PROSTHETIC DENTISTRY

A SYMPOSIUM

¹ Philadelphia, Pa.
² New York City

Whenever a subject is presented for consideration, a few important facts represent its sum and substance, and can be epitomized. Let us see what we have in this paper:

Pressure balance is the greatest factor in the stability of partial dentures. Through pressure balance we can often eliminate the different forms of attachment.

Pressure balance can be had only by a correct bite taken with a trial-plate that is as accurate as the finished denture, in order to control absolutely the wax upon which the bites are taken.

Whatever lateral movement the patient is able to take must be unrestrained and unobstructed in the excursion of the mandible through the occlusal plane and compensating curve—best obtained by milling-in the bites with some abrasive material incorporated inthe wax.

A denture of any kind must be subservient to anatomical function. Certain simple but definite engineering principles must be incorporated in its construction.

There must be no sacrifice of function to mechanism.

The life of any tooth to which a clasp is attached is more at the mercy of pressure balance than of adaptation of the clasp itself.

In the bilateral extension, the labial bar-plate is probably the best and most stable of all dentures.

The force exerted in mastication must be in the same direction as that exerted in the natural teeth; namely, through the long axis, and in conformation with the triangle or cone that definitely fixes the arc of the curve upon which teeth function, and compensates for the fact that the lower arch is larger than the upper.

Unless occlusal balance and the ability to exert all the pressure possible is borne in mind, there will always be abrasion and soreness, together with undue and undesirable absorption of the ridges, owing to strangulation. (This is the cause of many methods and much literature.) Older persons bring into play the lateral excursion more than younger patients.

An effort must be made to reproduce the mandibular path and the peculiar freedom of movement of the unrestrained natural excursion of that organ, as much for the actual efficiency of the denture as for its balance, and its comfort for the patient.

There is only one way to appreciate fully what is meant by "comfort," "efficiency", and that is for the operator to wear the type of denture referred to. Then he will neglect no opportunity to get correct articulation and pressure balance by making many preliminary steps and much final adjustment directly in the patient's mouth. When this is done, there will be fewer changes in the human countenance as time goes on.