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(BQ) Part 2 book “Concise oral medicine” has contents: Temporomandibular joint disorders, temporomandibular joint disorders, oral cancer and precancerous lesions, immunological diseases, forensic odontology, orofacial syndromes, differential diagnosis of miscellaneous diseases,… and other contents.
10 Temporomandibular Joint Disorders The temporomandibular joint also known as craniomandibular joint, is described as bilateral gingylimo-arthroidal diarthrosis, ginglymo because these joints show ‘hinge’ type of movement, bilateral because it is present on both sides and diarthrosis because each joint is divided into two components and is a freely movable joint Parafunction: It is defined as a non-functional oral habit, that is bringing together of the jaws for reasons other than mastication, deglution and speech Also habits such as chewing gum, nail biting, pencil chewing, etc can cause parafunction Parafunction often results in MPDS Intracapsular Disorders • • • • • • Local Factors • Pericoronitis • Defect in tooth form and occlusion • • • Systemic • Epilepsy • Paralysis • Dyskinesia • Psychological Insoluble personal problems (bruxism): Bruxism and clenching may be stress relieving habits, and are associated with severe attrition, occlusal wear facets, prominent linea alba on the cheeks, indentations on the tongue, hypertrophy of masseter muscle, pain observed on waking up in the morning Occupational: Weight lifter, people performing precision work, drivers, tend to clench their jaws more often than others • • Congenital Agenesis—unilateral, bilateral Double condyle Hyperplasia of condyle Condylar hypoplasia Infections – Osteomyelitis – Septic arthritis Rheumatoid—flattened condyle Osteoarthritis—osteophytes Traumatic—trauma to meniscus, fractured condylar head Functional—subluxation, dislocation and internal disk derangements of the disk Neoplastic—osteoma, osteochondroma Ankylosis Extracapsular Disorders • MPDS • Iatrogenic disorders—prolonged dental procedures, trauma during mandibular block • Infections—osteomyelitis, periostitis • Neoplasia—tumors of the condyle and the ramus 163 164 Concise Oral Medicine ARTHRITIS Rheumatoid arthritis is an inflammatory disease affecting periarticular tissue and secondarily bone It starts as a vasculitis of synovial membrane It is associated with round cell infiltration and subsequent formation of granulation tissue—pannus The cellular infiltrate causes erosion of underlying bone and flattening of convex condylar surface which is called as ‘sharpened pencil’ or ‘mouthpiece of flute’ type of appearance as seen on OPG or transpharyngeal view Signs and Symptoms • • • • • • Unilateral or bilateral pain Decreased mandibular movements Difficulty in chewing Deviation of mandible towards affected side Muscle pain Occasional swelling and redness over joint area • Morning stiffness observed—symptoms relieved by activity • Changes in interproximal phalanges of Swan neck deformity Treatment Methotrexate is often the initial therapy as it reduces disease activity, joint erosions and can provide long-term reduction in mortality Prednisolone, and azathioprine are also given Aspirin was also used in the past, can lead to defective platelet aggregation • Rest to joint • Soft diet • Reestablish occlusion—flat plane occlusal appliance may be helpful if parafunctional habits are present • Ibuprofen 400 mg TDS for 5–10 days (contraindicated in asthma due to bronchospasm) Other NSAIDs are taken by RA patients can result in gastric ulcerations and affect kidney function • Aspiration of fluid • Injection of triamcinolone acetonide 12–15 mg (intra-articular injection of steroids) • Exercise to increase the mandibular movements • Surgical option for patients with severe functional impairment or intractable pain SYNOVIAL CHONDROMATOSIS Diagnosis Morning stiffness >1 hr Arthritis >3 joints Arthritis of interphalangeal joints Symmetric arthritis Radiographic Changes • Narrowing of joint space • Flattening and erosions of the condylar head • Erosions of the condylar head and glenoid fossa are better appreciated on HRCT Serum: Several autoantibodies may be detected, but not specific for rheumatoid arthritis RA factor: Anti-cycilc citrullinated proteins (anti-CCP) factor present in 80% of adult RA patients Chondrometaplasia Synovial chondromatosis (SC) is an uncommon benign disorder characterized by the presence of multiple cartilaginous nodules of the synovial membrane that break off resulting in clusters of free-floating loose calcified bodies in the joint (Fig 10.1) Some cases appear to be triggered by trauma whereas others are of unknown etiology Extension of SC from the TM joint to surrounding tissues (including the parotid gland, middle ear, or middle cranial fossa) may occur Clinical Features • Slow progressive swelling in the pretragus region • Pain Temporomandibular Joint Disorders A 165 B Fig 10.1: (A) Coronal and (B) Sagittal CBCT showing multiple calcified bodies involving the synovium in a case of synovial chondromatosis • Limitation of mandibular movement • TMJ clicking, locking, crepitus • Intracranial extension may lead to neurologic deficits such as facial nerve paralysis Radiographs • Conventional radiography may not lead to the diagnosis, due to superimposition of cranial bones that may obscure the calcified loose bodies • A CT scan should be obtained if SC is suspected after clinical evaluation • The lesion may appear as a single mass or as many small loose bodies Treatment Treatment should be conservative and consist of removal of the mass of loose bodies This may be done arthroscopically when only a small lesion is present, but arthrotomy is required for larger lesions The synovium and articular disc should be removed when they are involved Lesions that extend beyond the joint space may require extensive resection DEGENERATIVE JOINT DISEASE Primarily a disorder of articular cartilage and the subchondral bone with secondary inflammation of synovial membrane It is localized joint disease without systemic manifestations It begins as loaded articular cartilage which thins and clefts (fibrillation) and then breaks down during joint activity leading to sclerosis of underlying bone, subcondylar cysts and osteophyte formations It is essentially a response of the joint to chronic microtrauma or pressure Chronic microtrauma may be due to continuous abrasion of the articular surfaces due to age related natural wear or due to chronic parafunctional habits (bruxism) Clinical Features The incidence of DJD increases with age and is also related to the rate and extent of dental attrition • Unilateral pain directly over the condyle • Limitation of mandibular opening • Crepitus • Feeling of stiffness after period of inactivity • Tenderness and crepitus of the joint on palpation through the external auditory meatus • Deviation of mandible to the affected side on opening • Presence of Ely’s cyst Radiographs • Narrowing of joint space • Flattening of articulating surface (Fig 10.2) • Condyle becomes irregular in outline with sharp and pointed osteophytes seen on superior surface in transorbital view • Osteophyte formation seen on tomograms or CT scans (Fig 10.3) • Anterior lipping of condyle 166 Concise Oral Medicine Fig 10.2: TMJ OPG showing bilateral condylar flattening A B Fig 10.3: Coronal and sagittal CT images showing osteophytes and anterior lipping • Ely’s cyst—a well-demarcated depression or cup-like defect seen on condyle called as Ely’s cyst (Fig 10.4), which is a misnomer as it is just a bony defect and not a cyst • Joint effusion detected on T2-weighted MRI as a hyperintense signal (Fig 10.5) Fig 10.4: Coronal CBCT image showing Ely’s cyst Treatment • Conservative treatment: NSAIDs, heat, soft diet, rest, occlusal splints • Intra-articular steroids injections • Anti-inflammatory effects of doxycycline therapy reduces symptoms Fig 10.5: T2-weighted MRI showing hyperintense signals suggestive of joint effusion (arrows) Temporomandibular Joint Disorders • In severe cases with significant loss of function—arthroplasty (removal of osteophytes and erosive areas) is performed According to Juniper, the terms ‘disk’ and ‘meniscus’ are both misnomers and fail to describe the exact shape of the intra-articular disk According to him, the disk resembles the cap of a jockey, which snugly fits over the head of the condyle and is attached to the medial and lateral poles of the condyle by strong ligaments The disc is a concavoconvex and anteriorly is attached to the superior head of the lateral pterygoid muscle The inferior head of the lateral pterygoid is attached to the pterygoid fovea of the condyle The disk has the following parts: • Anterior band which is thin • Intermediate zone which is very thin • Posterior band which is thick Distally the posterior band is attached to the bilaminar zone, the superior lamina is inserted into the squamotympanic fissure, and the inferior lamina is inserted on to the neck of the condyle Posterior to the disk the retrodiscal tissue has a rich neurovascular supply Pathogenesis of Click and Internal Disk Derangement In a patient having bruxism and clenching habits, the closing muscles Medial pterygoid and masseter are hyperactive The lateral pterygoid which is an opening muscle also shows contraction to counterbalance the closing muscles Greater the activity of the closing muscles, greater is the contraction of the lateral pterygoid, this results in anterior subluxation of the disc The disc now occupies a position such that the posterior band is placed anterior to the head of the condyle in closed position When patient opens his mouth, the condyle slips over the posterior band, producing the opening click When the patient closes the mouth, the disk again relocates itself anterior to the condyle and while so doing produces the reciprocal click 167 In anterior disk displacement with reduction, the disk recaptures its original position when patient opens the mouth (Fig 10.6) and therefore this condition is accompanied by opening and reciprocal click Midway during opening the jaw deviates towards the affected site and at the terminal phase of opening, jaw aligns itself in the midline In the anterior disk displacement without reduction, the disk is occupying a position which is anteromedial to the condyle and hence prevents complete opening so that the opening reduces from 45 to 30–35 mm The jaw deviates towards the affected side, and because of the pressure of the condyle on the retrodiscal lamina, there is severe pain on chewing As in this condition, the condyle does not glide against the posterior band, no opening or reciprocal clicks are heard However, these patients give history of clicking which has disappeared As the patient cannot open the mouth fully because of the physical presence of a malformed disk, anteromedial to the condyle, this condition is also termed as ‘the closed lock’ The malformed disk has been described as ‘gum ball appearance’ on MRI (Fig 10.7) ARTICULAR DISK DISPLACEMENT (ADD) It is an abnormal relationship between the disk, the mandibular condyle, and the articular eminence, resulting from the stretching or tearing of the attachment of the disk to the condyle and glenoid fossa ADD may result in: • Abnormal joint sounds • Limitation in mandibular range of motion • Pain during mandibular movement Loosened disks become displaced anterior to the mandibular condyle Posterior Disc Displacement When a portion of the disk is found posterior to the top of the condyle 168 Concise Oral Medicine A B Fig 10.6: MRI image showing anteriorly displaced disk in closed mouth position Disk repositioned to normal location in open mouth (s/o ADD with reduction) A B Fig 10.7: MRI image showing anteriorly displaced disk which in open position is deformed giving gum ball appearance (s/o ADD without reduction) Etiology Classification • Direct trauma to the joint from a blow to the mandible • Chronic low-grade microtrauma resulting from long-term bruxism or clenching of the teeth • Generalized laxity of joints • Combination of mechanisms related to the anatomy of the joint and the facial skeleton, connective tissue chemistry and chronic loading of the joint increases the susceptibility of certain individuals to a disturbance of the restraining ligaments and displacement of the disk Anterior disk displacement with reduction (clicking joint) Anterior disk displacement with intermittent locking Anterior disk displacement without reduction (closed lock) Clinical Features Pain or dysfunction when accompanied by capsulitis, synovitis, and joint effusions Anterior Disk Displacement with Reduction This condition is caused by an articular disk that has been loosened because of elongation or tearing of restraining ligaments and has moved from its normal position on the top of the condyle Clinical Features • Clicking is accompanied by pain Temporomandibular Joint Disorders • Dysfunction due to intermittent locking • Pain is most noticeable at the time of the click Palpation and auscultation of the TMJ will reveal: Reciprocal click: A clicking or popping sound during both opening and closing mandibular movements The clicking or popping sound due to anterior disk displacement with reduction is characterized by a click that occurs at a different point during opening and closing Anterior Disk Displacement without Reduction (Closed Lock) Closed lock may be the first sign of TMD occurring after trauma or severe long-term nocturnal bruxism It is detected more frequently in patients with clicking joints that progress to intermittent brief locking and then permanent locking A patient with an acute closed lock will often have a history of a long-standing TMJ click that suddenly disappears with a sudden restriction in mandibular opening.This limited mandibular opening occurs when the disk interferes with the normal translation of the condyle along the glenoid fossa Clinical Features • Pain directly over the joint during mandibular opening (especially at maximum opening) • limited lateral movement to the side away from the ADD • During maximum mandibular opening, the mandible will deviate towards the side of the displacement Palpation of the joints will reveal decreased translation of the condyle on the side of the disk displacement Posterior Disk Displacement Posterior disk displacement has been described as the condyle slipping over the anterior rim of the disk during opening, with the disk being caught and brought backward in an abnormal 169 relationship to the condyle when the mouth is closed The disk is folded in the dorsal part of the joint space, preventing full mouth closure Clinical Features • Sudden inability to bring the upper and lower teeth together in maximal occlusion • Pain in the affected joint when trying to bring the teeth firmly together • Forward displacement of the mandible on the affected side • Restricted lateral movement to the affected side • No restriction of mouth opening Management • ADD resolve over time either with no treatment or with minimal conservative therapy • Painful clicking or locking should initially be treated with conservative therapy • Recommended treatments for symptomatic ADD include splint therapy, manual manipulation and other forms of physical therapy, anti-inflammatory drugs, arthrocentesis, arthroscopic lysis and lavage, arthroplasty, and vertical ramus osteotomy Many of these nonsurgical and surgical techniques are effective in decreasing pain and in increasing the range of mandibular motion although the abnormal position of the disc is not corrected • Anterior disk displacement with reduction: Flatplane stabilization splints that not change mandibular position and anterior repositioning splints have both been used to treat painful clicking (potential side effects of these appliances, which include tooth movement and open bite) • Anterior disk displacement without reduction: Treatment options should depend on the degree of pain associated with the ADD Management of a locked TMJ may be nonsurgical or surgical The goals of successful therapy are to eliminate pain and to restore function by increasing the range of mandibular motion Replacing the disk in 170 Concise Oral Medicine a normal position is not necessary to achieve these goals Flat-plane occlusal stabilization appliance to decrease the adverse effects of bruxism is advocated Patients with severe pain on mandibular movement may benefit from either arthrocentesis or arthroscopy Flushing the joint with intra-articular corticosteroids to decrease inflammation or with sodium hyaluronate to increase joint lubrication and decrease adhesions has also been reported to help in decreasing the pain associated with nonreducing disk displacement MYOFASCIAL PAIN DYSFUNCTION SYNDROME (MPDS) MPDS or Costen’s syndrome is a disease entity that results from spasm of the muscles supporting the jaws due to multiple causes most important being overclosure or overextension of the muscles Etiology The various factors that have been associated in the cause of MPDS are as follows: • Parafunctional habits, e.g nocturnal bruxing, tooth clenching, lipor cheek biting • Emotional distress • Acute trauma from blows or impacts • Trauma from hyperextension, e.g dental procedures, oral • Intubation for general anesthesia, yawning, hyperextension associated with cervical trauma • Instability of maxillomandibular relationships • Laxity of the joint • Comorbidity of other rheumatic or musculoskeletal disorders • Poor general health and an unhealthy lifestyle Pathophysiology of MPDS (Laskin’s Theory) The pathophysiology of MPDS emphasizes mainly on the muscular tension caused by oral habits and dental irritants Figure 10.8 gives a lucid explanation to the mechanism involved in MPDS Fig 10.8: Pathogenesis of MPDS, proposed by Laskin Temporomandibular Joint Disorders Clinical Features • Patients complain of unilateral, dull pain in the ear or preauricular region • Pain is worse on awakening in the morning • Tenderness of muscle of mastication is present • Mouth opening is limited and painful The jaw deviates to affected side on opening the mouth Laskin’s four cardinal signs of MPDS Unilateral pain: There must be a dull ache in the preauricular region Pain is worse on waking up Muscle tenderness must be present on palpation Clicking/popping noise must be heard in the TMJ Mouth opening must be restricted Negative Features a Absence of radiographic findings b Lack of tenderness in the TMJ on palpation from the external auditory meatus Trigger Points These are localized deep tender areas of taut band of skeletal muscle, tendon or ligament that has the tendency to cause referred pain in a definite anatomic distribution when stimulated Presence of such trigger points are characteristic feature of MPDS The area perceived by the irritable trigger point is called the zone of reference In MPDS, pain is elicited by applying digital pressure on the trigger point whereas in trigeminal neuralgia, even light touch or breeze is sufficient to stimulate the trigger zone and precipitate an attack of pain 171 i Muscle must be evaluated in its entire length including its origin and insertion ii The muscles must be evaluated in rest and contracted position iii The muscles must be examined bilaterally to compare the difference iv The muscles must be palpated horizontally and vertically to the attachments While palpating the muscles, begin palpating with light pressures before proceeding to 3–4 pounds Muscle palpation may be performed by two methods, i.e Flat palpation: When muscle can be palpated over the bone, e.g masseter Pincer palpation: When the belly of the muscle can be held between the fingers, e.g sternocleidomastoid Treatment Consideration Multiple therapeutic approach is preferred in the management of MPDS beginning with patient education and counseling Pharmacotherapy NSAIDs are the drug of choice for immediate pain relief Ibuprofen 400 mg t.d.s or nimesulide 100 mg b.d are good choices of analgesics Diclofenac gel in pluronic lecithin organogel can be rubbed over the skin followed by hot fomentation which gives relief from pain and improves mouth opening Jump Sign Muscle relaxants such as chlorzoxazone 250 mg t.i.d., carisoprodol 350 mg t.i.d (tab soma) are valuable in reducing muscle spasm Diazepam 2–5 mg can be given for 10 days Cyclobenzaprine 10 mg before sleep has been tried recently and found effective It is the withdrawal of head, wrinkling of head or verbal response given by the patient on palpating the trigger points Tanaka’s recommendations for palpation of muscles Amitriptyline which is a tricyclic antidepressant can be given in the doses of 10 or 25 mg at bed time to reduce patient anxiety and provide a good refreshing sleep 172 Concise Oral Medicine Intraoral Appliance Therapy Hard and soft splints can be fabricated that help to unload TMJ and establish a harmonious relation between TMJ and muscles Trigger Point Therapy The spray and stretch technique provides stimulation of cutaneous afferent nerves and produces trigger point inhibition causing pain relief Fluoromethane spray is an effective choice for the same Alternatively injection of local anesthesia 0.5% procaine, bupivacaine into the trigger points reduces pain However, chances of myotoxicity and other reactions should be considered before initiating the therapy Relaxation Therapy This mode of therapy decreases sympathetic activity and arousal Brief methods such as deep breathing and deep methods such as meditation, progressive muscle relaxation can be performed under the supervision of a trained master to provide muscle relaxation ANKYLOSIS Ankylosis in Greek terminology means ‘stiff joint’ Hypomobility to immobility of the joint can lead to inability to open mouth partially or completely Classification of Ankylosis • • • • • False ankylosis or true ankylosis Extra-articular or intra-articular Fibrous or bony Unilateral or bilateral Partial or complete Psuedocauses Scar tissue formed in muscle of mastication Myositis ossificans Injury to zygomatic arch and union to coronoid process (forceps delivery) Ca nasopharynx and antrum True—may be fibrous or bony: • Fibrous—joint space seen • Bony—mass of bone seen between condyle and glenoid fossa (condyle cannot be visualized) This type is due to trauma or infection to condyle, so that the growth of mandible on that side comes to a standstill Physiotherapy Etiology Various types of treatments like moist heat, ultrasound and shortwave diathermy help immensely in reducing pain and dysfunction They act by increasing the vascularity of the muscle, resolution of inflammation and fibrosis and increasing the flexibility of connective tissue Isokinetic exercises of the jaws also provide a similar effect to the muscles Other methods such as massage, accupressure, homeopathic and herbal medicines, botulinum toxin are also used widely in the treatment of MPDS Exercises like reciprocal relaxation, active and passive stretch are found to be effective In reciprocal relaxation, patient is asked to open against pressure and this method relaxes the closing muscles which are tender in MPDS Two main factors predisposing to ankylosis is trauma and infections: • Trauma: Congenital, at birth (forceps delivery), hemarthrosis, and condylar fractures • Infections: Otitis media, parotitis, tonsillitis, furuncle, abscess around joint, osteomyelitis, actinomycosis • Inflammation: Rheumatoid arthritis, osteoarthritis, septic arthritis • Systemic diseases: Smallpox, scarlet fever, typhoid, gonococcal infections, scleroderma, Marie-Strumpell disease, ankylosing spondylitis • Others: Bifid condyle, prolonged trismus, prolonged immobilization, burns ... antidepressant can be given in the doses of 10 or 25 mg at bed time to reduce patient anxiety and provide a good refreshing sleep 1 72 Concise Oral Medicine Intraoral Appliance Therapy Hard and soft splints... oblique • Occlusal view with reduced exposure (Fig 12. 2) • Donovan’s technique (Fig 12. 3) d Sialography may show filling defect (Fig 12. 4) Fig 12. 3: Deeply located sialolith visualized on occlusal... advocated in cases where there is complete destruction Fig 12. 4: Sialogram showing filling defect caused by sialolith 1 92 Concise Oral Medicine • Lithotripsy and sialoendoscopy may be helpful