A joint located on each side of the head, allowing for mandible movement for mastication, speech, and respiration.
2
What are the key anatomical components of the TMJ?
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The TMJ is the articulation of the temporal bone and mandible on each side of the head.
3
When does the TMJ develop?
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The TMJ develops in the 11th to 12th week of prenatal development.
4
What is the mandibular notch?
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The mandibular notch is the depression located between the coronoid process and the condylar process of the mandible.
5
What is the alveolar process of the mandible?
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The alveolar process of the mandible is the part that contains the sockets for the teeth.
6
What is the articulating area of the TMJ on the temporal bone located on?
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The inferior aspect of the temporal bone
7
What are the two components of the articulating area on the temporal bone?
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Articular eminence and articular fossa
8
What is the function of the post-glenoid process?
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It is a sharp ridge posterior to the articular fossa
9
What is the mandibular bone and how does it articulate with the temporal bone?
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The mandibular bone articulates with each temporal bone at the head of each mandibular condyle.
10
What are the components of the condyle and what does fibrocartilage do?
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The condyle consists of compact bone overlying cancellous bone. Fibrocartilage overlies the periosteum at the articulating surface of the condyle.
11
Define Glenoid fossa and Articular eminence.
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Glenoid fossa is a bony concavity that houses the joint where the condyle inserts. Articular eminence is a bony protrusion in which the condyle moves along.
12
What is the location of a growth center in the mandibular condyle?
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Head of each mandibular condyle
13
What type of cartilage is found in the growth center of the mandibular condyle?
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Hyaline cartilage
14
What process replaces hyaline cartilage over time in the mandibular condyle?
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Endochondral ossification
15
What is the mandibular growth center in condyle and what does it allow?
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The mandibular growth center in condyle allows the increased length of the mandible needed for larger permanent teeth and larger adult brain capacity.
16
How does mandibular growth influence the overall face shape?
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Mandibular growth influences the overall face shape.
17
What is the growth pattern and what happens after full maturity?
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The growth pattern is charted/referred to during orthodontic therapy. After full maturity, the condyle's growth center disappears.
18
What is endochondral ossification?
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The formation of the osteoid within a cartilage model that subsequently becomes mineralized and dies.
19
What happens during endochondral ossification?
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Osteoblasts penetrate the disintegrating cartilage and form a primary ossification center that continues forming osteoid toward the ends of the bone during prenatal development.
20
What are the two layers of the joint capsule and what do they consist of?
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The outer layer is a firm fibrous connective tissue supported by surrounding ligaments, and the inner layer is a synovial membrane consisting of a thin connective tissue that contains nerves and blood vessels.
21
What is the function of the joint disc in the temporomandibular joint (TMJ)?
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The joint disc functions as a pad between the articulating surfaces of the joint bones, providing a cushion and facilitating joint movements.
22
What is the Temporomandibular Joint (TMJ)?
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The TMJ is a complex joint that connects the mandible (lower jaw) to the temporal bone of the skull.
23
What are the components of the TMJ shown in the image?
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The components shown are the Temporal bone, External acoustic meatus, Joint capsule, Temporomandibular ligament, and Stylomandibular ligament.
24
What divides the Temporomandibular Joint (TMJ) into two compartments?
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Joint disc
25
What is the function of the synovial membrane in the TMJ?
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It produces synovial fluid.
26
How is the joint disc attached to the mandibular condyle?
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It is attached to the lateral and medial poles of the mandibular condyle.
27
What is the Articular Eminence in the temporomandibular joint?
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The Articular Eminence is the bony prominence on the temporal bone that forms the superior border of the mandibular fossa.
28
What is the Synovial Cavities in the temporomandibular joint?
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The Synovial Cavities are the spaces within the temporomandibular joint that contain synovial fluid, which lubricates the joint.
29
What is the Mandibular Condyle in the temporomandibular joint?
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The Mandibular Condyle is the rounded projection on the mandible that articulates with the Articular Fossa of the temporal bone.
30
What is the function of the joint disc in the temporomandibular joint (TMJ)?
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The joint disc acts as a deformable pad between the non-congruent articular surfaces of joint bones.
31
Describe the shape of the joint disc in cross-section.
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In cross-section, the joint disc appears cap-like on the mandibular condyle, with its superior aspect concavo-convex from anterior to posterior and its inferior aspect concave.
32
What are discal ligaments and what do they do?
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Discal ligaments are attachments that limit the movement within the lower joint space to rotation.
33
Define disc (articulate meniscus).
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Disc (articulate meniscus) is a biconcave structure composed of dense collagen (hyaline) connective tissue.
34
What is the anterior band of the disc and where does it insert?
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The anterior band of the disc inserts into the superior belly of the lateral pterygoid muscle.
35
What is the most relevant muscle to condylar movement in the TMJ?
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Lateral pterygoid
36
Where does the lateral pterygoid muscle originate?
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Sphenoid bone
37
What is the insertion point of the lateral pterygoid muscle?
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Condyle
38
What are the origins of the Masseter muscle?
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Superficial head: zygomatic process of maxilla and anterior two-thirds of inferior border of zygomatic arch; Deep head: posterior one-third and medial surface of zygomatic arch
39
What is the insertion of the Temporalis muscle?
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Coronoid process of mandibular ramus
40
What are the associated movements of the Medial pterygoid muscle during bilateral contraction?
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Elevation of mandible during closing of jaws
41
What is the function of the lateral pterygoid muscle in relation to the condyle?
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The lateral pterygoid muscle pulls the condyle towards the right of the slide.
42
What are the key anatomical structures mentioned in the slide?
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The key structures mentioned are the lateral pterygoid muscle, condyle, and the bony and muscular structures involved in mandibular movement pathways.
43
What are the three primary ligaments that support the TMJ?
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Lateral and medial capsular ligament, discal ligaments (collateral ligaments)
44
What are the two accessory ligaments that support the TMJ?
What is the function of the accessory ligaments in relation to the primary ligaments?
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They function with primary ligaments to limit excessive joint movements.
46
What is the definition of rotation in the context of condylar movement?
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Object turning about an axis
47
What is the definition of translation in the context of condylar movement?
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All points within an object have an identical motion
48
Describe the sequence of condylar movement during jaw opening.
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First, condyle undergoes a rotational movement, then it translates down the articular fossa to create an even wider opening of the mouth.
49
What are the two basic types of mandible movement performed by TMJ and its associated muscles?
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Gliding movement and rotational movement
50
Where does the gliding movement of TMJ occur?
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Between the disc and articular eminence of the temporal bone in the upper synovial cavity
51
What are the movements accomplished during the rotational movement of TMJ?
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Depression of mandible (lowering the lower jaw) or elevation of mandible (raising the lower jaw)
52
What are the two types of jaw movements mentioned in the slide?
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Gliding and rotation
53
What movements occur during opening the jaws?
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Depression and protrusion of mandible
54
What movements occur during closing the jaws?
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Elevation and retraction of mandible
55
What is the functional movement of the condyle and disc of the temporomandibular joint during opening and closing?
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The disc is rotated posteriorly on the condyle as the condyle is translated out of the fossa. The closing movement is the exact opposite of the opening movement.
56
What are the key components of the temporomandibular joint?
At a depression inferior to each ear at the zygomatic arch and 1-2 cm anterior to tragus
70
What are parafunctional habits and how do they relate to TMD?
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Parafunctional habits include behaviors like clenching, bruxism, and excessive gum chewing, which can contribute to TMD.
71
What are some factors that can cause trauma to the jaw and lead to TMD?
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Trauma to the jaw can cause TMD, with the disc having adhesions to bony surfaces.
72
What are some factors that can contribute to poor posture and TMJ symptoms?
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Poor posture, such as holding the head forward or looking at a computer all day, can strain the muscles of the face and neck.
73
What is myofascial pain dysfunction syndrome?
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A condition where muscle pain is associated with muscle tissue trigger points.
74
How can trigger points be localized?
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By digital palpation intra-orally and extra-orally.
75
What does the slide state about the role of TMD in causing earaches and headaches, neck and back pain, or instability?
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Studies do not support the role of TMD in directly causing these symptoms.
76
What are the different treatment options for clinical considerations?
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Conservative and invasive options: stress management, relaxation therapy, NSAIDs, antidepressants, local anesthetics, muscle relaxants, steroids, heat/ice muscle applications, parafunctional habit control (splints), moderate home-based muscular exercises, maintaining good posture, safety measures, surgery (arthroscopy with an endoscope and lasers), replacement of jaw joint or disc with TMJ Implants, potentially tissue engineering.
77
What diagnostic tests are mentioned for muscle and joint differential diagnosis?
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Computed tomography (CT) and magnetic resonance imaging (MRI). CT is used for assessment of bony structures, and MRI for soft tissue study.
78
What is subluxation in the context of TMD?
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Subluxation occurs when the condyle head moves too far anteriorly past the articular eminence, preventing posterior movement due to bony relationship and spastic muscles.
79
What are the key symptoms of subluxation?
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Symptoms include trismus and inability to open the mouth.
80
What is the recommended treatment for subluxation?
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Treatment involves relaxing muscles and carefully moving the mandible downward and back to assume the usual posterior position.
81
What is the term for a dislocation of both the joints or subluxation?
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Dislocation of both the joints or subluxation
82
What is the purpose of a lateral radiographic view in dental imaging?
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To visualize the teeth and surrounding structures in a side view
83
What is crepitation (crepitus) in the context of TMJ?
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A crackling or snapping sound or noise emitted from the temporomandibular joint (TMJ) due to a disharmonious movement of mandibular condyles against articular discs.
84
What might cause the crackling noise in TMJ?
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The crackling noise might be caused by the articular disc snapping in or out of position or becoming locked in the wrong position.
85
When does crepitation typically not require treatment?
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Crepitation is not a rare occurrence and does not normally require treatment unless accompanied by pain, limited jaw opening, or trismus.
86
What is the term for the mandible slipping out of the articular fossa and moving forward beyond the articular eminence?
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Dislocation of Mandible
87
What is the term for the condition where the mandibular condyle comes off the disc, causing the jaw to lock open?
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Mandibular dislocation
88
What is the term for the condition where the mandibular condyle slips forward beyond the articular eminence?
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Luxation or condylar subluxation
89
What is occlusion in dentistry?
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The arrangement of teeth in the mouth when the jaws are closed.
90
What are the determinants of occlusion?
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The factors that influence the position and relationship of the teeth.
91
What is tooth morphology and how does it relate to occlusion?
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Tooth morphology refers to the shape and structure of teeth. It ties into occlusion by influencing how teeth fit together and function in the mouth.
92
What specific features of tooth morphology are mentioned in the slide?
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The slide mentions cusp heights, fossa depths, and groove direction as specific features of tooth morphology.
93
What are vertical determinants?
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Vertical determinants are factors that influence health from the top down, such as socioeconomic status and education.
94
What are horizontal determinants?
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Horizontal determinants are factors that influence health from the side, such as environmental factors and access to healthcare.
95
What is the role of anteriors in mutually protected occlusion?
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Anteriors protect posterior teeth during excursive movements.
96
What is the role of posteriors in mutually protected occlusion?
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Posteriors take on most of the force during mastication and MIP.
97
What is the ideal in natural dentition?
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Mutually protected occlusion.
98
What is anterior guidance?
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Disocclusion of posterior teeth during protrusive movements involving incisors/canine
99
What is canine guidance?
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Disocclusion of posterior teeth during lateroprotrusive movements involving canine
100
What is the posterior determinant in the context of dental anatomy?
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TMJ
101
What is the anterior determinant in the context of dental anatomy?
What anatomical structures contribute to occlusion in the TMJ?
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Inclination of articular eminence, shape of condyle, and morphology of glenoid/mandibular fossa.
105
What is Overjet?
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The protrusion of your anterior teeth, either by position or angle of tooth.
106
How is Overjet measured?
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How far is your upper anterior incisal edge from your mandibular anterior teeth.
107
What is Overbite?
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How much of your lower anterior teeth is covered by your upper teeth.
108
What is overjet?
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The horizontal distance between the labial surfaces of the maxillary and mandibular incisors when the teeth are in centric occlusion.
109
What is overbite?
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The vertical distance between the labial surfaces of the maxillary and mandibular incisors when the teeth are in centric occlusion.
110
What is the term for the distance between the condyles in the posterior (TMJ) section of the table?
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Intercondylar distance
111
What is the term for the curve that describes the path of the mandible during lateral translation in the anterior (teeth) section of the table?
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Curve of Spee
112
What is the definition of overjet?
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Horizontal overlap of the upper incisors over the lower incisors.
113
How does overjet affect the separation time during excursive movements?
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More overlap leads to a prolonged separation time.
114
What is the effect of overbite on the separation of posterior teeth?
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Less overlap leads to less separation of the posterior teeth.
115
What is the angle of the protrusive condylar pathway relative to the horizontal plane of the head called?
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Condylar guidance
116
What happens to the cusp heights and fossa depth when the angle of the protrusive condylar pathway is steeper?
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Cusp heights can be longer and steeper, fossa can be deeper without interference
117
What is the overall guideline mentioned for understanding cusp pathways?
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Be able to envision where cusps move in relation to their opposing teeth using diagrams for aid (picture the cusp pathways)
118
How do horizontal factors within the posterior/anterior determinants affect cusp pathways?
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They alter these pathways by changing their angles and directions
119
What type of movement is depicted by the green markers on the condyle in the left picture?
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Protrusive movement
120
What is the term for the movement where the right condyle rotates while the left condyle moves anteriorly?
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Lateroprotrusive movement
121
What is a complete denture?
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A complete denture is a removable prosthesis that replaces all missing teeth in the upper or lower jaw.
122
What is natural dentition occlusion?
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Natural dentition occlusion refers to the arrangement and function of teeth in the mouth as they naturally grow and develop.
123
What is the definition of mutually protected occlusion?
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A type of occlusion where the upper and lower teeth are in contact, protecting both the teeth and the soft tissues.
124
List the two types of guidance mentioned in the slide.
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Anterior guidance and Canine guidance.
125
What is the key feature of complete denture occlusion?
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Balanced occlusion.
126
What is the role of anteriors in mutually protected occlusion?
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Anteriors protect posterior teeth during excursive movements.
127
What is the role of posteriors in mutually protected occlusion?
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Posteriors take on most of the force during mastication and MIP.
128
What is anterior guidance?
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Anterior guidance is the disclusion of posterior teeth during protrusive movements involving incisors/canine.
129
What is canine guidance?
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Canine guidance is the disclusion of posterior teeth during lateroprotrusive movements involving canine.
130
What is the Group Function in dentistry?
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A group of anterior and posterior teeth contact during lateroprotrusive movements.
131
What are the key components of Group Function?
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Anterior and posterior teeth contact during lateroprotrusive movements.
132
What is group function in dentistry?
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Group function refers to the simultaneous contact of multiple teeth during occlusion, which can distribute forces more evenly and reduce the load on individual teeth.
133
When would group function be beneficial in dentistry?
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Group function would be beneficial when occlusion is balanced in all directions, as it helps distribute forces more evenly and reduces the load on individual teeth.
134
What are the three types of dentures mentioned in the slide?
What is the term for the position of the mandible when the upper and lower teeth are in contact?
Show answer
Centric Occlusion
136
What is balanced occlusion in dentures?
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Balanced occlusion in dentures is a technique that helps patients reorient their dentures if dislodged throughout the day by ensuring food is evenly distributed and teeth contact at all non-rest times.
137
What must patients do to maintain balanced occlusion?
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Patients must have food evenly distributed throughout their mouth during mastication and chew in an up-down orientation to minimize excursive movements.
138
What is Bilateral Balanced Occlusion?
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A dental occlusion where the upper and lower teeth meet symmetrically on both sides of the mouth.
139
What is Centric Occlusion?
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The position of the mandible when the teeth are in maximum intercuspation.
140
What are the two sides of the mouth in Bilateral Balanced Occlusion?
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Nonworking Side and Working Side.
141
What is the purpose of anterior vertical overlap/opening in denture design?
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It allows contacts of anterior teeth to occur simultaneously with posterior excursive contacts, providing more contact points to stabilize the denture.
142
How does anterior vertical overlap/opening contribute to denture stability?
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It provides more contact points, which helps stabilize the denture when it is most needed.
143
What is balanced occlusion?
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Balanced occlusion refers to a dental occlusion where the upper and lower teeth meet symmetrically and evenly, distributing forces evenly across the dental arches.
144
What is non-balanced occlusion?
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Non-balanced occlusion occurs when the upper and lower teeth do not meet symmetrically, leading to uneven distribution of forces and potential dental issues.
145
What is condylar guidance in the context of CD Balanced Occlusion?
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Condylar guidance refers to the path of the condyle during jaw movement, which influences the position of the mandible and the occlusion.
146
List the five general factors of CD Balanced Occlusion.