1. Temporomandibular joint -by Dr. ushma saini 2. Anatomy The temporomandibular joint is a synovial, condylar, and hinge-type joint with fibrocartilaginous surfaces rather than hyaline cartilage and an articular disc; this disc completely divides each joint into two cavities. Along with the teeth, these joints are considered to be a trijoint complex. Gliding, translation, or sliding movement occurs in the upper cavity of the temporomandibular joint, whereas rotation or hinge movement occurs in the lower cavity. The TMJs are one of the only synovial joints in the human body with an articular disc. The name derived from the two bones which form the joint: the upper temporal bone which is part of the cranium and the lower jaw bone called the mandible. 3. The Rotation occurs from the beginning to the midrange of movement. The upper head of the lateral pterygoid muscle draws the disc, or meniscus, anterioly and prepares for condylar rotation during movement. The rotation occurs through the two condylar heads between the articular disc and the condyle. In addition, the disc provides congruent contours and lubrication for the joint. Gliding, which occurs as a second movement, is a translatory movement of the condyle and disc along the slope of the articular eminence. Both gliding and rotation are essential for full opening and closing of the mouth. 4. Temporomandibular Joints Resting position: Mouth slightly open, lips together, teeth not in contact Close packed position: Teeth tightly clenched Capsular pattern: Limitation of mouth opening 5. Component There are six main components of the TMJ. 1. Mandibular condyles 2. Articular surface of the temporal bone 3. Capsule 4. Articular disc 5. Ligaments 6. Lateral pterygoid 6. Movements The temporomandibular joints actively displace only anteriorly and slightly laterally. When the mouth is opening, the condyles of the joint rest on the disc in the articular eminences, and any sudden movement, such as a yawn, may displace one or both condyles forward. As the mandible moves forward on opening, the disc moves medially and posteriorly until the collateral ligaments and lateral pterygoid stop its movement. The disc is then "seated" on the head of the mandible, and both disc and mandible move forward to full opening. 7. If this "seating" of the disc does not occur, full range of motion at the temporomandibular joint is limited. In the first phase - rotation occurs, primarily in the inferior joint space. In the second phase - mandible and disc move together, mainly translation occurs in the superior joint space. 8. Nerve supply Are innervated by branches of the auriculotemporal and masseteric branches of the mandibular nerve. The disc is innervated along its periphery but is a neural and avascular in its intermeeliate (force- bearing) zone. 9. ligament 1. Temporomandibular, or lateral, ligament. 2. Sphenomandibular and stylomandibular ligaments. The temporomandibular, or lateral, ligament restrains movement of the lower jaw and prevents compression of the tissues behind the condyle. In reality, this collateral ligament is a thickening in the joint capsule. 10. The sphenomandibular and stylomandibular ligaments act as "guiding" restraints to keep the condyle, disc, and temporal bone firmly opposed. The stylomandibular ligament is a specialized band of deep cerebral fascia with thickening of the parotid fascia. 11. Patient History Is there pain on opening or closing of the mouth? Is there pain on eating? What movements of the jaw cause pain? Do any of these actions cause pain or discomfort: Yawning? Biting? Chewing? Swallowing? Speaking? Shouting? Does the patient breathe through the nose or the mouth? Has the patient complained of any clicking? Has the mouth or jaw ever locked? Locking may imply that the mouth does not fully open or it does not fully close. 12. Does the patient have any habits such as pipe smoking, using a cigarette holder, leaning on the chin, chewing gum, biting the nails, chewing hair, pursing and chewing lips, continually moving the mouth, or any other nervous habits? Does the patient grind the teeth or hold them tightly? Are any teeth missing? If so, which ones and how many? Their presence or absence can have an effect on the temporoandibular joints. Does the patient have any habitual head postures? for example, holding the telephone between the ear and the shoulder compacts the temporomandibular joint on that side. Reading or listening to someone while leaning one hand against the jaw has the same effect. 13. Has the patient noticed any voice changes? Changes may be caused by muscle spasm. Does the patient have headaches? If so, where? Temporomandibular joint problems can refer pain to the head. Is there any history of infection or swollen glands? Does the patient ever feel dizzy or faint? Has the patient ever worn a dental splint? If so, when? For how long? 14. Observation When assessing the temporomandibular joints, the examiner must also assess the posture of the cervical spine and head. 1. Is the face symmetrical horizontally and vertically, and are facial proportions normal. Examiner should check the eyebrows, eyes, nose, ears, and corners of the mouth for symmetry on both horizontal and vertical planes. 2. The examiner should note whether there is any crossbite, underbite, or overbite. 15. 3. The examiner should note whether there is any malocclusion that may result in a faulty bite. Malocclusion may be a major factor in the development of disc problems of the temporomandibular joints. Occlusion occurs when the teeth are in contact and the mouth is closed. Malocclusion is defined as any deviation from normal occlusion. 4. What is the facial profile? The orthognathic profile is the normal, "straight-jawed" form. 5. The examiner should note whether the patient demonstrates normal bony and soft-tissue contours. When the patient bites down, do the masseter muscles bulge as they normally should? 16. 6. Is the patient able to move the tongue properly? Can the patient move the tongue up to and against the palate? Can the tongue be protruded or rolled? Is the patient able to "click" the tongue? 7. Where does the tongue rest? Is the tongue bitten frequently? 8. Do the lips part when swallowing? What is the tongue position when swallowing? Do the facial muscles tighten on swallowing? All of these factors give the examiner some idea of the mobility of the structures of the mouth and jaw and their neurological mechanisms. 17. Examination The exan1iner must remember that many problems of the temporomandibular joints may be the result of or related to problems in the cervical spine or teeth. Therefore, the cervical spine is at least partially included in any temporomandibular assessment. Active Movements With the patient in the sitting position, the examiner watches the active movements, noting whether they deviate from what would be considered normal range of motion and whether the patient is willing to do the movement. 18. During flexion of the neck, the mandible moves up and forward, and the posterior structures of the neck become tight. During extension, the mandible moves down and back and the anterior structures of the neck become tight. The movements of the mandible can be measured with a millimeter ruler, depth gauge, or Vernier calipers. When using the ruler, the examiner should pick a midline point from which to measure opening and lateral deviation.This same ruler can be used to measure protrusion and retrusion. 19. OPENING AND CLOSING OF THE MOUTH With opening and closing of the mouth, the normal arc of movement of the jaw is smooth and unbroken; that is, both temporomandibular joints are working in unison with no asymmetry or sideways movement, and both joints are bilaterally rotating and translating equally. PROTRUSION OF THE MANDIBLE The normal movement is 3 to 6 mm. RETRUSION OF THE MANDIBLE The normal movement is 3 to 4mm. 20. LATERAL DEVIATION OR EXCURSION OF THE MANDIBLE The normal lateral deviation is 10 to 5 mm. MANDIBULAR MEASUREMENT Measure the mandible from the posterior aspect of the temporomandibular joint to the notch of the chin. Both sides are measured and compared for equality (the normal distance is 10 to 12 cm). CRANIAL NERVE TESTING If injury to the cranial nerves is suspected, the cranial nerves should be tested. 21. PASSIVE MOVEMENTS The normal end feel of these joints is tissue stretch on opening and teeth contact ("bone to bone") on closing RESISTED ISOMETRIC MOVEMENTS 1. Opening of the mouth (depression). This movement may be tested by applying resistance at the chin or, using a rubber glove, over the teeth with one hand while the other hand rests behind the head or neck or over the forehead to stabilize the head. 22. ooopj 23. 2. Closing of the mouth (elevation or occlusion). One hand is placed over the back of the head or neck to stabilize the head while the other hand is placed under the chin of the patient's slightly open mouth to resist the movement. 24. 3. Lateral deviation of the jaw. One of the examiner's hands is placed over the side of the head above the temporomandibular joint to stabilize the head. The other hand is placed along the jaw of the patient's slightly open mouth, and the patient pushes out against it. FUNCTIONAL ASSESSMENT These activities incIude chewing, swallowing, coughing, talking, and blowing. 25. SPECIAL TESTS 1. The Chvostek test is used to determine whether there is pathology involving the seventh cranial (facial) nerve. The examiner taps the parotid gland overlying the masseter muscle. If the facial muscles twitch, the test is considered positive. 2. The examiner can listen to (auscultate) the temporomandibular joints during movement. The movements "listened to" include opening and closing of the mouth, lateral deviation of the mandible to the right and left, and mandibular protrusion. Normally, only on occlusion would a sound be heard. This is a single, solid sound, not a "slipping" sound. A slipping sound could occur if the teeth are not "hitting" simultaneously. 26. Chvostek test 27. auscultation 28. Reflexes 29. JOINT PLAY MOVEMENTS- Pain on performing these tests may indicate articular problems or pathology to the retrodiscal tissues. Longitudinal Cephalad and Anterior Glide-Wearing rubber gloves, the examiner places the thumb on the patient's lower teeth inside the mouth with the index finger on the mandible outside the mouth. The mandible is then distracted by pushing down with the thumb and pulling down and forward with the index finger while the other fingers push against the chin, acting as a pivot point. The examiner should feel the tissue stretch of the joint. Each joint is done individually while the other hand and arm stabilize the head 30. Lateral Glide of the Mandible. The patient lies supine with the mouth slightly open and the mandible relaxed. The examiner places the tl1umb inside tl1e mouth along the medial side of the mandible and teeth. By pushing the thumb laterally, the mandible glides laterally. Each joint is done individually. 31. Medial Glide of the Mandible- The patient is in side lying with the mandible relaxed. The examiner places the thumb (or overlapping thumbs) over the lateral aspect of the mandibular condyle outside the mouth and applies a medial pressure to the condyle, gliding the condyle medially, Each joint is done individually. 32. Posterior Glide of the Mandible- The patient is in side lying with the mandible relaxed. The examiner places the thumb (or overlapping thumbs) over the anterior aspect of the mandibular condyle outside the mouth and applies a posterior pressure to the condyle, gliding the condyle posteriorly. Each joint is done individually. 33. PALPATION Mastoid Processes -The examiner should palpate the skull, following the posterior aspect of the ear. The examiner will come to a point on the skull where the finger dips inward. The point just before the dip is the mastoid process 34. DIAGNOSTIC IMAGING Plain Film Radiography- On the anteroposterior view, the examiner should look for condylar shape and normal contours. On the lateral view the examiner should look for condylar shape and contours, position of condylar heads in the opened and closed positions, amount of condylar movement (closed versus open), and relation of temporomandibular joint to other bony structures of the skull and cervical spine. Magnetic Resonance Imaging This technique is used to differentiate the soft tissue of the joint, mainly the disc, from the bony structures. It has the advantage of using nonionizing radiation. 35. Thanks you