Bite Registration Flashcards
What’s facebow 2, and its types
FACEBOWS Most facebows are rigid, caliper-like devices that allow some adjustments.
Facebows are used to record the anteroposterior and mediolateral spatial position of the maxillary occlusal surfaces in relation to the transverse opening and closing axis of the patient’s mandible.
FACEBOWS Two types of facebows are recognized: arbitrary and kinematic.
What’s face bow used for?
The facebow is then attached to the articulator to transfer the recorded relationship of the maxilla by ensuring that the corresponding cast is attached in the correct position in relation to the hinge axis of the instrument. After the maxillary cast has been attached to the articulator with mounting stone or plaster, the mandibular cast is subsequently related to the maxillary cast with an interocclusal record.
Talk about visual articulators
computer-aided manufacturing (CAD/CAM), optical scanning of entire arches has become a fairly straightforward procedure.
• In its current form, the software used for such virtual instrumentation is not quite capable of rendering the simulation of mandibular movements
What are materials used for bite registration?
Elastomeric material
There are different materials for bite registration (inter occlusal record) Gauze mesh cloth forms with plastic holders, and zinc oxide–eugenol (ZOE) paste can be used instead of Elastomeric paste.
Recording technique with hard pink baseplate wax. After being Softened and folded into a double layer, the record is trimmed to the appropriate shape.
What’s centric relation record and its use?
- A CR record provides the orientation of mandibular to maxillary teeth in CR in the terminal hinge position, in which opening and closing are purely rotational movements.
- ( CR the condyles are in their most anterosuperior position in the glenoid fossae).
- is used to replicate, on the articulator, the relationship between the maxillary and mandibular arches.
What do we do for small errors in centric recording?
keeping the record thin. However, it is essential that the teeth not perforate the record. Any tooth contact during record fabrication can cause mandibular translation (because of neuromuscular protective reflexes governed by mechanoreceptors in the periodontium) and thereby render the resulting articulation useless.
What are Centric Relation Record Technique
- chin point guidance,
- bilateral manipulation, and
- the unguided method.
Talk about unaided method and bilateral manipulation
unguided method.
it can be difficult to achieve consistent results because of the patient’s muscle activity.
bilateral manipulation
bilateral manipulation In this technique,
- the dental chair is reclined,
- and the patient’s head is cradled by the dentist.
- With both thumbs on the patient’s chin and the fingers resting firmly on the inferior border of the patient’s mandible .
- the dentist exerts gentle downward pressure on the thumbs and upward pressure on the fingers, manipulating the condyle-disk assemblies into their fully seated positions in the mandibular fossae. Next, the mandible is carefully hinged.
What do we do when Cr and co do not coincide?
In some patients in whom CR does not coincide with MI, resistance may be encountered when the mandible is hinged. Because of well-established protective reflexes that are reinforced every time the teeth come together, such patients do not allow their mandibles to be manipulated and hinged easily. If tooth contact can be prevented, these reflexes disappear, and manipulation becomes easier. The teeth can be kept apart with cotton rolls, a plastic leaf gauge, or a small anterior programming device made of autopolymerizing acrylic resin (also known as a Lucia jig).
• If the mandible cannot be manipulated satisfactorily after an anterior programming device has been in place for 30 minutes, the patient is likely to have marked neuromuscular dysfunction. Normally, this is relieved by an occlusal device
How do we deprogramm muscles?
- A simple means of doing this is to place o A cotton roll between the anterior teeth and instruct the patient to “bite on your back teeth.” or o A plastic leaf gauge may be used to prevent habitual closure into maximal intercuspation.
- Or using anterior programming device
What do we gain from Centric Relation (CR) record
So from these records (CR record) on the articulator :-
- it is possible to observe tooth relationships and identify deflective contacts and/or other occlusal discrepancies from the casts (diagnosis)
- it is possible to treat complex cases (treatment)
Maximal Intercuspation (MI) Record or (CO) Record are used for?
Simple cases
How do we place condyle in unstrained position?
• To enable the condyles to be placed in an unstrained position, specially with complex cases, the musculature must first be deprogrammed from its habitual closing pattern..
