Mandibular Movement Flashcards
0
Q
When does translation occur?
A
When the incisors surpass 20-25mm of separation.
1
Q
What is rotation?
A
Mandibular movement about the terminal hinge axis or transverse horizontal axis (imaginary line between two condyles). Rotational movement is limited to 20-25mm of incisal separation.
2
Q
In a straight protrusive movement, both condyles will move ____________ as they slide along the eminences.
A
downward
3
Q
In lateral movements, the non-working condyle will move _________ and ___________. Whereas, the working condyle will rotate and move _______and______ OR ________and__________.
A
Non-working: downward and medial
Working: lateral and upward, or lateral and downward
4
Q
What did Ulf Posselt describe about the limits of mandibular movements?
A
Limits occur within a certain range that can be described in three planes of orientation. The starting reference point is between the two mandibular central incisors.
5
Q
Ulf Posselt’s range of movement can be referred to as what phrase?
A
Envelope of Motion
6
Q
What is centric relation?
A
The maxillomandibular relationship in which the condyles articulate with the thinnest avascular portion of their respective disks, with the complex in the anterior-superior position against the shapes of the articular eminences.
7
Q
True or False: Centric relation is independent of tooth contact.
A
True
8
Q
True or False: Centric relation is considered a reliable and reproducible reference position.
A
True
9
Q
What is centric occlusion?
A
When the mandible is manipulated upward on the centric relation arc until tooth contact occurs.
10
Q
Initial Points of Contact (first contacts in centric occlusion) occur on _____inclines of mandibular teeth and _______inclines of maxillary teeth.
A
Distal (mandibular)
Mesial (maxillary)
11
Q
What is maximal intercuspation?
A
The position in which all teeth intercuspate together as best as they can.
12
Q
What is centric slide?
A
The slide between centric occlusion (CO) and Maximum Intercuspation (MI). Susceptible to change throughout life.
13
Q
True or False: If there is a slide between CO and MI, it is not necessary to determine whether corrective therapy is needed before restorative treatment.
A
False: If there is a centric slide, it is important to determine whether corrective treatment is needed.
14
Q
What is the vertical dimension of occlusion?
A
The distance between two reference points (arbitrary points on the mandible and maxilla) when the teeth are in MI.
15
Q
Incisal Guidance is measured in ______ from the ______ plane.
A
Degrees
Horizontal
16
Q
The amount the mandible must drop in the anterior region is determined by the _______ guidance. The amount the mandible must drop in the posterior region is determined by the ________guidance.
A
anterior: incisal guidance
posterior: condylar guidance (angle of articular eminence)
17
Q
Articulators can be classified as one of three types. What are the three?
A
- Small, non-adjustable
- Semi-adjustable
- Fully adjustable
18
Q
Which type of articulator often leads to restorations with occlusal discrepancies because they cannot reproduce the full range of mandibular movement?
A
Small, non-adjustable articulator
19
Q
Which type of articulator uses a face-bow transfer to position the casts with sufficient accuracy to minimize the need for adjustment?
A
Semi-adjustable articulator
20
Q
Which type of articulator uses a pantograph to adjust the condylar elements?
A
Full adjustable articulator
21
Q
Articulators with the condyles connected to the lower member are known as_________ articulators.
A
Arcon (articulating condyle)
23
Q
The ear bow transfer relates the maxillary cast to the ______ _______ _______.
A
Terminal hinge Axis
24
Q
What is incisal guidance determined by?
A
- Lingual Concavities of maxillary anterior teeth
- Vertical overlap of maxillary and mandibular anteriors
- Horizontal overlap of maxillary and mandibular anteriors
25
True or False: The Habitual Arc of Closure is reproducible.
False
26
Centric Relation is _____ and ______.
Reliable
| Reproducible
27
What is the approximate range for Interocclusal Rest Distance? How is it found?
2-4mm
| VDR (rest) - VDO (occlusion)
28
Incisal guidance is used to define the protrusive path of the mandible and the path the incisors must follow during ______ jaw movements.
Lateral
29
In order for the condyles to articulate with the thinnest avascular portion of their disks, the complex must be in the _________ position.
Anterior-Superior
30
In the horizontal plane, the working condyle moves _______.
Forward and Lateral
or
Backward and Lateral
(within Cone of Bennet)
31
In the horizontal plane, the non-working condyle moves_______.
Forward and Medial
32
In the frontal plane, both condyles will move ______ during protrusive movement.
Downward
33
In the frontal plane, the non-working condyle will move ________ during lateral movements.
Down and medial
34
In the frontal plane, the working condyle will move _____during lateral movements.
Down and Lateral
or
Up and Lateral
35
Ulf Posselt's __________ describes the range of mandibular movements and its limits. Is this reproducible?
Envelope of Motion
| No, only border movements are reproducible through operator manipulation
36
During protrusive movement, which teeth will most likely be in contact?
Incisors or Canines
37
What does the angle of the articular eminence determine?
Condylar Guidance
| -the amount the mandible must drop in the posterior region
38
What are the posterior determinants of mandibular movement (x3)?
1. Inclination of articular eminence
2. Medial Wall of glenoid fossa
3. Intercondylar distance
39
What are the anterior determinants of mandibular movement (x2)?
1. Horizontal overlap of anterior teeth
| 2. Vertical overlap of anterior teeth
40
What are three additional determinants of mandibular movement (beyond anterior/posterior)?
1. Occlusal Plane
2. Curve of Spee
3. Neuromuscular Response
41
True or False: Bonwill and Balkwill triangles are important determinants of mandibular movement.
False. They show relationships that are important for placing dentures. Nothing beyond that
42
Which type of articulator will often lead to occlusal discrepancies? Why?
Small, Non-adjustable
| They cannot reproduce the full range of mandibular movements
43
Which type of articulator is about the same size as anatomic structures and uses an ear-bow transfer to position casts with accuracy?
Semi-Adjustable
44
Which type of articulator is capable of capturing border movements?
Full-Adjustable
45
The ______ cast is mounted by using the ear bow transfer.
Maxillary
46
The _______ cast is mounted by using the centric relation record.
Mandibular
47
The ear bow transfer allows the operator to relate the maxillary cast to the _______.
Terminal Hinge Axis
48
True or False: The Ear Bow Transfer allows correct orientation of the long axes of teeth in space and allows for extensive anterior restoration.
True
49
What is the horizontal reference in an ear bow transfer?
Interpupillary Line
50
In order to record centric relation, the patient's _______ that guide the mandible in habitual movement have to be blocked out.
Proprioceptive Impulses
51
A natural reflex action of the mandible is to close into a _______ or a _____ ______ position when something is introduced in the mouth (wax, bite registration material) and the patient is instructed to bite.
Lateral
| Lateral-protruded
52
True or False: The CR record should be obtained without tooth contact.
True
53
What are the three discussed methods for recording CR?
1. Chin-Point Guidance
2. Anterior Deprogrammer
3. Bilateral (Bimanual) Manipulation (Dr. Dawson)
54
True or False: Doing a poor job of occlusal equilibration is far worse than leaving the malocclusion.
True
*New interferences can create an awareness that will trigger extreme discomfort of the teeth, TMJs, and masticatory muscles
55
In MI position, posterior teeth come into contact and act as stops to minimize ________ load on anterior teeth.
Horizontal
56
Anterior teeth guide ____ movements of the mandible and prevent posterior contact.
Excursive (lateral or protrussive)
57
True or False: Disclusion of posterior teeth during excursive movements is the rule, not the exception.
True
58
Occlusal forces should be direct along ______.
The long axes of teeth
59
In MI, all mandibular teeth should contact opposing maxillary teeth _______ and with _________.
At the same time
| the same intensity
60
Working side contacts (canine or group function) should not be prevented from contacting due to _______.
Non-working interferences
61
Canine guidance creates posterior disclusion during _____ movement; incisal guidance creates disclusion during _____.
lateral
| protrusion
62
What is "group function?"
Mandibular (Buccal) working cusps contact lingual inclines of maxillary buccal cusps AND canines
63
What are the four parts of the equilibration procedure?
1. Reduction of contact that interferes with CR
2. Reduction of lateral interference
3. Elimination of posterior interference on protrusion
4. Harmonization
64
The rule for correcting anterior slide during closure is:
MUDL
mesial incline of upper
distal incline of lower
65
The rule for correcting deviation toward the cheek during closure is:
BULL
Buccal Upper
Lingual Lower
66
The rule for correcting deviation toward the tongue during closure is:
LUBL
Lingual Upper
Buccal Lower
67
If there is a lateral interference during opening that involves the non-working side, correct using:
BULL
| i think its "bull" that some people are not-working
68
If there is a lateral interference during opening that involves the working side, correct using:
LUBL
69
True or False: Canine guidance is the occlusion of choice because at the moment of posterior disclusion, the elevator muscle contraction is shut off and reduces the load on joints and anterior teeth.
False. ANTERIOR guidance does this
70
In order to eliminate protrussive interferences, the grinding rule is:
DUML
Distal Upper
Mesial Lower
71
What are the two uses of "incisal guide tables?"
1. Record existing guidance prior to preparing teeth
| 2. Protect wax patterns
72
The curve of spee utilizes a _______theory in which the axis lies along the mid-orbital plane.
Cylindrical
73
What is Carl Christensen known for?
Christensen's Phenomenon: During protrusion, there is posterior disclusion
74
Monson's Spherical theory used the ______ as a center of rotation for setting denture teeth.
Sella Turcica
75
The curve of Wilson is seen in the ______ plane.
Frontal (MedioLateral Curve)
76
The curve of Spee is seen in the ______ plane.
Sagital (AnteroPosterior Curve)
77
The Conical Theory used the _______ as the anatomic rotation center of the mandible.
External Occipital Protuberance
78
Increased Vertical Overlap allows for ______cusps during wax-up.
Longer
79
Decreased Vertical Overlap requires _______ cusps during wax-up.
Shorter
80
The superior head of the lateral pterygoid originates on the ______ and inserts on the ______.
O: sphenoid
I: medial side of condyle
81
The inferior head of the lateral pterygoid originates on the ____ and inserts on the ______.
O: outer pterygoid plate
I: neck of condyle
82
What is the action of the lateral pterygoid?
Open the mouth (digastric helps)
83
The Medial Pterygoid originates on the pterygoid plate and inserts on the ______.
Mandible
84
Which muscle is penetrated during anesthesia?
Meidal Pterygoid
85
Which muscles close the mouth?
Temporalis, Medial Pterygoid, Masseter
86
What type of joint is the TMJ?
Synovial
87
A protrusive movement is ____ in the horizontal plane and _____ in the frontal plane.
Forward
| Downward
88
The chewing movement is in the shape of a _____.
Teardrop
89
Which head of the lateral pterygoid works closely with the digastric to open the mouth?
Inferior head
90
Which teeth are embedded in compact bone?
Canines only
91
What technique is used to determine mandibular movements for use on a Fully Adjustable Articulator?
Pantograph (6 images with horizontal and sagittal angles)
92
For Pantograph sketches, which angle is horizontal and which angle is sagittal?
Bennetts: Horizontal
Fischers: Sagittal
93
Where should the ruler be placed in order to find the 3rd point of reference for the ear bow?
Between incisor and canine
94
There are arbitrary and kinematic measures for finding the hinge axis location, but percent error is negligible if within a range of _____mm of the actual point.
6mm
95
The ______ ____ ______ is located along the habitual arc of closure.
Physiological Rest Position
96
The _______ is a built-in anatomical defense mechanism for controlling occlusal pressure forces.
Periodontal Ligament
97
______-_____ occlusion is ideal.
Cusp-Fossa (tooth-to-tooth)
98
____-_____ occlusion is not as stable.
Cusp-Marginal Ridge (tooth-to-two teeth)
99
What is axial loading?
Cusp tip to flat surface (one point of contact). We AIM for "tripodization" during occlusion
100
Our jaw is a Class ____ lever which is less efficient and therefore requires that most force be applied toward the fulcrum (posterior teeth)
THREE
101
Posterior teeth contact will prevent _____ load on anterior teeth.
Horizontal
102
What are the effects of tooth loss?
1. Supraeruption of opposing arch
2. Tilting of adjacent teeth
3. Loss of contact
4. Loss of posterior support
5. Loss of vertical dimension
6. Flaring of anterior teeth
7. Non-working interference
103
What is the preferred order of occlusal therapy?
1. Selective Grinding
2. Fixed Prosthodontics
3. Orthodontic Therapy
4. Orthognathic Surgery
104
For the rule of thirds: Contact at the inner third would dictate______.
Selective Grinding within the enamel
105
For the rule of thirds: Contact at the middle third would dictate ______.
Fixed Prosthodontics
106
For the rule of thirds: Contact at the outer third would dictate _______.
Orthodontic Treatment
107
The _____ the slide, the more likely it is to selectively grind within the confines of enamel.
shorter (taller cusps allow shorter slide than flat teeth)
108
What is "gingival zenith?"
A slightly distal curve of the gingival margin
109
What is the difference between macro-, mini-, and micro-esthetics?
1. Macro = the face in three planes
2. Mini = the framework from lips and buccal corridors
3. Micro = teeth proportions, gingival shape, and color
110
What is the difference between "smile line" and "lip line"?
Smile: Lower lip compared to maxillary teeth
Lip: Upper lip height
111
_______ are a common subgroup of Orofacial pain disorders.
Temperomandibular Disorders (TMD)
112
What are the two basic types of TMD?
1. Myogenous (muscles related)
| 2. Arthrogenous (joint related)
113
The _____ muscle lies in front of the joint disc and the ______ lie behind the disc.
```
Lateral Pterygoid
Blood vessels (retrodiscal tissue + nerves)
```
114
True or False: The history of pain does not particularly matter when diagnosing a TMD issue.
False: Good history taking is the BASIS for accurate diagnosis (when? how?)
115
What are the cardinal criteria to consider when diagnosing TMD issues?
1. Pain
2. Limitation of Function
3. Limitation of Movement
4. Physical Changes (swelling)
5. Altered jaw relationship
6. Sounds that have been INCREASING in intensity and frequency
116
What must you consider when evaluating sounds of the TMJ?
Has the INTENSITY or frequency increased recently
| is it "normal"
117
The etiology of TMD involves [Normal Function] + {event} which results in a period of _________ before TMD symptoms arise.
Physiologic Tolerance
118
What is the importance of Physiologic Tolerance?
It is a narrow period of time during which the problem can be reversed before causing joint issues
119
TMD is multifactorial and may involve what kind of factors or structures?
1. pulp
2. occlusion
3. Perio (gingiva)
4. Muscles of mastication
5. Joint
6. Ear
7. Neck Muscles
8. Sinuses
120
Etiological Factors of TMD may be classified into what three categories?
1. Predisposing
2. Initiating
3. Perpetuating
{P.I.P. pop, make the pain stop!}
121
_____ factors increase the risk for TMD but do not cause it.
Predisposing (loss of teeth)
122
_____ factors CAUSE TMD
Initiating (Trauma, parafunctional habits)
123
______ factors enhance the progression of TMD.
Perpetuating (behavioral, social, emotional)
124
What are the five factors associated with TMD?
1. Occlusal Condition
2. Trauma
3. Emotional Stress
4. Deep Pain Input
5. Parafunctional Habits (nail biting, thumb sucking)
125
_______ occurs when the MI position of teeth is in harmony with the musculoskeletally stable position of the condyles in their fossae.
Orthopedic Stability
126
What are some examples of Diurnal parafunctional activity?
Clenching/Grinding (only "bruxism" if at night)
Thumb Sucking
Cheek Biting
Nail Biting
127
True or False: If occlusal interferences are found not to be related to TMJ pain, the dentist should use various therapies to find the cause.
False: Dentist should only provide care if occlusal interferences are the CAUSE of muscle symptoms
128
Prosthetic treatment in TMD patients should only be carried out after ___________ has resulted in relief of pain and the normalization of function.
Reversible Therapy (i.e. Night Guard)
129
_______ treatment of TMD is intended to directly eliminate or alter the cause of the disorder and its consequences.
Definitive
130
________ is directed toward altering the patient's symptoms, and reducing pain or dysfunction. No effect on the cause.
Supportive Therapy (pharmacological)
131
What is an occlusal appliance?
ANY removable device that fits over the occlusal and incisal surfaces of the teeth on one arch. Creates a POSTIVE OCCLUSAL CONTACT with the teeth of the opposing arch
132
Occlusal appliances may provide a temporary ______ join position, introduce an optimum functional _______, or protect teeth from abnormal forces.
Orthopedically Stable
| Occlusion
133
True or False: Occlusal appliances may reduce parafunctional muscle activity and reduce myogenous pain.
True
134
Stabilization appliances, Anterior positioning appliances, Anterior bite plane, Posterior bite plane, Pivoting appliances, and Soft appliances are all examples of ______.
Occlusal appliances
135
True or False: Inclined planes within the mouth are stable.
False, when contacting an incline plane the force will keep going until hitting a "stop"
136
What is the most common type of occlusal appliance?
Stabilization
137
How is an "Anterior Positioning Device" used to provide relief?
It provides mutually protected occlusion and allows retrodiscal tissue to heal when at rest
* ***Should not be used over a large span on time. Posterior teeth are designed to bear most of the load and should be allowed to do so.
* ****Wearing for a long time= posterior teeth supraeruption.
138
What is "Optimum Functional Occlusion?"
The condyles are in their most musculoskeletally stable position and teeth are able to contact EVENLY and SIMULTANEOUSLY to eliminate orthopedic instability
139
What is the most common arch for placement of occlusal appliances?
Maxillary
140
When are mandibular appliances used?
When patient grinds/clenches throughout the day
141
What are the two methods for fabricating occlusal appliances?
Indirect
| Direct
142
Anterior positioning appliances may be used to force the condyle ____ to reduce the disc.
forward
143
When making a single crown, in what position should the casts be related?
MI
| not at CO
144
BOARDS: Name the two condyles/sides for describing a right movement.
Right Working
Right Non-working (do not call it "left")
*Focus on the direction of movement, not the side of the jaw*
145
BOARDS: Name the two sides during a left movement of the mandible.
Left Working
Left Non-working (do not call it "right")
*Focus on the direction of movement, not the side of the jaw*
146
BOARDS: When the joint complex is in the _____ position, there is no pain because the force is taken by the avascular disc.
Anterior Superior
147
The working condyle moves in any direction within ______; the non-working condyle may move medially and protrude along ______ angle or it may move downward and forward along ______angle.
The Cone of Bennett
Medial/Protrudes: horizontal plane = Bennett's Angle
Downward/forward: Sagittal = Fischer's Angle
148
The mandibular buccal cusp will occlude with the _____ of the maxillary counterpart.
Mesial Fossa
149
Endentulous patients will still have _____ movements even if you cannot trace occlusion.
Border (CR record)
150
True or False: The arch of rotation is used to create wax-ups.
False: only use CR record because border movements are reliable and reproducible.
**The arch of rotation is nearly impossible to replicate
