L85: Intra-Oral Examination 3 Flashcards
What is occlusion?
The study of the relationships between the upper and lower teeth when they are closed together.
What is the functional purpose of occlusion?
Bringing the teeth together for chewing and swallowing.
Name the components of occlusion:
- Teeth;
- Periodontal Tissues;
- Jaws;
- TMJ;
- Muscles (temporalis, masseter!);
- Nervous Control.
Most of the time, the teeth are…
apart.
The ‘rest position’ of the mandible is when…
the teeth are apart.
The ‘intercuspal position’ (ICP) is when…
is the position in which the mandible is maximally braced against the maxilla (maximum inter-cuspation).
What is the typical (mm) between rest position and ICP?
3-4
How are rest position and ICP achieved?
Neuro-muscular memory
@ ICP, the stable contact points of the posterior teeth are:
The lower buccal cusps and the upper palatal cusps occlude against the fossa and marginal ridges of opposing teeth
@ ICP, the stable contact points of the anterior teeth are:
The lower incisal edges and canine tips occlude against the cingulum area of the opposing teeth
Which axis are forces directed down with ideal occlusal contacts?
The long axis
How can ICP contacts be tested clinically?
With shimstock or articulating paper
What type of movement brings the mandible forwards and downwards?
Translation
What type of movement brings the mandible downwards only?
Rotation
Name the two types of guidance during lateral movement of the mandible:
Canine and group
What is an articulator?
A device in which dental casts are held to mimic jaw relationship
What are the three types of tooth wear?
- Abrasion;
- Attrition;
- Erosion.
What is abrasion?
The loss of tooth material caused by abnormal rubbing from a non-dental object, e.g. a toothbrush at the gumline.
What is attrition?
The loss of tooth material between occluding tooth surfaces due to parafunctional activity, e.g. Bruxism (grinding).
What is erosion?
The loss of tooth material by a chemical process (acid), not bacterial. E.g. diet, regurgitation, environmental.
Why are restorations prone to failure?
- Secondary caries;
- Fracture;
- Pulp death;
- Incompatibility with periodontal tissues.
What should an intra-oral examination include?
- Assessment of the occlusion, static and functional;
- Assessment of signs of tooth wear;
- Evaluation of restorations.
