Patient preference for a mandibular complete denture with a broad or minimal base: A preliminary report

Patient with

preference a broad

Bernard Evan

Levin, D.

University

for a mandibular

or minimal

D.D.S.,*

Francis,

Simon

Major,

of Southern

USAF

California,

base:

Gamer,

complete

denture

A preliminary

report

D.D.S.,

and

(DC)**

School of Dentistry,

Los Angeles, Calif.

of the properly extended denture base have been doculh e b asic requirements mented and published in many standard prosthodontic textbooks. It is generally accepted that well-placed denture borders provide peripheral seal, and thus, greater retention and stability are attained. However, more important is the fact that correct extensions of the denture base result in greater distribution of stress. The forces of mastication then are distributed over the widest supporting area, and the forces on local areas are minimized. This enables the patient to chew a greater variety of foods with more comfort and with less possibility of ridge trauma and bone loss. Nevertheless, due to design or to possible patient demand, many dentures are made with grossly underextended borders. It is a rational assumption that the average denture patient would prefer to have his teeth replaced with the least amount of material. Patients who wear mandibular dentures often object to the retromylohyoid flange, the buccal flange, and the denture base that covers the retromolar pad. These areas never have contact with foreign material and also were never covered if the patient wore a fixed or a tooth-supported removable partial denture. All too often, even the distal-extension partial denture has minimally extended borders as excessive dependence is placed on the remaining teeth for retention and support. The presence of a new denture with correctly extended borders requires the patient to make a gross adjustment in the oral environment. Complaints of difficulties in speech, mastication, swallowing, and other areas are common. EXPERIMENTAL

DESIGN

A duplicate denture was made for the mandibular arch in each of 16 patients. The dentures were made by supervised graduate and undergraduate dental students. The patients were told that the dental school was interested in evaluating different Read before *Associate **Staff

the Pacific

Coast Society

Professor and Chairman,

Prosthodontist,

David

of Prosthodontists,

Department

San Diego,

of Removable

Calif.

Prosthodontics.

Grant Air Force Hospital.

525

526

Levin,

Gamer,

and Francis

J. Pros. Dent. May, 1970

denture plastics; therefore, they would receive two lower dentures. No mention was made of the difference that was planned in sizes of the denture bases. The final impression was completed making certain of correct extensions and correct border seal. The mandibular master cast was duplicated with reversible hydrocolloid. One cast was outlined so that the posterior border ended at the anterior edge of the retromolar pad, the buccal flange ended in the center of the buccal shelf, the posterior lingual flange ended at the mylohyoid ridge, and the anterior labial and lingual flanges ended short of the mucolabial and mucolingual folds. After the trial-denture appointment, the duplicate cast was inserted in the mandibular baseplate and was mounted on the lower member of the articulator. Both lower casts were mounted separately in the same position and at the same occlusal vsertical dimension. Duplicate sets of teeth were used, and they were arranged for rsthetics and were balanced so that both setups were identical. All three dentures were processed with heat-curing acrylic resin. After processing, the dentures and and all errors resulting from casts were attached to the articulator mountings, processing changes were eliminated. The second mandibular denture was corrected without making any occlusal changes on the maxillary teeth. At the insertion appointment, the adaptations of the maxillary denture and of one mandibular denture to the mucosa were examined with disclosing paste and were corrected as necessary. The subjects were alternated so that half of them received the smaller denture base first and the other half received the larger denture base first. New jaw relation records were made, and the dentures were remounted for the final occlusal equilibration. Each patient was seen as necessary for 7 to 10 days, and all adjustments were recorded. After the adjustment period or when the patient was comfortable, the other mandibular denture was inserted using the same procrdures as described for the first denture. The first mandibular denture was retained to make certain that the other denture would be used. The patient was examined in the same manner as was followed for the first denture, The lower denture was changed again, and the previous denture was retained. After the three alternate periods, the patient was given the extra denture and was instructed to use the mandibular denture that was most satisfactory and to retain the other one for a “spare.” The following information was recorded for each subject: (1) Student’s name, (2) patient’s name, (3) sex, (4) age, (5) health, (6) number of years edentulous, (7) number of previous dentures, (8) description of the lower ridge, (9) number of adjustments for the broad-base denture, and (10) number of adjustments for the minimal-base denture. All the patients were in fair or good health and ranged in age from 29 to 77 years. All of the patients were experienced denture wearers. RESULTS Dentures were completed for 16 patients during the initial phase of this study. The dentures were judged to be technically satisfactory before the patient was asked for an evaluation. The evaluation consisted of a series of five questions. Following is a report of the subjective answers.

Patient

preference

for dentures

527

Question No. I. Which lower denture is preferred? Eleven patients preferred the broad base, one preferred the minimal base, and four had no preference. All the patients who had no preference or preferred the minimal-base denture had fair or
520

Levin,

Gamer,

with the increased facial support was noted by only two patients. SUMMARY

AND

J. Pros.Dent.

and Francis

May, 1970

from the broad-base

dentures.

Difficulty

in speech

CONCLUSIONS

If the patient is an experienced denture wearer, a careful evaluation must be made of the patient’s dental and psychologic needs. If the ridges are good and if the patient has been wearing underextended dentures with no apparent difficulty, the new dentures will be more pleasing to the patient if made with minimum extensions. However, this patient, as all patients, should be educated and cautioned about the need for regular recall and examination. If the patient has deficient ridges, the dentures should have bases with maximum extensions. The preliminary clinical investigation indicated that patients will have a favorable experience with dentures with maximum extensions. DR. LEVIN: UNIVERSITY SCHOOL

OF SOUTHERN

CALIFORNIA

OF DENTISTRY

925 b’. %TH ST. Los ASGELES, CALIF.

9OOOi

DR. GAMER: 405 N. BEDFORD DR. BEVERLY

HILLS,

DR. FRANCIS : DAVID GRANT AIR

CALIF.

90210

FORCE HOSPITAL.

TKAVIS AIR FORCE BASE FAIRFIELD, CALIF. 95668