position . - Strain on these ligaments produces pain.
Capsular ligament- - surrounds & encompasses the entire TMJ. - attached superiorly to the temporal bone along the borders of the articular surfaces of the mandibular fossa & articular eminence. - attached inferiorly – to the neck of the condyle - resist any medial, lateral / inferior forces that tend to separate or dislocate the articular surfaces. - helps to retain synovial fluid & provides proprioceptive feedback.
Temporomandibular (Lateral) ligament 2 parts- • IHP- Inner horizontal portion • OOP- Outer oblique portion Oblique portion – resists excessive dropping of the condyle - aids in normal opening of the mouth. - in wider mouth opening- the condyle moves downwards & forward across the articular eminence.
• Accessory ligaments ; i) the sphenomandibular ligament ii) the stylomandibular ligament
• Innervation of TMJ – - The trigeminal nerve , provides both motor & sensory innervation to the muscles that control it. - Afferent innervation – by branches of the mandibular nerve. - Also by auriculo-temporal nerve as it leaves the mandibular nerve behind the joint & ascends laterally & superiorly to wrap around the posterior region of the joint. - Additional nerves – are deep temporal & masseteric nerve.
• In addition to the above mentioned nerves the tmj capsule also contains three types of mechanoreceptors. Mechanoreceptor Nature of the receptor Ruffini proprioception Golgi tendon Static mechanoreceptor Pacinian receptor Dynamic mechanoreceptor
• Vascularization – i) posteriorly- superficial temporal artery ii) anteriorly- middle meningeal artery iii) inferiorly- internal maxillary artery iv) other arteries are - the deep auricular - anterior tympanic - ascending pharyngeal arteries - condyle, receives supply through its marrow spaces by “feeder vessels” from inferior alveolar artery.
Lymphatic drainage AREA OF TMJ DRAINING LYMPH NODE Anterior surface parotid lymph nodes Posterior surface submandibular nodes Lateral surface preauricular lymph node Medial surface submandibular nodes
MUSCLES OF MASTICATION - MASSETER - TEMPORALIS - LATERAL PTERYGOID -MEDIAL PTERYGOID
MASSETER • Has 3 layers: superficial, middle & deep. • Has Multipinnate arrangement of fibers • It’s a Quadrilateral muscle that covers lateral surface of the mandible.
TEMPORALIS Fills the Temporal Fossa.  FAN shaped muscle. MUSCLE ORIGIN FIBERS INSERTION TEMPORALIS TEMPORAL BONE AND FASCIA CONVERGE & PASSES THROUGH GAP DEEP TO ZYGOMATIC ARCH - MARGIN & DEEP SURFACE OF CORONOID - ANT. BORDERS OF RAMUS OF MAND.
LATERAL PTERYGOID ORIGIN FIBERS INSERTION UPPER (SMALL) FROM INFRATEMPORAL SURFACE & CREST OF G.WING OF SPHENOID RUN BACKWARDS & LATERALLY. CONVERGE FOR INSERTION PTERYGOID FOVEA (CONDYLAR NECK) LOWER (LARGER) LATERAL SURFACE OF LATERAL PTERYGOID PLATE ANT. MARGIN OF ARTICULAR DISC & CAPSULE OF TMJ. MEDIAL PTERYGOID ORIGIN FIBERS INSERTION SUPERFICIAL (SMALL) TUBEROSITY OF MAXILLA & ADJOINING BONE DOWNWARDS, BACKWARDS & LATERALLY MEDIAL SURFACE OF ANGLE & RAMUS OF MANDIBLE DEEP (LARGE) MEDIAL SURFACE OF LATERAL PTERYGOID PLATE & ADJOINING PROCESS OF PALATINE BONE BELOW & BEHIND MANDIBULAR FORAMEN & MYLOHYOID GROOVE
• The relationship between the disk & the lateral pterygoid muscle--- The foot of the anterior part of disc blends with the capsule and provides a mechanism by which the foot is attached to the roof of the superior head of the lateral pterygoid muscle..
Relationship of tmj anatomy and pathology and related
Examination of TMJ FOLLOWING ARE NOTED-  Palpation – in closed position, at rest & various open positions  Deviation should be noted  Crepitus / abnormal sound  Palpation of the neck & sub mandibular area  Speech evaluation  Facial asymmetry  Pain in head & neck region  Opening movement  Examination of soft tissues  Examination of occlusion
Path of opening Alterations 1. Deviation 2. Deflection DEVIATION is any shift of the midline during opening that disappears with continued opening (i.e. returns to midline)
DEFLECTION is shift of midline to one side that becomes greater with opening and is maintained in that position at maximum opening (i.e. does not return to midline)
Lateral movements Less than 8mm is recorded as restricted movement
MAXIMUM JAW OPENING • The distance between the incisal edges of the upper and lower central incisors is measured with a Boley gauge. • The normal range of mouth opening is between 38-45mm. • In overbite cases this amount is added to the obtained value whereas in open bite it is subtracted.
-Patient is asked to open slowly until pain is first felt…. This is the MAXIMUM COMFORTABLE OPENING. -The patient is then asked to open the mouth maximally….. This is recorded as the MAXIMUM OPENING. -If the mouth opening is restricted it is helpful to test the END FEEL. END FEEL- DESCRIBES CHARACTERISTICS OF RESTRICTION. IT CAN BE EVALUATED BY PLACING FINGERS BETWEEN PATIENTS UPPER AND LOWER TEETH & APPLYING STEADY FORCE TO PASSIVELY INCREASE INTERINCISSAL DISTANCE. -A SOFT END FEEL suggests MUSCLE INDUCED RESTRICTION. -HARD END FEELS are more likely to be associated with intracapsular sources(Eg. DISC DISLOCATION)
Palpation of T.M.J. • Pain or tenderness of TMJ is determined by digital palpation when the mandible is in both stationary and dynamic movements. • The examiners finger tips are placed over the lateral aspect of joint areas simultaneously on both sides. • 4 point scale is used- • 0=pressure only,no pain 2=chronic pain • 1=pain on pressure only 3=patient grabs the dentist hand because of pain.
Lateral palpation • The finger tips should feel the lateral poles of condyles passing down towards articular eminence. • Once position is verified, the medial force is applied to the joint area to check for any pain
Posterior palpation: • Position the little finger in the external auditory meatus and palpate the posterior surface of condyle during opening and closing of the mandible. • Palpation is done in such a way that the condyle displaces the little finger when in full occlusion.
AUSCULATION OF THE T.M.J. • Sounds made by the TMJ can be examined with a stethoscope. Also the timing of clicking during opening and closure can be noted .
Clicking • It occurs due to the uncoordinated movement of condylar head and T.M.J disc. • Joint clicking is differentiated as: Initial Intermediate Terminal Reciprocal
• Initial clicking : It is a sign of retruded condyle • Intermediate clicking : Is a sign of unevenness of the condylar surfaces and articular disc • Terminal clicking : is an effect of the condyle being moved too far anteriorly in relation to the disc on maximum jaw opening. • Reciprocal clicking : is an expression of incoordination between displacement of the condyle & the disc.
MUSCLE EXAMINATION MUSCLES PALPATED  TEMPORALIS  MASSETER  LATERAL PTERYGOID  MEDIAL PTERYGOID FUNCTIONALLY ASSESED  INFERIOR BELLY OF LATERAL PTERYGOID  SUPERIOR BELLY OF LATERAL PTERYGOID  MEDIAL PTERYGOID
TEMPORALIS
Anterior region – above the zygomatic arch & anterior to the TMJ Middle – directly above the TMJ & superior to the zygomatic arch Posterior – above & behind the ears TEMPORALIS
With the index finger Palpate the cheek laterally at the Retromolar fossa. INTRAORALLY
• MASSETER
Palpated bilaterally at its Superior and inferior attachments Started anterior to TMJ and then dropped down to the inferior border of the ramus MASSETER
Masseter (intra oral) With the index finger intraorally Press laterally inside the cheek.
• Palpation of Inferior lateral pterygoid should no longer be considered as a standard clinical procedure because it is nearly impossible to palpate it anatomically & also the risk of false +ve findings by palpation of the medial pterygoid muscle is high.
FUNCTIONAL ANALYSIS OF MUSCLES • Lateral pterygoid • Medial pterygoid • Principle A muscle which is fatigued & symptomatic elicits pain on further function and is painful both on contraction and stretching
Inferior belly of Lateral pterygoid Contraction – mandibular protrusion, mouth opening or both Stretching – maximum intercuspation of teeth Differentiation test – place tongue blade in between posterior teeth. This prevents the teeth from reaching maximum intercuspal position. Hence lateral pterygoid does not stretch
Differential test – tongue blade is placed bilaterally & patient is asked to bite. This increases the pain if it is symptomatic while the stretching pain of inf. Belly of lateral Pterygoid is relieved Stretching – also produces clenching Differential test – patient is asked to open mouth widely. If pain is elicited it is from the elevator muscles SUPERIOR BELLY OF LATERAL PTERYGOID
Medial pterygoid Contraction – clenching Differential test – tongue blade is placed bilaterally & patient is asked to bite. This increases the pain if it is symptomatic because elevators are still contracting.
Relationship of tmj anatomy and pathology and related
Two dimensional imaging Panoromic radiographs Transcranial view Transpharyngeal view Transorbital view Reverse Towne’s view Submento-vertex (SMV) view Conventional tomography Arthrography Three dimensional imaging Computed tomography (CT) Magnetic resonance imaging (MRI)
Panoramic view Used as screening projection Provides non corrected tomographic view of the condyles on one film
Transcranial projection - modified Schuller method Provides sagittal view of lateral aspects of condyle and temporal component Indication Gross changes on the lateral aspect of joint Displaced joint fractures Range of motion
Transpharyngeal projection Limitations Temporal components are not imaged well Indications To visualize gross erosive changes of the condyle Provides sagittal view of the medial pole of the condyle
Transorbital projection Transmaxillary, antero posterior view Provides an anterior view of the TMJ perpendicular to the transcranial and transpharyngeal views Indication  It provides images of entire mediolateral dimension and the articular eminence , condylar neck and condylar head are imaged Range of motion cannot be assessed Mainly for detection of condylar neck fractures
Reverse Towne’s view Similar to transorbital view Useful for viewing medial displacements of the condyle
Submentovertex (SMV) projection Provides view of the base of the skull with condyles superimposed on the condylar neck and rami
Conventional tomography Provides the most definitive diagnostic information about the osseous structures of the TMJ Provides visualization of anatomic structures free from superimposition
Arthrography Provides information regarding soft tissue of the joint Technique – intra- articular administration of radio-opaque iodinated contrast agent is done under fluoroscopic guidance After both the joint spaces are filled with the contrast agent the disk function is studied using fluoroscopy supplemented by tomography Advantage – it is advantageous over MRI in identifying any perforations b/w the superior and inferior joint compartments Disadvantages– 1. expensive 2. patient may develop allergy to contrast medium 3. invasive
Relationship of tmj anatomy and pathology and related
Computed tomography Incorporates the principles of direct digital (computed) electronic imaging & cross sectional radiography (tomography) Provides visualization in all 3 planes Sagittal (lateral) Coronal (frontal) Axial
Computed tomography
Magnetic resonance imaging (MRI) Used to image soft tissues of the TMJ to visualize Joint effusion Disk position Disk shape Inflammatory changes
TEMPEROMANDIBULAR DISORDERS • TMD – cluster of joint and muscle disorders in the orofacial area characterized primarily by – Pain – Joint sound and – Irregular or deviating jaw functions
Signs and symptoms of temporomandibular joint (TMJ) syndrome include pain in the jaw joint, clicking of the jaw, ear pain, popping sounds in ears, headaches, stiff or sore jaw muscles, pain in the temple area, or locking of the jaw
Epidemiology • Epidemiologic studies has shown that 60-70% of the general population have functional disturbances of the masticatory apparatus. • Its most prevalent between the ages of 20-40 years and predominantly affects women.
Etiology • Multifactorial – Parafunctional habits . – Emotional stress. – Acute trauma from blows / impacts. – Trauma from hyperextension. – Instability of maxillo-mandibular relationships. – Laxity of the joints. – Rheumatic / musculo-skeletal disorders. – Poor general health and unhealthy lifestyle.
Classification • Intracapsular disorders of the TMJ Source Disorder Degenerative (non-inflammatory) Degenerative joint disease Inflammatory Rheumatoid arthritis Psoriatic arthritis Infections Spread from contiguous site Developmental Condylar hyperplasia, hypoplasia and agenesis Traumatic Condylar fracture, ankylosis, dislocation and disc displacement. Burket’s
I. Developmental disturbances of the TMJ 1. Aplasia of the mandibular condyle – Condylar aplasia or failure of development of the mandibular condyle  which may occur unilaterally or bilaterally. – It is a rare condition
• Clinical features: – Associated with other anatomically related defects such as a defective / absent external ear, an under developed mandibular ramus or macrostomia. – Unilateral condylar aplasia  Facial asymmetry – A shift of the mandible towards the affected side occurs during opening – In bilateral cases this shift is not present • Treatment – Osteoplasty – Orthodontic appliances – Cosmetic surgery  in correcting facial deformity
2. Hypoplasia of the mandibular condyle – Under development / defective formation of the mandibular condyle • Congenital hypoplasia – etiology could be Idiopathic – Characterized by uni / bilateral under-development of the condyle • Acquired hypoplasia – May be due to any agent which interferes with the normal development of the condyle. Causes: – Forceps deliveries – External trauma – X-ray radiation
• Clinical features: – Condylar hypoplasia depends upon whether the disturbance has affected one or both condyles and upon the degree of malformation. – Age of the patient at the time of involvement – The duration of the injury and its severity – Unilateral involvement is the most common clinical type
– Facial asymmetry – Limitation of lateral excursion on one side – Mandibular midline shift during opening and closing – The distortion of the mandible results in lack of downward and forward growth of the body of the mandible – Due to arrest of the chief growth center of the mandible i.e., condyle.
• Treatment & prognosis – Cartilage / bone transplants – Unilateral and bilateral osteotomy to improve the appearance of the patient with asymmetry and retrusion.
3.Hyperplasia of the mandibular condyle – Condylar hyperplasia is a rare unilateral enlargement of the condyle Causes: Mild chronic inflammation which stimulates the growth of the condyle or adjacent tissue.
Clinical features : patient usually exhibit A unilateral, slowly progressive elongation of the face with deviation of the chin away from the affected side. The enlarged condyle may be clinically evident The affected joint may or may not be painful A severe malocclusion is a usual sequela of the condition
• Radiographic Features: – Condyle with an elongated neck and enlarged condylar head – Scintigraphy using 99mTc-MDP used for assessing degree of bone activity in condylar hyperplasia.
• Treatment and prognosis – If growth is occurring  condylectomy – If growth is ceased  orthognathic surgery is performed – Resection of condyle is done to restore normal occlusion.
Developmental disturbance of TMJ Bifid condyle • Double headed mandibular condyle. • They have a medial and lateral head divided by A-P groove. • Some condyles may be divided into an anterior and posterior head.
Etiology: Uncertain. A-P bifid condyle is mostly traumatic in origin. Mediolaterally divided condyles  causes are trauma, abnormal muscle attachment, teratogenic agents.
Clinical Features: – Unilateral – Asymptomatic – Pop or click of TMJ Radiographic Features: – Bilobed appearance of the condylar head. Rx & Prognosis: – Asymptomatic  no treatment necessary.
II. Traumatic disturbances of the TMJ 1. Luxation and subluxation (complete & incomplete dislocation) – Dislocation of the TMJ :when the head of the condyle moves anteriorly over the articular eminence into such a position that cannot be returned voluntarily to its normal position. – Luxation of the joint  complete dislocation while subluxation is a partial / incomplete dislocation
• Clinical features: – Sudden locking and immobilization of the jaws when the mouth is open. – Accompanied by prolonged spasmodic contraction of the temporal, internal pterygoid and masseter muscles with protrusion of the jaw.
Treatment: Relaxation of the muscles and then guiding the head of the condyle under the articular eminence into its normal position by an inferior and posterior pressure of the thumbs in the mandibular molar area.
2. Ankylosis (hypomobility) – Most incapacitating of all diseases involving the TMJ. – It involves fusion of head of the condyle to the temporal bone. • Etiology – Traumatic injuries – Infection in and about the joint – Abnormal intrauterine development – Birth injury – Trauma to the chin forcing the condyle against the glenoid fossa, particularly with bleeding into the joint space. – Injuries associated with fracture of the molar zygomatic compound. – Congenital syphilis – Primary inflammation of the joint
– Inflammation of the joint secondary to a local inflammatory process. Ex. Otitis media; mastoiditis; osteomyelitis of the temporal bone / condyle. – Inflammation of the joint secondary to a blood stream infection Ex: Septicemia – Metastatic malignancies
• Clinical features: – Occurs at any age – Most cases occur before the age of 10 years – Distribution is equal between the genders – The patient may / may not be able to open his mouth to any appreciable extent, depending on the type of ankylosis
• TMJ Ankylosis (depending on anatomic sites of ankylosis) Intra-articular ankylosis Extra-articular ankylosis Joint undergoes progressive destruction of the meniscus Flattening of the mandibular fossa and. thickening of the head of the condyle & narrowing of the joint space Results in a “splinting” of the TMJ by a fibrous or bony mass external to the joint proper But movement is possible in this type
II. Traumatic disturbances of the TMJ • Radiographic Features: – Reveals abnormal / irregular shape of the head of the condyle • Treatment: – Surgical osteotomy / removal of section of bone below the condyle. – Fibrous ankylosis can be treated by functional methods.
III. Fractures of the condyle Condylar fracture. • Caused due to- Acute traumatic injury to the jaw • SYMPTOMS- Limitation of motion, pain and swelling over the involved condyle • Deformity is noted upon palpation and loss of normal condylar excursion.
• The fractured condyle fragment is frequently displaced anteriorly and medially into the infratemporal region because of the forward pull of the external pterygoid muscle and reduction of the fracture is often difficult because of this displacement. • Healing of such fracture without reduction results in loss of function, limitation of motion or any other complication.
IV. INFLAMMATORY DISTURBANCES OF THE TMJ • Arthritis / inflammation of the joints, is one of the most frequent pathological condition affecting the TMJ. • TMJ may suffer from any form of arthritis but there are 3 common types given by Mayne and Hatch. – Arthritis due to a specific infection. – Rheumatoid arthritis. – Osteoarthritis / degenerative joint disease.
HISTOPATHOLOGIC FEATURES • There is a variable amount of destruction of the articular cartilage and articular disk. • The joint spaces become obliterated in the healing phase by the development of granulation tissue • It Subsequently transforms into scar tissue. TREATMENT: • Antibiotics – in the acute phase – Meniscetomy / condylectomy is advocated in the advanced cases.
2) Rheumatoid arthritis • Is a chronic multisystem disease of unknown antigen, triggers an autoimmune response in genetically susceptible individual. • Proinflammatory kinins and cytokines play important role in pathogenesis of rheumatoid arthritis. • TMJ involvement  NEARLY 20% CLINICAL FEATURES: • M:F 2:1 Rheaumatoid Arthritis in early stages manifests as- • Slight fever. • Loss of weight • Fatigability. • Joints affected are swollen • Patient c/o pain and stiffness on movement of the jaw. • Ankylosis of the joint over a period of time.
Histopathologic features: • The joints show edema and inflammation of the synovial tissues and diffuse infiltration of chronic inflammatory cells into the articular architecture. • With increase in bone resorption there is a destruction of articular surface of the condyle. • Invasion of the cartilage and its replacement by granulation tissue is seen.
Rx & Prognosis: • No specific treatment for Rheumatoid Arthritis. • Administrations of Adrenocorticotrophic hormone/ Cortisone. • Surgical intervention in the form of condylectomy may be necessary to regain movement.
3. Osteoarthritis (degenerative joint disease, hypertrophic arthritis). • Is most common type of arthritis associated with aging process. Etiology: unknown.
CLINICAL FEATURES: • Signs and symptoms are absent since it is not a weight bearing joint. • Patients c/o of clicking and snapping in the TMJ due to atypical disk motion. HISTOPATHOLOGIC FEATURES: • The cartilage cells often exhibit degeneration and areas of dystrophic calcification may occur and this can progress to actual ossification ,also there may be necrosis of the disk. Rx: • Condylectomy.
V. NEOPLASTIC DISTURBANCES OF THE TMJ • Neoplasms and tumor-like growths, benign and malignant, may involve the TMJ. • It is very uncommon. • Origin: • Within the bone of the mandibular condyle. • Joint capsule or articular disk. • Chondromas, osteomas and osteochondromas are common benign tumors.
VI. EXTRA-ARTICULAR DISTURBANCES OF THE TMJ • A variety of extraarticular disturbances may manifest themselves clinically as TMJ problems. – Impacted molar teeth – Sinusitis – Middle ear disease – Infratemporal cellulitis – Impingement of coronoid process on the tendon of the temporal muscle. – Neuritis of the 3rd division of the trigeminal nerve. – Odontalgia. – A foreign body in the infratemporal fossa. – Overclosure of the mandible accompanied by severe dental attrition. – Costen’s syndrome.
VII. TEMPOROMANDIBULAR JOINT SYNDROME (TM disorder) • TMJ syndrome or TMD is the most common cause of facial pain after toothache. • TMD can be classified broadly as: – TMD secondary to myofacial pain and dysfunction (MPD). – TMD secondary to true articular disease
1. Myofacial pain disorder type forms the majority of the cases of Temperomandibular disorder   and is associated with pain without apparent destructive changes of the TMJ on x-ray. • Seen commonly in bruxism and day time jaw clenching in a stressed and anxious person.
DIGAMMATIC RERESENTATION OF ETIOLOGY OF MPDS PSYCHOPHYSIOLOGIC THEORY OF MPDS (Modified by LASKIN in 1969)
2. True intra-articular disease : – Disk displacement disorder. – Chronic recurrent dislocations. – Degenerative joint disorders. – Systemic arthritis conditions – Ankylosis. – Infection – Neoplasms. • Etiology: – Multifactorial and includes: – Malocclusion. – Jaw clenching. – Bruxism. – Personality disorders – Increased pain sensitivity. – Stress and anxiety.
Clinical features: – Affects young woman aged 20-40 yrs. – M:F – 1:4. – 4 cardinal signs and symptoms of the syndrome: 1. Pain 2. Muscle tenderness. 3. Clicking / popping noise in the TMJ. 4. Limitations of the jaw motion unilaterally / bilaterally with deviation on opening. – The pain is usually periauricular. – Associated with chewing and may radiate to head. – May be unilateral or bilateral in MPD.
• In TMD, pain is associated with clicking, popping and snapping sounds. • Limited jaw opening due to pain / disk displacement. • TMD acts as a trigger in patient prone to headaches. Lab findings: – Blood examination. – Blood count – Rheumatoid factor – ESR – Antinuclear antibody. – Uric acid
• Treatment & Prognosis: 1. Self limiting. 2. Conservative treatment involving self care practices. – Rehabilitation aimed at eliminating muscle spasms. – Restoring correct coordination. 3. Non steroidal anti inflammatory drugs. Eg: Diclofenac sodium – Prognosis is usually good.
Use of Fixed orthodontics in tmd treatment • Jco interview volume 1981 may (333-350) • Dr .eugene h. williamson on occlusion and tmj function. • Dr williamson stated that in patients with dysfunction there are two variables which always seem to be present. One variable is the abnormal emotional status of the patient, the other is the presence of prematurities or deflective tooth contacts
• It is important not to introduce splint dependency but to endeavour to resolve the occlusal imbalance related to tmd. successful treatment requires the reconstruction of functional occlusion with the condyle positioned correctly in the glenoid fossa. • Depending on the etiology of the condition this may involve orthopaedic repositioning, orthodontic balancing of the occlusion , occlusal reconstruction or a combination of these disciplines.
. The treatment of tmd by interocclusal devices followed two paths: ( journal of oral rehabilitation 2004) Occlusal splints Functional orthopedic appliance provide symptomatic relief do not modify the occlusal discrepencies. help in the movement of the teeth as well as the jaws to a musculoskeletally stable position thus providing relief
• Orthodontic treatment should be carried out to achieve a functional occlusion which is in harmony with the craniofacial musculature. • The finished cases should have the condyles as close to centric relation as possible, preferably with Centric relation coinciding with the Centric occlusion.
Orthodontic treatment by means of fixed and functional appliance bring about the movement of the teeth and jaws to a musculoskeletally stable position . Thus targeting one of the causative factors in temperomandibular disorders and hence providing a definitive therapy .
References 6. Shafer’s Textbook of Oral Pathology. 5th edition. 7. Neville: Oral & Maxillofacial Pathology. 2nd edition. 8. Jaffery P. Okeson – Management of Temporomandibular disorders and occlusion. 1. Gray’s Anatomy 2. Fundamentals of occlusion and TMJ disorders -- Okeson 3. Grant’s Atlas of Human Anatomy 4. Occlusion – Ash RamfJord 5. Orthodontics Principles and Practice -- T.M.Graber
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Relationship of tmj anatomy and pathology and related

  • 1. TMJ ANATOMY AND ASSOCIATED NEUROMUSCULAR DISORDERS DR. AJAY SRINIVAS DEPT OF ORTHODONTICS PG STUDENT
  • 2. CONTENTS • INTRODUCTION • CLASSIFICATION OF JOINTS • TMJ ANATOMY • MUSCLES OF MASTICATION • TMJ IMAGING • TMJ DISORDERS • USE OF ORTHODONTICS IN TMD TREATMENT • REFERENCES
  • 3. INTRODUCTION TMJ IS A:  COMPOUND  BICONDYLAR  GINGLIMO-ARTHROID  ELIPSOIDAL  SYNOVIAL JOINT.
  • 4. The TMJ influences the function, esthetics, & structural harmony of the teeth, dentition, face and thus a person in total.Therefore an understanding of the anatomy , physiology, biomechanics of the masticatory system is very much necessary.
  • 5. Classification of Joints 3 TYPES: 1. FIBROUS: IMMOVABLE JOINT 2. CARTILAGENOUS JOINT : LIMITED MOVEMENT •PRIMARY •SECONDARY
  • 6. • 3. SYNOVIAL JOINT: permits free movement between two bones; surrounded by capsule enclosing joint cavity filled with synovial fluid. Eg: TMJ
  • 7. TMJ ANATOMY BONY COMPONENTS SOFT-TISSUE COMPONENTS 1. Glenoid fossa 1. Articular disk 2. Condylar head 2. Joint capsule 3. Articular eminence 3. Ligament
  • 9. GLENOID FOSSA The glenoid fossa is the depression in the temporal bone that articulates with the mandible. In the temporal bone, it is bounded, in front, by the articular tubercle; behind, by the tympanic part of the temporal bone, which separates it from the external acoustic meatus; it is divided into two parts by a narrow slit, the petrotympanic fissure (Glaserian fissure). It is also referred to as the mandibular fossa.
  • 10. CONDYLAR HEAD • Oval – mediolaterally • 15-20 mm long (M-L); 8-10 mm wide (A-P); 8-12 mm thick • Medial pole is more prominent than lateral pole. • Articulating surface is convex anteroposteriorly & slightly convex mediolaterally. Anterior view Posterior view
  • 11. Medial pole more prominent than lateral pole Articular surface of Posterior aspect > anterior aspect
  • 12. • A line drawn through the centers of the poles of the condyles, usually extends medially & posteriorly towards the anterior border of the foramen magnum. 1450
  • 13. ARTICULAR EMINENCE Its Sigmoid in shape and has Anterior & posterior slopes  Saddle – shaped in coronal section – concave mediolaterally  Along with articular disc, it guides mandibular movement during jaw opening
  • 15. • Articular disc Seperating the 2 bones from direct articulation is the Articular disc. It serves as a non ossified bone that permits complex movements of the joint. - The disc is composed of dense fibrous connective tissue AB- anterior border PB- posterior border IZ- intermediate zone
  • 16. Anterior view – the disc is slightly thicker medially than laterally. LP- lateral pole MP- medial pole
  • 17. • The articular disc is attached to the capsular ligament ,not only anteriorly & posteriorly, but also medially & laterally; this attachment divides the joint into : a) the upper cavity [superior cavity] b) the lower cavity [inferior cavity]
  • 18. • Specialized endothelial cells forms a synovial lining surrounding the internal surface of the cavities. • This lining along with a specialized synovial fringe located at the anterior border of the retrodiscal tissues, produce synovial fluid. Synovial Fluid – i) It provides metabolic requirements to the non-vascular articular surfaces of the joint. ii) provides lubrication during function,thus reducing friction.
  • 19. • Lubrication – 2 types i) Boundary lubrication ii) Weeping lubrication • Boundary lubrication – -when the joint moves, the synovial fluid is forced from one area of the cavity to another. -prevents friction & is the primary mechanism of joint lubrication • Weeping lubrication – -due to the ability of the articular surfaces to absorb a small amount of fluid. -forces during function drive a small amount of fluid in & out of the articular tissues,this helps in metabolic exchange.
  • 20. LIGAMENTS • They are Non-elastic collagenous structures which restrict and limit the movements of a joint . • They restrict the distance by which articulating bones can be separated from each other without causing tissue damage • According to definition– joint capsule is also a ligament • True ligaments: 1. COLLATERAL / DISCAL LIGAMENTS 2. CAPSULAR LIGAMENT 3. TEMPOROMANDIBULAR / LATERAL LIGAMENT • Accessory ligaments: 1. SPHENOMANDIBULAR LIGAMENT 2. STYLOMANDIBULAR LIGAMENT
  • 21. • Collateral (discal ligaments) : - Attaches the medial & lateral borders of the articular disc to the poles of the condyles. - Divides the joint mediolaterally into the superior & inferior cavities. - True ligaments , do not stretch & restricts movement of the disc away from condyle. - They are Responsible for hinging movement of the TMJ. - They Have both vascular supply as well as neural innervation , providing movement information regarding joint position . - Strain on these ligaments produces pain.
  • 22. Capsular ligament- - surrounds & encompasses the entire TMJ. - attached superiorly to the temporal bone along the borders of the articular surfaces of the mandibular fossa & articular eminence. - attached inferiorly – to the neck of the condyle - resist any medial, lateral / inferior forces that tend to separate or dislocate the articular surfaces. - helps to retain synovial fluid & provides proprioceptive feedback.
  • 23. Temporomandibular (Lateral) ligament 2 parts- • IHP- Inner horizontal portion • OOP- Outer oblique portion Oblique portion – resists excessive dropping of the condyle - aids in normal opening of the mouth. - in wider mouth opening- the condyle moves downwards & forward across the articular eminence.
  • 24. • Accessory ligaments ; i) the sphenomandibular ligament ii) the stylomandibular ligament
  • 25. • Innervation of TMJ – - The trigeminal nerve , provides both motor & sensory innervation to the muscles that control it. - Afferent innervation – by branches of the mandibular nerve. - Also by auriculo-temporal nerve as it leaves the mandibular nerve behind the joint & ascends laterally & superiorly to wrap around the posterior region of the joint. - Additional nerves – are deep temporal & masseteric nerve.
  • 26. • In addition to the above mentioned nerves the tmj capsule also contains three types of mechanoreceptors. Mechanoreceptor Nature of the receptor Ruffini proprioception Golgi tendon Static mechanoreceptor Pacinian receptor Dynamic mechanoreceptor
  • 27. • Vascularization – i) posteriorly- superficial temporal artery ii) anteriorly- middle meningeal artery iii) inferiorly- internal maxillary artery iv) other arteries are - the deep auricular - anterior tympanic - ascending pharyngeal arteries - condyle, receives supply through its marrow spaces by “feeder vessels” from inferior alveolar artery.
  • 28. Lymphatic drainage AREA OF TMJ DRAINING LYMPH NODE Anterior surface parotid lymph nodes Posterior surface submandibular nodes Lateral surface preauricular lymph node Medial surface submandibular nodes
  • 29. MUSCLES OF MASTICATION - MASSETER - TEMPORALIS - LATERAL PTERYGOID -MEDIAL PTERYGOID
  • 30. MASSETER • Has 3 layers: superficial, middle & deep. • Has Multipinnate arrangement of fibers • It’s a Quadrilateral muscle that covers lateral surface of the mandible.
  • 31. TEMPORALIS Fills the Temporal Fossa.  FAN shaped muscle. MUSCLE ORIGIN FIBERS INSERTION TEMPORALIS TEMPORAL BONE AND FASCIA CONVERGE & PASSES THROUGH GAP DEEP TO ZYGOMATIC ARCH - MARGIN & DEEP SURFACE OF CORONOID - ANT. BORDERS OF RAMUS OF MAND.
  • 32. LATERAL PTERYGOID ORIGIN FIBERS INSERTION UPPER (SMALL) FROM INFRATEMPORAL SURFACE & CREST OF G.WING OF SPHENOID RUN BACKWARDS & LATERALLY. CONVERGE FOR INSERTION PTERYGOID FOVEA (CONDYLAR NECK) LOWER (LARGER) LATERAL SURFACE OF LATERAL PTERYGOID PLATE ANT. MARGIN OF ARTICULAR DISC & CAPSULE OF TMJ. MEDIAL PTERYGOID ORIGIN FIBERS INSERTION SUPERFICIAL (SMALL) TUBEROSITY OF MAXILLA & ADJOINING BONE DOWNWARDS, BACKWARDS & LATERALLY MEDIAL SURFACE OF ANGLE & RAMUS OF MANDIBLE DEEP (LARGE) MEDIAL SURFACE OF LATERAL PTERYGOID PLATE & ADJOINING PROCESS OF PALATINE BONE BELOW & BEHIND MANDIBULAR FORAMEN & MYLOHYOID GROOVE
  • 33. • The relationship between the disk & the lateral pterygoid muscle--- The foot of the anterior part of disc blends with the capsule and provides a mechanism by which the foot is attached to the roof of the superior head of the lateral pterygoid muscle..
  • 35. Examination of TMJ FOLLOWING ARE NOTED-  Palpation – in closed position, at rest & various open positions  Deviation should be noted  Crepitus / abnormal sound  Palpation of the neck & sub mandibular area  Speech evaluation  Facial asymmetry  Pain in head & neck region  Opening movement  Examination of soft tissues  Examination of occlusion
  • 36. Path of opening Alterations 1. Deviation 2. Deflection DEVIATION is any shift of the midline during opening that disappears with continued opening (i.e. returns to midline)
  • 37. DEFLECTION is shift of midline to one side that becomes greater with opening and is maintained in that position at maximum opening (i.e. does not return to midline)
  • 38. Lateral movements Less than 8mm is recorded as restricted movement
  • 39. MAXIMUM JAW OPENING • The distance between the incisal edges of the upper and lower central incisors is measured with a Boley gauge. • The normal range of mouth opening is between 38-45mm. • In overbite cases this amount is added to the obtained value whereas in open bite it is subtracted.
  • 40. -Patient is asked to open slowly until pain is first felt…. This is the MAXIMUM COMFORTABLE OPENING. -The patient is then asked to open the mouth maximally….. This is recorded as the MAXIMUM OPENING. -If the mouth opening is restricted it is helpful to test the END FEEL. END FEEL- DESCRIBES CHARACTERISTICS OF RESTRICTION. IT CAN BE EVALUATED BY PLACING FINGERS BETWEEN PATIENTS UPPER AND LOWER TEETH & APPLYING STEADY FORCE TO PASSIVELY INCREASE INTERINCISSAL DISTANCE. -A SOFT END FEEL suggests MUSCLE INDUCED RESTRICTION. -HARD END FEELS are more likely to be associated with intracapsular sources(Eg. DISC DISLOCATION)
  • 41. Palpation of T.M.J. • Pain or tenderness of TMJ is determined by digital palpation when the mandible is in both stationary and dynamic movements. • The examiners finger tips are placed over the lateral aspect of joint areas simultaneously on both sides. • 4 point scale is used- • 0=pressure only,no pain 2=chronic pain • 1=pain on pressure only 3=patient grabs the dentist hand because of pain.
  • 42. Lateral palpation • The finger tips should feel the lateral poles of condyles passing down towards articular eminence. • Once position is verified, the medial force is applied to the joint area to check for any pain
  • 43. Posterior palpation: • Position the little finger in the external auditory meatus and palpate the posterior surface of condyle during opening and closing of the mandible. • Palpation is done in such a way that the condyle displaces the little finger when in full occlusion.
  • 44. AUSCULATION OF THE T.M.J. • Sounds made by the TMJ can be examined with a stethoscope. Also the timing of clicking during opening and closure can be noted .
  • 45. Clicking • It occurs due to the uncoordinated movement of condylar head and T.M.J disc. • Joint clicking is differentiated as: Initial Intermediate Terminal Reciprocal
  • 46. • Initial clicking : It is a sign of retruded condyle • Intermediate clicking : Is a sign of unevenness of the condylar surfaces and articular disc • Terminal clicking : is an effect of the condyle being moved too far anteriorly in relation to the disc on maximum jaw opening. • Reciprocal clicking : is an expression of incoordination between displacement of the condyle & the disc.
  • 47. MUSCLE EXAMINATION MUSCLES PALPATED  TEMPORALIS  MASSETER  LATERAL PTERYGOID  MEDIAL PTERYGOID FUNCTIONALLY ASSESED  INFERIOR BELLY OF LATERAL PTERYGOID  SUPERIOR BELLY OF LATERAL PTERYGOID  MEDIAL PTERYGOID
  • 49. Anterior region – above the zygomatic arch & anterior to the TMJ Middle – directly above the TMJ & superior to the zygomatic arch Posterior – above & behind the ears TEMPORALIS
  • 50. With the index finger Palpate the cheek laterally at the Retromolar fossa. INTRAORALLY
  • 52. Palpated bilaterally at its Superior and inferior attachments Started anterior to TMJ and then dropped down to the inferior border of the ramus MASSETER
  • 53. Masseter (intra oral) With the index finger intraorally Press laterally inside the cheek.
  • 54. • Palpation of Inferior lateral pterygoid should no longer be considered as a standard clinical procedure because it is nearly impossible to palpate it anatomically & also the risk of false +ve findings by palpation of the medial pterygoid muscle is high.
  • 55. FUNCTIONAL ANALYSIS OF MUSCLES • Lateral pterygoid • Medial pterygoid • Principle A muscle which is fatigued & symptomatic elicits pain on further function and is painful both on contraction and stretching
  • 56. Inferior belly of Lateral pterygoid Contraction – mandibular protrusion, mouth opening or both Stretching – maximum intercuspation of teeth Differentiation test – place tongue blade in between posterior teeth. This prevents the teeth from reaching maximum intercuspal position. Hence lateral pterygoid does not stretch
  • 57. Differential test – tongue blade is placed bilaterally & patient is asked to bite. This increases the pain if it is symptomatic while the stretching pain of inf. Belly of lateral Pterygoid is relieved Stretching – also produces clenching Differential test – patient is asked to open mouth widely. If pain is elicited it is from the elevator muscles SUPERIOR BELLY OF LATERAL PTERYGOID
  • 58. Medial pterygoid Contraction – clenching Differential test – tongue blade is placed bilaterally & patient is asked to bite. This increases the pain if it is symptomatic because elevators are still contracting.
  • 60. Two dimensional imaging Panoromic radiographs Transcranial view Transpharyngeal view Transorbital view Reverse Towne’s view Submento-vertex (SMV) view Conventional tomography Arthrography Three dimensional imaging Computed tomography (CT) Magnetic resonance imaging (MRI)
  • 61. Panoramic view Used as screening projection Provides non corrected tomographic view of the condyles on one film
  • 62. Transcranial projection - modified Schuller method Provides sagittal view of lateral aspects of condyle and temporal component Indication Gross changes on the lateral aspect of joint Displaced joint fractures Range of motion
  • 63. Transpharyngeal projection Limitations Temporal components are not imaged well Indications To visualize gross erosive changes of the condyle Provides sagittal view of the medial pole of the condyle
  • 64. Transorbital projection Transmaxillary, antero posterior view Provides an anterior view of the TMJ perpendicular to the transcranial and transpharyngeal views Indication  It provides images of entire mediolateral dimension and the articular eminence , condylar neck and condylar head are imaged Range of motion cannot be assessed Mainly for detection of condylar neck fractures
  • 65. Reverse Towne’s view Similar to transorbital view Useful for viewing medial displacements of the condyle
  • 66. Submentovertex (SMV) projection Provides view of the base of the skull with condyles superimposed on the condylar neck and rami
  • 67. Conventional tomography Provides the most definitive diagnostic information about the osseous structures of the TMJ Provides visualization of anatomic structures free from superimposition
  • 68. Arthrography Provides information regarding soft tissue of the joint Technique – intra- articular administration of radio-opaque iodinated contrast agent is done under fluoroscopic guidance After both the joint spaces are filled with the contrast agent the disk function is studied using fluoroscopy supplemented by tomography Advantage – it is advantageous over MRI in identifying any perforations b/w the superior and inferior joint compartments Disadvantages– 1. expensive 2. patient may develop allergy to contrast medium 3. invasive
  • 70. Computed tomography Incorporates the principles of direct digital (computed) electronic imaging & cross sectional radiography (tomography) Provides visualization in all 3 planes Sagittal (lateral) Coronal (frontal) Axial
  • 72. Magnetic resonance imaging (MRI) Used to image soft tissues of the TMJ to visualize Joint effusion Disk position Disk shape Inflammatory changes
  • 73. TEMPEROMANDIBULAR DISORDERS • TMD – cluster of joint and muscle disorders in the orofacial area characterized primarily by – Pain – Joint sound and – Irregular or deviating jaw functions
  • 74. Signs and symptoms of temporomandibular joint (TMJ) syndrome include pain in the jaw joint, clicking of the jaw, ear pain, popping sounds in ears, headaches, stiff or sore jaw muscles, pain in the temple area, or locking of the jaw
  • 75. Epidemiology • Epidemiologic studies has shown that 60-70% of the general population have functional disturbances of the masticatory apparatus. • Its most prevalent between the ages of 20-40 years and predominantly affects women.
  • 76. Etiology • Multifactorial – Parafunctional habits . – Emotional stress. – Acute trauma from blows / impacts. – Trauma from hyperextension. – Instability of maxillo-mandibular relationships. – Laxity of the joints. – Rheumatic / musculo-skeletal disorders. – Poor general health and unhealthy lifestyle.
  • 77. Classification • Intracapsular disorders of the TMJ Source Disorder Degenerative (non-inflammatory) Degenerative joint disease Inflammatory Rheumatoid arthritis Psoriatic arthritis Infections Spread from contiguous site Developmental Condylar hyperplasia, hypoplasia and agenesis Traumatic Condylar fracture, ankylosis, dislocation and disc displacement. Burket’s
  • 78. I. Developmental disturbances of the TMJ 1. Aplasia of the mandibular condyle – Condylar aplasia or failure of development of the mandibular condyle  which may occur unilaterally or bilaterally. – It is a rare condition
  • 79. • Clinical features: – Associated with other anatomically related defects such as a defective / absent external ear, an under developed mandibular ramus or macrostomia. – Unilateral condylar aplasia  Facial asymmetry – A shift of the mandible towards the affected side occurs during opening – In bilateral cases this shift is not present • Treatment – Osteoplasty – Orthodontic appliances – Cosmetic surgery  in correcting facial deformity
  • 80. 2. Hypoplasia of the mandibular condyle – Under development / defective formation of the mandibular condyle • Congenital hypoplasia – etiology could be Idiopathic – Characterized by uni / bilateral under-development of the condyle • Acquired hypoplasia – May be due to any agent which interferes with the normal development of the condyle. Causes: – Forceps deliveries – External trauma – X-ray radiation
  • 81. • Clinical features: – Condylar hypoplasia depends upon whether the disturbance has affected one or both condyles and upon the degree of malformation. – Age of the patient at the time of involvement – The duration of the injury and its severity – Unilateral involvement is the most common clinical type
  • 82. – Facial asymmetry – Limitation of lateral excursion on one side – Mandibular midline shift during opening and closing – The distortion of the mandible results in lack of downward and forward growth of the body of the mandible – Due to arrest of the chief growth center of the mandible i.e., condyle.
  • 83. • Treatment & prognosis – Cartilage / bone transplants – Unilateral and bilateral osteotomy to improve the appearance of the patient with asymmetry and retrusion.
  • 84. 3.Hyperplasia of the mandibular condyle – Condylar hyperplasia is a rare unilateral enlargement of the condyle Causes: Mild chronic inflammation which stimulates the growth of the condyle or adjacent tissue.
  • 85. Clinical features : patient usually exhibit A unilateral, slowly progressive elongation of the face with deviation of the chin away from the affected side. The enlarged condyle may be clinically evident The affected joint may or may not be painful A severe malocclusion is a usual sequela of the condition
  • 86. • Radiographic Features: – Condyle with an elongated neck and enlarged condylar head – Scintigraphy using 99mTc-MDP used for assessing degree of bone activity in condylar hyperplasia.
  • 87. • Treatment and prognosis – If growth is occurring  condylectomy – If growth is ceased  orthognathic surgery is performed – Resection of condyle is done to restore normal occlusion.
  • 88. Developmental disturbance of TMJ Bifid condyle • Double headed mandibular condyle. • They have a medial and lateral head divided by A-P groove. • Some condyles may be divided into an anterior and posterior head.
  • 89. Etiology: Uncertain. A-P bifid condyle is mostly traumatic in origin. Mediolaterally divided condyles  causes are trauma, abnormal muscle attachment, teratogenic agents.
  • 90. Clinical Features: – Unilateral – Asymptomatic – Pop or click of TMJ Radiographic Features: – Bilobed appearance of the condylar head. Rx & Prognosis: – Asymptomatic  no treatment necessary.
  • 91. II. Traumatic disturbances of the TMJ 1. Luxation and subluxation (complete & incomplete dislocation) – Dislocation of the TMJ :when the head of the condyle moves anteriorly over the articular eminence into such a position that cannot be returned voluntarily to its normal position. – Luxation of the joint  complete dislocation while subluxation is a partial / incomplete dislocation
  • 92. • Clinical features: – Sudden locking and immobilization of the jaws when the mouth is open. – Accompanied by prolonged spasmodic contraction of the temporal, internal pterygoid and masseter muscles with protrusion of the jaw.
  • 93. Treatment: Relaxation of the muscles and then guiding the head of the condyle under the articular eminence into its normal position by an inferior and posterior pressure of the thumbs in the mandibular molar area.
  • 94. 2. Ankylosis (hypomobility) – Most incapacitating of all diseases involving the TMJ. – It involves fusion of head of the condyle to the temporal bone. • Etiology – Traumatic injuries – Infection in and about the joint – Abnormal intrauterine development – Birth injury – Trauma to the chin forcing the condyle against the glenoid fossa, particularly with bleeding into the joint space. – Injuries associated with fracture of the molar zygomatic compound. – Congenital syphilis – Primary inflammation of the joint
  • 95. – Inflammation of the joint secondary to a local inflammatory process. Ex. Otitis media; mastoiditis; osteomyelitis of the temporal bone / condyle. – Inflammation of the joint secondary to a blood stream infection Ex: Septicemia – Metastatic malignancies
  • 96. • Clinical features: – Occurs at any age – Most cases occur before the age of 10 years – Distribution is equal between the genders – The patient may / may not be able to open his mouth to any appreciable extent, depending on the type of ankylosis
  • 97. • TMJ Ankylosis (depending on anatomic sites of ankylosis) Intra-articular ankylosis Extra-articular ankylosis Joint undergoes progressive destruction of the meniscus Flattening of the mandibular fossa and. thickening of the head of the condyle & narrowing of the joint space Results in a “splinting” of the TMJ by a fibrous or bony mass external to the joint proper But movement is possible in this type
  • 98. II. Traumatic disturbances of the TMJ • Radiographic Features: – Reveals abnormal / irregular shape of the head of the condyle • Treatment: – Surgical osteotomy / removal of section of bone below the condyle. – Fibrous ankylosis can be treated by functional methods.
  • 99. III. Fractures of the condyle Condylar fracture. • Caused due to- Acute traumatic injury to the jaw • SYMPTOMS- Limitation of motion, pain and swelling over the involved condyle • Deformity is noted upon palpation and loss of normal condylar excursion.
  • 100. • The fractured condyle fragment is frequently displaced anteriorly and medially into the infratemporal region because of the forward pull of the external pterygoid muscle and reduction of the fracture is often difficult because of this displacement. • Healing of such fracture without reduction results in loss of function, limitation of motion or any other complication.
  • 101. IV. INFLAMMATORY DISTURBANCES OF THE TMJ • Arthritis / inflammation of the joints, is one of the most frequent pathological condition affecting the TMJ. • TMJ may suffer from any form of arthritis but there are 3 common types given by Mayne and Hatch. – Arthritis due to a specific infection. – Rheumatoid arthritis. – Osteoarthritis / degenerative joint disease.
  • 102. HISTOPATHOLOGIC FEATURES • There is a variable amount of destruction of the articular cartilage and articular disk. • The joint spaces become obliterated in the healing phase by the development of granulation tissue • It Subsequently transforms into scar tissue. TREATMENT: • Antibiotics – in the acute phase – Meniscetomy / condylectomy is advocated in the advanced cases.
  • 103. 2) Rheumatoid arthritis • Is a chronic multisystem disease of unknown antigen, triggers an autoimmune response in genetically susceptible individual. • Proinflammatory kinins and cytokines play important role in pathogenesis of rheumatoid arthritis. • TMJ involvement  NEARLY 20% CLINICAL FEATURES: • M:F 2:1 Rheaumatoid Arthritis in early stages manifests as- • Slight fever. • Loss of weight • Fatigability. • Joints affected are swollen • Patient c/o pain and stiffness on movement of the jaw. • Ankylosis of the joint over a period of time.
  • 104. Histopathologic features: • The joints show edema and inflammation of the synovial tissues and diffuse infiltration of chronic inflammatory cells into the articular architecture. • With increase in bone resorption there is a destruction of articular surface of the condyle. • Invasion of the cartilage and its replacement by granulation tissue is seen.
  • 105. Rx & Prognosis: • No specific treatment for Rheumatoid Arthritis. • Administrations of Adrenocorticotrophic hormone/ Cortisone. • Surgical intervention in the form of condylectomy may be necessary to regain movement.
  • 106. 3. Osteoarthritis (degenerative joint disease, hypertrophic arthritis). • Is most common type of arthritis associated with aging process. Etiology: unknown.
  • 107. CLINICAL FEATURES: • Signs and symptoms are absent since it is not a weight bearing joint. • Patients c/o of clicking and snapping in the TMJ due to atypical disk motion. HISTOPATHOLOGIC FEATURES: • The cartilage cells often exhibit degeneration and areas of dystrophic calcification may occur and this can progress to actual ossification ,also there may be necrosis of the disk. Rx: • Condylectomy.
  • 108. V. NEOPLASTIC DISTURBANCES OF THE TMJ • Neoplasms and tumor-like growths, benign and malignant, may involve the TMJ. • It is very uncommon. • Origin: • Within the bone of the mandibular condyle. • Joint capsule or articular disk. • Chondromas, osteomas and osteochondromas are common benign tumors.
  • 109. VI. EXTRA-ARTICULAR DISTURBANCES OF THE TMJ • A variety of extraarticular disturbances may manifest themselves clinically as TMJ problems. – Impacted molar teeth – Sinusitis – Middle ear disease – Infratemporal cellulitis – Impingement of coronoid process on the tendon of the temporal muscle. – Neuritis of the 3rd division of the trigeminal nerve. – Odontalgia. – A foreign body in the infratemporal fossa. – Overclosure of the mandible accompanied by severe dental attrition. – Costen’s syndrome.
  • 110. VII. TEMPOROMANDIBULAR JOINT SYNDROME (TM disorder) • TMJ syndrome or TMD is the most common cause of facial pain after toothache. • TMD can be classified broadly as: – TMD secondary to myofacial pain and dysfunction (MPD). – TMD secondary to true articular disease
  • 111. 1. Myofacial pain disorder type forms the majority of the cases of Temperomandibular disorder   and is associated with pain without apparent destructive changes of the TMJ on x-ray. • Seen commonly in bruxism and day time jaw clenching in a stressed and anxious person.
  • 112. DIGAMMATIC RERESENTATION OF ETIOLOGY OF MPDS PSYCHOPHYSIOLOGIC THEORY OF MPDS (Modified by LASKIN in 1969)
  • 113. 2. True intra-articular disease : – Disk displacement disorder. – Chronic recurrent dislocations. – Degenerative joint disorders. – Systemic arthritis conditions – Ankylosis. – Infection – Neoplasms. • Etiology: – Multifactorial and includes: – Malocclusion. – Jaw clenching. – Bruxism. – Personality disorders – Increased pain sensitivity. – Stress and anxiety.
  • 114. Clinical features: – Affects young woman aged 20-40 yrs. – M:F – 1:4. – 4 cardinal signs and symptoms of the syndrome: 1. Pain 2. Muscle tenderness. 3. Clicking / popping noise in the TMJ. 4. Limitations of the jaw motion unilaterally / bilaterally with deviation on opening. – The pain is usually periauricular. – Associated with chewing and may radiate to head. – May be unilateral or bilateral in MPD.
  • 115. • In TMD, pain is associated with clicking, popping and snapping sounds. • Limited jaw opening due to pain / disk displacement. • TMD acts as a trigger in patient prone to headaches. Lab findings: – Blood examination. – Blood count – Rheumatoid factor – ESR – Antinuclear antibody. – Uric acid
  • 116. • Treatment & Prognosis: 1. Self limiting. 2. Conservative treatment involving self care practices. – Rehabilitation aimed at eliminating muscle spasms. – Restoring correct coordination. 3. Non steroidal anti inflammatory drugs. Eg: Diclofenac sodium – Prognosis is usually good.
  • 117. Use of Fixed orthodontics in tmd treatment • Jco interview volume 1981 may (333-350) • Dr .eugene h. williamson on occlusion and tmj function. • Dr williamson stated that in patients with dysfunction there are two variables which always seem to be present. One variable is the abnormal emotional status of the patient, the other is the presence of prematurities or deflective tooth contacts
  • 118. • It is important not to introduce splint dependency but to endeavour to resolve the occlusal imbalance related to tmd. successful treatment requires the reconstruction of functional occlusion with the condyle positioned correctly in the glenoid fossa. • Depending on the etiology of the condition this may involve orthopaedic repositioning, orthodontic balancing of the occlusion , occlusal reconstruction or a combination of these disciplines.
  • 119. . The treatment of tmd by interocclusal devices followed two paths: ( journal of oral rehabilitation 2004) Occlusal splints Functional orthopedic appliance provide symptomatic relief do not modify the occlusal discrepencies. help in the movement of the teeth as well as the jaws to a musculoskeletally stable position thus providing relief
  • 120. • Orthodontic treatment should be carried out to achieve a functional occlusion which is in harmony with the craniofacial musculature. • The finished cases should have the condyles as close to centric relation as possible, preferably with Centric relation coinciding with the Centric occlusion.
  • 121. Orthodontic treatment by means of fixed and functional appliance bring about the movement of the teeth and jaws to a musculoskeletally stable position . Thus targeting one of the causative factors in temperomandibular disorders and hence providing a definitive therapy .
  • 122. References 6. Shafer’s Textbook of Oral Pathology. 5th edition. 7. Neville: Oral & Maxillofacial Pathology. 2nd edition. 8. Jaffery P. Okeson – Management of Temporomandibular disorders and occlusion. 1. Gray’s Anatomy 2. Fundamentals of occlusion and TMJ disorders -- Okeson 3. Grant’s Atlas of Human Anatomy 4. Occlusion – Ash RamfJord 5. Orthodontics Principles and Practice -- T.M.Graber

Editor's Notes