i am facing frequent difficulties in jaw relation .i am unable to understand where i did wrong.almost every patient of mine so i suffering. please help...
every time i record jaw relation,hold lower bite plate well , it is checked in try in well..
but in final denture there is open bite or crossbite..
what and where is the fault...
Are you new to dentistry and are you a dentist? If you are new to dentistry then you shouldn't worry.
There are a few things that you need to do to ensure you have the best chance of success with complete dentures.
1. make sure you have the best possible primary impression, this will ensure the wax bite registration block (if using) seat down and suck up over the upper and lower.
2. make sure you trim your wax blocks well so that they meet all the way round to avoid any lifting and tilting off the ridges
3. there is only 1 correct point of occlusion in a patient who has had no surgery or facial skeletal abnormalities and it is called centric occlusion. this is the point where the mandibular condyle is at the upper most point when resting in the glenoid fossa. if you see mostly elderly patients who have neglected to change their dentures at least every 5 to 7 years or have purchased poor quality soft teeth NHS dentures, then it is most likely these dentures will have significant lack of posterior occlusion. This means that as the teeth wear, the patient will have slowly grown into a habit of posturing the mandible forward in order to regain some occlusion. This posturing happens slowly and the longer it is allowed to continue the harder it is for the patient to adapt to dentures in the correct height and occlusion. usually patients have a preferred side to chew on which causes the dentures to become uneven, this causes the patient to bite posturing the mandible forward and to the left or right, again, in order to gain occlusion so the patient can chew.
firstly you need asses you patient. check the dentures while they are in the mouth and ask them to bite on the their back teeth. if there is significant occlusal wear you should see this before the patient slides forward. some patients will have had one set of dentures for 60 plus years without ever changing them. these patients will usually have postured so far forward and for so long that the mandible becomes stuck in this position and seems almost impossible to correct.
with occlusal wear comes loss of overall vertical dimension. This is the classic look that most denture wearers dread and wish to avoid but invariably eventually achieve through neglect and fear of the problems new, badly made and badly occluded dentures can cause.
If a patient presents to you like this then you must never tell them that you can solve all their denture problems. you should explain how hard it will be for them to adapt to the changes and be prepared for a patient to return many times and be prepared to persevere with a patient like this, you are all they have to help them.
Because of the length of time involved in some patients wearing the same dentures, they become used to them. So right from the get go you need to make clear what the patient needs to expect. if you feel you cannot help then tell them that. it is better to send them away than spend a month loosing money and time and to be left with a complaint.
so back to the bite, firstly you should look at the extent of movement of the lower mandible by asking the patient to posture forward, if there is no movement then the patient is already posturing forward as far as is possible. next ask the patient to bring their jaw back as far as possible, if this is difficult for the patient then you can assist the patient by placing your thumb an forefinger on the patients chin and ask them to relax while manipulating the mandible gently into occlusion some pressure may be needed if the patient resists but do not force the jaw back.
you should ask the patient to bite on their back teeth while holding down the lower, prepared, bite to prevent it from tipping and moving.
the best technique to achieve centric occlusion is with the use of the Gerber or similar technique which uses a fecebow and Gothic arch tracing plates. this allows you to see the full extent of movement and record it this in conjunction with centric tray is the absolute best way and would highly recommend using it. i hope i have been of some help. please let me know if you have any more questions
take a look at these links copy and paste www.dentalgarzon.com/pdf/impression.pdf http://www.condylator.com/home.html
Andrew Pattinson dipcdtRCS(Eng)