Temporo-mandibular Joint (TMJ) Anatomy and Disorders PDF

The Temporo-mandibular Joint (TMJ) Oral and Dental Sciences 2 GDC Learning Outcomes 1.1.5 Describe relevant and appropriate dental, oral, craniofacial and general anatomy and explain their application to patient management 3 Intended learning outcomes...

The Temporo-mandibular Joint (TMJ) Oral and Dental Sciences 2 GDC Learning Outcomes 1.1.5 Describe relevant and appropriate dental, oral, craniofacial and general anatomy and explain their application to patient management 3 Intended learning outcomes By the end of this session, you will be able to:  At the end of this session, you will be able to  List the components of the TMJ and describe their function  Describe the movement of the mandible  List some common problems associated with the TMJ 4  The temporomandibular joint (TMJ) is the joint that connects your mandible (lower jaw) to your skull. The joint can be found on both sides of your head in front of your ears. It allows your jaw to open and close, enabling you to speak and eat. 5 6 The temporomandibular joint  Articulation between the mandibular condyle & the inferior surface of the temporal bone.  There is bilateral articulation, both right & left sides work as a unit.  It is the only visible and free moving articulation in the head, all others are sutures and fixed.  Complex, co-ordinated jaw movements are controlled by reflexes 7  It plays an essential role in speech and mastication. Bony landmarks of the TMJ  Mandibular (glenoid) fossa  Articular eminence of the temporal bone  Mandibular condyle 8 Bones of the TMJ-mandibular (glenoid)  fossa Depression in temporal bone of skull in which mandible sits  Covered with layer of cartilage which allows smooth movement  Dense cortical bony surface of temporal bone, but thin at roof  Posterior to articular eminence 9 Bones of the TMJ-articular eminence of the temporal bone  Front (anterior) of fossa  Gentle slope of bone  Covered with cartilage  Condyle moves forward over eminence of bone on wide mouth opening, side to side movement or jaw protrusion – translation. 10 Bones of the TMJ- mandibular condyle  Dense cortical bone covered with dense fibrous connective tissue with irregular cartilage like cells  This layer of cartilage allows for smooth motion within joint 11 12 Other components of the TMJ  Articular capsule  Synovial tissue  Articular disc  Ligaments 13 Articular Capsule  The capsule is a fibrous membrane that surrounds the joint and attaches to the articular eminence, the articular disc and the neck of the mandibular condyle. 14 Synovial tissue  is connective tissue that lines the inside of the joint capsule. 15 Articular disc  This is a fibrous extension of the capsule that runs between the two articular surfaces of the temporomandibular joint.  It is biconcave in shape with the condyle sitting in the depression of the disc.  The disc articulates with the mandibular fossa of the temporal bone above and the condyle of the mandible below. 16 17 Ligaments  The ligaments give passive stability to the TMJ.  The temporomandibular ligament is the thickened lateral portion of the capsule, and it has two parts, an outer oblique portion and an inner horizontal portion.  The stylomandibular ligament runs from the styloid process to the angle of the mandible.  The sphenomandibular ligament runs from spine of the sphenoid bone to the lingula of the mandible. 18 19 Functions of ligaments  Accessory ligaments may limit border movements of the mandible  Fibrous capsule and TMJ ligaments may limit extreme lateral movements in wide opening of mandible 20 Movement of the mandible 21 Movement of the mandible  The mandible moves in a variety of ways:  Depression and elevation (up and down)  Lateral deviation (side to side)  Protrusion and retrusion (backwards and forwards) 22 23 Movements of the mandible  Initially on opening, the condyle rotates within the glenoid fossa  For rotational movement:  Horizontal axis of rotation (hinge axis)  Frontal (vertical) axis of rotation  Sagittal axis of rotation 24 Horizontal axis of rotation 25 Frontal axis of Sagittal axis of rotation rotation 26 27 The TMJ during opening 28 29  Temporomandibular Joint (TMJ) Anatomy and Disc Displ acement Animation - YouTube 30 Disorders of the TMJ  Today, researchers generally agree that temporomandibular disorders fall into three main categories:  Myofascial pain, the most common form of TMD, which is discomfort or pain in the muscles that control jaw function and the neck and shoulder muscles. Internal derangement of the joint, meaning a dislocated jaw or displaced disc, or injury to the condyle Degenerative joint disease, such as osteoarthritis or rheumatoid arthritis in the jaw joint  A person may have one or more of these conditions at the same time. 31 Symptoms of TMJ disorders  Headaches (often mimicking  Jaws that "get stuck," lock or migraines), earaches, and pain go out and pressure behind the eyes Jaws that "get stuck," lock or go out Tenderness of the jaw muscles Tenderness of the jaw muscles  A clicking or popping sound A sudden change in the way the upper and lower teeth fit together when you open or close Limited your opening -Atrismus sudden change in the way mouth the upper and lower teeth fit together  Pain brought on by yawning, opening the mouth widely or  Limited opening - trismus chewing 32 Treatment for TMJ disorders  Exercises  Soft diet  Heat  GDP/ oral surgeon - Jaws that "get stuck," lock or go out biteguard/splint Tenderness of the jaw muscles  Medication – pain relief, muscle A sudden change in the way the upper and lower teeth fit together relaxants Limited opening -A trismus sudden change in the way the upper and lower teeth fit  Botox together  Surgery - arthroscopy & arthrocentesis 33 - joint surgery 34 Dislocated Jaw 1. Pain in the face or jaw, located in front of the ear or on the affected side, that gets worse with movement. 2. Bite that feels "off" or crooked. 3. Problems talking. 4. Inability to close the mouth. 5. Drooling because of inability to close the mouth. 6. Locked jaw or jaw that protrudes forward. 35 36 37 X-Ray showing a Bilateral Dislocation of the Mandible. Notice how open the patient’s mouth is. 38 Jaw Relocation  After wrapping their fingers with gauze, doctors or dentists place their thumbs inside the mouth on the lower back teeth.  They place their other fingers around the bottom of the lower jaw.  They press down on the back teeth and push the chin up until the jaw joints return to their normal location. 39 40  Reducing the Dislocated Jaw - YouTube 41 Trismus  Trismus occurs when a person is unable to open their mouth more than 35 millimeters (mm).  It can occur as a result of trauma to the jaw, oral surgery, infection, cancer, or radiation treatment for cancers of the head and throat.  Often occurs after a long dental appointment or ID block local analgesia. 42 43 44 Treatment  Stretching exercises  Soft diet  Time…especially if temporary. 45 Trismus  (PDF) Management of trismus following radiation thera py by cost-effective approach (researchgate.net)  Trismus | HSTalks 46 Useful links  Temporomandibular joint & muscles of mastication – YouTub e  https://youtu.be/SCS4MiHJ5Xw  Temporomandibular Joint (TMJ) Anatomy (3D Anatomy Tutor ial) – YouTube  Temporomandibular Joint (TMJ) Anatomy and Disc Displace ment Animation – YouTube  Temporomandibular joint & muscles of mastication – YouTub e  Home - Mr Luke Cascarini 47 The End!