Position of condyle in cl ii & iii /certified fixed orthodontic courses by Indian dental academy

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Position of condyle in cl ii & iii /certified fixed orthodontic courses by Indian dental academy

  1. 1. POSITION OF CONDYLE IN THE GLENOID FOSSA IN CLASS II & CLASS III MO INDIAN DENTAL ACADEMY Leader in continuing dental education www.indiandentalacademy.com www.indiandentalacademy.com
  2. 2. Introduction Orthodontists are constantly being challenged with the task of providing their patients with acceptable esthetics and masticatory function. Although for the patient, esthetics is the immediate and primary goal, function becomes far more important in the lifetime. Developing a sound, functional masticatory system is the primary goal of all orthodontic therapy. www.indiandentalacademy.com
  3. 3. Functional anatomy of the TMJ The TMJ is a typical diarthrosis. It is classified anatomically as the gingilymoarthroidal joint which means that the joint has relative sliding or gliding movement between the bony surfaces in addition to the hinge movement common to the diarthroidal joints. This is a synovial joint of the condylar variety. The joint consists of the upper and lower articular surfaces. The upper articular surface is formed by the Articular eminence Anterior part of the mandibular fossa www.indiandentalacademy.com
  4. 4. The inferior part of the articular fossa is formed by the mandibular condyle. The joint is divided into upper and lower parts by the interarticular disc. The articular fossa is on the inferior surface of the squamous part of the temporal bone that forms a small part of the floor of the middle cranial fossa. The posterior limit of the joint is formed by the squamotympanic fissure and the medial relation is the petrotympanic fissure. www.indiandentalacademy.com
  5. 5. The disc is slightly thicker medially than laterally. LP, Lateral pole; MP. Media pole Articular disc, fossa, and condyle ( lateral view) The mandibular condyle is basically ellipsoid connected to the ramus of the mandible by a narrow bony isthmus or neck. The condyle is longer lateromedially than in the other dimensions. The average composite shape of the condyle has a superior surface that is markedly convex from front to back and gently convex from side to side. www.indiandentalacademy.com
  6. 6. The condyle is the portion of the mandible that articulates with cranium, around which movement occurs. From the anterior view it has a medial and a lateral projection, called poles. The medial pole is generally more prominent than the lateral. From above, a line drawn through the centres of the poles of the condyle will usually extend medially and posterioly toward the anterior border of the foramen magnum. The total mediolateral length of the condyle is 15 to 20mm, and the anteroposterior with is between 8 and 10mm. The actual articulating surface of the condyle extends both anterior and posteriorly to the most superior aspect of the condyle. www.indiandentalacademy.com
  7. 7. The posterior articulating surface is greater than the anterior surface. The articulating surface is greater of the condyle is quite convex anteroposterioly and only slightly convex mediolaterally. The mandibular condyle articulates at the base of the cranium with squamous portion of the temporal bone is made up of a concave manibular, in which the condyle is situated and which has also been called the articular or glemoid fossa. www.indiandentalacademy.com
  8. 8. Inter articular disc or the meniscus Is a fibrous connective tissue wafer filling most of the space between the condylar head and the articular fossa and dividing the joint cavities into 2 compartments. The disk itself normally occupies only half of the joint space, with its posterior attachments filling the posterior half. The disc and its posterior attachments are generally referred to as the soft tissue component of the TMJ. www.indiandentalacademy.com
  9. 9. Sagitally a biconcave structure, the thin portion in the center serves as the articulating cushion between the condyle and the articular eminence. The anterior border of the disc is attached to the superior head of the lateral pterygoid. As the condyle translates forward, the disk also moves forward. So that the thin central part remains between the articulating convexities of the condylar head and the articular eminence. As the moves forward, the tension is produced in the elastic portion of the posterior attachment. This tension is thought to be responsible for the smooth recoil of the disc posteriorly as the jaw closes. www.indiandentalacademy.com
  10. 10. According to Dr. Upton it shouldn’t be forgotten that the disc also facilitates the gliding of the condyle along the articular eminence, because of its slick surfaces. Joint bony relationship Joint space is the radiographic term for the cresent shaped radiolucency between the bony structures of the TMJ when the teeth are in occlusion. The soft tissue structure of the joint projected as uniform radiolucency over and around the condyle. A comparison of the radiographic dimension of the several portions of the joint space is often used by the clinician as a guide by which the position of the condyle is determined. www.indiandentalacademy.com
  11. 11. Condylar concentricity is the term for that condylar position around which the anterior and posterior aspects of the radiolucent joint space are uniform in width. The condyle is said to be protruded when the posterior joint space is larger. The condyle is said to be retruded if the posterior joint space is less than the anterior. www.indiandentalacademy.com
  12. 12. Normal posisiton of the condyle • Williamson-Superior-anterior fossa position • Stuart-Rearmost, midmost & uppermost position of condyles in their respective fossae with the mandible in the closed position • The mandible should be able to close into maximum intercuspation without deflecting the condyles from their most ideal relationship in the fossae www.indiandentalacademy.com
  13. 13. Centric Relation • An idealized treatment goal • CR of the mandible is a superior limit position of the condyles in the fossae with the mandible centered and its most closed position www.indiandentalacademy.com
  14. 14. Inferior and superior lateral pterygoid muscles Function of the inferior lateral pterygoid: protrusion of the mandible www.indiandentalacademy.com
  15. 15. Medial pterygoid muscle Function: elevation of the mandible www.indiandentalacademy.com
  16. 16. Temporal muscle, AP, Anterior portion MP – Middle portion, PP – Posterior portion Temporal muscle, AP, Anterior portion MP – Middle portion, PP – Posterior portion www.indiandentalacademy.com
  17. 17. Masseter muscle. DP, Deep portion: Function: elevation of the mandible www.indiandentalacademy.com
  18. 18. Mandible, temporomandibular joint, and accessory ligaments www.indiandentalacademy.com
  19. 19. Muscles of mastication A: Diagnostic muscle, B-Function : depression of the mandible www.indiandentalacademy.com
  20. 20. Four movements of the mandible Posterior opening border Anterior opening border Superior contact border Functional movements Posterior opening border – in slight opening of the mouth there is rotational movement of the mandible with the codyles in the terminal hinge position. This pute rotational opening can occur until the anterior teeth are some 25 mm apart. There is no translation of the condyle. www.indiandentalacademy.com
  21. 21. www.indiandentalacademy.com
  22. 22. In the maximal opening of the mouth the temporomandibular ligament tightens after there is an anterior and inferior translation of the condylealong with the gliding of the disc. Maximum opening is reached when the capsular ligaments present further movement of the condyle. Maximal opening is between 40 to 60mm when measured between the Incisal edges of the maxillary and mandbular teeth. www.indiandentalacademy.com
  23. 23. With the mandible opened, the closure accompanied by contraction of the inferior lateral pterygoid. Due to the tightening of the ligaments there is posterior movement of the condyle during closure. There is not a pure hinge movement but there is some eccentricity during closure. The disc also moves along. www.indiandentalacademy.com
  24. 24. Diagnosis The diagnosis of the temporomandibular disorder or the fit of the joint is very important to determine the harmony of the stomatognathic system. The diagnosis includes Anscultation Palpation Functional analysis www.indiandentalacademy.com
  25. 25. Anscultation is done in the joint area to determine if there is any creptius or clicking in the joint area. Palpation includes the palpation of the joint which also includes the palpation of the muscles to rule out the possibility of any masticatory muscle tenderness. The functional analysis includes the checking of the various functional movements of the mandible. www.indiandentalacademy.com
  26. 26. It also includes the dental examination which will determine the presence of the following due to the close relationship of the joint and the occlusion. The dental examination includes the Occlusal and incisal wear Restorations Mobility of the teeth Periodontal status of the teeth Cross bite or scissor bite Occlusion www.indiandentalacademy.com
  27. 27. Other diagnostic aids Radiographic technique Conventional radiography – TMJ is technically one of the most difficult areas of the body to visualize well because of multiple superimposition. Transcranial projection – posterior auricular approach. The central beam is projected across the cranium through the petrous ridge of the temporal bone on the film side and finally through the TMJ with the long axis of the obliquely oriented condyle. www.indiandentalacademy.com
  28. 28. It is taken in both open mouth and centric occlusion. To determine the bony relationship between the condyle and the glenoid fossa when the mouth is closed and the degree of anterior condylar movement as the mouth is opened. It helps to detect, The changes in the lateral aspect of the articulating surface. Position of the condyle in the fossa. www.indiandentalacademy.com
  29. 29. Disadvantage Only the changes in the lateral aspect of the condylar head can be seen. Abnormal changes in the condylar neck is obsured by the ipsilateral petrous ridge. Stereoscopic transcranial projection-provides depth prescription differentiating the multitude of the superimposition bony shadows in this area. Advantages - The crest of the ipsilateral petrous ridge can be dissociated from the condylar neck. www.indiandentalacademy.com
  30. 30. Infracranial projection – transpharyngeal or Mc Queen projection X ray film positioned against the side of the patient head, parallel to the sagittal plane next to the TMJ of the interest. The X ray tube head is placed on the skull opposite the TMJ to be imaged. Central beam through the tube side sigmoid notch (window between the condylar and coronoid process) below the base of the skull. Open mouth view – move the condyle away from dense superimposing base of the skull into a soft tissue region, providing far from the greater radiographic contrast. www.indiandentalacademy.com
  31. 31. Enlarge the tube side window between the mandibular notch and zygomatic process. www.indiandentalacademy.com
  32. 32. Disadvantage In taken in closed mouth, the condylar head superimposed by articular eminence. Can be done only in the open mouth. No diagnostic information about articular fossa of the TMJ. Uses Gross visualization of the condylar process from mandibular ramus to the condylar apex. Diagnosis of the fracture of the condylar neck. www.indiandentalacademy.com
  33. 33. Transorbital view-Zimmer’s or transmaxillary view Central beam passes throught the ipsilateral orbit and through TMJ of interest. Advantages Lack of major superimposition over the most of the condylar process. Entire latero medial of convex articulating surface of the condyle and the articular eminence. Demonstration of the convex articulating surface of the condyle and the slightly concave or flat, broad ridge of the articular eminence. www.indiandentalacademy.com
  34. 34. Facial Projection Panoramic View With slight variations in the standard technique it can provide screening of the condyles. To view the condyle best it is often necessary for the patient to open the mouth maximally so that the structures can be seen without any superimposition on the condyle. Since the panoramic radiograph is a transpharyngeal view the lateral pole of the condyle becomes superimposed over the condylar head. Therefore the area that appears to represent the superior sub articular surface of the condyle is actually only the sub articular surface of the medial pole. Water view – with petrous ridge depressed, the condylar and temporal surfaces of the TMJ may be seen by clearly. Bulk of the inferior portion of the condyle will be superimposed by the petrous part of the temporal bone. www.indiandentalacademy.com
  35. 35. Submentovertex Reverse towne view unilateral or bilateral condylar fracture superomedial displacement of the condylar fragments. Tomography these are true lateral projections. Tomography used controlled movement of the head of the X ray tube and the fill to obtain a radiograph of the desired structure that deliberately blurs out other structures. www.indiandentalacademy.com
  36. 36. Advantages More accurate than panoramic or transcranial radiographic for identifying bony abnormalities or changes. Elevates the condylar position in the fossa more accurately than in the transcranial view. Disadvantages Expensive Inconvenient Patient exposure to radiation increased Uses Lateral view of the cortical margin of TMJ. Position of the condyle in the mandibular fossa. Range of translatory movement. www.indiandentalacademy.com
  37. 37. Arthrography On a conventional radiograph the image is formed as a result of differential attenuation Of an X ray beam passing through the structures. If the structure lack density to attenuate the beam then they do not appear on the radiograph. If the density of the structure is too low or if the subject contrast is too low to meet the diagnostic records the contrast and the density can be improved artificially. Compounds of iodine are used for the contrast as the dye material. Water soluble compound are preferred in the joint examination. They supply information about the soft tissue structures of the joint which is one of the major advantages of the technique. The main contraindication is hypersensitivity reactions and exacerbates the irritation of an already existing joint disease. www.indiandentalacademy.com
  38. 38. Uses Displacement of the disc. Herniation of the disc or loss of integrity of the attachments. Scarring and fibrosis of the joint. Post operative evaluation. Disadvantages Invasive procedure. Special training required. Expensive. High level of radiation. www.indiandentalacademy.com
  39. 39. Computerd tomography – was introduced in the year 1970. CT scan provides a digital data measuring the extent of X-ray transmission through an object. This numerical information is transformed into a density scale and used to generate or reconstruct an image. The greatest advantage of the CT scan is that it images of both soft tissue and hard tissue. This the condyle disc relationship can be observed and evaluated without disturbing the existing anatomy relationship. For imaging the TMJ the GE system produces slices 1.5 mm thick in an axial, sagittal or coronal plane. The sagittal is the best for the evaluation of the TMJ. The TMJ disc composed of high density fibrous tissue will appear white on the CT scan. Anteriorly dislocated disc is seen as a whiter projection anterior to the condyle in the closed mouth view. www.indiandentalacademy.com
  40. 40. Disadvantages Increased radiation exposure. Equipment very expensive. Time consuming and expensive procedure. Do not offer benefits of dynamic joint movements. www.indiandentalacademy.com
  41. 41. TMJ Video Tape (Angle Orthodontist, 1988 No. 2, 101 104: TMJ Diagnosis and Treatment in a Multidisciplinary Environment – a follow-up study. Michael C. Alpern, Douglas) Video tape provides an effective method of patient/parent education and informed consent. This video tape assists in education the patient in what TMJ pathology is, what its causes are (heredity, stress, and function) (GLLB 1977), and introduces the idea that if a patient comes to an orthodontist with a hereditary or developmental or congenital problem of bad bite of the teeth or jaws, this problem also could involve the temporomandibular joint. In other worlds, not everyone is born with a perfect temporomandibular joint. www.indiandentalacademy.com
  42. 42. Any joint can be subject to a hereditary predisposition toward joint disease; everyone is familiar with these variations in the joints of the extremities and the spine, and the TMJ is not immune. Finally, joints are subjected to the stresses of life, and the TMJ is especially vulnerable to physical stress arising from the emotional stresses of our society. Such stress can be a direct cause of the patient chronically cracking or moving the jaw or excessively using and abusing the jaw or teeth. www.indiandentalacademy.com
  43. 43. The video tape is repetitive, using a series of vignettes, and tends to say the same thing that the orthodontist wants to tell the patient. The patient begins to understand that, as the orthodontist approaches the bite problem, he is not just going to be moving teeth around. He is, instead, going to be approaching the total facial problem from the incisal edges of the teeth to and including the temporomandibular joints, the airway, and the swallowing mechanism. www.indiandentalacademy.com
  44. 44. The patient is informed initially that because of their TMJ problem, treatment must be multidisciplinary. Altering heredity is impossible, but can alter stress and function. Stress will be approached by a psychological examination. The patient will be referred to a competent TMJ team psychologist for testing with an MMPI (Minnesota Multiphasic Personality Inventory) as well as other psychological evaluations. The patient and/or parents will be informed of the level of stress that the patient is under and appropriate recommendations for stress counseling and therapy will be made if indicated. The patient is also give a score of 1 through 5 using the Wharton psychological rating scale. www.indiandentalacademy.com
  45. 45. The patient is told that if there is headache or head pain not directly associated with the temporomandibular joint, that the orthodontist may refer them for examination by a competent board-certified neurologist to identify or rule out any neurological problems. The patient is informed that in addition to complete orthodontic diagnostic records, the orthodontist may find it necessary to prescribe direct parasagittal CT or MRI scans to evaluate pathology in the temporomandibular joints. www.indiandentalacademy.com
  46. 46. Finally, the patient is told that orthodontic therapy may include some form of splint therapy. With splint therapy, there are three things that can happen: The patient’s temporomandibular joint dysfunction will improve and continue to improve, and no other treatment will be needed. The TMJ symptoms will continue and at or nearing the end of orthodontic therapy, temporomandibular joint arthroscopic surgery may be necessary. A crisis may be precipitated in the temporomandibular joint. Arthroscopic surgery may be required, followed by continued splint therapy. www.indiandentalacademy.com
  47. 47. Magnetic Resonance Imaging MRI has emerged as the prime diagnostic modality for imaging assessment of patients with suspected internal derangement had soft tissue abnormalities of the TMJ. This is the result of the surface coil hat allows high quality imaging of superficially located parts of the musculoskeletal system. MRI provides an image of both the soft tissue and hard tissue components of the joint and its surrounding structure. There is no radiation. No harmful biological effects. MRI can be achieved in multi plane which is a significant advantage for the detection of medial and lateral displacements of the TMJ. www.indiandentalacademy.com
  48. 48. Absolute contra indication Cerebral Aneurysms Cardiac pace makers Relative contraindication Uncooperative patients Pregnant women With metallic prosthetic heart valves Femo magnetic foreign bodies www.indiandentalacademy.com
  49. 49. Thermography Electronic thermography has shown promise as an objective tool for assessing TMJ disorders. It is a tool for selecting normal subjects from subjects with TMD symptoms. Thermography can measure the skin surface temperature overlying TMJ with an accuracy of 0.1ºc. Thermography has been recently applied to the assessment of TMD. www.indiandentalacademy.com
  50. 50. CEPHALOMETRIC KEYS TO INTERNAL DERANGEMENT OF TEMPOROMANDIBULAR JOINT SOUNDS AND CONDYLE / DISK RELATIONS ON MAGNETICREASONANCE IMAGES AJO (101) : 70-8; 1992 (Sug Joon Ahn, Woo Kin and Dond Seok Natim) Sug –Joon Ahn et al (2004) determined the association between the progression of internal derangement and the alterations in dento facial morphology in women with Class II malocclusion by analyzing routine lateral cephalograms. Lower facial height and ramus height, backward rotation of ramus and mandible and relative protrusion of upper and lower lips were found in patients with internal derangement of the TMJ. www.indiandentalacademy.com
  51. 51. backward rotation of ramus and mandible and relative protrusion of upper and lower lips were found in patients with internal derangement of the TMJ. These changes became increasingly severe as internal derangement progressed to disc displacement without reduction (DDNR) via disc displacement with reduction (DDR). www.indiandentalacademy.com
  52. 52. COMPUTED TOMOGRAPHY EVALUATION OF TEMPOROMANDIBULAR JOINT ALTERATIONS IN PATIENTS WITH CLASS II DIVISION 1 SUBDIVISION MALOCCLUSIONS: CONDYLEFOSSA RELATIONSHIP AJO 126:48-52; 2004. ( Robert Willer Farinazzo Vitral, Carlos de Souza Telles, Marcelo Reis Fraga, Robert Sotto Major Fortes de Oliveira, Orlando Motohiro Tanaka) Robert Willer Farinazzo Vitral et al (2004) assessed the depth of the mandibular fossa angulation of www.indiandentalacademy.com
  53. 53. the articular tubercle, condyle-fossa relationship and the concentric position of the condyles in persons with Class II Division 1 malocclusions using computed tomography (CT). They concluded that it is feature of Class II malocclusion to exhibit more anteriorly placed condyles. www.indiandentalacademy.com
  54. 54. The treatment prognosis for class II malocclusion depends on the analysis of relationship and the determination of path of closure. www.indiandentalacademy.com
  55. 55. In the malocclusions without functional disturbance the path of closure from rest to occlusion is straight up and forward, with a hinge movement of the condyle in the fossa. These are true Class II malocclusions Hinge movement from the rest (A) to occlusal (B) position in a functionally correct Class II relationship with a normal path of closure. www.indiandentalacademy.com
  56. 56. In Class II malocclusions with functional disturbances a rotary action of the condyle in the fossa from postural rest to occlusion is evident. From initial contact to full occlusion, condylar action is both rotary and translatory up and backward (posterior shift). Thus the movement combines rotary and sliding components as Boman (1952) and Blume (1952) showed in their research, this type of activity is the most common, particularly in cases of excessive overbite. This functional type of Class II malocclusion appears more severe than it actually is sagittally www.indiandentalacademy.com
  57. 57. In Class II malocclusions with functional disturbances in which the path of closure is up and forward from rest to initial contact (usually in the molar region), the mandible may be anteriorly displaced from initial contact as the cusps guide the mandible into a forward position, with translatory movement of the condyle down and forward on the posterior slope of the articular eminence. The path of closure appears more up and forward than it is without tooth interference. This condition has been illustrated by Woodside (1984) in his research. This malocclusion is more severe than it appears with the teeth in occlusion. However, this variation of path of closure is least frequent for Class II malocclusions www.indiandentalacademy.com
  58. 58. Temporomandibular joint growth changes in hyperdivergent and hypodivergent Herbst subjects. A long-term roentgenographic cephalometric study - Hans Pancherz, AMJ The aim of this long-term study was to assess the amount and direction glenoid fossa displacement, condylar growth, and “effecive” temporomandibular joint (TMJ) changes in 3 vertical facial-type groups of Class II Division 1 malocclusions treated with the Herbst appliance. www.indiandentalacademy.com
  59. 59. Glenoid fossa displacement During normal growth, the glenoid fossa is displaced in a posterior-inferior direction. During Herbst treatment the fossa in all groups was displaced in an anterior and inferior direction. This was most likely the result of remodeling processes at the posterior fossa wall. www.indiandentalacademy.com
  60. 60. Condylar growth In untreated subjects having different vertical facial morphologies, Bjork and Skieller demonstrated a vertical condylar growth pattern (predominantly superiordirected condylar growth) in hypodivergent subjects and a sagittal condylar growth pattern (predominantly posterior-directed condylar growth) in hyperdivergent subjects. www.indiandentalacademy.com
  61. 61. Conclusion The amount and direction of TMJ grouth changes (fossa displacement, condylar growth, and “effective” TMJ changes) were only tmporarily affected favorably in the sagittal direction by Herbst treatment. For glenoid fossa displacement changes, no differences existed between hypodivergent and hyperdivergent subjects t any examination period. But condylar growth and “effective” TMJ changes, on the other hand, were directed more posteriorly in hyperdivergent than in hypodivergent Herbst subjects during treatment and post treatment. www.indiandentalacademy.com
  62. 62. Roth (1970) described that in certain malocclusions it is difficult to achieve a satisfactory functional result. These could range from simple dental problems like tooth size discrepancy, crowding, poor tooth structure etc. to severe skeletal problems like severe Class II / III situations and facial asymmetry cases. An unstable occlusion produces joint compression during interdigitaion. Coexisting remodeling stimuli (Para functional habits, macrotrauma, systemic diseases) may accentuate condylar remodeling producing dysfunction. Articular disc displacement may be a sign of dysfunctional remodeling. www.indiandentalacademy.com
  63. 63. However, these changes may remain asymptomatic depending on the patient’s tolerance level and adaptive capacity. As the adaptive capacity reduces with age, psychological stress may dominate and precipitate symptoms. www.indiandentalacademy.com
  64. 64. RICKETTS (1953) conducted a radiographic study of 180 pathologic TMJ cases and observed that four distinct types of traumatic joint disturbances seemed to stem from four different types of clinical malocclusions. These were described as follows : TYPE 1 Abnormal overjet characterized by the typical Class II, division 1 relationship. Such patients move their mandibles forward in compensation for the protruding teeth during incision and speech, but the condyle usually is drawn backward to a normal position in the fossa during forced closure. www.indiandentalacademy.com
  65. 65. Ricketts did observe some patients who sustained this forward postured position even during closure of the teeth. This abnormal range of function was felt to stress the joint and result in joint trauma. TYPE 2. This is identified as true distal or posterior displacement, characterized by the typical class II division 2 patient. As the condyle is displaced distally, it is said to lodge behind the bulbous portion of the articular disc, resulting in clicking on opening as it moves onto the disc and closing as it slips off the disc. www.indiandentalacademy.com
  66. 66. TYPE 3 is related to bicuspid and molar interferences. Balancing side interferences represent the classic example of this phenomenon. Other examples are seen in cases with extruded molars (i.e 3rd molars) and posterior cross bite. TYPE 4 is represented by cases with a loss of posterior support, as occurs with loss of posterior teeth. This is said to allow the condyles to seat more superiorly in the joints, so the joints receive stresses that should normally be borne by the teeth. www.indiandentalacademy.com
  67. 67. • Since that original study, RICKETTS(1983) has observed other types of conditions that were associated with concurrent TMJ pathologies and categorized these into the following aquired occlusal functional disorders; • • • • • • • • Loss of posterior support Abnormal levering against the joints Distal displacvement of the condyle Interferences of the teeth Mandibular eccentricity Third molar effects Failure of long term growth prediction Post-surgical complications www.indiandentalacademy.com
  68. 68. Although this list of factors serves as an excellent starting point for further evaluation and better understanding of the relationship between malocclusion and joint pathology, there appear to be areas of overlap among the categories. For example, third molar effect is also a form of abnormal levering againstthe joint, a category which has also been extensively described by ROTH (1970). A failure of longterm growth prediction can result in distal condyle displacement and could therefore be considered a subcategory of distal displacement www.indiandentalacademy.com
  69. 69. • Finally interferences of teeth may be found in all over the other seven categories, and categories 1 through 5 are frequently seen as results of postsurgical complications. • The above categories do not relate speciafically to the diagnosis and treatment of orthodontic patients. Such diagnosis and treatment is usually related to the vertical (high angel versus low angle), the horizontal (Class III versus Class II), and the lateral (functional side shift versus true skeletal asymmetry) discrepancies. Hence, the following developed by the author may be more appromitely utilized the evaluation of the skeletal and dental component of TMJ dysfunction www.indiandentalacademy.com
  70. 70. • Vertical Discrepancy Lack of posterior support Molar or bicuspid fulcruming • Horizontal Discrepancy Anterior skids or anterior posturing Distal displacement • Lateral Discrepancy Functional side shift True vertical asymmetry These categories reflect disharmony in centric position, and when supplemented with the eccentric disharmonies of lateral and postrusive interferences provide an overall perspective of the extra-articular skeletal and dental components of TMJ dysfunction www.indiandentalacademy.com
  71. 71. AJO-DO1987 Preventing adverse effects on TMJ through orthodontic treatment Wyatt In the Class II malocclusions with deep interlocking cusps headgear and/or Class II elastics are often used in an effort to get the patient into a Class I cuspal relationship. 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 conceivable cause an anterior dislocation of the disk. To correct this problem in orthodontic treatment , a possible solution is a flat palen of acrylic, which can be bonded on the occlusal surfaces of the lower molars and premolars after the fixed appliance has been placed. www.indiandentalacademy.com
  72. 72. • When cusps get past a “point-to-point” contact, the flat oclusal acrylic plate is removed. Now the cuspal inclines tend to move the mandible forward and the maxilla backward on maximum closure. This ,may aid in the retraction of the maxilla, but since the mandible moves forward, one could assume it might also alleviate TMJ problems. www.indiandentalacademy.com
  73. 73. CORRELATIONS BETWEEN CONDYLAR CHARACTERISTICS AND FACIAL MORPHOLOGY IN CLASS II PREADOLESCENT PATIENTS AJO 114(3):328-336; 1998. (Gail Burke, Paul Major, Kenneth Glover, Narashimha Prasad) Most Class II, division 1 patients exhibit distraction of the condyle during various functions. This sustained forward posture position could lead to abnormal stresses and trauma in the joint. This joint trauma is accentuated in high angle cases-which manifest as decreased disk spaces with posteriorly angled condyles in a tomographic assessment by Burke and co-workers. This increased prevalence of internal derangements in class II high angle cases has lead us to select these cases for CT assessment of the temporomandibular joint. www.indiandentalacademy.com
  74. 74. Correlations Between Condylar Characteristics and Facial morphology in Class II preadolescent patients 336;1998 - Gail Burke, Paul Major, Kenneth Glover, Narashimha Prasad, AJO, 114(3):328- Gail Burke et al (1998) determined correlations between condylar characteristics measured from preorthodontic tomograms of preadelescents and their facial morphologic chaacteristics. They concluded that patients with vertical facial morphologic characteristics displayed decreased superior joint spaces and posteriorly angled condyles which could be due to remodeling and degenerative changes of the disc with thinning of the posterior band. www.indiandentalacademy.com
  75. 75. Cephalometric keys to internal derangement of temporomandibular joint in women with class ii malocclusion - Sug Joon Ahn, Woo Kin and Dond Seok Natim, AJO,486-495;2004 Sug –Joon Ahn et al (2004) determined the association between the progression of internal derangement and the alterations in dento facial morphology in women with Class II malocclusion by analyzing routine lateral cephalograms. Lower facial height and ramus height, backward rotation of ramus and mandible and relative protrusion of upper and lower lips were found in patients with internal derangement of the TMJ. www.indiandentalacademy.com
  76. 76. These changes became increasingly severe as internal derangement progressed to disc displacement without reduction (DDNR) via disc displacement with reduction (DDR). www.indiandentalacademy.com
  77. 77. COMPUTED TOMOGRAPHY EVALUATION OF TEMPOROMANDIBULAR JOINT ALTERATIONS IN PATIENTS WITH CLASS II DIVISION 1 SUBDIVISION MALOCCLUSIONS: CONDYLEFOSSA RELATIONSHIP AJO 126:48-52; 2004. ( Robert Willer Farinazzo Vitral, Carlos de Souza Telles, Marcelo Reis Fraga, Robert Sotto Major Fortes de Oliveira, Orlando Motohiro Tanaka) Robert Willer Farinazzo Vitral et al (2004) assessed the depth of the mandibular fossa angulation of www.indiandentalacademy.com
  78. 78. the articular tubercle, condyle-fossa relationship and the concentric position of the condyles in persons with Class II Division 1 malocclusions using computed tomography (CT). They concluded that it is feature of Class II malocclusion to exhibit more anteriorly placed condyles. www.indiandentalacademy.com
  79. 79. CLINICAL EXPERIENCE WITH MRI IN INTERNAL DERANGEMENTS OF THE TMJ AO (1) : 21-32; 1988 (Raphael T Schach, Lionel Sadowsky P) Rapheal T Schach et al (1988) evaluated MRI images of 50 symptomatic temporomandibular joints in twenty six individuals. They concluded that MRI diagnosis of disc / condyle relationship was satisfactory in 89.5% of the cases as compared to arthrography. www.indiandentalacademy.com
  80. 80. TMD STATUS OF JUVENILE PATIENTS AJO (101) : 54-9; 1992 (Hans, Liberman, Gold Berg, Rozencweig and Bellon) Hans et al (1992) compared clinical examination, history and MRI for identifying TMJ disorders in orthodontic patients who presented with primary compliant of malocclusion. MRI was selected for use because of its high specificity for identification of abnormal condyle-disk relationships. They concluded that thorough history and clinical examination are the diagnostic tests of choice because they identify potential temporomandibular disorders. www.indiandentalacademy.com
  81. 81. AJO (101): 88-96; 1992 (Sakuda, Tanne, Tanaka and Takasugi) Sakuda et al (1992) utilized polytomography, which takes hypocycloidal motion (POLYTONE-U, Philips Co. Ltd., The Netherlands) to evaluate a three dimensional position of the condyle relative to the glenoid fossa in the TMJ space and to investigate the accuracy of the method. In addition, clinical application of this technique was attempted to elucidate its availability for diagnosis of TMD before orthodontic treatment. www.indiandentalacademy.com
  82. 82. TEMPOROMANDIBULAR JOINT SOUNDS AND CONDYLE / DISK RELATIONS ON MAGNETIC RESONANCE IMAGES AJO (101): 70-8; 1992 (Sutton, Sadowsky, Bernreuter, Mccutcheon & Lakshminarayanan) Sutton et al (1992) compared the condyle / disk relationsthip on magnetic resonance images (MRI’s) in a group of subjects with completely silent TMJ when tested clinically with those in subjects with readily discernible TMJ sounds. Of the silent joints, 89% were found to have sounds when tested with accelerometer. www.indiandentalacademy.com
  83. 83. MRI scanning was used to determine the relationship of the disk to the head of condyle, the relationship of condyle / disk complex to the slope of the eminence. They concluded that the clinically discernable joint sound group had a change in the condyle / disk position in the image immediately after the position of the joint sounds. www.indiandentalacademy.com
  84. 84. PREVALENCE OF TMJ DISC DISPLACEMENT IN A PRE ORTHODONTIC ADOLESCENT SAMPLE AO (70) 6: 454-463; 2000 (Nebbe B, Major PW) Nebbe B et al (2000) evaluated the prevalence of the TMJ disc displacement in 194 preadolescents by means of MRI. Unilateral and bilateral normal disc position was more prevalent in boys compared to girls. All forms of anterior, rotationally and medial disc displacement were more prevalent in the female sample. www.indiandentalacademy.com
  85. 85. OBSERVATION OF THREE CASES OF TEMPOROMANDIBULAR JOINT OSTEOARTHRITIS AND MANDIBULAR MORPHOLOGY DURING ADOLESCENCE USING HELICAL CT, J ORAL REHABIL 31.(4):298-305; 2004 (Yamada K, Saito I, Hanada K, Hayashi T) Yamada et al (2004) used helical computed tomography and ceogalometry to analyse relationships between the pattern and location of condylar remodeling and the changes in craniofacial morghology in three patients with temporomandibular joint osteoarthritis and found that the mandible usually rotates posteriorly, resulting in an unsatisfactory profile, especially in patients with pre-treatment mandibular retrusion www.indiandentalacademy.com
  86. 86. CONDYLAR BONY CHANGE AND CRANIOFACIAL MORPHOLOGY IN ORTHODONTIC PATIENTS WITH TEMPOROMANDICULAR DISORDERS (TMD) SYMPTOMS : A PILOT STUDY USING HELICAL COMPUTED TOMOGRAPHY AND MAGNETIC RESONANCE IMAGING CLIN ORTHOD RES.2(3) : 133-42 ; 1999 Yamad K, Hiruma Y, Hanada K, Hayashi T, Koyama J, Ito J Yamada et al (1999) investigated how condylar bony changes relate to craniofacial morphology using helical CT and MRI in 29 orthodontic patients. www.indiandentalacademy.com
  87. 87. Craniofacial morphology of orthodontic patients with condylar bony changes was compared with Japanese standard. Disk displacement without reduction was seen in 90.6% of the bilateral group, and in 76.9% of the unilateral group. Retrognathic mandibles were shown in the bilateral group. All subjects exhibited a lateral shift of the menton toward the condylar bony changed side in the unilateral group. They concluded that condylar body changes may be related to a lateral shift of the mandible and a retrognatic mandible in orthodontic patients with TMD symptoms. www.indiandentalacademy.com
  88. 88. www.indiandentalacademy.com
  89. 89. Hinge-type condylar function is often associated with Class III malocclusions with straight paths of closure. If the path of closure is up and back (an anterior postural rest position), the prognosis is even poorer. In Class III malocclusions with anterior displacement that creates an up and forward path of closure with combined rotary and translatory action of the condyle from postural rest to habitual occlusion, the prognosis is much better and treatment success is possible, even in the permanent dentition. A: Anterior rest position in a severe Class III malocclusions B: Posterior rest position in a forced bite type of Class III malocclusion www.indiandentalacademy.com
  90. 90. In cases of class III, the condyle that is forwardly placed has a good prognosis, and the condyle that is posteriorly placed has a better prognosis. The wear of the functional appliances causes a remodeling of a glenoid fossa. Both the removable and fixed functional appliances are known to have remodeling effect on the glenoid fossa. www.indiandentalacademy.com
  91. 91. Chin cup therapy www.indiandentalacademy.com
  92. 92. • The effects on chin cup therapy on the TMJ are as follows (1988, AJO, Tosho et al) • Forward bending of the condylar neck • Enlargement of the joint cavity • Closing of the angle of the mandible • Force distribution on the lateral surface of the temporal bone may affect the size and position of the craniofacial structures. www.indiandentalacademy.com
  93. 93. Sometimes a skeletal Class III relationship is partially compensated by labial tipping of the maxillary incisors and lingual tipping of the mandibular incisors. Because of the extreme tipping possible, an anterior sliding movement into occlusion can occur. Uprighting the incisors into their proper axial inclinations results in a severe Class III sagittal tooth relationship. Treatment of this type of malocclusion by orthodontic means is difficult because dentoalveolar compensation is not possible; the incisors are already overcompensated before treatment. Orthognathic surgery should be considered and discussed with the patient. This type of malocclusion is referred to as a pseudo-forced bite or displacement www.indiandentalacademy.com
  94. 94. Magnetic Resonance Imaging assessment of the positional relationship between the disk and condyle in asymptomatic young adult mandibular prognathism: AO 73:550-555; 2003 Hatice Gokalp (2003) studied the disk position relative to condyle and condylar position relative to glenoid fossa in clinically asymptomatic and orthodontically untreated young adult Class III patients by MRI. They concluded that clinically asymptomatic Class III patients may be candidates for TMJ derangements and the anterior positioning of the articular disk could be due to anterior pull of the superior lateral pterygoid www.indiandentalacademy.com
  95. 95. Midline switch / cross elastics Midline switch or cross elastics have a more subtle effect. As the jaw is pulled to one side, distal pressure is put on one condyle only. If this creates a TMJ problem, midline elastics should be worn only during waking hours so that muscle can help to hold the mandible forward. www.indiandentalacademy.com
  96. 96. RPHG and Class III elastics RPHG and Class III elastics produce a distal driving force of the mandible and condyle. This would produce a reciprocal forward displacement of the disc and pressure on retrodiscal tissues. • It is better to have the patient wear lower or reverse headgear and Class III elastics only during waking hours. • Muscle tone (tension) positions the mandible forward. • When worn at night, the muscles are relaxed and there is more distal pressure on the condyle because compensating muscle activity is not in play. www.indiandentalacademy.com
  97. 97. Treatment effects of Frankel functional regulator III in children with Class III malocclusions - Hyoung S.Baik, AJO, 2004 The purpose of this study was to evaluate the skeletal and dental effects produced by the Frankel functional regulator III appliance in growing children with Class III malocclusions. The treatment efects found were mainly from backward and dwonward rotation of the mandible and linguoversion of the mandibular incisors. www.indiandentalacademy.com
  98. 98. TMDs www.indiandentalacademy.com
  99. 99. Definition Temporomandibular disorders (TMDs) are defined as “either functional or anatomic damage to the joint, leading to uncoordinated condyle-fossa relationships in static and dynamic phases or alterations in the spatial positions of the mandible. The etiology of TMDs is complex and multifactorial The etiologic classification as given by Roth in the year 1980, Jco is given below along with the exacerbating features as given by Bishara Systemic (Wyatt, 1987, AJO) Acquired www.indiandentalacademy.com
  100. 100. Cluster of related disorders in the stomatognathic system Perpetuating factors (Samir E. bishara) Behaviroal factors Social factors Emotional factors Congnitive factors Etiology of the TMD, as given in Angle Orthodontist, Inc.), 1988 : Malocclusion and the Temporomandibular Joint – An Historical Perspective Richard P.McLaughlin. The relationship between dental malocclusion and TMJ dysfunction has been discussed in dentistry for over sixty years. Historically, the greatest emphasis has been placed on malocclusion as the primary etiologic factor in TMJ dysfunction. More recently, while malocclusion has continued to be accepted as an important element in many of these problems, other conditions have also been recognized as important etiologic factors. www.indiandentalacademy.com
  101. 101. The challenge for dentistry today is to differently diagnose patients who present with TMJ dysfunction. It is essential to look beyond the occlusion to identify all of the etiologic factors that may be involved, and then establish the extent to which each contributes to the problem COSTEN (1934) contended that loss of vertical dimension leads to compression of the joint structures, causing symptoms of pain and dysfunction within the temporomandibular joints. He recommended bite opening procedures to correct the problem. SCHUYLER (1935) contended that occlusal disharmony, and not a “closed bite” was the chief cause of TMJ problems. He rejected Costen’s hypothesis, and recommended correction of occlusal disharmony for the treatment TMJ pain and dysfunction. www.indiandentalacademy.com
  102. 102. SICHER (1949), an anatomist, presented studies on the functional anatomy and biomechanics of the temporomandibular joint. Sicher contended that it was anatomically impossible for Costen’s proposed theory to be correct, and shortly thereafter “Costen’s Syndrome” was rejected by the profession. In 1956, SCHWARTZ discussed the importance of the musculature relative to TMJ disorders, and introduced the “Myofascial Pain Dysfunction (MPD) Syndrome”. He contended that occlusal disharmony led to muscle dysfunction in many patients and this in turn was responsible for subsequent pain and damage to the temporomandibular joints. www.indiandentalacademy.com
  103. 103. Internal Derangement The term “internal derangement” (ID) is defined as an abnormal positional and functional relationship between the disk, mandibular condyle and the articulating surface of the temporal bone, resulting in soft tissue interference of joint function. The most common abnormality encountered when imaging patients of TMDs is different forms of disk displacement. Disk displacement can occur in any anatomic direction www.indiandentalacademy.com
  104. 104. Cephalometric keys to internal derangement of temporomandibular joint in women with Class II malocclusions -Sug-Joon Ahn, AJO,Oct,2004 The aim of this study was to find cephalometric keys to provide imformation on the progression of tempromandibular internal derangement. The sample consisted of 58 women with Class II malocclusions. They were examined with routine lateral cephalograms and magnetic resonance imaging of the temporomandibular joint (TMJ) before orthodontic treatment. They were classified into 3 groups according to the results of the magnetic reasonance imaging: normal disk position, disk displacement with reduction and disk displacement without reduction. www.indiandentalacademy.com
  105. 105. INTERNAL DERANGEMENT OF TEMPORO- MANDIBULAR JOINT - Isberg, Widmalm and Ivarsson, AJO 453-460; 1985 Isberg et al (1985) examined fifteen patients with internal derangement of the temporomandibular joint (TMJ) clinically and radiographically. Electromyographic activity of temporails and masseter muscles were also assessed. All the patients with internal derangement demonstrated interferences on the ipsilateral side. This was interpreted as the result of the disc displacement producing a reduced joint space and, consequently, a decreased verticaldimension on the symptomatic side. www.indiandentalacademy.com
  106. 106. In association with disc displacement, electromyographic activity of the temporalis and masseter muscles occurred when the condyle slid over the posterior band of the disc and could be interpreted as an arthrokinetic reflex caused by distraction. Anterior disc displacement without reduction (closed lock) could cause spastic activity in the temporalis muscle on the affected side. Spastic activity of the masseter and temporalis muscles occurring on the same side as a joint with anterior disc displacement hinders or inhibits the condylar movement necessary to achieve reduction. www.indiandentalacademy.com
  107. 107. Skeletal and dental patterns in patients with alterations of TMJ, - Stringent AND Worms, AJO:285-297;1986 Stringent et al (1986) examined skeletal and dental characteristics of subjects with documented internal derangements of the TMJ and compared these characteristics to those of a matched control group. Specific attention was given to skeletal variations in the anteroposterior and vertical planes as well as overbite and overjet. Cephalometrically, there was a tendency of hyperdivergency, increased horizontal skeletal discrepancy and no difference in the angular relationships of the anterior teeth in each arch to their respective skeletal bases. www.indiandentalacademy.com
  108. 108. Internal Derangement of The TMJ-changes associated with mandibular repositioning and orthodontic therapy, - Stephen D Keeling, Charles Gibbs, Matthew B Hall, Stephon Lupkiewics Stephon Keeling et al (1989) assessed the chronic painful internal derangement of patients using transcranial radiographs, arthrograms, lateral cephalometric radiographs and recordings of mandibular movements. The patients were treated with anterior positioning splint therapy and orthodontic treatment. Post treatment findings revealed a decrease in ANB, more anterior positioning of the mandible and more confined sagittal envelope of motion in Posselt’s diagram www.indiandentalacademy.com
  109. 109. TMJ and craniomandibular disorders -Paesani, westesson, Hatala, and tallents: AJO,(101):41-47’1992 Paesani et al (1992) determined the prevalence of temporomandibular joint internal derangement in patients with signs and symptoms of craniomandibular disorders, bilateral imaging was performed in a consecutive series of 115 patients with signs and symptoms of craniomandibular disorders. The TMJ arthrography was performed bilaterally on 51 patients, and magnetic resonance imaging (MRI) was performed bilaterally on 64 patients. 78 % had different stages of unilateral or bilateral internal derangements. The study indicates that almost 80% of patients with signs and symptoms of craniomandibular disorders have different forms of internal derangement. www.indiandentalacademy.com
  110. 110. Pediatric TMJ Derangement: Effect on Facial Development, - Schellhas, Pollei and Wilkes: AJO:51-59;1993 Schellhas et al (1993) evaluated the relationship between internal derangement of TMJ and disturbed facial skeletal growth (dysmorphogenesis) in 128 children aged fourteen years or younger using combined radiographic & MR imaging studies of both TMJs. Of 60 retrognathic patients, 56 were found to have TMJ derangement, generally bilateral and often of advanced stage. In cases of lower facial asymmetry, the chin was uniformly deviated towards more degenerated TMJ. They concluded that TMJ derangements are common in children and may contribute to development of retrognathia with or without asymmetry. www.indiandentalacademy.com
  111. 111. Relationship between TMJ disk displacement and skeletal facial form - Brand, Nielson, Tallents, Nanda, Currier, and Owen, AJO 121-128;1995 Brand et al (1995) compared skeletal and dental relationships in a group of twenty four females with clinical evidence of internal derangements and a group of twenty three females with evidence of normal disk position using magnetic resonance imaging and cephalometric radiography, and concluded that patients with ID had significantly smaller lengths of maxillary and mandibular bodies. www.indiandentalacademy.com
  112. 112. Subluxation Subluxation of the TMJ represents a sudden fowrard movement of the condyle during the latter face of mouth opening. When the condyle moves beyong the crest of the eminence, it appears to jump forward to the wide open position. This occurs because the steep eminence requires a great deal of rotational movement of the disc on the condyle when the condyle translates out of the fossa. www.indiandentalacademy.com
  113. 113. Spontaneous dislocations Spontaneousl dislocation represents a hyperextension of the TMJ resulting in a condition that fixes the joint in the open position, preventing any translation. This condition is clinically referred to as an open lock because the patient cannot close the mouth. Like subluxation, it can occur in any joint that is forced open beyond the normal restrictions provided by the ligaments. When the condyle is in the full forward translatory position, the disc is rotated to its fullest posterior extent on the condyle and firm contact exists between it. The condyle, and the articular eminence. In this position the strong retracting force of the superior retrodiscal lamina, along with the lack of activity of the superior lateral pterygoid, prevents the disc from being anteriorly displaced. The superior lateral pterygoid normally does not become active until the turn around phase of the closing cycle www.indiandentalacademy.com
  114. 114. Clinical features of TMD Clicking: • Always reciprocal. • A product of the anatomical shape of the disc and its stereoscopic relationship of the head of the condyle at the beginning of the opening movement. • 2 are heard-one on mouth opening and the other at the same point on mouth closing. • Opening click is loud and audible; closing click may or may not be audible. • Due to continuous abuse of the ligaments, the disc may be pushed ahead of the condyle during the entire course anterior recess of the capsule becomes distorted and enlarged to accommodate the conglomeration of the discal and associated ligamentous tissues referred to as “balled-up disk”. It represents a disc that is perpetually jammed ahead of the translating condyle, thus limiting the range of translocation itself. This condition is referred to as “clinical closed-lock”. www.indiandentalacademy.com
  115. 115. Crepitus: • Sound of denued bone on bone. • Chronic abuse of the disc by superior posterior displacement of condyle can cause perspiration of the disc. • The noise of the crepisus results from contact of the head of the condyle with either the dome or slope of the articular eminence without any intervening shock absorbing disc due to perforstation. • Creptus is always a sign of long standing and severe posteriosuperior displacement of the condyle and an advanced level of intra-articular degeneration. www.indiandentalacademy.com
  116. 116. Axiography The most valuable use of axiography is in the early detection of subclinical discopathies and factors capable of causing dysfunction. It provides data necessary to substantiate other clinical findings and to make a differential diagnosis temporomandibular joint pathology By comparing hinge-axis pathways of patients with dysfunctions with those of healthy patients without dysfunctions it is possible to develop a classification differential diagnosis www.indiandentalacademy.com
  117. 117. Rotation of the jaw bases www.indiandentalacademy.com
  118. 118. Base plane angle and inclination angle are used to evaluate the rotation of the upper and lower jaw bases. These rotations are of special interest in treatment with functional appliances because they show whether such appliances are indicated and provide the criteria for appliance construction. www.indiandentalacademy.com
  119. 119. The rotation of the mandible is growth conditioned and depends on the direction and mutual relations of growth in crements in the posterior and anterior facial skeleton. If condylar growth proceeds at a greater rate, horizontal rotation results. If growth increments are balanced, paralled growth down the Y-axis occurs. www.indiandentalacademy.com
  120. 120. Bjork (1962) differentiates the two processes involved in rotational growth of the mandible. Remodeling of the mandible in the symphyeal and gonial areas – this remodeling is called matrix and often results in subsequent rotation. More apposition in the gonial area and resorption in the symphyseal area lead to horizontal rotation. Greater apposition in the symphseal area and resorption in the gonial area causes vertical rotation. Vertical or horizontal rotation of the mandible in its neuromuscular envelope – This rotation is called matrix rotation, or relocation of the functional matrix, according to Moss and Enlow (1962). Rotation observed cephalometrically is called total rotation, it consists of both intermatrix and matrix rotation. www.indiandentalacademy.com
  121. 121. The following types of rotations can be differentiated, as shown by Laverangne and Gasson (1982) in human implant studies: Covergent rotation of the jaw bases – This rotation creates a severe, deep overbite that is difficult to man age using functional methods. www.indiandentalacademy.com
  122. 122. Divergent rotation of the jaw bases This rotation can cause marked open-bite problems. In severe cases,orthognathic surgery is required for correction www.indiandentalacademy.com
  123. 123. Cranial rotation of both bases In this horizontal growth pattern a relatively harmonious rotation of both jaws occurs in an upqard and forward direction. This rotation of the maxilla compensates for upward and forward mandibular rotation, offsetting a deep bite. The result is a normal overbite www.indiandentalacademy.com
  124. 124. Caudal, or down and back, rotation of both bases This rotation occurs in a relatively harmonious manner. The down and back maxillary rotation offsets the open bite created by down and back mandibular rotation. www.indiandentalacademy.com
  125. 125. Importance of condyle in orthognathic surgery All procedures, however, that involve movement of the entire maxilla or mandible must have some influence on the temporomandibular joints. Segmental osteotomies may also influence the occlusion so that TMJ function is altered www.indiandentalacademy.com
  126. 126. Open-bite with the condyle seated Proper positioning of the condyles during surgery by autorotating the maxilla and mandible wired together permits recognition of posterior bony contact . Note that the direction of finger pressure is upward and forward www.indiandentalacademy.com
  127. 127. Thank you www.indiandentalacademy.com
  128. 128. INTERNAL DERANGEMENT OF TEMPORO- MANDIBULAR JOINT AJO 453-460; 1985 (Isberg, Widmalm and Ivarsson) Isberg et al (1985) examined fifteen patients with internal derangement of the temporomandibular joint (TMJ) clinically and radiographically. Electromyographic activity of temporails and masseter muscles were also assessed. All the patients with internal derangement demonstrated interferences on the ipsilateral side. This was interpreted as the result of the disc displacement producing a reduced joint space and, consequently, a decreased verticaldimension on the symptomatic side. www.indiandentalacademy.com
  129. 129. In association with disc displacement, electromyographic activity of the temporalis and masseter muscles occurred when the condyle slid over the posterior band of the disc and could be interpreted as an arthrokinetic reflex caused by distraction. Anterior disc displacement without reduction (closed lock) could cause spastic activity in the temporalis muscle on the affected side. Spastic activity of the masseter and temporalis muscles occurring on the same side as a joint with anterior disc displacement hinders or inhibits the condylar movement necessary to achieve reduction. www.indiandentalacademy.com
  130. 130. CLINICAL EXPERIENCE WITH MRI IN INTERNAL DERANGEMENTS OF THE TMJ AO (1) : 21-32; 1988 (Raphael T Schach, Lionel Sadowsky P) Rapheal T Schach et al (1988) evaluated MRI images of 50 symptomatic temporomandibular joints in twenty six individuals. They concluded that MRI diagnosis of disc / condyle relationship was satisfactory in 89.5% of the cases as compared to arthrography. www.indiandentalacademy.com
  131. 131. TMD STATUS OF JUVENILE PATIENTS AJO (101) : 54-9; 1992 (Hans, Liberman, Gold Berg, Rozencweig and Bellon) Hans et al (1992) compared clinical examination, history and MRI for identifying TMJ disorders in orthodontic patients who presented with primary compliant of malocclusion. MRI was selected for use because of its high specificity for identification of abnormal condyle-disk relationships. They concluded that thorough history and clinical examination are the diagnostic tests of choice because they identify potential temporomandibular disorders. www.indiandentalacademy.com
  132. 132. AJO (101): 88-96; 1992 (Sakuda, Tanne, Tanaka and Takasugi) Sakuda et al (1992) utilized polytomography, which takes hypocycloidal motion (POLYTONE-U, Philips Co. Ltd., The Netherlands) to evaluate a three dimensional position of the condyle relative to the glenoid fossa in the TMJ space and to investigate the accuracy of the method. In addition, clinical application of this technique was attempted to elucidate its availability for diagnosis of TMD before orthodontic treatment. www.indiandentalacademy.com
  133. 133. TEMPOROMANDIBULAR JOINT SOUNDS AND CONDYLE / DISK RELATIONS ON MAGNETIC RESONANCE IMAGES AJO (101): 70-8; 1992 (Sutton, Sadowsky, Bernreuter, Mccutcheon & Lakshminarayanan) Sutton et al (1992) compared the condyle / disk relationsthip on magnetic resonance images (MRI’s) in a group of subjects with completely silent TMJ when tested clinically with those in subjects with readily discernible TMJ sounds. Of the silent joints, 89% were found to have sounds when tested with accelerometer. www.indiandentalacademy.com
  134. 134. MRI scanning was used to determine the relationship of the disk to the head of condyle, the relationship of condyle / disk complex to the slope of the eminence. They concluded that the clinically discernable joint sound group had a change in the condyle / disk position in the image immediately after the position of the joint sounds. www.indiandentalacademy.com
  135. 135. DETECTABILITY OF ANTERIOR DISPLACEMENT OF THE ARTICULAR DISK IN THE TEMPOROMANDIBULAR JOINT ON HELICAL COMPUTED TOMOGRAPHY : THE VALUE OF OPEN MOUTH POSITION, ORAL SURG ORAL MED ORALPATHOL ORAL RADIOL ENDOD. 1999 (1): 106-11. (Hayashi T, Ito J, Koyama J, Hinoki A, Kobayashi F, Torikai Y, Hiruma Y) Hayashi et al (1999) examined ninety-four consecutive patients through use of both computed tomography and magnetic resonance imaging. www.indiandentalacademy.com
  136. 136. They found that in evaluation of articular disk position, the sensitivity, specidicity and accuracy for helical computed tomography were 91% , 100%, and 97%, respectively in the closed mouth position and 96%, 99% and 98%, respectively, in the open mouth position and concluded that the detectability on axial helical computed tomography of anterior displacement of the articular disk in the temporomandibular joint in the open mouth position was almost equal to that on the magnetic resonance imaging. www.indiandentalacademy.com
  137. 137. PREVALENCE OF TMJ DISC DISPLACEMENT IN A PRE ORTHODONTIC ADOLESCENT SAMPLE AO (70) 6: 454-463; 2000 (Nebbe B, Major PW) Nebbe B et al (2000) evaluated the prevalence of the TMJ disc displacement in 194 preadolescents by means of MRI. Unilateral and bilateral normal disc position was more prevalent in boys compared to girls. All forms of anterior, rotationally and medial disc displacement were more prevalent in the female sample. www.indiandentalacademy.com
  138. 138. OBSERVATION OF THREE CASES OF TEMPOROMANDIBULAR JOINT OSTEOARTHRITIS AND MANDIBULAR MORPHOLOGY DURING ADOLESCENCE USING HELICAL CT, J ORAL REHABIL 31.(4):298-305; 2004 (Yamada K, Saito I, Hanada K, Hayashi T) Yamada et al (2004) used helical computed tomography and ceogalometry to analyse relationships between the pattern and location of condylar remodeling and the changes in craniofacial morghology in three patients with temporomandibular joint osteoarthritis and found that the mandible usually rotates posteriorly, resulting in an unsatisfactory profile, especially in patients with pre-treatment mandibular retrusion www.indiandentalacademy.com
  139. 139. COMPARISON OF SKELETAL AND DENTAL MORPHOLOGY IN ASYMPTOMATIC VOLUNTEERS AND SYMPTOMATIC PATIENTS WITH UNILATERAL DISC DISPLACEMENT WITH REDUCTION. AO 74:212-219; 2004 (Ioanna K Gidarakou, Ross H Tallents, Stephanos Kyrkanides, Scott Stein, Mark E Moss) Ioanna K Gidarakou et al (2004) evaluated the effect of unilateral disk displacement with reduction on the skeletal and dental patterns of the affected individuals using MRI and lateral cephalogram. www.indiandentalacademy.com
  140. 140. They concluded that alterations in the skeletal morphology with unilateral disk displacement with reduction (UDDR) include short anterior and posterior cranial base, short posterior ramus height and retro positioned upper and lower denture bases. www.indiandentalacademy.com
  141. 141. CONDYLAR BONY CHANGE AND CRANIOFACIAL MORPHOLOGY IN ORTHODONTIC PATIENTS WITH TEMPOROMANDICULAR DISORDERS (TMD) SYMPTOMS : A PILOT STUDY USING HELICAL COMPUTED TOMOGRAPHY AND MAGNETIC RESONANCE IMAGING CLIN ORTHOD RES.2(3) : 133-42 ; 1999 Yamad K, Hiruma Y, Hanada K, Hayashi T, Koyama J, Ito J Yamada et al (1999) investigated how condylar bony changes relate to craniofacial morphology using helical CT and MRI in 29 orthodontic patients. www.indiandentalacademy.com
  142. 142. Craniofacial morphology of orthodontic patients with condylar bony changes was compared with Japanese standard. Disk displacement without reduction was seen in 90.6% of the bilateral group, and in 76.9% of the unilateral group. Retrognathic mandibles were shown in the bilateral group. All subjects exhibited a lateral shift of the menton toward the condylar bony changed side in the unilateral group. They concluded that condylar body changes may be related to a lateral shift of the mandible and a retrognatic mandible in orthodontic patients with TMD symptoms. www.indiandentalacademy.com
  143. 143. www.indiandentalacademy.com
  144. 144. Thank you For more details please visit www.indiandentalacademy.com www.indiandentalacademy.com

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