Pros - jaw reg Flashcards
What is step 1 of jaw reg
adjust the upper wax rim to maximise retention
describe how you would adjust the upper wax rim to maximise retention
o It is important that the upper wax rim stays in place when we are recording occlusion
o If it is dropping, then there is overextension of the peripheries
o You want to see if the rim is retained when holding the tissues away because if is dropping it means it is not well adapted or there is too much lip support
what is step 2 of the jaw reg
adjust the upper record block for tooth position
How do you adjust the upper record block for tooth position/occlusal plane
we adjust it for: lip support incisal level midline buccal corridor occlusal plane
How do we adjust it for incisal level
Think of how much tooth will be showing. Want to ask the patient to practice saying ‘f’. Consult with patient on how much they’d like to show. Trim the block to the correct height so it is showing the correct amount of ‘tooth’
For the anterior teeth you want them about 1cm anterior to the incisive papilla but aim for less
For the canines we want them below the nose
Use a fox’s bite plane to check the incisal plane orientation – it should be in line with the intrapapillary line (from eye to eye)
Mark the lip line (high smile line & then at rest mark how much incisor should be showing)
How do we adjust for the midline
Mark the centre line – this should be centralised with the philtrum and the lips
How do we adjust for the buccal corridor
Mark the mid canine line in relation to the buccal corridor – use some floss and line it up with the corner of the patients eye and the end of their nose
What is the occlusal plane forHow do we adjust for the occlusal plane
Using fox’s bite plane – you are comparing it to alatragus line
What is step 3 of jaw reg
lower tooth position
How do we do the lower tooth position for the jaw reg
o Ensure the tongue isn’t cramped (too lingual)
o Ensure cheek isn’t pushing on it (too buccal)
o Want the teeth to be over the ridge
o Want the anterior teeth to have a shallow overbite and an overjet
o Want the posterior teeth to be either in normal occlusion or cross bite if the natural upper teeth are retained and you want them to be lingualised
What is step 4
measure vertical dimension and establish face height
How do we measure RVD
We need two measuring points in the midline of the face and they must be on sites of minimal influence from the muscles of facial expression
Ask the patient to moisten their lips and bring them into relaxed light contact while wearing the adjusted rims
Can tell the patient to say the letter ‘m’ repeatedly
How do we get patient in OVD
Insert the upper and lower record blocks
Need the patient to close in the retruded axis position – do this by getting patient to curl their tongue to the back of their throat and practice this multiple times and measure the OVD
Reduce the lower wax rim in height until it contacts the upper rim evenly
The OVD should be 2-4mm less than the RVD
What is step 5
registration
How do we do the registration
o Need to adjust the lower mandibular block so that the lower block comes into contact evenly with the upper block at the decided OVD
o The bite is registered at the RCP which in complete dentures is when the two bite blocks come together
o Before recording the occlusion put a line down both sides of the blocks so you know when you are recording the occlusion, it is where you expect it to be
o To record the occlusion make some notches in the blocks, then use some recording paste and get the patient to bite together
How do we select anterior teeth for denture
For deciding shape we can use photos and previous dentures
For the width of anterior teeth we can use the mid canine length – bare in mind that this will be smaller than the canine to canine width on the mould as that goes from distal to distal
For the height of the incisors we can use the high smile line. Bare in mind the neck of the tooth will be hidden by acrylic so will be shorter than the height prescribed in the mould
There will be a corresponding lower anterior mould number for the chosen upper anterior
What posterior teeth do we pick
hybrid teeth (12 degree angle) for complete dentures
What are the steps for partial denture jaw reg
Check record blocks on the study models. Assess the fit, extension and occlusion
Assess the upper record blocks inside the mouth looking at stability, retention and support
Correct any over or under extensions with a heated wax knife
Adjust the labial/buccal thickness and aim for nasiolabial angle of 90 degrees
Adjust any under/overextensions and relieve frenulum area
Orientate the posterior occlusal plane parallel to the alar-tragus line
Orientate the incisal plane parallel to the inter-pupillary line
Remove wax from palatal aspect to improve tongue space
Assess lower record block inside the mouth
Adjust labial/buccal thickness and remove wax from lingual aspect
Correct any under/overextension
Relieve the frenulum areas and cut back the heels on upper and lower rims until there is an even bilateral occlusion intra orally
Ask patient to close in ICP with rims in place and check if the reference teeth are separated – trim any premature contacts until the reference teeth contact as before
Measure OVD – ensure it’s the same as before if you are using conformative approach. If not aim for 4-5mm FWS. (not as important for patient with quite a lot of teeth)
For missing anterior teeth, mark the centre, canine and smile lines on the upper rim and the centre lines on the lower rim
For conformative approach, practice closing into ICP with the patient but for reorganised practice getting patient into retruded axis position (get px to put tongue to back of their throat
For kennedy class I and II, cut locating notches into the wax edentulous areas
Apply Vaseline into wax rim notches and guide patient into ICP or retruded axis position and maintain until material sets and remove rims as one unit
Reconfirm to selected shade with the patient
Disinfect the rims and send to the lab
