s10 - TMJ Disorders Flashcards
What type of joint is the temporomandibular joint (TMJ)?
A diarthrodial synovial joint.
What are the two main compartments of the TMJ?
The superior and inferior compartments.
What type of motion occurs in the inferior compartment of the TMJ?
Hinge (ginglymoid) motion.
What type of motion occurs in the superior compartment of the TMJ?
Translatory (arthrodial) movement.
What is the function of synovial fluid in the TMJ?
Lubrication and nutrition of avascular joint structures.
What are the main bony components of the TMJ?
The mandibular condyle and temporal bone (glenoid fossa and articular eminence).
What type of cartilage covers the TMJ surfaces?
Dense fibrous connective tissue (not hyaline cartilage).
What are the three regions of the articular disc?
Anterior band, intermediate zone, and posterior band.
What structure stabilizes the articular disc to the condyle during function?
The superior head of the lateral pterygoid muscle.
What is the role of the retrodiskal tissue in TMJ function?
It provides vascular supply and elasticity, limiting excessive anterior translation of the disc.
What are the two primary types of TMJ movement?
Rotation and translation.
Which part of the TMJ is responsible for rotational movement?
The inferior joint compartment (between condyle and disc).
Which part of the TMJ is responsible for translatory movement?
The superior joint compartment (between disc and temporal bone).
How much pure hinge movement is possible in normal mandibular function?
About 2.5 cm at the incisal edges.
What is the maximum forward translation movement of the condyle?
Approximately 1.5 cm.
What structure prevents excessive posterior movement of the condyle?
The inner horizontal portion of the temporomandibular ligament.
What happens to the condyle-disc complex during mandibular opening?
It rotates first, then translates forward along the articular eminence.
How does lateral excursion of the mandible occur?
One condyle rotates while the other translates forward (Bennett movement).
What are the main arteries supplying the TMJ?
Superficial temporal and maxillary arteries.
Which artery supplies the anterior region of the TMJ?
The masseteric artery.
What is the function of the venous plexus in the retrodiskal tissue?
It fills and empties during jaw movements to maintain joint stability.
What nerve primarily innervates the TMJ?
The auriculotemporal nerve.
Which additional nerves contribute to TMJ innervation?
Masseteric nerve and posterior deep temporal nerve.
What type of nerve fibers are most common in the TMJ?
Vasomotor and vasosensory fibers involved in pain and synovial fluid production.
What is the function of the collateral (diskal) ligaments?
They attach the disc to the condyle and restrict excessive movement.
What is the primary role of the capsular ligament?
It encloses the TMJ and retains synovial fluid.
What is the function of the outer oblique portion of the temporomandibular ligament?
It limits excessive downward movement of the condyle.
What is the function of the inner horizontal portion of the temporomandibular ligament?
It restricts posterior movement of the condyle to protect the retrodiskal tissue.
What is the function of the sphenomandibular ligament?
It acts as a pivot point for mandibular movements.
What is the function of the stylomandibular ligament?
It limits excessive mandibular protrusion.
What type of tissue composes the articular disc?
Dense fibrous connective tissue.
Why is the articular disc avascular and non-innervated?
To withstand high mechanical stress without pain.
What are the three main bands of the disc?
Anterior band, intermediate zone, and posterior band.
What structure holds the articular disc in place?
The capsular ligament and collateral ligaments.
What are the two main components of the retrodiscal tissue?
The superior and inferior retrodiscal lamina.
What is the function of the superior retrodiscal lamina?
It contains elastic fibers that retract the disc posteriorly.
What is the function of the inferior retrodiscal lamina?
It prevents excessive forward displacement of the disc.
How are TMJ disorders generally classified?
As nonarticular (muscle-related) or articular (joint-related).
What are common examples of nonarticular TMJ disorders?
Myofascial pain dysfunction syndrome and occlusal trauma.
What are common examples of articular TMJ disorders?
Internal derangements, degenerative joint disease, and ankylosis.
What are the two main types of disc displacement?
Disc displacement with reduction and without reduction.
What are the primary symptoms of TMJ internal derangement?
Joint pain, clicking, locking, and limited jaw movement.
What are the three main classifications of TMJ hypomobility?
Trismus, pseudoankylosis, and true ankylosis.
What are common odontogenic causes of trismus?
Myofascial pain, malocclusion, and erupting teeth.
What are common infectious causes of trismus?
Pterygomandibular and lateral pharyngeal infections.
What are common traumatic causes of trismus?
Mandibular fractures and muscle contusions.
What are common psychological causes of trismus?
Hysteric trismus.
What are common pharmacological causes of trismus?
Phenothiazine-induced muscle rigidity.
What are common neurological causes of trismus?
Tetanus and neurological disorders affecting mastication.
What is the primary imaging modality for assessing TMJ ankylosis?
CT scan for detailed anatomical evaluation.
What are the two main types of TMJ hypermobility?
Subluxation and dislocation.
How is subluxation different from dislocation?
Subluxation is self-reducing, while dislocation requires external reduction.
What are common intrinsic causes of TMJ hypermobility?
Yawning, vomiting, wide biting, and seizure disorders.
What are common extrinsic causes of TMJ hypermobility?
Trauma, intubation, endoscopy, and dental extractions.
What are connective tissue disorders associated with TMJ hypermobility?
Hypermobility syndromes (e.g., Ehlers-Danlos syndrome).
What is the initial management of a TMJ dislocation?
Manual reduction before muscle spasm develops.
What are general non-surgical management options for TMJ hypermobility?
Diet modification, short dental appointments, and bite blocks.
Why should TMJ dislocation be reduced quickly?
To prevent muscle spasm and difficulty in reduction.
What is the role of sclerosing agents in chronic dislocation?
They induce fibrosis but may cause joint damage.
What surgical techniques can be used for severe TMJ dislocation?
Plication procedures, zygomatic arch down-fracture, and tendon sacrifice.
How is botulinum toxin (Botox) used in TMJ hypermobility?
It relaxes overactive muscles to prevent recurrent dislocation.
What is the long-term concern with untreated TMJ hypermobility?
It may lead to joint degeneration and internal derangement
What is the most common nonarticular TMJ disorder?
Myofascial pain dysfunction syndrome (MPDS).
What is the occlusal trauma theory for MPDS?
It suggests that malocclusion causes abnormal muscle function leading to pain.
What is the psychogenic theory for MPDS?
It suggests that stress and psychological factors contribute to TMJ pain.
What are the primary signs and symptoms of MPDS?
Referred pain, limited range of motion, muscle tenderness.
What are common trigger points in TMJ myofascial pain?
Masseter, temporalis, and lateral pterygoid muscles.
What is the definition of internal derangement of the TMJ?
An abnormal positional and functional relationship between the disc and articulating surfaces.
What is the most common direction of TMJ disc displacement?
Anterior displacement.
What are the main etiological factors for TMJ disc displacement?
Trauma, functional overloading, joint laxity, and degenerative joint disease.
What is the role of the lateral pterygoid muscle in TMJ disc displacement?
Hyperactivity may contribute to anterior disc displacement.
What are the two types of disc displacement?
With reduction and without reduction.
What are the clinical signs of disc displacement with reduction?
Joint clicking, pain, and deviation during mouth opening.
What are the clinical signs of disc displacement without reduction?
Limited mouth opening (closed lock) and restricted lateral movement.
Why is pain a major complaint in TMJ internal derangement?
Due to inflammation and strain on retrodiscal tissues.
What systemic conditions can contribute to TMJ disc displacement?
Rheumatoid arthritis and connective tissue disorders.
What are the primary imaging modalities used to diagnose TMJ internal derangement?
MRI (for disc position) and CT scan (for bony changes).
What is functional overloading in TMJ disorders?
Excessive stress on the TMJ due to parafunctional habits like bruxism and clenching.
What are the two main types of bruxism?
Awake bruxism and sleep bruxism.
What are the common triggers for awake bruxism?
Stress, concentration, and emotional states.
Why is sleep bruxism harder to manage than awake bruxism?
It occurs subconsciously during sleep and cannot be stopped voluntarily.
What are the key clinical signs of bruxism?
Tooth wear, jaw pain, morning headaches, and enlarged jaw muscles.
How does sleep bruxism differ from awake bruxism in terms of treatment?
Sleep bruxism often requires occlusal splints, while awake bruxism can be managed with behavior modification.
What is the primary purpose of a night guard in bruxism treatment?
To protect teeth from wear and reduce TMJ strain.
What systemic condition is often associated with sleep bruxism?
Obstructive sleep apnea.
What are the two broad categories of TMJ internal derangement treatment?
Extrajoint therapy and intrajoint therapy.
What are common forms of extrajoint therapy?
Splint therapy, therapeutic manipulation, physical therapy, and pharmacotherapy.
What is the goal of splint therapy in TMJ disorders?
To stabilize the bite and reduce joint stress.
What is the role of physical therapy in TMJ treatment?
It helps to reduce pain and improve jaw function.
What is the most commonly used pharmacotherapy for TMJ pain?
NSAIDs, muscle relaxants, and corticosteroids.
What are two primary types of intrajoint therapy?
Arthroscopy and arthrocentesis.
How does arthroscopy help in TMJ disorders?
It allows visualization and treatment of joint pathology.
What is arthrocentesis, and how does it work?
A minimally invasive procedure using sterile fluid to flush the joint and reduce inflammation.
What is the main advantage of arthrocentesis over open surgery?
It is less invasive, has a shorter recovery time, and avoids major surgical risks.
What is the primary indication for TMJ surgical treatment?
Severe pain and dysfunction that do not respond to conservative treatments.
What dietary modifications are recommended for TMJ disorders?
Soft diet, avoiding hard or chewy foods, and eliminating gum chewing.
How do NSAIDs help in TMJ pain management?
They reduce inflammation and relieve pain.
What is the role of muscle relaxants in TMJ disorders?
They reduce muscle tension and spasms.
What are the main goals of occlusal appliance therapy?
To redistribute occlusal forces and reduce joint strain.
What is the purpose of jaw exercises in TMJ therapy?
To improve mobility and strengthen jaw muscles.
What is transcutaneous electrical nerve stimulation (TENS) used for in TMJ therapy?
To relieve pain by stimulating nerve activity.
How does ultrasound therapy help TMJ disorders?
It provides deep tissue heating to improve blood circulation and reduce pain.
What is the primary role of heat therapy in TMJ treatment?
To relax muscles and increase blood flow.
How does cryotherapy (cold therapy) help in TMJ disorders?
It reduces inflammation and muscle soreness.
What is the purpose of trigger point injections in TMJ therapy?
To relieve pain from muscle spasms and hyperirritable trigger points.
What is the main difference between passive and active jaw exercises?
Passive exercises involve assisted movement, while active exercises are performed by the patient.
What is the most effective occlusal splint type for TMJ disorders?
A full-arch hard acrylic splint.
What is the main mechanism of botulinum toxin (Botox) in TMJ treatment?
It blocks neuromuscular transmission to relax overactive muscles.
What is arthrocentesis, and why is it considered a contemporary treatment?
A minimally invasive lavage technique to reduce joint inflammation.
What is the purpose of intra-articular drug delivery in TMJ disorders?
To provide prolonged drug action within the joint space.
