Fixed Practical Flashcards
What is the importance of identifying condylar movements?
Condylar movements impact the direction of mandibular movement and occlusion.
How does occlusion relate to TMJ anatomy?
TMJ anatomy influences mandibular movements and tooth morphology.
What is the significance of centric occlusion in occlusion analysis?
Centric occlusion provides a reference point for analyzing occlusal relationships.
Why is understanding occlusal schemes in static and dynamic occlusion important?
It helps in diagnosing occlusal prematurities and designing treatment plans.
What is the benefit of the cusp-fossa relationship in occlusion?
It helps in distributing occlusal forces efficiently, improving stability and function.
What is the role of the TMJ in mandibular movements?
TMJ facilitates rotation and translation movements of the mandible.
What are the key anatomical structures of the TMJ?
The condyle, glenoid fossa, and articular disc are key components.
What type of articulation is the TMJ?
TMJ is a ginglymoarthrodial joint, allowing both rotational and translational movements.
What is the condyle and why is it important
The condyle is a rounded projection involved in mandibular movements.
What is the function of the articular disc in the TMJ?
The articular disc cushions the joint and aids in smooth mandibular movements.
Where is the glenoid fossa located?
The glenoid fossa is located in the temporal bone, housing the condyle during mandibular movements.
How does the TMJ allow both rotational and translational movements?
The TMJ’s complex structure allows a combination of hinge and sliding actions.
What are the main muscles of mastication involved in occlusion?
The masseter, temporalis, lateral pterygoid, and medial pterygoid muscles.
What is the role of the TMJ capsule?
The TMJ capsule surrounds the joint, providing stability and containing synovial fluid.
What are the main ligaments associated with the TMJ?
The temporomandibular, sphenomandibular, and stylomandibular ligaments stabilize the joint.
Define centric relation.
Centric relation is a bone-to-bone relation where the condyles are in their most posterior and superior position.
What is centric occlusion?
Centric occlusion is the tooth-to-tooth relationship when the mandible is in centric relation.
How does centric occlusion differ from maximum intercuspation?
Maximum intercuspation is the complete interdigitation of teeth, which may or may not coincide with centric occlusion.
What is the importance of centric relation in occlusal analysis?
Centric relation provides a repeatable and stable position for diagnostic and restorative procedures.
What happens if centric relation and maximum intercuspation do not coincide?
This creates an eccentric position, potentially leading to occlusal instability.
What is the most recent definition of centric relation?
Centric relation is the maxillo-mandibular relationship where the condyles articulate with the thinnest avascular portion of their discs.
What are the two main types of condylar movements?
Rotation and translation.
What occurs during rotational movement of the condyle?
The condyle rotates in place, enabling the mandible to open and close.
What occurs during translation of the condyle?
The condyle moves forward and downward along the glenoid fossa during translation.
How do rotation and translation work together in mandibular movements?
They allow the mandible to move in various directions during function.
What is the sequence of movements during mandibular opening?
The condyle first rotates, then translates as the mandible fully opens.
What role does translation play in mandibular opening?
Translation moves the condyle out of centricity, increasing the range of opening.
What is protrusive movement of the mandible?
Protrusive movement involves the condyles moving forward and downward as the mandible moves anteriorly.
How does protrusive movement affect posterior teeth?
Posterior teeth disclude during protrusive movement, preventing occlusal interferences.
What occurs during lateral excursion on the working side?
The working side condyle rotates with slight downward and backward movement.
What is the function of the rotating condyle during lateral excursions?
It allows lateral movement while stabilizing the working side.
What is the non-working side during lateral excursions?
It is the side opposite to where the mandible moves, with the condyle translating medially and forward.
What is the orbiting condyle’s role in non-working side movement?
It moves medially and forward, contributing to mandibular stability during lateral movements.
What is Bennett movement?
Bennett movement is the lateral shift of the working condyle during lateral excursions.
What determines the extent of Bennett movement?
The medial wall of the glenoid fossa on the non-working side determines the extent of lateral shift.
What are posterior determinants of occlusion?
Posterior determinants include TMJ anatomy and condylar movements that affect tooth morphology.
How does the articular eminence influence cusp height?
A steeper articular eminence allows for greater cusp height and steeper cusp angles.
What effect does the protruding condyle have on occlusal morphology?
The condyle’s downward and forward movement affects fossa depth and ridge direction.
How does the rotating condyle affect the working side during lateral excursions?
It allows the buccal cusps of molars to pass without contact, depending on the fossa’s steepness.
How does the orbiting condyle affect the non-working side during lateral excursions?
It moves medially and downwards, influencing cusp height and fossa depth.
What is the effect of the occlusal plane on mandibular movements?
A divergent occlusal plane allows for greater cusp height and steeper inclines.
How does the curve of Spee affect mandibular movements?
The curve of Spee influences cusp height based on its divergence from the condylar path.
How does the facial position of teeth influence occlusion?
Teeth positioned laterally or anteriorly affect the groove direction and cusp location.
What is the relationship between vertical and horizontal overlap of anterior teeth and posterior cusp height?
Greater vertical overlap increases posterior cusp height, while greater horizontal overlap decreases it.
What is the purpose of the occlusion of teeth?
To transmit masticatory forces along the long axes of teeth.
What is an overbite?
An overbite is the vertical overlap of the maxillary incisors over the mandibular incisors.
What is an overjet?
An overjet is the horizontal overlap of the maxillary incisors over the mandibular incisors.
How does occlusion relate to mastication forces?
Occlusion ensures forces are directed along the long axis of the teeth, preventing damage.
What is incisal guidance?
It is the inclination of the lingual surfaces of the upper anterior teeth that guides mandibular movements.
How does incisal guidance affect occlusion?
Incisal guidance influences posterior occlusal morphology by determining anterior tooth guidance during function.
What is Posselt’s envelope of motion?
It is a diagrammatic representation of mandibular border movements, including tooth contact and TMJ limits.
What role do teeth play in Posselt’s envelope of motion?
Tooth contact defines the upper border of Posselt’s envelope, with the TMJ and muscles guiding other movements.
What are stamp and shear cusps?
Stamp cusps engage in occlusal contact, while shear cusps pass closely to aid in cutting food.
What is an A contact in occlusion?
An A contact is between the upper buccal shear cusp and the lower buccal stamp cusp.
What is a B contact in occlusion?
A B contact occurs between the upper and lower stamp cusps.
What is a C contact in occlusion?
A C contact is between the upper lingual stamp cusp and the lower lingual shear cusp.
What are closure stoppers in occlusion?
Closure stoppers are contacts that stop the upward movement of the mandible during closure.
What are equalizers in occlusion?
Equalizers balance the closure forces by preventing torque on the teeth.
What is the unit of occlusion?
The unit of occlusion is a cusp in a fossa, with pathways for movement in working and non-working directions.
What is tripodization in occlusion?
Tripodization is the formation of three contact points between a cusp and a fossa, providing stability.
Why is the cusp-fossa relationship important in occlusion?
It ensures occlusal stability by distributing forces evenly across the teeth.
What is the cusp-ridge pattern in static occlusion?
It is when a stamp cusp fits into an opposing embrasure, forming a tooth-to-two-teeth contact.
What is the cusp-fossa pattern in static occlusion?
It is when a stamp cusp fits into a fossa, forming a tooth-to-one-tooth contact.
What is the advantage of the cusp-fossa pattern over cusp-ridge?
The cusp-fossa pattern provides more stability and reduces food impaction between teeth.
What is bilateral balanced occlusion?
Bilateral balanced occlusion involves all teeth contacting during centric and eccentric movements.
What is unilateral balanced occlusion?
In unilateral balanced occlusion, only the working side teeth contact during lateral movements.
What is long centric?
Long centric is a flat area between centric relation and maximum intercuspation without altering vertical dimension.
What is cuspid-protected occlusion?
Cuspid-protected occlusion involves posterior teeth protecting anterior teeth in centric, and canines guiding lateral movements.
What is organic occlusion?
Organic occlusion involves cuspid protection, cusp-fossa relationships, and simultaneous posterior contact in centric.
Why is bilateral balanced occlusion not recommended for natural teeth?
Bilateral balanced occlusion distributes harmful lateral forces across all teeth, which can damage natural teeth.
What is the role of canines in cuspid-protected occlusion?
Canines guide the mandible during lateral movements, protecting posterior teeth from lateral forces.
What is the significance of long centric?
Long centric allows freedom of movement without interferences between centric relation and maximum intercuspation.
What are the indications for occlusal adjustment?
Indications include trauma from occlusion, TMJ dysfunction, tooth mobility, and excessive wear.
Why is occlusal adjustment needed before restorative work?
It ensures the occlusion is stable and free from interferences before extensive restorations are placed.
What is the aim of occlusal adjustment?
To remove centric and eccentric prematurities to achieve maximum intercuspation of teeth in centric relation.
What is the first step in occlusal adjustment?
The first step is correcting protrusive interferences by removing contacts in the posterior teeth during mandibular movement.
How are non-working side interferences corrected?
Non-working side interferences are corrected by creating grooves to guide the opposing cusps during movement.
What is the final step in occlusal adjustment?
The final step is deepening the fossae to ensure a more stable centric relation closure.
