TMJ Lecture 1 Flashcards
What is TMJ?
Refers to temporomandibular joint
What is TMD?
Disorders of the joint
What is CMD?
Craniomandibular disorder
- Broader definition
Where does TMD rank in terms of chronic pain world wide? (1st?, 5th?, 10th?, etc…)
3rd
Do women or men more commonly develop TMD?
Women (3.3:1)
When does TMD peak?
Between 20 - 40 years old
When does TMJ disc displacement/ internal derrangements peak?
30 years of age
When does arthridies of the TMJ peak?
50 years of age
What are the 3 skeletal components of the TMJ?
- Maxilla
- Temporal bone
- Mandible
(condyle forms a bony joint partner)
What are the shapes of the mandibular joint surfaces?
- Convex anterior-posteriorly, and medial-laterally
Which pole of the mandible is most prominent from an anterior view?
Medial
What structure of the temporal bone does the mandible slide over during mouth opening?
The articular eminence
Where does the mandibular bone rest with the mouth shut?
- On the mandibular fossa
Which portion of the articular disc is thinnest?
The middle portion between the anterior and posterior aspects.
What structure controls the movement of the disc from the posterior aspect?
The retrodiscal laminae
What structure on the anterior aspect of the disc helps to control movement?
The lateral pterygoid muscle.
What structural effect does the disc have on the joint space?
- Divides it into an upper and lower portion
What are the 4 passive structures that stabilize the TMJ?
- Joint capsule
- Lateral TM ligament
- Stylomandibular ligament
- Sphenomandibular ligament
What are the 2 lateral ligaments of the TMJ, and what is their function?
- Lateral temporomandibular ligament
- Stylomandibular ligament
- Control end-range positioning
What structures are closely associated with the TMJ passive structures?
- Nerves and blood vessels
- Maxillary artery
- Lingual nerve
What ligament is found on the medial side of the TMJ?
- Sphenomandibular ligament
What areas receive sensory innervation from C2, C3, and C4?
C2: Back half of the head
C3: Lower posterior portion of head into the shoulder
C4: Shoulder, anterior and posterior thorax
What nerve innervates the face?
- The trigeminal nerve
Which trigeminal nerves are purely sensory, and what portions of the face do they innervate?
- Opthalmic: Forehead to eyes
- Maxillary: Maxilla
Which trigeminal nerve is both sensory and motor? What does it innervate?
- Mandibular nerve
- Sensory to mouth and jaw
- Motor control of muscles of mastication
Where does the afferent input of the trigeminal nerve originate before it enters the spinal tract?
At the level of the pons
What other pain fibers also synapse on the spinal nucleus of the the trigeminal nerve?
C1 - C4
What 4 muscles close the jaw?
- Temporalis
- Masseter
- Medial pterygoid
- Portions of lateral pterygoid
What 4 muscles open the jaw?
- Diagastric
- Mylohyoid
- Genohyoid
- Omohyoid
What 3 muscles assist gravity in opening the mouth?
- Infrahyoid
- Suprahyoid
- Inferior head of lateral pterygoid
Which portion of the lateral pterygoid may be active in pulling the disc forward in mouth opening?
- Superior head of lateral pterygoid.
What 3 muscles are concentrically active during mouth closing?
- Temporalis
- Masseter
- Medial pterygoid
What muscle is eccentrically active during mouth closing?
- Superior head of lateral pterygoid
What 5 muscles are innervated by the mandibular branch of the trigeminal nerve?
- Masseter
- Temporalis
- Medial Pterygoid
- Inferior Lateral Pterygoid
- Superior Lateral Pterygoid
What is the bilateral, and unilateral action of the inferior lateral pterygoid?
- Bilateral: Protrusion
- Unilateral: Lateral deviation to contralateral side
What amount of ROM occurs in the early and late phases of TMJ opening?
Early: 35 - 50 %
Late: 50 - 65 %
What amount of translation of the mandible on the temporal bone occurs in the early and late phases of opening?
20 - 25 mm in both
Where does rotation occur in the joint space, and during which phase of opening?
- Rotation in the inferior joint space during the early phase of mouth opening
Where does anterior translation occur in the joint space, and during which phase of opening?
- Translation of the mandible and the disc on the temporal bone occurs in the superior joint space
What structure’s tension increases during the early phase?
- Oblique portion of lateral TM ligament
What structure’s tension increases during the late phase of mouth opening?
- Superior retrodiscal lamina
What are the means and lower limits of normal of mouth openingfor men and women of the TMJ?
Female: 53/ 38
Male: 58/ 42
When does the mandible slip over the articular eminence?
At 3/4ths opening
When does rotation occur during mouth closing, and when does translation occur during mouth closing?
Early: Translation
Late: Posterior rotation
What structure pulls the disc back into place during TMJ closing?
- The retrodiscal lamina
What structure controls movement of the disc during mouth closing? During which phase does this occur?
- The superior lateral pterygoid controls the movement of the disc during the early phase of TMJ closing
What is the arthrokinematic motion of the TMJ during protrusion?
- Bilateral anterior translation of the mandible in the superior joint space
How is protrusion measured?
Have teeth slightly separated, protrude the jaw, and measure with a ruler
What are the arthrokinematic motions of lateral glides of the TMJ?
- Ipsilateral rotation around the condyle of the mandible
- Contralateral anterior translation of the condyle in the anterior joint space
What is the average motion and lower limit of normal of lateral glides of the TMJ?
10mm/5mm
What does regional interdependence require the practitioner to consider when evaluating the TMJ?
- Upper and lower C-spine
- Upper T-spine
- Potentially beyond
What muscles have increased passive tension due to forward head posture?
- Suprahyoid
- Infrahyoid
- Potential shortened SCM
In what direction does a forward head posture pull the mandible? What functional effect does this have?
- Inferiorly
- Posteriorly
- Occlusal pattern changes
According to a study by Nicolakis, what were the 3 effects of c-spine position on the TMJ?
- Masseter and Temporalis muscle EMG changes
- Mandibular movement changes
- Rest position changes
What are the 3 classic signs/ symptoms of TMD?
- TMJ pain and/or myofascial pain in the craniomandibulocervical area
- TMJ sounds
- Restriction, deviation or defleciton of the jaw during opening/ closing
What are 6 variable symptoms associated with TMD?
- Neck pain
- Facial pain
- Ear pain
- Tinnitus
- Dizziness
- Headaches
What percentage of patients with TMD have joint sounds?
29 % - 66 %
What percentage of patients were found to have symptoms by Gesch?
49.9 %
How can a patient’s body chart be modified with TMD like symptoms?
- More focused on the cranial region
Should TMD always be treated conservatively initially?
- Yes, if there are no contraindications
What are the 3 elements of the biopsychosocial model of TMD treatment?
- Dental
- Psychosocial
- Musculoskeletal
In what type of patients is the psychosocial element especially influential?
Patients with chronic conditions
What is the dental element of TMD dysfunction?
- Teeth malalignment
- Missing teeth
- Extra teeth
What is the treatment of dental TMD?
- Dental surgery
- Alignment correction
What is evidence supporting a relationship between TMD and occlusion patterns?
- Present, but inconclusive as to which type
What is major contributing factor of TMD symptoms?
- Bruxism
What is bruxism?
- Involuntary, non-functional grinding or clenching of teeth
Which type of bruxism is more storngly associated with TMD?
- Daytime (vs. nighttime)
How successful has Flat Plane occlusal appliances proven to be in RTCs?
Same results as placebo.
May need to find the categorization of people on whom it works.
Intake of what type of beverage can lead to bruxism?
- Caffeinated beverages
What factors make up the psychosocial component of TMD?
- Behaviors/ habits
- Emotional and stress influences
What parafunctional oral behaviors should be assessed during the patients history for influence on TMD?
- Chewing pencil
- Smoking cigars
- Chewing gum
- Tongue thrusting
What 3 mental factors can influence TMD?
- Depression
- Anxiety
- Stress
What type of approach is recommended for TMD in addition to (or in replacement of) conservative therapy?
- Cognitive-behavioral approach
CBT has been proven to be successful in improving: pain, function, and ____
Beliefs and behaviors
What 3 health professionals working together result in the best outcomes for TMD?
- Dentist
- Psychologist
- Physical Therapist
What are the 7 classifications of MS conditions in TMD?
- Capsulitis/ Synovitis
- Capsular Fibrosis
- Disorders of Muscles of Mastication
- Hypermobiltiy
- Anterior disc displacement with reduction
- Anterior disc displacement without reduction
- Osteoarthritis
Which classification is the most common?
- Muscle disorders
What should be considered when classifying a patient?
Categories are not mutually exclusive. The patient commonly falls into multiple
What is meant by anterior displacement “with reduction”?
- Disc reduces (pops) on either opening or closing or both
