Acquiring space for partial dentures

William J. McGill, D.D.S.

Veterans Administration Hospital, Cleveland, Ohio

L ack of interarch space in edentulous regions is one of the obstacles to satis- factory partial denture construction. In most patients, the maxillary tuberosity and retromolar pads are involved. The long-standing absence of a sufficient number of opposing teeth has resulted in extrusion of the unopposed teeth. Correction of conditions which produce chronic irritation to the oral mucosa is a primary ob- jective of dental therapy.

EXAMPLE 1. INSUFFICIENT SPACE BETWEEN A LOWER MOLAR AND THE UPPER RIDGE

The teeth of patient No. 1 (Fig. 1, A) show an interarch relationship which needs consideration. The patient was a 25-year-old man who was well nourished, and maintained excellent oral hygiene. His remaining teeth were in a good state of repair. The alveolar mucosa in this patient was indented and irritated from the extruded lower teeth. He had been using a partial upper acrylic resin denture (Fig. 1, C) which had a perforation in the extension area (arrow). This accommo- dated the lower right second molar. Clinical examination showed that the partial denture was not adequate, mainly because of the trauma to the right maxillary mucosa from the pressure of the opposing teeth.

Some of the submucosal fibrous tissue was removed surgically, and the sutures were removed five days later. A cold curing acrylic resin was placed in the denture in the region of the surgery. The patient was instructed to wear the denture con- tinually.

Later, the denture was relined twice by the same method. Excellent results (Fig. 1, B) were accomplished in thirty-one days: Adequate interarch space was obtained, and the source of chronic trauma had been eliminated.

Alginate (irreversible hydrocolloid) impressions were made, and a chrome- cobalt partial upper denture, with metal cusp-forms over the treated area, was constructed (Fig. 1, D) and inserted.

EXAMPLE II. INSUFFICIENT SPACE BETWEEN AN UPPER MOLAR AND THE LOWER RIDGE

Another common relationship in the third molar region is shown in Fig. 2. This patient was a 23-year-old man. His remaining teeth were in a fair state of

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Fig. 1 A, The tipped and extruded molar occupies the space needed for an upper denture base. B, Space is provided by surgical removal of tissue from the maxilla, and a series of relines of the denture base. C, The lower molar had worn a hole through the partial denture. D, The chrome-cobalt denture carries metal cusp forms in the region of the newly acquired space.

repair. Clinical and roentgenographic examination indicated sufficient height of mucosa, so it was not necessary to remove any bone.

In order to treat this situation, the final maxillary and mandibular casts were mounted on an articulator. Then the lower cast was scraped over the retro- molar area to produce a minimal interarch space. A temporary partial lower den- ture (Fig. 2, B) was constructed, and it extended sufficiently to cover the critical area.

The excess submucosal fibrous tissue was surgically removed from the man- dibular third molar region. The denture base was relined with a cold curing acrylic resin. The patient was advised to wear the partial denture continually, and to maintain good oral hygiene. Later, the denture was relined twice with cold curing resin in order to maintain pressure and secure the desired interarch space.

When the chrome-cobalt frameworks for partial upper and lower dentures were made (Fig. 2, E), a metal base was used for attaching the acrylic resin on

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Acquiring space for partial dentures 165

Fig. 2 A, An extruded upper molar occupies the space necessary for a lower partial denture base. B, The space is made available by surgical removal of fibrous tissue, and subsequent re- lining of a temporary partial denture base. C, The relationship before treatment. D, The treatment partial lower denture. E, The metal frameworks in position on their casts.

the right side. Should future changes of supporting structures occur, these could be rebased when indicated.

SUMMARY

Two methods which will aid in the solution of problems relating to insufficient inter-arch space for partial dentures have been described.

10701 EAST BLED. CLEVELAND, OHIO 44106