Tmd part i


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Tmd part i

  1. 1. Manifestations of TMD and Orthodontic interrelationships-I INDIAN DENTAL ACADEMY Leader in continuing dental education
  2. 2. Contents - I • Introduction. • Structural and functional anatomy of the TMJ. • Biomechanics of movements. • Prevalence and frequency of TMD`S • Etiology. • Signs and symptoms of TMD`S • Condyle-disc fossa relationships in various malocclusions. • Malocclusion and TMD`S. • Functional disorders of the TMJ. • TMJ imaging.
  3. 3. Contents -II • TMD`S and occlusal disharmony. • TMD`S and orthodontic treatment - extraction of premolars. - joint sounds. • TMD`s and orthopedic appliances - Mandibular advancement appliances (Does bite jumping effect the TMJ?) - Herbst, twin block, frankel etc - Headgears - Chincup • TMD`s and orthognathic surgery
  4. 4. • Different condylar modifications. • Management of TMD`S. • Treatment modalities. • Splint therapy. • Conclusion. • References.
  5. 5. Introduction • Temporomandibular disorders (TMD) is a collective term embracing a number of clinical problems that involve the masticatory musculature, the TMJ, and associated structures or both. • TMD`S are characterized by facial pain in the region of the TMJ and/or muscles of mastication, limitation or deviation in the mandibular range of motion and TMJ sounds during jaw movement and function. • Causes of most TMD remains unknown, numerous hypotheses have been proposed however.
  6. 6. • In 1934, James Costen described a group of symptoms that centered around the ear and TMJ. Because of his work the term Costen`s syndrome developed. • In 1959 Shore introduced the term “TMJ dysfunction syndrome”. • In 1971, Ramfjord and Ash coined the term, “Functional TMJ disturbances”. • McNeill et al 1980, have suggested a broader term “Craniomandibular disorders” • ADA in 1983 adopted the term “Temporomandibular Disorders”.
  7. 7. Structural and functional anatomy of the TMJ. • TMJ -TMJ - • Ginglymos – hinge type movements.Ginglymos – hinge type movements. • Synovial jointSynovial joint • Arthroidal joint – gliding movements.Arthroidal joint – gliding movements. • Compound + complex joint ( upto 3 bones)Compound + complex joint ( upto 3 bones) • The articular disc serves as a non ossified thirdThe articular disc serves as a non ossified third bone which permits complex movements.bone which permits complex movements. • BicondylarBicondylar • ““ GINGLYMO ARTHROIDAL JOINT ”GINGLYMO ARTHROIDAL JOINT ”
  8. 8.
  9. 9. • Non-ossified bone permits complex movements.Non-ossified bone permits complex movements. • Composed of dense fibrous connective tissue.Composed of dense fibrous connective tissue. • Devoid of blood vessels & nerves.Devoid of blood vessels & nerves. • Divided into 3 regions-Divided into 3 regions- - Anterior zone- Anterior zone - Intermediate zone- Intermediate zone - Posterior zone- Posterior zone • During movement disc adapts to functionalDuring movement disc adapts to functional demands of articular surfaces.demands of articular surfaces. • Disc maintains its morphology unless destructiveDisc maintains its morphology unless destructive forces occur in joint.forces occur in joint. Articular DiscArticular Disc
  10. 10.
  11. 11. • Articular disc divides the joint into upper and lower compartments. Passive volume of upper compartment is 1.2ml and of lower compartment is 0.9ml. • Two mechanisms of lubrication of the synovial joint. • Boundary lubrication – it is the primary mechanism of lubrication. When the joint is moved, synovial fluid located in border or recess areas is forced on the articular surfaces and thus provides lubrication and prevents friction in moving joint. • Reservoir of synovial fluid.
  12. 12. • Weeping lubrication – during joint function forces created between the articular surfaces drive small amounts of synovial fluid in and out of articular surfaces. Metabolic exchange mainly occurs by this mechanism. small amounts of friction is eliminated in compressed joints. prolonged forces exhaust this supply. • Momentary high pressure even with extensive movement is harmless.
  13. 13. • Overloading in occluded position (Bruxism) has the potential to exceed the protective effect of weeping lubrication and may predispose to damage. • Occlusal conditions (normal or abnormal) that operate prior to intercuspation of the teeth are not damaging to articular structures, because they do not violate the limits of weeping lubrication.
  14. 14. Retrodiscal tissue • Mass of soft tissue that occupies the space behind the disc and condyle. • Arises from the posterior band of the disc and attaches to the squamo-tympanic fissure at the inferior margin of posterior articular slope of the condyle. • Rich blood and nerve supply. • Made of elastin.
  15. 15. Biomechanics of movements. • Two types of movements are possible- • Rotational or hinge movements in the lower compartment. • Sliding movements or translation in the upper compartment. • During movement stability within each TMJ is maintained by anterior and posterior disc rotation that keeps the intermediate zone of disc between the condyle and eminence.
  16. 16. • Superior retrodiscal lamina rotates the disc posteriorly and superior lateral pterygoid moves disc in anterior direction. • Normal biomechanical function of TMJ must follow certain orthopedic principles. - Ligaments do not actively participate in normal function of TMJ, they act as guide wires restricting certain movements while permitting others.
  17. 17. • Articular surfaces must be maintained in constant contact. • This is achieved by muscles ( elevators, temporalis, masseter and medial pterygoid) that pull across the joints and produce this contact.
  18. 18.
  19. 19.
  20. 20. Prevalence and frequency of TMD`S
  21. 21. • The prevalence of TMJ signs and symptoms has been noted in several reports and ranges from 35% to 72%. • Riolo in AJO (1987) confirmed the surprisingly high frequency of signs and symptoms of TM Dysfunction in children and young adults. • The percent frequency of clicking associated with overjet was only significant above 6 mm. This is interesting since traditionally a normal range for overjet has been loosely defined as being in the 1 to 4 mm range.
  22. 22. • Cusp-to-cusp relationship represented a greater risk factor for clicking than Class I .Female subjects older than 12 years with cusp-to-cusp relationships exhibited higher percent frequencies of clicking than their Class I cohorts. • Class II relationship did not consistently appear to be a greater risk factor for clicking than Class I. • Buccal crossbite was significantly associated with clicking, particularly within the oldest ages studied (15 to 17 years).
  23. 23. • Acc to Montegi et al (AO1992), prevalence of symptoms in Japanese children is lower about 12 to 20 pc. • Agerberg (1991) noted incidence of joint sounds to be 17.5 pc over 2 years in young adults. • Although epidemiologic data are inadequate, the number of TMD sufferers in the United States is estimated at more than 10 million.
  24. 24. Prevalence, Study of Signs and Symptoms of TMD`S in a Turkish Population. Ozan etal, jcdp 2007 • Women were reported to have signs of TMDs more than men with as much as a 10-15% greater frequency of TMJ clicking and more mandibular osteoarthrosis. • Compared to Scandinavian and Arab populations the tenderness or pain in the TMJ was higher while joint sounds were shown to be of a lower prevalence.
  25. 25. • Epidemiologic studies show that TMD symptoms are most prevalent among patients between 15 and 25 years old; symptoms then level out as patients approach age 35. • Pullinger, Ericksson and Carlson (1987,90) independently have reported that signs and symptoms of TMD generally increase in frequency and severity beginning in the second decade of life.
  26. 26. • Because of the longitudinal nature of orthodontic treatment an understanding of the changes in the signs and symptoms of TMD in a healthy population is essential. • The occurrence of joint sounds during treatment must be considered within the context of longitudinal changes in a comparable untreated population studied during the same interval.
  27. 27.
  28. 28.
  29. 29. • The great drive in epidemiologic studies on TMD came about with Helkimo who developed a clinical Helkimo index (1974) and the Fonesca`s Anamnestic index (1992) that quantitatively measured the severity of TMD symptoms. • The Craniomandibular Index ( CMI, Friction and Shiffman, 1986) • The Research Diagnostic Criteria for TMD ( RDC/TMD, Dworkin and LeResche, 1992).
  30. 30. Anamnestic Questionnaire • Do you find it difficult to open your mouth? • Do you find it difficult to move your jaw sideways? • Do you feel discomfort or muscular pain on chewing? • Do you have frequent headaches? • Do you have pain in the neck and/or shoulders? • Do you have earache or pain close to your ears? • Do you notice any TMJ noise? • Do you consider your bite "normal"? • Do you chew on only one side of your mouth? • Do you have facial pain on waking?
  31. 31. Etiology of TMD`S
  32. 32. • The cause of TMD`S is multifactorial and complex. • There are numerous factors that can contribute to TMD. • Predisposing factors – increase the risk. These include a mixture of morphological, physiological, psychological, and environmental variables that heighten an individual's susceptibility to develop a certain problem. • Precipitating factors – cause the onset. These include various combinations of trauma, stress, hyperfunction, and possibly failure of natural inhibiting factors, all of which lead to the onset of symptoms.
  33. 33. • Perpetuating factors – enhance the progression. These include poor healing capacity, failure to control etiologic factors, secondary gains from staying sick, and negative effects from inappropriate treatments. (Greene, Seminars in Orthod 1995)
  34. 34. • Occlusal disharmony. • Malocclusion. • Orthodontic treatment. • Malposition or malformation of the condyle • Abnormal form or position of the glenoid fossa • Previous trauma • Bruxism • Diet • Stress • Muscle parafunction • Oral posture
  35. 35. • Abnormal form or position of the glenoid fossa – it has been suggested that the fossa itself may be at fault and certainly there is evidence to suggest that the temporal bone together with the glenoid fossa, may be displaced during orthodontic treatment. (Agronin and Kokich, 1987) • Studies related to functional appliances show that glenoid fossa remodels by several mms after the mandible is held forward. In all these instances the joint remodels so that the ball was returned to the centre of the socket.
  36. 36. • Because the joint seems so adaptable in both adult animals and man , it seems illogical to suggest that these deformations are the cause of TMD, as they clearly follow displacement of the joint. • They should therefore be classified as “resultant” and not “precipitating”. • Previous trauma – Wilkes (1989) suggested that trauma was the single most frequent cause of subsequent TMD. This explanation is at odds with the low incidence of TMD in primitive population who are equally if not more, exposed to damage.
  37. 37. • Follow up of patients who have had fractured condyles, which must involve substantial trauma to the joint has shown that they subsequently have few objective symptoms. (Dahlstrom et al, 1989) • Bruxism- Intermittent clenching or grinding can inflict heavy loads on the teeth and joints. However many people brux and yet have no TMD problems, and so it would seem that additional factors such as irregular contacts or previous damage, need to be present before symptoms will appear.
  38. 38. • Diet – it seems that food either by its consistency or content could have an influence on the joint. A hard diet seems to be no disadvantage (Helkimo,1979) but this is a relatively poorly researched area. • Stress- it is recognized that emotional stress can precipitate episodes of TMD (Wadhwa et al,1993) • It is claimed that there is association between TMD symptoms, muscle tension, trigger points, headaches and migraine (Higson,1985)
  39. 39. • Muscle parafunction- EMG studies show that TMD patients often have abnormal patterns of activity (Moss, 1975). However this may be the result of patient`s attempts to avoid premature contacts, rather than the cause. • Oral posture- Costen put forward the opinion that overclosed bites resulted in retropositioning of the head of the condyle and were associated with TMD. • Dibbets (1996) have found that increased forward growth was associated with reduced signs of TMD.
  40. 40.
  41. 41. Signs and Symptoms
  42. 42. • Temporomandibular Disorder (TMD) is a term generally applied to a condition or conditions characterized by pain and/or dysfunction of the masticatory apparatus. • Its characterization has been difficult because of the large number of symptoms and signs attributed to this disorder and to variation in the number and types manifested in any particular patient. (Cooper BC, Cranio 2007 )
  43. 43. • Symptoms most commonly reported on the questionnaire included (i) pain (96.1%), (ii) headache (79.3%), (iii) TMD (75.0%) and (iv) ear discomfort or dysfunction (82.4%). • In the 4,338 patients who showed signs, the most prevalent was tenderness to palpation of the pterygoid muscles (85.1%), followed by tenderness to palpation of the TMJ (62.4%). • Pain symptoms and signs were often accompanied by compromised mandibular movements, TMJ sounds and dental changes, such as incisal edge wear and excessive overbite.
  44. 44. • Clearly prevalence of pain disclosed by the symptoms and signs examinations was high. • Patients showed variable prevalence and nonprevalence of eight categories of painful symptoms and seven categories of painful signs.
  45. 45. Signs and symptoms of temporomandibular disorders in adolescents. Bonjardim LR Braz Oral Res. 2005 • Joint sound during opening was present in 19.8% of the sample and during closing in 14.7%. • The most prevalent symptoms were joint sounds (26.72%) and headache (21.65%). • There was no statistical difference between genders except for the tenderness of the lateral pterygoid muscles, which presented more prevalence in girls. • In conclusion, clinical signs and symptoms of TMD can occur in adolescents; however, gender influence was not perceived.
  46. 46. • An epidemiological study of an African population by Beighton et al (1973) showed female TMJs are more mobile than men at any age and general joint mobility is age-dependent and diminishes most rapidly in childhood. • Previous studies (Gray 1994,Klienberg 1998) reported the occurrence of a higher prevalence of signs associated with mandibular disorder among women. • The highest prevalence of women classified with some degree of TMD may be related to typical physiologic differences between females and males such as regular hormonal variations, muscular structure, and different characteristics of the conjunctive tissue.
  47. 47. Malocclusion and TMD`S.
  48. 48. • Malocclusion has been associated with TMD, when it is believed that the alteration of form might cause alteration in the stomatognathic system function. • With the intention of elucidating this relation, several authors have studied Class I, II malocclusion, posterior crossbite, anterior open bite, horizontal overlap and vertical overlap, suggesting that these alterations are responsible for the onset of TMD symptoms. • Corotti et al. (J. Appl. Oral Sci. 2007)
  49. 49. TMD in relation to malocclusion and orthodontic treatment Mohlin B, Axelsson S AO 2007 • Associations between certain malocclusions and TMD were found in some studies, whereas the majority of the reviewed articles failed to identify significant and clinically important associations. • TMD could not be correlated to any specific type of malocclusion, and there was no support for the belief that orthodontic treatment may cause TMD. Obvious individual variations in signs and symptoms of TMD over time according to some longitudinal studies further emphasized the difficulty in establishing malocclusion as a significant risk factor for
  50. 50.
  51. 51.
  52. 52. Unilateral posterior crossbite is not associated with TMJ clicking in young adolescents. Farella M JDR 2007 • Unilateral posterior crossbite has been considered as a risk factor for temporomandibular joint clicking, with conflicting findings. The aim of this study was to investigate a possible association between unilateral posterior crossbite and temporomandibular disk displacement with reduction, by means of a survey carried out in young adolescents • Posterior unilateral crossbite does not appear to be a risk factor for temporomandibular joint clicking, at least in young adolescents.
  53. 53. • Unilateral posterior crossbite was found in 157 participants (12.2%). • Fifty-three participants (4.1%) were diagnosed as having disk displacement with reduction. • Logistic regression analysis failed to reveal a significant association between unilateral posterior crossbite and disk displacement with reduction
  54. 54. Malocclusion traits and symptoms and signs of temporomandibular disorders in children with severe malocclusion. Sonnesen L EJO 1998 • Symptoms and signs of TMD were significantly associated with distal molar occlusion, extreme maxillary overjet, open bite, unilateral crossbite, midline displacement, and errors of tooth formation. • There is a higher risk of children with severe malocclusions developing TMD. • Errors of tooth formation in the form of agenesis or peg-shaped lateral teeth showed the largest number of associations with symptoms and signs of TMD • These associations have not previously been reported in the literature.
  55. 55.
  56. 56.
  57. 57. Condyle-disc fossa relationships in different malocclusions
  58. 58. • TMJ morphology has not been studied adequately in subjects with various types of malocclusion, and it is not known if TMJ morphology and facial morphology are related. • Such knowledge might assist in the establishment of biological treatment strategies, especially when the TMJ is the target of the treatment plan.
  59. 59. Condyle and fossa shape in Class II and Class III skeletal patterns: a morphometric tomographic study. Katsavrias EG, Halazonetis DJ.AJO 2005 • Condylar and fossa shapes were found to be different between the groups; the Class III group had a more elongated and anteriorly inclined condylar head and a wider and shallower fossa. • In the Class III group, the condyle was closer to the roof of the fossa. • The 2 Class II divisions differed only in the position of the condyle in the fossa, which was situated more anteriorly in the Class II Division 1 group.
  60. 60. Relationship between fossa-condylar position, meniscus position, and morphologic change in patients with Class II and III malocclusion. Zhou D, Hu M, Liang D, Zhao G, Liu A.Chin Den Res 2000 • The variation of condyle-fossa positions for identical types of malocclusion was very large. • Skeletal and functional Class III malocclusion patients demonstrated significantly more anteriorly positioned condyles. • Class II division 1 patients showed concentrically positioned condyles, but with slightly anterior displacement. • Class II division 2 patients demonstrated more posteriorly positioned condyles. • When condyles were in anterior or concentric positions, meniscus positions and morphology were normal and in concavoconcave
  61. 61. • When condyles were in posterior positions, most meniscus positions were in normal or slightly anterior range and their shapes were also concavoconcave. • The rest were significantly more anterior and their shapes were abnormal, as evidenced by thickened anterior bands. • Class III and Class II division 1 malocclusion demonstrated normal structure and function of the TMJ. Class II division 2 malocclusion was obviously associated with abnormal structure and function of the TMJ.
  62. 62. Temporomandibular joint morphology and disc position in skeletal class III patients. Ueki K J Crani Surg 2000. • The purpose of this study was to investigate the relationship between TMJ morphology, including discal tissue and clinical symptoms in class III dentofacial deformity patients. • They were divided into two groups, consisting of a class III symmetry and a class III asymmetry group. • The incidence of internal derangement in asymmetrical class III patients is higher than in symmetrical mandibular prognathism, and this difference is associated with a difference in TMJ morphology of both
  63. 63. • Anteriorly displaced discs in the asymmetry group (56.8%) occurred significantly more frequently than in the symmetry group (18.2%) • TMJ symptoms (clicking, crepitus, closed lock, pain) were seen in 17/44 joints (38.6%) of the symmetry and 24/44 joints (54.5%) of the asymmetry group
  64. 64. The relationship between temporomandibular joint disc morphology and stress angulation in skeletal Class III patients. Ueki K EJO 2005. • There was also a significant correlation between disc position and stress angulation. • Stress angulation was higher at the deviation side as compared to the non deviation side. • In the asymmetry group, a significant correlation between the difference in stress angulation (between the deviation side and the non-deviation side) and the degree of asymmetry (measured by the angle of asymmetry).
  65. 65. Computed tomography evaluation of temporomandibular joint alterations in patients with class II division 1 subdivision malocclusions: condyle-fossa relationship. Vitral RW, Telles Cde S, Fraga MR, de Oliveira RS, Tanaka OM .AJO 2004 • No statistically significant asymmetries were found in the depth of the mandibular fossa, the angulation of the posterior wall of the articular tubercle, or the condyle-fossa relationship. • However, a statistically significant (P <.05) anterior positioning of the condyles was observed.
  66. 66. Morphology of the temporomandibular joint in subjects with Class II Division 2 malocclusions. Katsavrias EG.AJO 2006 • The results suggest that fossa morphology and condylar length attain their final sizes early. • articular eminence and ramus morphology (height, inclination) have great variability • some joint components such as eminence height with eminence inclination, eminence height with ramus inclination, eminence inclination with ramus inclination, and fossa anteroposterior dimensions are highly correlated with each other • the most prevalent condylar and fossa anteroposterior shape is oval.
  67. 67. Condylar position and Class II deep-bite, no-overjet malocclusions. Gianelly AA, Petras JC, Boffa J. AJO 1989 • By means of corrected tomography, the positions of the condyles in 19 click-free persons with Class II malocclusions characterized by a bite depth greater than 50%, no overjet, and an interincisal angle of greater than 140 degrees were compared with a positions of the condyles in 21 control subjects. • Average condylar position in both groups was concentric and no significant differences between groups were found. In addition, no significant correlation was noted when condylar position was related to bite depth.
  68. 68. Comparison of deep bite and open bite cases: normative data for condylar positions, paths and radiographic appearances. Ari-Demirkaya A .J Oral Rehab 2004 • Results of this study showed that open bite cases show larger vertical CR-CO slides and, shorter protrusion paths than normal and deep overbite cases. • Open bite cases had significantly shorter condylar paths. • The erosion rates were higher in the open bite group, but flattening was seen more often in the deep bite group • This study indicates that the clinician should be paying special attention to the TMJ status of open bite patients.
  69. 69. An evaluation of mandibular asymmetry in adults with unilateral posterior crossbite. ajo 1995 O'Byrn BL, Sadowsky C, Schneider B, BeGole EA. • A retrospective study was conducted to determine whether mandibular symmetry in adults with untreated unilateral posterior crossbite was different from that found in adults with untreated Class I malocclusions. • Skeletally, the mandible showed no asymmetry. Relative to the cranial floor, the mandible was "rotated" so that the condyle on the crossbite side was positioned relatively posteriorly in comparison to the contralateral side.
  70. 70. • A relative posterior positioning of the glenoid fossa was inferred, since there was no demonstrable mandibular skeletal asymmetry or condylar displacement within the fossa as shown on corrected tomograms in the crossbite group as compared with the Class I group • The results question whether it is appropriate to correct unilateral posterior crossbites in adults by orthodontic tooth movement alone, given the skeletal remodeling in the temporomandibular joint, which may have already occurred.
  71. 71. Transverse skeletal and dental asymmetry in adults with unilateral lingual posterior crossbite. Langberg BJ, Arai K, Miner RM.ajo 2005 • A statistically significant difference in mandibular transverse dental asymmetry was observed between adults with PUXB and the control group. • However, no significant differences were found in the right-left skeletal asymmetry, although the PUXB group showed more positional deviation of the mandible. • Moreover, condylar position analysis indicated that the crossbite group did not show any greater functional shifts than the control group.
  72. 72. • We concluded that PUXB in adults is primarily due to dentoalveolar asymmetry and positional deviation of the mandible and not simply to right-left skeletal asymmetry of the mandible. • These data suggest that untreated PUXB in children might lead to progressive asymmetric compensation of the condyle-fossa relationship and result in a positional deviation of the mandible, which, along with a distinct dentoalveolar asymmetry, maintains the crossbite occlusion in adults.
  73. 73. Functional disorders of the TMJ.
  74. 74. • They can be broadly divided into 3 categories, • Derangements of the condyle- disc complex. Internal derangement of the TMJ can be defined as an abnormal relationship between the intra-articular disc and the condyle when the teeth are in occlusion. - disc displacements with reduction - disc displacements without reduction. • Structural incompatibility of the articular surfaces. - deviations, adhesions, subluxation and dislocation. • Inflammatory joint disorders.
  75. 75. Disc displacements with reduction
  76. 76. Disc displacements without reduction
  77. 77. • Considerable attention has been given in the literature to the clinical significance of reciprocal clicking of the TMJ, with the implicationthat it is a more serious situation than the mere presence of a click on opening of the mouth. • Actually, the same changes in the disc Condyle relationship occur whether or not a click is heard on mouth closure. In patients whose TMJ clicks every time they open their mouth, the disc has to slip off the condyle during mouth closure so that the process can repeat itself.
  78. 78. • The difference is that, in some patients, the passage of the condyle over the posterior band as the disc again slips forward during closure is associated with a clicking sound, but in others it occurs silently and can only be detected by the slight jarring sensation felt by palpation over the joint or the mandibular angle. • Thus, the presence or absence of reciprocal clicking does not seem to have any real clinical significance.
  79. 79.
  80. 80. TMJ imaging • Although many of the disorders involving the TMJ and associated structures can be diagnosed clinically on the basis of the history and physical findings, there are others that require the use of various imaging techniques to make an accurate diagnosis or to determine the extent of involvement. • To take maximum advantage of the benefits of these procedures, however, it is not only important for the clinician to be able to select the correct methods, but also to understand their limitations as well as their capabilities.
  81. 81. Transcranial Radiographs • Transcranial radiography (TR) has been used extensively as a diagnostic aid for TMDs, partly caused by the technique's simplicity and the wide availability of the required equipment. • Historically, transcranial radiographs have been used to evaluate the status of joint hard tissue and the spatial relationship of the condyle to the fossa.
  82. 82.
  83. 83. Transmaxillary Radiography • This technique provides a frontal view of the TMJ, sometimes referred to as the transantral, transorbital, or infraorbital projection. The entire mediolateral profile of the condyle is imaged, making this view a very useful supplement to a saggital view, such as the transcranial projection. Used together, the views provide a three-dimensional perspective not possible with either of the views alone.
  84. 84.
  85. 85. Computed tomography • CT has good validity for diagnosing osseous abnormalities. However, tomography should be considered for this purpose because it costs much less and its validity is comparable with that of CT. Probably the best use of CT is for diagnosing intraosseous lesions. • Moreover, CT has a large area of coverage that is not only useful for diagnosing tumors in theTMJ, which are very rare, but also in adjacent anatomic regions.
  86. 86.
  87. 87. Arthrography • Arthrography is a technique used to highlight or outline joint structures by using a radiopaque contrast medium to enhance their images on plane or tomographic films. • In the case of the TMJ, the contrast medium is injected into the upper or lower joint space or both. The disc then appears as a radiolucent mass against the background of contrast medium on conventional radiographs, tomography, or fluoroscopy.
  88. 88.
  89. 89. Magnetic Resonance Imaging • Magnetic resonance imaging (MRI) has several distinct advantages over previously discussed imaging techniques. • Chief among these advantages is the substitution of relatively harmless superconducting magnets and radio wave energy for the well known hazards of ionizing radiations. • Method of choice to assess disc position in open and closed mouth positions.
  90. 90. References 1. Mohlin B, Axelsson S, Paulin G, Pietilä T, Bondemark L, Brattström V, Hansen K, Holm AK .TMD in relation to malocclusion and orthodontic treatment. Angle Orthod. 2007,May;77(3):542-8. 2. Farella M, Michelotti A, Iodice G, Milani S, Martina R . Unilateral posterior crossbite is not associated with TMJ clicking in young adolescents.J Dent Res. 2007 Feb;86(2):137-41 3. Ueki K, Nakagawa K, Takatsuka S, Shimada M, Marukawa K, Takazakura D, Yamamoto E .Temporomandibular joint morphology and disc position in skeletal class III patients. J Craniomaxillofac Surg. 2000 Dec;28(6):362-8.
  91. 91. 4. Katsavrias EG, Halazonetis DJ Condyle and fossa shape in Class II and Class III skeletal patterns: a morphometric tomographic study. AJO 2005,Sep;128(3):337-46. 5. Katsavrias EG Morphology of the TMJ in subjects with Class II Division 2 malocclusions. AJO 2006,Apr;129(4):470-84 6. Gianelly AA, Petras JC, Boffa J Condylar position and Class II deep-bite, no-overjet malocclusions. AJO 1989, Nov;96(5):428-32. 7. Zhou D, Hu M, Liang D, Zhao G, Liu A Relationship between fossa-condylar position, meniscus position, and morphologic change in patients with Class II and III malocclusion. Chin Den Res 2000,Feb;2(1)
  92. 92. 8. Bonjardim LR, Gavião MB, Pereira LJ, Castelo PM , Garcia RC. Signs and symptoms of temporomandibular disorders in adolescents. Braz Oral Res. 2005, Apr-Jun;19(2):93-8. 9. Cooper BC, Kleinberg I Examination of a large patient population for the presence of symptoms and signs of temporomandibular disorders.Cranio. 2007 Apr;25(2):114-26. 10. Özan F, Polat S, Kara I˙, Küçük D, Polat HB. Prevalence Study of Signs and Symptoms of TMDS in a Turkish Population. J Contemp Dent Pract 2007 May;(8)4:035-042.
  93. 93. 11. Vitral RW, Telles Cde S, Fraga MR, de Oliveira RS, Tanaka OM Computed tomography evaluation of temporomandibular joint alterations in patients with class II division 1 subdivision malocclusions: condyle-fossa relationship. AJO 2004 , Jul;126(1):48-52 12. Sonnesen L, Bakke M, Solow B. Malocclusion traits and symptoms and signs of temporomandibular disorders in children with severe malocclusion. EJO 1998,Oct;20(5):543-59. 13. Charless Greene. TMD. Facts and Fallacies. Seminars in Orthod 1995, vol 1:4 pg 195-278.
  94. 94. 14. Karyna Valle-CorottiI; Arnaldo PinzanII; Caio Vinícius Martins do ValleIII; Ana Carla Raphaelli NahásIV; Mauro Vinícius CorottiV. Assessment of temporomandibular disorder and occlusion in treated class III malocclusion patients J. Appl Oral Sci. vol.15 no.2 Bauru Mar./Apr. 2007. 15. Ari-Demirkaya, S. Biren,H. Özkan & N.Küçükkeleş Comparison of deep bite and open bite cases: normative data for condylar positions, paths and radiographic appearances. J Oral Rehab 2004,31,3,231-224.
  95. 95. 16. Cooper BC, Kleinberg I. Examination of a large patient population for the presence of symptoms and signs of TMJ disorders. Cranio. 2007 Apr;25(2):114-26. 17. Koichiro Ueki , Kiyomasa Nakagawa , Kohei Marukawa , Shigeyuki Takatsuka , and Etsuhide Yamamoto The relationship between temporomandibular joint disc morphology and stress angulation in skeletal Class III patients. EJO 2005. Oct;27(5):501-6.
  96. 96. 18. O'Byrn BL, Sadowsky C, Schneider B, BeGole EA.An evaluation of mandibular asymmetry in adults with unilateral posterior crossbite. Am J Orthod Dentofacial Orthop. 1995 Apr;107(4):394-400. 19. Langberg BJ, Arai K, Miner RM Transverse skeletal and dental asymmetry in adults with unilateral lingual posterior crossbite. Am J Orthod Dentofacial Orthop. 2005 Jan;127(1):6- 15; discussion 15-6.
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