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Tmd in orthodontics /certified fixed orthodontic courses by Indian dental academy


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Tmd in orthodontics /certified fixed orthodontic courses by Indian dental academy

  1. 1. TMD in Orthodontics INDIAN DENTAL ACADEMY Leader in continuing dental education
  5. 5.  Orthodontists are constantly being challenged with the task of providing their patients with acceptable esthetics and masticatory function. Although esthetics is often the patient’s immediate and primary goal, function becomes far more important over the lifetime. So developing a sound, functional masticatory system is the primary goal of all orthodontic therapy.
  6. 6.  The frequency of TMJ complaints has multiplied in the last few years. This may have been brought about by the increased stresses of our fast paced world, or at least we now recognize that there is a stress strain tension release syndrome that often manifests itself with nocturnal parafunctional activity.
  7. 7.  Dentists, through many accepted dental procedures may inadvertently exert distal pressure on the mandibular complex, which can be the beginning of a TMJ disorder.
  8. 8.  Few examples of such dental problems and their treatment are :  Firstly, Extractions leading to horizontal or vertical dental changes can add to distal and elevated mandibular pressure.  Secondly, Crowns, bridges, fillings that alter physiologic intercuspation can create adverse functional pressure on the mandible.
  10. 10.  The craniomandibular articulation is a complex synovial system composed of temperomandibular joints together with their articular ligaments and masticatory muscles.
  12. 12.  The craniomandibular articulation presents several features that complicate diagnosis and treatment.
  13. 13.  Unique mechanism for providing joint stability : The human craniomandibular articulation is structurally the most complex synovial system in the body, consisting of two quiet separate but functionally interdependent TM joints . It consists of a double joint within a single capsule. Each is composed of a lower hinge joint and a freely movable upper joint capable of both sliding and pivoting movements.
  14. 14.  Impact of Occlusion : Disharmony between the effect of occlusion and that of muscle action may induce masticatory dysfunction or cause overloading of the articular tissues.
  15. 15.  Lack of Regenerative Capability of the Disc The osseous supported articular surfaces of the TM joint have capability to undergo active remodeling in response to the demands of function. But articular disc does not display regenerative or remodeling behaviour.
  16. 16.  Importance of Retrodiscal Tissue : Retrodiscal tissue is essential for both the normal metabolic activity as well as functional movements of the joint.  It is the major source of synovial fluid for both compartments of the joint, which is essential for nutrition and lubrication of the moving parts.  Damage to this tissue predisposes to both masticatory dysfunctions as well as degenerative changes. 
  17. 17.
  18. 18. DEFINITION
  19. 19.  Temperomandibular disorder, in the broad sense are to be considered a cluster of joint and muscle disorders in the orofacial area, characterized primarily by pain, joint sounds and irregular or deviating jaw function.
  20. 20. The pain is neither of neurogenic, psychogenic or visceral origin nor of periodontal, dental or cutaneous .
  21. 21.  According to “American Academy of Orofacial Pain” – Temperomandibular disorder is a collective term embracing a number of clinical problems that involve the masticatory musculature,temperomandibular joint and associated structures or both.
  22. 22. Therefore, TMD includes disorders related to the joint itself and of the masticatory cervical muscle complex.
  24. 24. A notion has persisted for half a century that dysfunction’s of the masticatory apparatus comprises syndrome initially referred to as Costen's syndrome or TM syndrome. In 1956 Schwartz introduced the TM pain dysfunction syndrome. Then came the myofacial pain dysfunction (MPD) syndrome in 1969.
  25. 25. A partial list of the attempts to label TMJ related conditions Costen Syndrome ( Costen,1934 )  TMJ Syndrome ( Schwartz,1956 )  TMJ Dysfunction Syndrome ( Shore 1959 , Lupton 1969 )  TMJ Pain Dysfunction Syndrome (Schwartz1959)  Pain Dysfunction Syndrome ( Voss , 1964 ) 
  26. 26.  Arthrosis Deformatus ( Boering , 1966 )  Oto Dental Syndrome ( Myrhaug , 1969 )  Autodestruction (Drum , 1969 )  Functional Temperomandibular Joint Disturbances and Disorders ( Olson 1969 , Ramjford 1971 )  Occluso Mandibular Disturbances
  27. 27.  Mandibular Dysfunction (Hickimo , 1974 )  Myoarthropathy of TMJ ( Graber , 1972 )  Craniocervical Mandibular Syndrome ( Geeb 1975 )  Mandibular Stress Syndrome ( Ogus and Teller , 1981 )  Craniomandibular Disorders
  28. 28.  Temperomandibular PainDysfunction Syndrome ( Mersken , 1986 )  Temperomandibular Disorders ( Bele 1982 , Mcneil 1990 )
  30. 30. It is interesting to note that in the medical dictionary the only joint disorder listed as a syndrome is Costen’s. This syndrome concept has no doubt contributed to the one disease – one treatment myth.  The clinical signs and symptoms displayed by masticatory disorders are much too varied to be classified as a “Syndrome”. 
  31. 31.  According to a medical definition, a SYNDROME is a set of symptoms which occur together as a symptom complex. This term is meant to apply to symptoms as such.
  32. 32. A DISORDER is a derangement or abnormality of function, a morbid physical or mental state. This term applies not to symptoms but to conditions.
  34. 34.  The American Academy of Orofacial Pain has published a TMD classification system that is integrated with an existing medical diagnostic classification used by the International Headache Society. Although no classification has been accepted by all the practitioners, the AAOP classification has received general acceptance.
  35. 35. 1. Temperomandibular joint disorder 2. Masticatory muscle disorders 3. Congenital and developmental disorders
  36. 36. 1. Temperomandibular joint disorder A Deviation in form  Articular surface defects  Disc thinning and perforation. B Disc displacement  Disc displacement with reduction  Disc displacement without reduction C Displacement of disc condyle complex  Hypermobility  Dislocation D Inflammatory conditions  Capsulitis and synovitis  Retrodiscitis
  37. 37. E Degenerative disease  Osteoarthrosis  Polyarthritis  Osteoarthritis F Ankylosis  Fibrous  Bony Masticatory muscle disorders A Acute 2.    Myositis Reflex muscle splinting Muscle spasm
  38. 38. B Chronic  Myofacial pain Muscle contracture Hypertrophy Myalgia 3. Congenital and developmental disorders  Condylar hyperplasia Condylar hypoplasia Aplasia Neoplasms Fractures       
  39. 39.  SECOND CLASSIFICATION OF TMJ DISORDERS (E.W.William, AJO 1987, 91):  A) Systemic : These are disorders that have direct manifestations in the joint, but the cause is systemic disease (e.g. arthritis).  B) Acquired : These are disorders induced from a variety of causative factors. Trauma, stress, any dental procedure which may inadvertently exert distal pressure on the mandibular complex.
  41. 41.  The etiology of TMD remains mired in controversy. It is generally agreed that the etiology of symptoms of TMD is multifactorial. That is several different factors acting alone, or in varying combinations may be responsible.
  42. 42. The etiological factors sometimes be called as contributing factors that can be defined as factors that initiate, perpetuate or result in a disorder .
  43. 43. Predisposing factor – factors that increase the risk of developing TMD or orofacial pain.  Initiating factors – factors that cause the onset of disorder.  Perpetuating factors – factors that interfere with healing and complicate management . 
  44. 44.  Predisposing factors can be subdivided into : Systemic factors – medical conditions such as rheumatic infections, nutritional and metabolic disorders can influence masticatory system to an extent that TMD may emerge. Psychologic factors - Personality,behaviour can affect masticatory system.
  45. 45. Structural factors – All types of occlusal discrepancies, improper dental treatment, postural abnormalities ,skeletal deformation, past injuries etc. Genetic factors.
  46. 46.  Initiating factors : Trauma – Microtrauma or Macrotrauma Overloading of joint structures Parafunctional habits etc.
  47. 47.  Perpetuating factors : Mechanical and Muscular stress. Metabolic problems.
  48. 48.  All the above factors can be broadly grouped into three major factors. Anatomical Psychological Neuromuscular
  49. 49.  The three main groups anatomic, neuromuscular and psychologic factors will influence each other and act together.  Depending on the type of disorder and depending on the pathology in individual patient, the three can act as predisposing initiating or perpetuating factor.
  51. 51.  Epidemiological studies in many parts of the world confirms a very high prevalence of signs and symptoms of TMJ dysfunction.  Most of the studies report at least 50% of individuals having at least one sign (e.g. muscle tenderness or joint clicking) although only 30% of subjects may be aware of such symptoms.
  52. 52. Symptoms of TM disorders are common in all age groups. Older age groups have slightly more symptoms than the young.  At the same time there is higher frequency of symptoms of dysfunction in females as compared to males. 
  54. 54.  Pain : Pain may arise from TM Joint and muscles of mastication. It is the most common symptom causing patients to seek treatment. Pain may be present as a constant or periodic dull ache over the joint, the ear and the temporal fossa. Pain is usually elicited by mandibular movement or by palpation of the affected regions.
  55. 55.  Pain can be :  Myogenic pain : Mechanical trauma and muscle fatigue.  Articular pain : Arises as a result of inflammation of articular and periarticular tissues caused by :  Overloading or trauma  Degenerative changes such as occurring in osteoarthrosis
  56. 56.  Joint Sounds : Crepitus : This is a grating or scraping noise that occurs on movement. It is caused by the roughened, irregular articular surfaces of the osteoarthritic joint. Clicking: It is caused by uncoordinated movement of condylar head and articular disc.
  57. 57.  Limitation of Mandibular Movement a) Muscular restriction: It is most common reason for limitation of mandibular movement. The restriction is caused by contraction of group of muscles. b) Disc displacement: An anteriorly displaced disc may prevent the forward translation of the mandibular condyle. This results in limitation of opening of the mouth.
  58. 58. c) Ligamentous restriction: The ligaments normally restrict the movements of the joint in all direction and operate when the muscles are unable to stop the movement and when there is a risk of dislocation of joint. Eg. Following sudden, voilent movements .
  59. 59.  Dislocation : On wide opening of the mouth the head of the condyle normally passes over the articular eminence. Occasionally patient may be unable to close the mouth as condyle can not return into the fossa. The patient may eventually be able to reduce the dislocation himself or may present at hospital for treatment.
  60. 60.  Ear Symptoms : Subjective ear symptoms are commonly associated such as tinnitus, itching in the ear, vertigo.
  61. 61.  Recurrent headache : It is frequently associated with pain and tenderness in the masticatory muscles. TM disorder is mostly associated with temporalis muscle contraction , headache and sometimes migraine headaches .
  64. 64.  The orthodontist have long been interested in the problems associated with diagnosis and management of Temperomandibular disorders.  Indeed orthodontic treatment has been characterized in diverse publications as both causing and curing temperomandibular disorder.
  65. 65.  The interest of the orthodontic speciality concerning the association or lack of association between Orthodontic treatment and TMD has increased dramatically during the past decade.
  66. 66.  The attention of the orthodontic community regarding TMD however was heightened in the late 1980s after litigation involving the allegations that orthodontic treatment was the proximal cause of TMD in orthodontic patients.
  68. 68. In the 1980’s articles in various journals and trade magazines suggested that orthodontic treatment might play a role in initiating temperomandibular disorder.  On the other hand it was also claimed that orthodontic treatment might be effective in alleviating the signs and symptoms of TMD. 
  69. 69.  The conflict became earnest when result of the famous Michigan orthodontic / TMJ law suit was announced. This litigation turned on the argument that a form of orthodontic treatment had been the cause of the patient’s TMD, the six member jury were in favour of the patient.
  70. 70. The patient named Susan Brimm, when she was 16 years began treatment to correct a Class II Div I malocclusion with a 7 mm of anterior open bite. Her treatment included the removal of her upper first premolars, the use of headgear and bonding of her upper and lower teeth.
  71. 71. At the time the treatment was initiated she exhibited no temperomandibular symptoms. She complained that when braces were removed she suffered a severe click with severe pain and limited opening. Ultimately the matter was settled by a payment of a large sum of money to the patient.
  72. 72. This litigious climate stimulated the American Association of Orthodontics not only to sponsor a series of risk management teleconferences and newsletter, but also to underwrite research concerning the relationship of orthodontic treatment to TMD.
  74. 74.  The benefits of orthodontic treatment in the management of Temperomandibular Disorder is questionable, since the occlusion is considered as having a limited role in the cause of TMD.  But the potential detrimental effects of orthodontic treatment on TMJ has captured the attention of orthodontic community.
  75. 75. Some of the examples of Orthodontic treatment which can lead to Temperomandibular Disorders are :
  76. 76.  1) Effect of headgear and/or class II elastics in correction of Class II malocclusions with deep interlocking cusps. Headgear or Class II elastics are often used in an effort to get the patient into a Class I cuspal relationship. By the headgear force, as the maxilla is moved backward the muscles of mastication will attempt to retract the mandible when the patient closes into maximum intercuspation. This compensating movement by the mandible can put distal pressure on the condyles and conceivably cause an anterior dislocation of the disk.
  77. 77. To correct this problem in orthodontic treatment, a possible solution is to give flat plane of acrylic which can be bonded on the occlusal surface of lower molars and premolars after the fixed appliance has been placed or it can be a removable bite plane.
  78. 78. When the bonded bite planes are used, then maxillary teeth move freely distally as there is no cuspal inter locking hence no effect on the mandible.
  79. 79. Once cusps get past a point to point contact, the bite plane is removed. Now the cuspal inclines tend to guide the mandible forward and maxillae backward on maximum closure. This may aid in the retraction of the maxilla but at the same time the mandible is moved forward .
  80. 80.
  81. 81.
  82. 82.
  83. 83.  2) Effect of Cross elastics to correct the midline : The cross elastics have a little effect on TMJ. As the jaw is pulled to one side, distal pressure is put only on one condyle and chances of anterior dislocation of disc. If it creates a TMJ problem then elastics should be worn only during waking hours so that the muscles can help to hold the mandible forward because of muscle tension.
  84. 84.  3) Effect of Reverse Headgear or Class III Elastics for Correction of Class III malocclusion : This again can put distal pressure on the mandible. If there is a developing problem, then patient is asked to wear reverse headgear or Class III elastics during waking hours as muscle tension or tone, positions the mandible forward. Since at night, the muscles are relaxed and there is more distal pressure on condyle since compensating muscle activity is not in play.
  85. 85. If then also patient cannot tolerate, then orthodontic treatment must be compromised or surgical line of treatment should be considered.
  86. 86.  4) Effect of Lower Expansion and Upper Contraction : In most cases, the crowded lower anterior teeth are in contact with the lingual of the upper anterior teeth. There is a spacing in upper anterior. The common request that the patient makes is to close the spaces in the upper anterior teeth. If a orthodontist tries to close down the anterior (upper) spaces without opening the bite, it may create a premature contact with the lower anterior teeth and exert distal pressure on the mandible that may result in TMJ pain.
  87. 87. In these deep bite cases one should first open the bite and carefully plan the proper interincisal anterior angulation, so that the maxillary space closure can be carried without impinging on the lower anterior teeth.
  88. 88.  5) The Retentive Phase : According to many TMJ observers, the retentive phase of orthodontic treatment may cause more TMJ problems than any other orthodontic procedure. Some clinicians believe that it is the good antero posterior interdigitation in the retentive phase which is the main offender for TMJ problems.
  89. 89. The majority of orthodontically treated cases mostly have dental deep bite at the beginning. If the deep bite is treated by extrusion of the posteriors, there will be increase in the vertical dimension of the lower face. In most of the cases vertical dimension of the lower face will largely tend to revert to its original height.
  90. 90. So in cases of orthodontically treated deep bite malocclusions, the bite will tend to close at varying speeds, ranging from months to years.
  91. 91. As the bite deepens four possible adverse effects can be seen. Spacing in upper anterior teeth.  Crowding in lower anterior teeth.  Tends to move maxilla forward.  Drives the mandible distally 
  92. 92. Since most of the orthodontists give a 3 to 3 fixed retainer on both upper and lower anterior teeth after the active treatment. These retainers prevent  Firstly, lower anterior teeth from crowding or collapsing.  Secondly, prevent the upper anterior teeth from rotating, separating or moving forward.
  93. 93. But at the same time the retainer cannot prevent other two adverse effects i.e. forward movement of maxilla and distal movement of mandible, which can again lead to TMJ problems.
  94. 94. Then how to prevent forward movement of maxilla and distal movement of mandible ?
  95. 95.  When the fixed appliances are debonded, a retainer Begg labial bow minus a bite plane is placed on the same day.  There must be a minimal lapse of time between debonding and seating of the retainer.
  96. 96.  The bite is allowed to deepen with the retainer in place for 2-3 weeks. The curve of spee will begin to return to the occlusal plane.  When the bite has deepened sufficiently for anterior guidance (e.g bite closure of 1-2 mm) the lingual bite plane is added to retainer.
  97. 97.
  98. 98.  If the patient continously wears the retainer 24 hours a day usually the bite will not deepen dentally and there will be no distal pressure exerted on the mandible during retention unless there are major increments of upward and forward rotating mandibular growth occurring.
  99. 99.  If there is no distal pressure on the mandible by giving anterior upper bite plane, the condyles are not driven posteriorly and the articular disks would stay in place, thus TMJ problems are much less likely to occur .
  101. 101. Ten years prior, very few clinical studies regarding the relationship between orthodontic treatment and TMD were published.
  102. 102.  In a comprehensive review of the literature on this subject that was published between 1966 to 1988 .  Reynders divided above publications into three categories :  View point articles.  Case reports  Sample studies
  103. 103.  The view point articles were not suitable for critical evaluation of association between two entities, however useful in identifying questions that may be worthy of scientific investigation.
  104. 104. 1) What is the prevalence of signs and symptoms of TMD in orthodontically untreated population ?  Numerous epidemiologic studies have shown a significant prevalence, with an average of 32% reporting at least one symptom of TMD and an average of 55% demonstrating at least one clinical sign.  Several investigators have noted that signs and symptoms of TMD generally increase in frequency and severity in the second decade of life.
  105. 105. 2) Does orthodontic treatment lead to a greater incidence of TMD ?  Two of the first major investigations sponsored by the National Institute of Health to consider relationship between orthodontics and TMD revealed no statistically significant differences between the treated and untreated groups.
  106. 106.  The results of these studies provide evidence in support of the concept that orthodontic treatment performed during adolescence generally did not increase or decrease the risk of developing TMD later in life.  Another study of the long term effects of orthodontic treatment was conducted by Larsson and Ronnerman. They stated that comprehensive orthodontic treatment can be under taken without fear of creating TMD problems.
  107. 107. 3) Does the type of appliance (e.g. fixed functional or orthodontic vs orthopedic) make a difference ?  In the major longitudinal study conducted by Dibbets et al consisting of 171 patients, 75 of whom were treated by Begg mechanotherapy, 65 were treated by activator and 30 patients were treated with chin cups, revealed that at the end of treatment, fixed appliance group had a higher percentage of objective symptoms than did the functional group, but no differences existed at the 20 year follow up
  108. 108.  Another prospective study conducted by Pancherz examined the effects of functional mandibular advancement in patients with Class II div I malocclusion. He used bonded Herbst appliance. After an initial edge to edge bite registration , several patients reported muscles tenderness during first 3 months of treatment. However, at 12 months following treatment, the number of subjects with symptoms was the same as that before treatment.
  109. 109. 4) Does the removal of teeth as part of an orthodontic protocol lead to a greater incidence of TMD ?  View point articles and tests have strongly associated the extraction of premolars with the occurrence of TMD in orthodontic patients.  But clinical studies that have dealt with this issue have not shown relationship between premolar extraction and TMD.
  110. 110.  Sadowsky and Coworkers conducted a study on 160 patients and reported that joint sounds were evident before and after treatment in 87 extraction patients and 68 non extraction orthodontic patients. They reported there is no increase in the risk of development of joint sounds regardless of whether teeth were removed .
  111. 111.  Another study done by O’Reilly et al examined 60 treated subjects and 60 untreated subjects. The treated patients, underwent fixed orthodontic treatment that included extraction and the wearing of Class II intermaxillary elastics. No difference were seen between the treated and untreated groups .
  112. 112.  Finally Pullinger et al noted that the contribution of the extraction of two or four teeth per se, as part of an orthodontic treatment protocol, was negligible in most cases when other variables were controlled.
  113. 113. 5) Can orthodontic treatment lead to a posterior displacement of the mandibular condyle?  A number of viewpoint articles have asserted that a wide variety of traditional orthodontic procedures e.g. premolar extraction, extraoral traction, retraction of maxillary anterior teeth cause TMD signs and symptoms by producing a distal displacement of condyle .
  114. 114.  Gianelly et al did the study collecting the tomograms to evaluate condylar position. They took the tomograms before orthodontic treatment in 37 consecutive patients aged 10 to 18 years and compared them with tomograms from 30 consecutively treated patients with fixed mechanotherapy and removal of four premolars. No differences in condylar position were noted between groups .
  115. 115.  Another study conducted by Luecke and Johnston evaluated the pretreatment and post treatment cephalograms of 42 patients treated with fixed appliances in conjunction with the removal of two upper premolars.  The result of the study indicated that the majority of patients about 70% undergo a forward mandibular displacement and a slight opening rotation of mandible. The remainder of the sample had distal movement of the condyle.
  116. 116.  Thus researchers concluded that posterior condyle position was not a result of orthodontic treatment.
  117. 117. 6) Should the occlusion of orthodontic patients be treated to specific gnathologic standards ?  Several view point articles including those by Roth et al and Williamson have maintained that TMDs may result from a failure to treat orthodontic patients to gnathologic standards that include the establishment of a “mutually protected occlusion” and proper seating of the mandibular condyle within the glenoid fossa.
  118. 118.  Pullinger et al reported that small occlusal slides less then 1 mm are common in asymptomatic subjects as well as patients with TMD.
  119. 119.  It probably is prudent to establish morphologic treatment goals that mimic what is observed in untreated occlusions that have been judged ideal. The establishment of an occlusion that meets gnathologic ideals probably is unnecessary particularly in adolescent patients and sometimes impossible to attain in some adult patients .
  120. 120. 7. Does orthodontic treatment prevent TMD ?  One of the few investigations that found improved TMD health in a treated group was the sample studied by Magnusson et al, Egermark and Thilander. The investigators noted that clicking recorded at the first examination sometimes disappeared at subsequent examination. At the same time the clinical dysfunction index outcome was lower in those who had undergone orthodontic treatment in those who had not undergone orthodontic treatment.
  121. 121. A trend toward decreased prevalence of TMD signs and symptoms in treated patients also was noted by Sadowsky , Polson and Dahl et al.
  122. 122.
  123. 123. Palpation of T.M.J. Pain or tenderness of TMJ is determined by digital palpation when the mandibular is in both stationary and dynamic movements. • The examiners finger tips are placed over the lateral aspect of joint areas simultaneously on both sides. •
  124. 124. Lateral palpation The finger tips should feel the lateral poles • of condyles passing down towards across articular eminence. • Once position is verified, the medial force is applied to the joint area to check for any pain •
  125. 125. 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.
  126. 126. 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 .
  127. 127. Crepitation This is a grating or scalping noise that occurs on jaw movements . Sound like when sand paper is rubbed against a surface. • Crepitation is very uncommon in asymptomatic joint and may be an early sign of degenerative joint disease.  crepitus is caused by roughened, irregular anterior surface. •
  128. 128. 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
  129. 129. 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 incordination between displacement of the condyle & disc.
  130. 130. MAXIMUM JAW OPENING The distance between the incisal edges of the upper and lower central incisors is measured with a Boley gauge. • Normal value is 4045mm. • In overbite cases this amount is added to the obtained value whereas •
  131. 131. Diagnostic imaging of T.M.J HARD TISSUE IMAGING • to evaluate the osseous contours, the positional relationship of the condyle and fossa and range of motion. • Because T.M. Joint’s proximity to temporal bone, mastoid air cells and auditory structures, imaging of the joint can be problematic, so a combination of imaging technique may be required. •
  132. 132. 1) Panaromic Projection: this provides an overall view of the teeth and jaws, it serves as a screening projection to identify odontogenic diseases and other disorders that may be a source of T.M.J. Symptoms. • These are of limited usefulness because the thick image layers and oblique distorted view of the joint they provide severely limited image quality.
  133. 133. No information about condylar position or function is provided because the mandible is partly opened and protruded when this radiograph is exposed. • Mild osseous changes may be obscured and only marked changes in articular eminence morphology can be seen as a result of superimposition by skull base and zygomatic arch. •
  134. 134. 2) Transcranial (Lateral Oblique) projection or imaging • • • Initial screening for gross osseous abnormalities can be seen with transcranial view. The x-ray tube is placed at a true vertical angle at 250 (source distance 22” or 56 cm) from target to film. Routine transcranial imaging includes projections of TMJ in both closed and maximally opened position
  135. 135. •Condylar position cannot be reliably determined It provides sagittal view of lateral aspects of the condyle and temporal component displaced condylar features, range of motion.
  136. 136. New transcranial lateral oblique system. • In this, the office x-ray machine can be used to take transcranial lateral oblique view with a specific film cassette and a head holding system .
  137. 137. Transpharyngeal (Parma) Projection • • • It provides a sagittal view of the medial pole of the condyle. It provides for limited diagnostic information as temporal component is not visible. It is effective in visualizing erosive changes in condyle rather than more subtle ones.
  138. 138. Transorbital projection & Transmaxillary projection • • • Both provide an anterior view of the T.M.J. The projection is done perpendicular to transcranial and transpharyngeal projection. Here the source and head position in such that head forms an angle of 300 to the source.
  139. 139.
  140. 140. • • Here the mediolateral dimension of articular eminence,condylar head and condylar neck is visible. So it is useful for visualizing condylar neck features. It is an useful adjunct in diagnosis of gross degenerative changes or other anomalies of condylar head.
  141. 141. Submento vertex view: • • It provides the view of the skull base and condyles superimposed on condylar necks and mandibular rami. It is particularly useful for evaluating facial asymmetries, Condylar displacement, rotation of mandible in horizontal plane associated with trauma or orthognathic surgery.
  142. 142. Tomography Basic principle: • Both the radiation source and film are moving simultaneously to blur all the anatomy anterior and posterior to the point of plane convergence. • Conventional Tomography Computed tomography
  143. 143. Conventional Tomography: • It produces multiple thin image slices permitting visualization of an anatomic structure free of superimposition of overlapping structures. Here the image slices are taken in closed (maximum intercuspation position) maximal open position.
  144. 144. Computed Tomography (CT) • • Indicated when more information is needed about the 3 dimensional shape and internal structure of the osseous components of joint or if information regarding the surrounding soft tissues is required. Cannot produce accurate images of the articular disc.
  145. 145. Soft Tissue Imaging: Soft tissue imaging is indicated when T.M.J pain and dysfunction is present. • Or when the clinical findings suggest disk displacement along with symptoms that are unresponsive to conservative therapy. •
  146. 146. Arthrography It is a technique in which an indirect image of the disk is obtained by injecting a radiopaque contrast agent under a fluoroscopic unit. • Arthrography is indicated when information about disk position, function and morphology and integrity of discal attachment is required. • Arthrography is superior in diagnosis of small disk perforation and joint adhesions. •
  147. 147. • • • • Arthrography involves injection of water soluble iodinated contrast material About 0.4 – 0.5 cc of contrast material is injected into the joint cavities. Later needle is withdrawn then images and Video recordings are done. These are illuminated with xenon light which provides brighter images.
  148. 148. Magnetic Resonance Imaging MRI uses a magnetic field radiofrequency rather than ionizing radiation to produce multiple digital images to soft tissue. • In MRI, the operator electronically tunes an external radiofrequency to match the magnetic frequency of the tissue sample . • When the external RF is tuned to region of interest and is intensified, the protons of the tissues rise to a higher energy •
  149. 149. state upon termination of RF pulse, which lasts less than one sec, the responding photons will immediately begin to relax and release occurred energy • Faster the relaxation rate stronger is the signal, brighter is the image and vice versa • Slice thickness usually varies from 3 and 10 mm thinner sections result in improved image quality . •
  150. 150. • • • In MRI of TMJ the position of the articular disc is of utmost importance. The disc is made of fibrocartilage, so it gives out a low signal and hence black in appearance. This is seen in contrast to adjunct superior and inferior, joint spaces, which of intermediate intensity (grey in colour)
  151. 151. • • A round 3 inch diameter surface coil, placed with its central opening directly over patients T.M.J provides the best images. A series of images in closed open mouth position as well as coronal images in closed mouth position are obtained bilaterally when the patient is in supine position.
  152. 152. Xeroradiography The xeroradiographic method uses of selenium coated plate, and charged plastic powder a toner, producing variation in shades of blue.  The bone will appear blue or white, and the soft tissues will appear more clearly than on the usual radiography. 
  154. 154.  It is extremely important to begin treatment early so that the condition may still be reversible and the tissues can heal without the need for joint surgery.
  155. 155.  FIRST PHASE OF TREATMENT (COMFORT PHASE) : The primary purpose is to eliminate the pain, clicking, popping, locking headaches, neckaches, backaches, which are frequently related to condyle that is improperly positioned in the fossa and disc that is frequently displaced forward in the fossa.
  156. 156. The TMJ splint repositions the mandible in such a position that the condyles are centered in the fossa and any impingement of the tissues is reduced.  The treatment is usually for 6-12 months. 
  157. 157.  SECOND PHASE THERAPY : The highest priority is to maintain the condyles in the proper position, whatever it takes to maintain TMJ health. It includes the following steps :
  158. 158.  A) TMJ Recall : If the patient feels fine with no symptoms when the splint is out and can move the mandible back to their original bite position, they can be placed on category of TMJ recall and further no treatment is planned at that time. They can be examined once in a year .
  159. 159.  B) TMJ Treatment (Orthopedics / Orthodontics) : If the TMJ disorder symptoms return,whenever the splint is removed and patient tries to move their lower jaw back to its pre treatment position, this confirms the original diagnosis of TMJ disorder . The patient no longer knows where to bite and patient finds it necessary to wear splint full time .
  160. 160. Then additional treatment will be needed to align the teeth and jaws to the proper position of the condyles in the craniomandibular fossa.
  161. 161.  Then following treatment methods can be carried :  1) Orthopedic / Orthodontic treatment to rearrange the teeth to the proper condylar position. It is important to establish a new occlusion at the position that the condyles are healthy.
  162. 162.  Orthopedic Phase : It involves the development of bones and muscles to develop arch width, length and vertical dimension.  Orthodontic Phase : To align crooked teeth as needed.
  163. 163. Crown and bridge to build up all the teeth to correct the bite. • Individual crowns should be done on all the teeth to build them upto a right height to protect the temperomandibular joints. • Implants or bridges can be given to replace missing teeth.  2)
  164. 164. Overly partial denture to replace the splint and any missing teeth : This is more durable material it would not wear down and would better increase and maintain vertical dimension. It can be a good choice if the patient has many missing permanent teeth .  3)
  165. 165.  4) Orthognathic Surgery : Surgery can also be carried to rearrange the jaws to the correct bite position for the temperomandibular joints. It is the best choice if there is a major skeletal imbalance or facial deformity needing correction that falls out of standard orthodontic and orthopedic treatment range .
  166. 166.  If due to some reason the second phase of treatment has to be delayed, in that case patient should continue wearing a splint to maintain healthy TM joints and prevent further breakdown.
  168. 168.  A) For first 2-3 days the splint can be removed for a short period of time if facial muscles get tense to allow these muscles to adjust to new position of mandible. The primary purpose of the splint is to allow the tissues of the temperomandibular joint to heal.
  169. 169. After the initial adjustment period, the splint must be worn full time, including eating except brushing in order for damaged ligaments and TM joint space to heal.  Eating without the splint is like pulling apart suture that are helping to heal a bad cut on the skin. 
  170. 170.  B) Diet : A softer diet is recommended for the few first weeks until many of the symptoms subside to reduce stress and pressure on TM joint.
  173. 173. SPLINTS
  174. 174.  These appliances are necessary for the maxillary and mandibular arches to ensure that each dental arch is stabilized for a given period of time during the day.  If possible a maxillary full coverage appliance is used for night time wear.  Mandibular full coverage appliance are generally used to day time wear.
  175. 175.    There are many types of splints anterior splints and posterior splints, maxillary splints and mandibular splints, full coverage splints and partial coverage splints. The exact splint to be used for a given patient depends not only on patients condition but also on the doctor’s training and preference. All splints change jaw relationships and as a consequence change the relationship of condyle in the glenoid fossa.
  176. 176. Splints basically relieve stress within the joint and from the muscles of mastication.  They even prevent the patients from bruxing and grinding their teeth. 
  177. 177.     LOWER FULL COVERAGE SPLINT A lower full coverage splint gives the best support for healing the TMJ. It give the best result only if worn all the time except brushing. With it, it is easy to speak or eat since it has the least amount of bulk. The support given to the TMJ is similar to that given by a cast to a broken bone and allows the tissues to heal.
  178. 178.  UPPER ANTERIOR BITE PLANE  It can also be used to unload the posterior teeth thereby unloading the condyle. The bite plane can be made flat, so that the mandible can seat its own anterior-posterior position. If the patient skids back into dysfunction, an inclined plane can be used to guide it.  
  179. 179.  It allows for “natural body correction” in those patients with an overclosed vertical dimension and a deep overbite.  This helps in developing the vertical dimension by allowing posterior teeth to erupt.
  181. 181.  They are very useful in jaw repositioning and stabilization of the mandible to the cranium .  They can treat the cause rather than the symptoms of temperomandibular joint
  182. 182.  The action of functional appliance is to bring the condyle forward and downward e.g. in the centre of glenoid fossa that result in unloading the condyle .  So they are effective for pain relief by repositioning the condyle. Eg. Twin block, Occlusal splint.
  184. 184.  It can be administered to break the pain spasm cycle of the craniofacial muscles .  Practicing correct ,erect posture during walking ,sitting can be of great value .
  185. 185. Applying pressure and massaging the muscles of mastication and oro-facial musculature produces relaxation which then permits a greater range of movement of the mandible.
  186. 186.  Vaso-coolant spray applied to the affected fatigued and painful muscles brings about muscle relaxation and result in decrease or loss of pain .  Muscle pain and spasm can be controlled by regulating the electrical impulses in the affected muscles by Transcutaneous Electrical Nerve Stimulation (TENS)
  187. 187. TMJ SURGERY
  188. 188.  TMJ Surgery should be reserved for clearly diagnosed conditions known to be amenable to surgical improvement .  It is necessary in cases of degenerative bone disease , adhesions , ankylosis etc
  189. 189.  Arthroscopic surgery and TMJ irrigation procedures may be helpful in some cases with internal joint disk mobility .  The injection of corticosteroids into the TMJ may be useful in rheumatoid arthritis cases.
  190. 190.  It is always a good practice to treat TMJ problems with a conservative way first and only when approach is unsuccessful should go for surgery .
  192. 192.  The addition of composite to the occlusal surfaces in order to alter condyle / fossa relationships is an alternative to phase II therapy.  Because of the non-compliance of patients, fixed splints in the form of selective composite addition to the occlusal surfaces of teeth can be placed .
  194. 194.  The bicuspid buildup technique is simply the application of self curing resin to the etched buccal, lingual and occlusal surfaces of upper first bicuspids.  This enables the clinician to bring about changes in occlusal relationship in vertical, transverse and positions.
  195. 195.  Bicuspid buildup is as an alternative or aid of doing orthodontics Phase II treatment of temperomandibular disorder.  The major part of primary therapy consist of creating patient awareness of his problem and at the same time wearing a splint
  196. 196.  Sometimes orthodontic treatment is essential as phase II treatment and this idea may often be rejected by the patient because of cost, timing, age etc.  In these case the bicuspid buildup has the greatest effectiveness.
  197. 197.
  198. 198. OVERVIEW
  199. 199.  Orthodontic treatment has been a favourite “whipping boy” of TMJ specialists.  Orthodontic treatment can be one of the most conservative and permanent ways of contributing to the correction of TMJ problems.  It is imperative that during active orthodontic treatment and in retention of treated cases, persistent distal pressure should not be exerted on the mandibular condyle complex. When this is prevented orthodontic correction can be used as an aid not a hindrance, of TMJ function
  200. 200.  The intention of this seminar is to illustrate an equally fascinating side associated with research about temperomandibular disorders. It should be obvious from the above literature that conducting research is no guarantee for an unambiguous interpretation of findings. On the contrary, opposing and often conflicting views make it very difficult to take a position on these issues.
  201. 201. CONCLUSION
  202. 202.  My comments may seem an over statement, but it is not unfair to say that orthodontists are in good position to organize the research and collaborate to solve the important problems of TMJ dysfunction.  What is needed is a research team comprising knowledge and skills of (1) Craniofacial biometry, (2) TMJ function, (3) Statistical modelling and (4)Craniofacial growth.
  203. 203.  The role of occlusion in the origin of TMJ disorders is a problem in craniofacial development. Craniofacial development is what orthodontics is all about. We orthodontists owe it to our colleagues and our patients to intensify the research in this field, for only through research will the answers be found.
  204. 204.  It is the mission of the researcher to unravel the Gordian knot of TMD. To blunty cut it would not yield an solution and it would only deny our patients.
  205. 205. BIBLIOGRAPHY
  206. 206.  Temperomandibular joint and masticatory muscle disorders.George A.Zarb , Barry J. Sessle , Gunnar E.Carlson .  Temperomandibular disorder,classification, diagnosis and management ,-Weldon E.Bell.  Clinical management of
  207. 207.  Temperomandibular disorders and orofacial pain. DCNA,Jan 1991  TMJ Dysfunction and Treatment – DNCA,July 1983  Adult Orthodontics-DNCA  Tempero-Mandibular disorders – Fonesca, 4th Volume .  Fundamentals of occlusion and Temperomandibular disorders – Jeffrey P.Okeson
  208. 208.  William E. Wyatt. Preventing adverse effects on TMJ through orthodontic treatment . AJO 1987; 91: 493 –499  Reint M. Reynders Orthodontics and temporomandibular disorders: A review of the literature (1966-1988) AJO 1990; 97: 463-471  Sadowsky C, BeGole EA. Long-term status of temporomandibular joint function and functional occlusion after orthodontic treatment. AM J ORTHOD 1980;78:201-12.
  209. 209.  James A.McNamara,Jr., Orthodontic treatment and temperomandibular disorders.OOO 1997;83 : 107-117  Burton H.Goldstein . Temperomandibular disorders .OOO 1999 ;88:379-383
  210. 210. Thank you For more details please visit