Exam I Review Flashcards
What does the Outer Oblique Portion (OOP) limit?
Limits normal rotational opening movements
What does the Inner Horizontal Portion(IHP) limit?
Limits posterior movement of condyle & disc
Centric Relation is:
a) Condylar postion…
b) Establishes the position of the what?
c) Articulation is on the what?
d) It is described as …
e) A position of the mandible where…
a) CONDYLAR position, & DOES NOT need any tooth contact to be obtained.
b) Establishes position of condyle in a SUPERIOR and ANTERIOR location w/ disc properly interposed between condyle & TEMPORAL bone.
c) Articulation on the THIN portion of the articular disc
d) Described as MOST STABLE position of the condyle
e) A position of mandible where the MUSCULATURE display MINIMAL TONUS
Maximum Intercuspation Clinical Conditions:
- ________ determines the occlusal position
- If central relation & maximum intercuspation do not coincide the patients will have a ___________
- Most patients have some degree of a slide from centric relation into ___________________ (it is approximately ___________ in length)
- Maximum Intercuspation is simultaneous contact of all teeth & is the ________ of the slide
- All occlusal forces should be concentrated ____________________________
- _____________ position is DYNAMIC in nature and will CHANGE throughout a patient’s life
- Teeth
- “Slide”
- Maximum intercuspation
- 1-2 mm
- “endpoint”
- Down the long axis of posterior teeth
- Maximum intercuspation
What is considered as the NORMAL functions/actions of the TEMPORALIS?
1) ELEVATE (closing) mandible in a superior direction to eventually contact maxillary teeth
2) RETRACTS or RETRUDES mandible
(Helps seat the condyles into mandibular fossa)
3) Positions mandible to obtain centric relation (CR)
* It is not normally involved w/ producing LATERAL movement of the mandible.
What is considered as parafunctional functions/actions of the TEMPORALIS?
1) Clenching of the teeth to occur when the muscle is overused
Regarding the Medial Pole of Condyle & Medial Pterygoid Muscle (3)
1) Relationship of the medial pole of condyle & medial pterygoid on one side establishes the MID-MOST POSITION of the MANDIBLE at CENTRIC RELATION.
2) Normal curve of occlusion is possible because the interaction of the medial pole of the condyle w/ the steep medial wall of the fossa PREVENTS mandibular POSTERIOR teeth from moving straight HORIZONTALLY toward the MIDLINE
3) As a result ideal patents, mandibular lateral translation (or direct lateral movement of mandible toward midline) is impossible from fully seated positions of condyle in fossa.
(Not mentioned in review)
What are the actions of the Superior Head of the LATERAL PTERYGOID MUSCLE?
1) Maintains a sustainable & consistent psotion of the articular disc (normal function)
2) It is PROGRESSIVELY active during “CLOSING” movement of mandible (normal function)
3) It FREQUENTLY displays SPASM as a result of some types of OCCLUSAL DYSFUNCTION
-spasm will result in articular disc being pulled anteriorly out of glenoid fossa
(Parafunctional activity)
4) Muscle works in concert w/ ACTION & INACTIVITY of the inferior head of the lateral pterygoid
5) Muscle of mastication is DEEP in PLACEMENT & is mostly covered by the medial pterygoid, clinician CAN palpate SOME portion of muscle
What are the actions of the MYLOHYOID MUSCLE?
1) Will SLIGHTLY DEPRESS the mandible
(open, doesn’t close)
2) ELEVATE the HYOID, the FLOOR of the ORAL CAVITY and the TONGUE
3) Very important during SPEAKING & SWALLOWING
Which actions occur during LATE MANDIBULAR OPENING MOVEMENT?
1) INFERIOR HEAD of the Lateral Pterygoid is at MAXIMUM POINT of contracture
- TM ligament, stylomandibular ligament, sphenomandibular ligament & capsular ligament “prevents” any further anterior movement of condyle.
2) CONDYLE has moved as FAR to the ANTERIOR as it CAN MOVE
- Now located @ inferior border of slope of articular eminence
3) Articular disc has ROTATED POSTERIORLY OVER the POSTERIOR PORTION of the HEAD of the CONDYLE
- Superior head of lateral pterygoid is maximum contracture, attempting to hold articular disc over the head of condyle.
4) SUPERIOR RETRODISCAL TISSUE are in MAXIMUM TAUTNESS (not inferior) & CAN’T further hold articular disc in position over the head of the condyle w/out either stretching or tearing.
- Posterior portion of collateral ligament is LACKING in tautness
- Anterior portion is TAUT
What is the directional length of the Anterior, Middle, & Posterior TEMPORALIS force vector?
-SUPERIOR
What is the directional length of the MASSETER force vector?
-SUPERIOR
What is the directional length of the MEDIAL PTERYGOID MUSCLE** force vector?
**SUPERIOR & SLIGHTLY MEDIAL (MEDIOTRUSIVE) ***
What is the directional length of the INFERIOR HEAD of the LATERAL PTERYGOID muscle force vector:
-ANTERIOR & MEDIAL (slightly mediotrusive)
Like all articulated joints in the human body the temporomandibular joint is innervated by what?
- The SAME nerve that provides motor & sensory innervation to muscles that control it.
- Primarily the TRIGEMINAL NERVE (V)
MOST of the innervation to the TMJ is by the what?
- The AURICULOTEMPORAL NERVE (75%)
- Additional innervation (SENSORY) is supplied by the DEEP TEMPORAL & MESSETERIC NERVE branching of TRIGEMINAL-3 (V3)
Primary vascularization of the TMJ is with the ?
SUPERFICIAL TEMORAL BRANCH of the external carotid ARTERY
The condyle receives vascular supply throughout what?
Its MARROW SPACES from INFERIOR ALVEOLAR ARTERY & FEEDER VESSELS from other branches that perforate head from various angles
Why does the maxillary arch form DOMINATE the mandibular arch?
1) Maxillary arch is LARGER** than mandible from the distal of a 3rd molar on one side thru middle of each tooth to the 3rd molar on the other side
2) Maxillary arch is **WIDER* or larger in measurements from R/L sides
3) Esthetics are embedded MORE in the maxillary arch than in mandibular b/c smile line is extremely evident w/ maxillary ant. teeth
Intra-arch Alignment of Teeth:
- Teeth primarily contact their ___________?
- Most teeth contact ___________________?
- Which 2 teeth only have ONE antagonist in the opposing arch?
- Namesake in the opposing arch
- One additional tooth in the opposing arch
- The maxillary third molars and mandibular central incisors
Regarding Plane of Occlusion:
- The ideal plane is?
- A flat plane allows what?
- The proper plane of occlusion will permit what?
- A curved plane permits what?
- How are teeth positioned in the arch?
- The IDEAL plane is NOT FLAT
- A FLAT plane allows for TOO MANY contacts on most POSTERIOR TEETH on BOTH sides of the mouth
- The PROPER PLANE of occlusion will PERMIT SIMULTANEOUS FUNCTIONAL contacts to occur in controlled areas of arch
- A CURVED plane permits MAXIMUM USE of TOOTH CONTACTS during FUNCTION
- The teeth are “strategically positioned” in the ARCHES at VARIED & COORDINATED degrees of inclination
What is forces exerted on the first premolars are approximately what ?
50% LESS than those exerted on the 3rd molars
Occlusal contacts should occur between what?
- Should IDEALLY occur between a CUSP TIP and the DEPTH of a FOSSA, or between a CUSP TIP & a FLAT SURFACE, which is considered MORE STABLE.
- Contacts SHOULD NOT occur on CUSPAL INCLINES, because these are LESS STABLE
Regarding Classification of Occlusion what is the Ideal CLASS I ?
1) Ideal 1ST MOLAR relationship
2) Ideal CANINE relationship