TMD Flashcards
What are the different names for TMJ dysfunction?
Temporomandibular dysfunction (TMD)
Myofascial pain dysfunction
Pain dysfunction syndrome
Facial arthromyalgia
Costen’s syndrome
What is the origin and insertion of masseter muscle?
Origin- zygomatic arch/zygomatic
Insertion- lateral angle of mandible
What is the origin an insertion of temporalis?
Origin- temporal fossa/fascia
Insertion- Coronoid process/ramus
What is the origin an insertion of medial pterygoid?
Origin- medial surface of lateral pterygoid plate
Insertion- medial angle of mandible
What is the origin an insertion of lateral pterygoid?
Origin- base of skull/lateral surface of lateral pterygoid plate
Insertion-pterygoid fovea/capsule of TMJ (and disc)
What are the suprahyoid muscles? (accessory MoM- slightly involved in opening)
Digastric
Mylohyoid
Geniohyoid
Stylohyoid
What are the infrahyoid muscle? (acc. MoM)
Thyrohyoid
Sternohyoid
Omohyoid
Sternothyroid
What nerve supplies the EAM, how does this relate to TMJ?
Auriculotemporal nerve- some times TMD can present as ear pain
What are the anatomical features of the TMJ?
Mastoid process/EAM behind
2 joint cavities- upper and lower
Anterior band of disc is not innervated (posterior part and bilaminar zone is- pain on compression)
What are the causes of TMD?
Degenerative diseases- OA (localised)/RA (generalised)
Myofascial pain
Disc displacement- slips out of place
Chronic recurrent dislocation- tends to lock open (joint is stuck in front of articular eminence)
Ankylosis- condyle is fused to base of skull (mostly pseudo- genetics)
Hyperplasia- one condyle grows more (facial asymmetry- require surgery)
Neoplasia- tumours (related to bone and cartilage- RARE)
Infection of joint- incredible rare can result in ankylosis
What are the types of disc displacement?
Anterior with reduction (goes back into place)
Anterior without reduction (gets stuck in front of condyle)
How is chronic recurrent dislocation of TMJ treated?
Thumbs in buccal sulcus, push down and backwards slowly
-> Muscle relaxants may be required
Which elements can be involved in the pathogenesis of TMD?
Inflammation of muscles of mastication or TMJ secondary to parafunctional habits
Trauma, either directly to the joint or indirectly e.g. sustained opening during dental treatment
Stress
Psychogenic
Occlusal abnormalities - no evidence to support this, although a restoration that is significantly “high” may cause muscle pain due to posturing
What would you want to find out when determining HPC when assessing for TMD?
Location, nature, duration, exacerbating / relieving factors, severity, frequency, time of occurrence
(in the morning – bruxism; during the day – habits)
->Associated pain elsewhere – neck, shoulders
What EO checks should be completed when examining for TMD?
Muscles of mastication
Joints
-> Clicks – early/late
-> Crepitus- crunching noise indicating arthritis/degeneration
Jaw movements- measure max opening with willis bite gauge
Facial asymmetry
How are lateral/medial pterygoids checked in EO exam?
Medial pterygoid exam- check in lingual surface, pressing medial angle of mandible
Lateral pterygoid- not a useful examination
-> Would need to palpate behind tuborosity
Which IO checks should be carried out when examining for TMD?
Signs of parafunctional habits
-> Cheek biting (morsicatio buccarum)
-> Linea alba- white lines on cheek
-> Tongue scalloping- wavy appearance due to imprint of lingual surfaces of teeth
Occlusal non-carious tooth surface loss- attrition (seen in grinding- not clenching)
Which special investigations may be utilised in TMD examination? (not required unless pathology is expected)
OPT- excludes dental pathology
CT / Cone-beam CT- if pathology of jaw joint
MRI- if disc is out of place
Transcranial view (TMJ view)
Nuclear imaging (Technetium-99)
Arthrography (dye into capsule)
Ultrasound- good for checking if displacement but not reduction