Quiz 1 part 1 Flashcards
Define the Craniomandibular Apparatus
The entire cranial-mandibular complex that encompasses the articulation of the teeth and the surrounding structures that produce and limit movement.
Define the temporal bone in the context of occlusion
- A portion of this bone forms the glenoid or mandibular fossa.
- The shape of this fossa determines many of the limits of mandibular movement.
Define the Condyle
The portion of the mandible that articulates in the mandibular fossa.
- there is a right and left condyle, about which movement of the mandible occurs.
- The shape of the heads of the condyles determine many of the limits of mandibular movement.
- Only bone in the human body that possesses two axes of rotation.
How many axes of rotation does the condyle possess?
Two
Functions & purposes of the ligaments supporting the temporomandibular joint and mandible
- Limit mandibular movement
- Protect the musculature, especially during extreme movement
- They are non-elastic, non-contractile and do not have innervation
Name the two accessory ligaments of the mandible
Stylomandibular & Sphenomandibular ligaments
Function of Stylomandibular ligament
Limits excessive protrusive movement of the mandible
Function of Sphenomandibular ligament
Plays a role of limiting protrusive movement and lateral mandibular movement to either the right or left side.
T or F, The mandible is one of only two bones in the human body that possesses two axes of rotation
False, It is the only bone in the human body that has two axes of rotation
The position of the temporomandibular ligament is designed to do what?
Limit the pure hinge axis ROTATIONAL movement of the mandible.
What is the ideal full length of opening of the temporomandibular ligament
Occurs at no more than 15-20 mm of opening
How do you measure the length of the opening of the temporomandibular ligament
Measured between the incisal edges of the maxillary and mandibular incisors
T or F, The ligaments supporting the temporomandibular joint and mandible do not have innervation, are non-elastic and highly contractile
False, Non-contractile
Describe the Temporomandibular or Articular Disc (7)
- It consists of fibrous connective tissue
- It interfaces between the mandible and the temporal bone
- It is somewhat pliable in texture
- It is bi-concave in shape
- Collateral ligaments attach it to the condyle in a medial and lateral position
- It does not have any innervation
- It does not have any vascularization
T or F, the temporomandibular disk is innervated by the trigeminal nerve (V3)
False, it has no innervation
T or F, The temporomandibular disk consists of fibrous connective tissue
True
Describe the Maximum Intercuspation
- Also known as centric occlusion (CO), which is now an obsolete term
- Commonly referred to as habitual occlusion or habitual centric, because the patient can achieve this position by “habit”
- Maximum intercuspation describes an occlusal relationship or tooth position
- The teeth are contacting in a position that the patient finds the most comfortable
- It is easily achievable, but not always reproducible, by the patient
T or F, the temporomandibular disk receives it’s blood supply from the external carotid artery
False, it has no vascularization
T or F, the temporomandibular disk is pliable and bi-concave in shape
True
4 key points to clinical conditions regarding the slide from centric relation to maximum intercuspation
- Only 15% of the population have no centric relation to maximum intercuspation discrepancy or slide
- For patients with a slide, after the first occlusal contact in centric relation is obtained (this is usually on two or more posterior teeth), the patient continues to close and slide on inclines of posterior teeth
- Maxillary and mandibular teeth will come together more completely in the maximum intercuspation position
- Condyles must move out of their most ideal position when the teeth come fully together and this position is anterior, superior and slightly lateral to the maximum intercuspation position
What is maximum intercuspation also known as?
Centric occlusion, which is now an obsolete term
Maximum intercuspation is commonly referred to what because the patient can achieve this position by habit
Habitual occlusion or habitual centric
T or F, Only 15% of population have a centric relation to maximum intercuspation discrepancy or slide.
False, 15% have NO slide or centric relation to maximum intercuspation discrepancy. So in other words, 15% have ideal occlusion whereas 85% have slide
For patients with a slide, after the first occlusal contact in centric relation is obtained, the patient continues to close and slide how?
on the inclines of posterior teeth
T or F, Maximum intercuspation describes an occlusal relationship or tooth position
true
T or F, In maximum intercuspation, the patients teeth are contacting in a position that the patient finds uncomfortable
False, Patient finds it most comfortable
In regards to slide, the condyles must move out of their most ideal position when the teeth come fully together and this position is what to the maximum intercuspation position
Anterior, superior and slightly lateral
Describe Canine protected articulation:
Implies that ONLY the canines are touching during the complete extent of lateral movement
Describe Group Function occlusion
Entails that ONE or MORE of the posterior teeth, in combination with some of the anterior teeth, are in some degree of contact during the complete extent of lateral movement
Which version of occlusal guidance schemes is considered the ideal occlusal scheme?
Canine protected articulation
What is the most practical approach in occlusal guidance schemes?
Group function occlusion
- Also considered the secondary occlusal scheme
Older patients commonly exhibit what type of occlusal guidance scheme?
Group function occlusion more commonly than canine protected articulation
Describe the 6 summary points to an Ideal Occlusion
- Centric relation and maximum intercuspation occur simultaneously
- All teeth contact simultaneously
- All occlusal forces on posterior teeth are directed down the long axis of the teeth
- Posterior tooth contacts dominate over anterior tooth contacts
- All eccentric movements are guided by the anterior teeth
- No crossover contacts on posterior teeth should be seen
All eccentric movvements of an ideal occlusion are guided by which teeth?
Anterior teeth
No crossover contacts in an ideal occlsuion should be seen on what teeth?
Posterior teeth
Which teeth dominate over the other teeth in an ideal occlusion
Posterior tooth contacts dominate over anterior teeth contacts
