The Fit of Your Dentures
What factors determine fit?
- Anatomical undercuts – Bony areas of the gums that the dentures are able to grab onto
- Sponginess of the tissue – When tissue is depressed it can bounce back
- Saliva – Moisture between the denture and the gums
- Spacing, size and function of the dentures – the dentures must be made within the limitations of the patients’ mouth……
Do Complete Upper and Lower Dentures Fit the Same?
No. They are completely different. The upper denture is held in place by suction, most of the time. The lower denture just sits on top of the gums and the patient must balance the denture while they eat.
It is unrealistic to compare the fit of the upper denture to that of the lower.
The Complete Upper Denture Fit
The upper denture fit is easy to attain if the following factors are present:
- Bony undercuts
- Spongy Tissue
- Saliva
- Denture made within the spacing of the patient’s mouth……
If the patient has little to no upper gum remaining due to bone loss……the upper denture will become more difficult to fit than that of the lower due to gravity.
Denture adhesive, bone grafting and or implant over dentures are the only other alternatives.
The Complete Lower Denture Fit?
This is the difficult denture to fit in comparison to the upper. The lower just sits on top of the gums while the tongue and cheek muscles are lifting it. The lower denture literally must be balanced by the patient while eating.
If there are bony undercuts in the anatomy they will be present in the design of the lower denture. Bony undercuts allow the denture to lock on to the gum. If they are not present, there is very little that can be done.
Denture adhesive, bone grafting and or implant over dentures are the only other alternatives.
When it comes to the fit of the lower denture we want you to be as comfortable as possible.
Lower dentures can lift and when bitten down sideways are painful. As the tissue looses moisture and collagen due to aging, the sensitivity to a hard based lower denture increases. In addition, as the lower gum resorbs, the base of the denture is sitting directly on top of the nerve bundles under the tissue. When the patient bites down in the above scenario it is painful. We recommend a soft liner on the lower denture in most cases.
A soft liner offsets the hard jarring motion of biting down on the lower denture, acting as a mini-shock absorber on the gums.
For all the above reasons, the expectations are not realistic when comparing the fit of the lower to that of the upper.