Exam 2 Flashcards
The position of the TM ligament is designed to limit what?
the pure hinge axis rotational movement of the mandible
The full length of the TM ligament occurs at what distance of opening? Measured between incisal edges of the max and mand incisors
15-20mm of opening
The TM ligament has a pivot point at 15-20mm of opening at which the movement of the mand commences, this is classified as?
Translation
Although the POSTERIOR border of the articular disc is THICKER than the anterior border, most of the mandible movement occurs where?
In both the INTERMEDIATE zone (which is the thinnest) and the ANTERIOR region
5 characteristics of retrodiscal tissue of the TMJ
- Elastic
- Highly innervated
- Highly Vascular
- “Loading” can be painful
- Trauma can cause inflammation
In class 1 occlusion, what 2 groups of teeth have an important relationship.
- First molars
2. Canines
In maximum intercuspation, there must be an ______ _____ of the maxillary over mandibular teeth, occlusal forces should be exerted down the LONG AXIS of ______ teeth. There must be simultaneous _____ of ALL max and mand teeth. Posterior teeth should _______ over the anterior teeth. Anterior teeth should display “____” occlusal contact or _____ occlusal contact with each other. There should be ______ occlusal contacts on ALL teeth that adequately distributes forces.
Adequate overlap Posterior Contact Dominate Passive Minimal Multiple
2 main functions of the Temporalis
- Retrude/retract mandible (helps seat the condyles into the mandibular fossa)
- positions mandible to obtain CR
Main function of the medial pterygoid
Produce MEDIOTRUSIVE movements
Main function and a parafunction of the lateral pterygoid superior head muscle.
Function - Closing/elevating mandible
Parafunction - spasms due to occl dysfunction
Actions during normal closure of the mandible. The condyle will be located primarily within the ____ ___. The ____ fibers of the temporalis muscle will CONTRACT. The ____ pterygoid and _______ muscle will CONTRACT. The _____ and _____ relax. The posterior neck musculature will minimally _____ to hold cranium in place.
Glenoid fossa ANTERIOR Medial Masseter Suprahyoids and Intrahyoids Contact
8 factors that influence arch alignment of the teeth
Normal functional activities like chewing/speaking will NOT negatively affect alignment of the teeth
- Max/mand ARCH SIZE
- Occlusal CONTACTING relationships
- MUSCULATURE (facial lingual equilibrium)
- PARAFUNCTIONAL ACTIVITY
- MISSING TEETH
- FRACTURED CUSPS
- SEVERELY CARIOUS TEETH
- ROTATED OR ECTOPICALLY -positioned teeth
Teeth primarily contact their _____ in the opposing arch. Which teeth only have ONE contact in the opposing arch?
Namesake
- Max 3rd molars
- Mand. central incisors
Occlusal forces placed on posterior teeth are intended to go which directions?
Go up and down the long axes of the root.
Preferred name for the cusp-fossa relationship of posterior teeth?
Centric (this is for max lingual cusps and mand facial cusps)
Occlusion concepts - The student should envision the ____ ____ and max intercuspation positions as COINCIDENT when attempting to describe the ideal tooth position. On each individual tooth there are ____ locations of where occlusal contacts should be placed when the mand has completely closed against the maxilla. Tooth contacts should be precise, _____ and ____ lasting. The arches should receive the contact and _____ or disengage from each other when movement commences. Many contacts are ______-_____, in that there are strategically BETTER locations in each collective arch that determines the most ____ location of stationary occlusal contact.
Centric Relation Precise Minimal Short Release Anatomically-driven Optimal
Cusp-fossa/marginal ridge location for NON-CENTRIC cusps on MANDIBULAR posterior teeth (in max-intercuspation) is located where?
ML cusp of mand 2nd molar = lingual embrasure between the max 1st and 2nd molars
Cusp-fossa/marginal ridge location for NON-CENTRIC cusps on MAXILLARY posterior teeth (in max-intercuspation) is located where?
DF cusp of the max 1st molar = DF groove on the mand 1st molar or the facial embrasure between mand molars
What pathway is located at a 45 degree angle between protrusion and working movements?
Lateral Protrusive (excursion) (Example - line travels from a 1st molar central fossa in a diagonal direction towards/over the MF cusp and through the MF line angle)
Right sided lateral movement of the mandible, but the tooth in question is on the left side then this is an example of what?
Left non working movement
Non-working cusps/pathways example: DL cusp mand. 1st molar as pt undergoes movement of the mandible to right side, what will this DL cusp travel from?
Travels from lingual sulcus in diagonal direction towards anterior portion of the palate (away from the maxillary posterior teeth.
The base of the bold black arrow in the CF of mand left 1st molar pointing through lingual groove towards the tongue. This designates what type of movement?
Left working (laterotrusive)
The base of the bold black arrow in the CF of maxillary left 1st molar, the arrow in pointing straight towards the facial surface. This designates what type of movement?
Non-functional
What border movement in the sagittal plane is most anterior?
Maximum protrusion
