Changes Caused by a Mand Rpd Opposing a Max CD

8/10/2019 Changes Caused by a Mand Rpd Opposing a Max CD

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Changes caused by a mcmd r remov p4BHkll

denture oppesing a muxitkwy compbe de&we

Ellsworth Kelly, D.D.S.*

School of Dentistry, Uniuersity of California, San Francisco, Calif.

A

though many advances have been made in denture prosthetics, the great prob-

lem is stil l with us: coping with the resorption of the residual alveolar ridge and

managing or preventing the secondary soft tissue changes brought on by bone

loss.

The resorption occurring beneath denture bases has been investigated*- and we

have some knowledge of the rate of resorption of the residual bony ridge. Investi-

gators agree that individual differences in the rate of resorption of the ridges are

very great. Underlying metabolic, hormonal, and nutritional causes account for this

difference and we know very little about these factors.

From clinical experience and clinical studies,lj l1 we have considerable knowledge

of the prosthetic factors which influence bony resorption. We know that moderate,

intermittent forces exerted on the bony ridge by a prosthesis may be stimulating and

help preserve rather than destroy the bony ridge. l2 We know that excessive force

causes resorption of the residual ridge. De Van I3 stated that compressive forces are

well tolerated by the edentulous ridges while shearing forces are not. This concept has

been utilized by many techniques which minimize the lateral forces exerted by

dentures. The principle of wide coverage with the complete or partial removable

denture base to minimize the force per unit area is basic14 and has served us well.

Yet we are not able to do anything for those people who are very susceptible to bone

loss because o f underlying systemic causes and who, in spite of our best efforts, often

end up with ve ry little bone remaining. On the other hand, we do have the knowledge

to prevent excessive bone loss from traumatic forces exerted by or on the denture

bases. Observation of a number of denture patients will show that we are failing to

put this knowledge into practice. Destruction of the residual ridge from occlusal

trauma is not uncommon. Very common is the almost total loss of bone in the

anterior part of the maxillae brought about by only natural anterior teeth remaining

in the mandible and occluding with a compelte upper denture. The anterior

part

of the maxillae is the weakest part of the upper arch to resist stress and when the

Read before the Academy of Denture Prosthe tics in Detroit, Mich.

*Professor of Removable Prosthodo ntics.

140


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Volume 27

Number 2

Partial denture opposing

complete

denture 141

Fig. 1. A maxillary arch that has supported a complete upper denture against six natural lower

anterior teeth and a Class I partial denture for 14 years shows the changes that this combina-

tion often effects.

lower anterior teeth occlude anterior to the basal support, trauma is inevitable. Many

of these patients have distal-extension partial lower dentures but this does not seem

to prevent this type of destruction in the upper jaw. The degenerative changes, in

these patients include more than the loss of bone. An overgrowth of the maxillary

tuberosities often occurs. These enlargements are usually fibrous but they may be

bony enlargements. Papillary hyperplasia of the palatal mucosa may occur concur-

rently. The remaining mandibular anterior teeth seem to extrude along with the

bony process, and excessive bone loss occurs in the posterior part of the ridge under

the partial denture bases. These five changes may constitute a syndrome, as they

are quite characteristic. These changes are (1) loss of bone from the anterior part

of the maxillary ridge, (2) overgrowth of the tuberosities, (3) papillary hyperplasia

in the hard palate, (4) extrusion of the lower anterior teeth, and (5) the loss of

bone under the partial denture bases. I call this the combination syndrome.

COMPLETE UPPER DENTURES OPPOSING PARTIAL LOWER DENTURES

Completely edentulous maxillae and partially edentulous mandibles with only

anterior teeth remaining are common situations. In the past two years, 130 of 495

patients treated in the prosthodontic clinic at the School of Dentistry of the University

of California received complete maxillary dentures opposing mandibular partial

dentures. This represents 26 per cent of the denture patients. Some of the partial

dentures had distal support but most of them did not.

THE COMBINATION SYNDROME

The early loss of bone from the anterior part of the maxillary jaw is the key to

the other changes of the combination syndrome. With the anterior loss of bone, a

flabby hyperplastic connective tissue makes up the anterior part of the ridge. This

hyperplastic tissue does not support the denture base and usually it folds forward,


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142 Kelly

.I. Prosthet. Dent.

February, 1972

Fig. 2. Mounted diagno stic cast s show bony loss and rolled (hyperplastic) soft tissue in the

upper anterior region, enlarged tuberosities, and extruded lower anterior teeth.

Fig. 3. With the loss of anterior maxillary bone, overgrowth of the tuberosities, and upward

migration of the lower anterior teeth, the patient shows no upper anterior teeth but does show

upper posterior teeth becaus e of the dropping of the dista l end of the occ lusa l plane of his

dentures.

forming a characte ristic

deep fold or crease (Fig. 1). As bone and ridge height arc

lost anteriorly, the posterior residual ridge becomes larger with the development of

enlarged tuberosities. These enlarged tuberosities are usually made up of fibrous

tissue,

but in some patients the bone height seems to have increased also. With these

changes, the occlusal plane migrates up in the anterior region and down in the back.

After a time, the natural lower anterior teeth migrate upward, the anterior teeth

on the complete denture disappear under the patients lip, and both dentures migrate

downward in the posterior region. The esthetics are poor with the patient showing

none of the upper anterior teeth and too much of the lower anterior teeth, and the

occlusal plane drops down to expose the upper posterior teeth (Figs. 2 and 3 i .

Excessive bony resorption under the lower removable partial denture bases occurs

to permit these changes, and often inflammatory papillary hyperplasia develops in

the palate (Fig. 4).

The histopathology of the hyperplastic anterior ridge tissue, and the fibrous tissur

which develops over the tuberosities is revealing. Microscopic examination of these

tissues shows that the flabby tissue and the hard tissue over the tuberosities are in-

distinguishable. They are made up of mature, dense, fibrous connective tissue. This

tissue in both locations has dense bundles of collagen fibers, with relatively few ceilu-

lar elements, with very few inflammatory cells. It is rather avascular with an over-

lying epithelium that is almost normal, but shows some evidence of hyperplasia

(Fig. 5). This is also the histopathology of a mature epulis fissuratum if we discount

the area of ulceration caused by the denture border. This similarity is surprising

because the hyperplastic anterior tissue is freely movable while the fibrous tissue

over the tuberosity is hard. However, all three of these conditions (the flabby anterior


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Volume 27

Number 2

Partial denture opposing complete denture 143

Fig. 4. Papillary hyperplasia in the palate often accomp anies the other changes of the com-

bination syndrome.

ridge, the fibrous tuberosity, and the epulis fissuratum) are the result o f prolonged

trauma from the denture base. Therefore, the fact that the tissue response is the

same is logical.

The difference in consistency of fibrous tuberosities and flabby anterior ridges

must be explained on a mechanical basis. The anterior bony ridge has virtually dis-

appeared and the connective tissue replacement is a narrow projection of tissue virtu-

ally unsupported on the labial or lingual surface. On the other hand the fibrous tissue

over the tuberosity is supported by a broad base of bone below.

MECHANICS WHICH PRODUCE THE COMBINATION SYNDROME

The resorption of the bone in the anterior region initiates the changes which we

call the combination syndrome. Natural anterior maxillary teeth have increased

bony resorption under maxillary dentures. + 5 While bone is being lost in the anterior

region in the upper jaw, bony resorption also occurs under the mandibular partial

denture bases. The maxillary denture then moves up in the anterior region and

down in the posterior region in function. This tipping action is illustrated in the

diagram (Fig. 6) which was traced from cephalometric radiographs of a patient who

had been wearing a complete upper denture opposing a lower partial denture for 16

years. The fulcrum of movement in this patient is in the cuspid-first bicuspid region,

Our patients show that at first the fulcrum is well to the posterior, just anterior to

the tuberosity.

With the posterior palatal seal, a negative pressure is produced posterior to the

fulcrum line. This negative pressure may account for the enlarged tuberosities and

the papillary hyperplasia. Carlssonl observed one patient who had an increase in

the maxillary ridge height in the molar region after wearing dentures for two years.

He postulated : It may have been due to the development of a fibrous part pos-

siblyl owing to the suction ef fect when the denture moved. A number of authors15-1r

have associated a void, a suction chamber, or other form of negative pressure with


5/11

144 Kelly

Fig. 5, A B. Histolo gic sect ions of the lesion s: (A) A flabby (hyperplastic) anterior ridge

(x100) ; (B) fibrous tube rosity (x100).

inflammatory papillary hyperplasia of the palate. Wictorin states that to prevent

bony resorption, mechanical forces must be distributed over as large an area of the

basal seat as possible, and the denture must make as little movement as possible

against its basal seat, and that these factors are strongly interconnected. With the

lower anterior teeth causing trauma and bone loss from the anterior part of the

maxillae, and with the denture base moving more and more on its foundation, a very

destructive situation exists.

All kinds of questions come to mind. How fast do the degenerative changes de-

velop? Is excessive bone loss in the anterior part of the maxillae with the other

changes that follow inevitable or does it occur only in neglected patients, those

without proper follow-up treatment in refitting the denture bases and readjustment of


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z zr2


Fig. 5, C D. (C) Inflammato ry papillary hyperp lasia (x40) ; (D) the sam e (x100). The

similarity of A (hyperplastic ridge tissue) and B (fibrous tuberosity) is discu ssed in the text.

The papillary hyperplasia shows (n) the fibrous core, (b) the hyperplastic epithelium, and (c)

inflammatory cells.

occlusion? If it is from neglect, what kind, and what amount of care is necessary to

prevent it? Will the changes occur in all patients or only in susceptible patients with

underlying metabolic, hormonal, or nutritional deficiency?

PATIENT HISTORIES WITH CEPHALOMETRIC RADIOGRAPHS

In an effort to find answers to some of these questions, we started a study of 20

patients who were receiving complete maxillary dentures opposing distal-extension

removable partial dentures. Only six of these patients have returned fai thfully over


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146

Kelly

J. Prosthet. Dent.

Frbruary, 1972

Fig. 6. A diagram made from tracings from two cephalom etric radiographs, one at physiologic

rest position and the other with the teeth in centric occlu sion. In this patient, with an advanced

combina tion syndrome, the movement of the denture base is very great, cau sing positive pres-

sure anterior to the fulcrum (F) and negative pressure posterior to this position.

Fig. 7. A lateral cephalom etric radiograph of one of the subjec ts shows the lead wire outlining

the soft tissues of the ridge.

Fig. 8. The lead wire is in place after the radiograph was made. The lead wire adheres to

and is very slightly embedded into the soft tissue.

a three-year period so no conclusions can be drawn from this preliminary report.

We made serial cephalometric radiographs with a 0.25 mm. diameter lead wire

outlining the soft tissue on the right side of the ridge (Figs. 7 and 8). All of the

patients received maxillary complete immediate dentures opposing Class I lower

partial dentures. All were first-time denture wearers. The immediate dentures were

constructed after the posterior teeth had been extracted and a healing period al-

lowed. The first radiograph was made after the initial healing of the anterior part

of the maxillary ridge had taken place, and after the anterior section of the im-

mediate denture had been refitted with cold-curing acryl ic resin. This was usually

about four weeks after insertion of the dentures.


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Volume 27

Number 2


Fig.

9. Cephalometric tracings of each of the six subje cts. They were made three years apart,

and show the changes that have occurred. The solid lines show the initial outline the bone

and soft tissue, the dotted lines indicate these outlines three years later (Table I).

A second radiograph was made after six to eight months. The patients were

seen regularly over the first few months, and the dentures refitted and serviced as

needed. After the first year, the third radiograph was made. At this time, the max-

illary denture was relined or a new denture was constructed. After this, the patients

were called annually for examination and radiographs.

Measurements were made directly on the radiographs, using the sella-nasion line

as a base. The results are expressed as millimeters of increase (plus) or millimeters

of decrease (minus) in the residual ridge height. Table I shows these data for the

maxillary bone and soft tissue.

Tracings were made from the cephalometric radiographs. These show the

changes graphically but not as accurately as the measurements directly on the radio-

graphs (Fig. 9).

All of the patients showed a loss of 1 to 3 mm. of ridge height in the anterior

region. All of the subjects showed a loss of the underlying bone as well. All o f the

subjects showed an increase of 1 to 2.5 mm. height of the tuberosity with all but

one having a corresponding increase in the height of the underlying bone. One sub-

ject had an increase in the height of the tuberosity but a slight loss of underlying

bone. All of the subjects show a 1 .O to 1.5 mm. extrusion of the lower anterior teeth.


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148

elly

J. Prosthet. Dent.

Februaty, 1972

Fig. 10. One of the subjec ts, although given follow-up treatment, shows the beginning of de-

generative changes . The soft tissue in the anterior part of the maxillary ridge is thickened and

soft. Note the characte ristic horizontal fold on the labial surface of the maxillary ridge.

Table I. Each figure represents an increase or decrease in millimeters of ridge height

over a period of three years

Posterior tuberosity ridge height (

Anterior ridge height

Patient

A, age 63

B, age 51

C, age 46

D, age 43

E, age 35

F, age 34

Soft tissue j Bony ridge Soft tissue 1 Bony ridge

+2.5 +1.7 -2.2 -1.7

+1.0 +1.0 -3.0 ..~3.0

+1.3 +0.5 -2.2 -1.2

12.0 +1.7 -1.5 -1.0

cl.0 --0.2 -2.9

-0.7

+1.3 +o..i -1 .o

--0.5

This is significant since the measurements are very accurate because of the stability

of the bony landmarks at the midline.

One patient is beginning to show signs of the deterioration of the anterior part

of the upper ridge which we attribute to trauma from the lower anterior teeth. This

patient has a flabby thickening of the tissue, inflammation of the incisive papilla, and

the beginning of a fold forming the labial surface of the ridge (Fig. 10) .

All of the subjects have been successful denture wearers, well satisfied with their

prosthesis. They have received better than average follow-up treatment in refitting

the bases and equilibrating the occlusion. With the loss of tissue demonstrated in the

anterior part of the upper jaw, and with a positive change developing in the posterior

part of the ridge, and with the lower anterior tooth migration, it appears that any or

all of these patients could develop the typical signs of the combination syndrome.

PREVENTION OF THE COMBiNATION SYNDROME

Preventing the degenerative changes that complete maxillary dentures opposing

the Class I partial dentures bring about may only be possible through treatment


10/11

Volume 27

Number 2


planning to avoid this combination of prostheses. Complete lower dentures opposing

natural maxillary teeth are impossible prosthodontic combinations. Treatment plan-

ning should avoid the necessity for such a combination. The same could be done to

eliminate the combination of complete upper dentures opposing Class I lower partial

dentures. I do not advocate extracting lower anterior teeth to accomplish this but

rather to retain weak posterior teeth as abutments by means of endodontic and

periodontic techniques. Endosseous endodontic implants and the amputation of one

lower molar root to preserve the other as an abutment are examples of some of the

methods that could be applied. An overlay denture on the lower may avoid the com-

bination syndrome from developing. Overlay dentures utilizing the lower tooth

roots for stabilization provide a complete denture occlusion.

SURGICAL CORRECTION OF CHANGES IN THE BASAL SEAT

Even after much damage has been done and gross changes have taken place,

many dentists and patients prefer to remake the combination rather than sacrifice the

remaining lower anterior teeth to make complete dentures. Surgery can do much to

rehabilitate these patients. The flabby (hyperplastic) tissue can be removed, the

papillary hyperplasia can be eliminated, and the enlarged tuberosities can be re-

duced. This allows the distal end of the occlusal plane to be raised to the proper

level, and allows the lower partial denture bases to be fully extended. This is ex-

tremely important, and covering the maximum area possible for support of

partial denture bases would help prevent the combination syndrome. Covering the

retromolar pad where muscle and raphe attachments prevent or reduce resorption,

and covering the buccal shelfI is necessary to retard bone loss. Often this is not

done with removable partial dentures.

SUMMARY

Almost inevitable degenerative changes develop in the edentulous regions of

wearers of complete upper and partial lower dentures. We have followed six patients

over a three-year period with cephalometric radiographs to determine if these

changes could be detected. In all six subjects, early changes that could become gross

changes were apparent. In one of them degenerative clinical change is beginning to

appear.

This problem might be solved with treatment planning to avoid the combination

of complete upper dentures against distal-extension partial lower dentures. The

alternative of complete maxillary and mandibular dentures is not attractive to pa-

tients. Preserving posterior teeth to serve as abutments to support lower partial

dentures and to provide a more stable occlusion is a better alternative.

Ill-fi tting dentures have been blamed for all of the lesions of the edentulous

tissues, yet the most perfect denture will be ill-fitting after bone is lost from the

anterior part of the ridge. Removable dentures need periodic attention at least as

often as the natural teeth.

The author would like to express his appreciation to Dr. Louis S. Hansen for his help and

advice on oral pathology and to Dr. Leonard Chong for his help with the cephalom etric

radiographs and tracings.


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150 Kelly

J. Prosthet. Dent.

February, 1972

References

1. Carlsson, G. E.: Measurements on Casts of the Edentulous Maxilla, Odont. Revy. 17:

386-402, 1966.

2. Carlsson, G. E.: Changes in the Jaws and Facial Profile after Extractions and Prosthe tic

Treatment, Trans. R. Sch ools Dent., Stockholm and Umea, No. 12: 16, 1967.

3. Carlsson, G. E., and Persson, G.: Morphologic Changes of the Mandible after Extraction

and Wearing of Dentures, Odont. Revy. 18: 27-54, 1967.

4. Carlsson, G. E., Bergman, B., and Hedegard, B.: Changes in Contour of the Maxillary

Alveolar Proces s Under Im mediate Dentures, Acta Odont. S tand. 25: 1-31, 1967.

5. Wictorin, L.: Bone Resorption in Cases With Complete Upper Denture, Acta Radiol.

Sppl. 228, 1964.

6. Hedegard, B.: Some Observations on Tis sue Changes With Immediate Maxillary Dentures,

Dent. Pratt. 13: 70-78, 1962.

7. Atwood, D. A.: A Cephalometric Study of the Clinic al Rest Positio n of the Mandible.

II. The Variability in the Rate of Bone Loss Following the Removal of Occ lusal Contacts,

J. PROS THET. DENT . 7: 544-552, 1957.

8. Atwood, D. A.: Some Clinic al Factors Related to Rate of Resorption of Residual Ridges,

J. PROS THET. DENT . 12: 441-450, 1962.

9. Atwood, D. A.: Reduction of Residual Ridges as a Disease Entity, Essay presented at

meeting of the American Prosthodontic Society, Las Vegas, 1970.

10. Neufeld, J. 0.: Changes in the Trabecular Pattern of the Mandible Following the Loss

of Teeth, J. PROS THET. DENT . 8: 685-697, 1958.

11. Applegate, 0. C.: Conditions Wh ich May Influence the Choice of Partial or Complete

Denture Service, J. PROS THET . DENT. 7: 182-196, 1957.

12. Carlsson, G. E., Thilander, H., and Hedegard, B.: Histolo gic Changes in the Upper

Alveolar Proces s After Extractions With or Without Insertion of an Immediate Full

Denture, Acta Odont. Stand. 25: 123-146, 1967.

13. De Van, M. M.: An Analys is of Stress Counteraction on the Part of Alveolar Bone With

a View to Its Preservation, Dent. Cosmo s 77: 109-123, 1935.

14. Boucher, C. 0.: A Critical Analys is of Mid-Century Impression Tech niques for Full

Dentures, J. PRO STHET . DENT. 1: 472-491, 1951.

15. Fairchild, J. M.: Inflammatory Hyperplasia of the Palate, J. PROS THET. DENT . 17: 232-

237, 1967.

16. Hickey, J. C., and Stromberg, W. R.: Preparation of the Mouth for Complete Dentures.

J. PROS THET . DENT . 14: 61 l-622, 1964.

17. Campb ell, R. L.: Relief Chambers in Complete Dentures, J. PROS THET. DENT . 11: 230-

236, 1961.

UNIVERSITY

O F

CALIFORNIA

SCHOOL OF DEN TISTR Y

SAN FRANCISCO, CALIF. 94422

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