Resor Ption

8/18/2019 Resor Ption

1/13

The continuing reduction of the residual alvealar

ridges in complete denture wearers: A

mixed-longitudinal study covering 25 years

Antje Tallgren, L.D.S., Odont.Dr.*

The Royal Dental College, Copenhagen, Denmark

1 he ef fect of the wearing of complete dentures on facial morphology has been

the object of a series of longitudinal studies by the present author.l-* The resorption

of the residual alveolar ridges during a seven-year period of denture wear was found

to have caused a pronounced reduction of the pre-extraction morphologic face

height and an accompanying although less marked reduction in the rest fact

height.2 In subjects provided with complete upper and partial lower free-end den-

tures, the decrease in facial height was, on the average, only half that noted in

the complete denture group. The adaptive changes in the rest face height to the

alterations in the morphologic face height have been confirmed in several other

studies.5-10

A study of the morphologic changes in the facial skeleton during seven years

of complete denture wear3 revealed that the decrease in facial height was mainly

due to a pronounced reduction of the mandibular ridge and a consequent forward-

upward rotation of the mandible. The change in mandibular position was accom-

panied by a marked increase in mandibular prognathism, i.e., a forward positioning

of the chin in relation to the upper part o f the face. The reduction of the residual

alveolar ridges was most rapid during the first year of denture wear.* This is in

accordance with findings by other authors for various categories of denture

wearers.11-15 Despite the marked alveolar bone loss and resultant alterations in jaw

relationship, no dimensional changes were found in the cranial base, the upper part

of the face, or the basal parts o f the mandible. Nor was there any evidence of

remodelling changes in the gonial process.3

Th is study was supported by a United States Pub lic H ealth Service research grant

DE-02858 from the National Institute of Dental Research, National Institutes of Health,

Bethesda, Md., and by the Danish Medical Research Counc il.

Presented before the Greater New York Academy of Prosthod ontics, New York, N. Y.

*Research Ass ociate, Institute of Orthodontics, Royal Dental College, Copenhagen, and

Lecturer in Prosthe tics, University of Turku, Finland.

120


2/13

Reduction

of

ridges in denture wearers 121

A study of the positional changes of the complete dentures due to the alveolar

resorption* revealed particularly marked changes of the lower denture. In addition

to a pronounced settling on the basal seat, the lower denture displayed also a for-

ward slide on the residual ridge. The upward rotation of the mandible and the

forward slide of the lower denture led to a reduction in the horizontal overlap, and

in some patients, even to a horizontal overlap of the lower teeth over the upper ones.

The resorption of the residual ridges and the changes in jaw and occlusal re-

lationships showed great individual variation. Analysis of the relationship between

morphologic characteristics of the facial skeleton and the anterior bone loss during

seven years of denture wearlG revealed a marked association between the mandibular

shape and the resorption, especially of the lower ridge.

In order to investigate the continuing reduction of the residual ridges during

protracted wearing of dentures, a cephalometric radiographic follow-up study was

made of two groups of complete denture wearers-those with 15 and those with

25 years’ experience with denture wear. Furthermore, the individual variations in

mandibular bone loss were subjected to closer analysis.

MATERIAL AND METHODS

Samples studied

The two groups studied consisted of subjects who had been provided with com-

plete maxillary and mandibular dentures at the Institute of Dentistry, Universi ty

of Helsinki. The first sample Group A) comprised nine subjects from a sample of

11 complete denture wearers, previously followed during seven years of denture

wear.2, 3 The nine subjects seven women and two men) were examined after a

total of 13.5 years of denture wear, and six of these also after a total of 15 years of

denture wear. The mean age of the nine subjects who were examined after 13.5

years was 63.7 years range 33 to 76 years). The reductions of the sample were in

two instances due to death, one subject had moved to another area of the country

and was not able to attend, and two subjects did not respond to repeated attempts

at follow-up.

The second sample Group C) consisted of 20 subjects from a previous sample

of 45 subjects, who at the initial examination1 had been wearing complete dentures

for ten years. These 20 subjects, all women, were re-examined 15 years after the

first examination, that is, after a total of 25 years of denture wear. The mean age

of the subjects at the 25 year stage was 72.1 years range 59 to 88 years). The re-

duction of the initial sample was in 11 instances due to death, four subjects could not

be traced, six subjects did not respond to repeated attempts at follow-up, and four

subjects were unable to attend due to illness or old age.

Prosthetic treatment

Details regarding the prosthetic treatment have been given in a previous pub-

1ication.l In both groups, the treatment undertaken was of the conventional type,

the dentures being constructed tw? to four months after extraction. In Group C,

all dentures were made of vulcanite; in Group A, the dentures were made of acrylic

resin. In both groups the dentures were provided with porcelain teeth cusp angula-

tion about 15 degrees) .


3/13

122 Tallgren

J. Prosthet. Dent.

February, 1972

Fig. 1. Measurements of alveolar resorption. The anterior height of the upper and lower

alveolar ridges at two stages of observation a and

b).

The difference a -

b

represents the

reduction in height of the alveolar ridges between the stages of observation. The shaded area

represents the area of resorption.

Fig. 2. The shape of the mandibular base in terms of the P-angle and the gonial angle

RL-ML) .

For the subjects in Group A no rebasing of the dentures had been done during

the first seven years of denture wearing. For subjects Nos. 17, 31, 32 and 53 see

Fig. 6), the dentures were remade or rebased between the seven-year and the

13.5 year controls, and for subject No. 2, the dentures were rebased after the 13.5

year control.

In Group C, seven of the 20 subjects Nos. 4, 7, 12, 19, 29, 43, and 45-see

Fig. 7) were still using their 25-year-old vulcanite dentures without any corrections

of the dentures having been made. For the remaining 13 subjects, new dentures of

acrylic resin had been made during the period between the two radiographic ex-

aminations.

Radiographic procedure

The standardized radiographic cephalometric procedure for obtaining the pro-

file head f ilms has been accounted for in previous publications.l, 2 The fi lm series

of each subject obtained in the present follow-up study consisted of two or three

radiographs made in the rest position of the mandible and one radiograph made

with the teeth in occlusion. The rest position exposures were made both with and

without the dentures in the mouth.

The enlargement of the structures in the median plane was the same as in

previous recordings 6.6 per cent) . No corrections have been made for this enlarge-

ment.

Measurements

The variables studied were the reduction in anterior height of the bony alveolar

ridges and the anterior resorption areas Fig. 1). Furthermore, the shape of the

mandible was measured in terms of the P-angle LindegHrd17) and the gonial

angle, RL-ML Fig. 2). For details regarding measurements and method errors

the reader is referred to a previous article.

3 A brief survey of methods of measure-

ment is given below.


4/13

Reduction

of


ANTERIOR HEIGHT OF ALVEOLAR RIDGES

H E I GH T

m m

30 -

MANDIBLE

RoUPC

MAXILLA

GROUP C

I I t I

I

I

BE Al’Jzlyr. lY% . 1yrs. 10yrs.

13syrs.

25yrs.

Fig. 3. The mean reduction in anterior height of the bony alveolar ridges in 9 subje cts of

Group A during 13.5 years of com plete denture wearing (3 years: n = 6), and in Group C

between the 10 year and 25 year stages of denture wearing (n = 20). The diagram is based

on the mean height of the residual alveolar ridges at the different stages of observation.

BE = Before extraction. AI = After insertion.

All measurements were obtained from the rest position films without dentures,

the other films from the same series being used as an additional check o f bony

contours and of measuring points. The linear and angular measurements were made

directly on the films according to the method of Bjork and So10w.~~ The measure-

ments of the resorption areas Fig. 1) were made on contour tracings by planimeter,

the mean of three .registrations of each area bein g used in the subsequent analysis.

The statist ical methods used in the present study have been reported else-

where.3’ lG Examination of the relationship between pairs of variables was per-

formed graphically and by calculation of correlation coefficients. The 5 and 1 per

cent significance limits for the correlation coefficients for the sample size of 20 are

0.44 and 0.56. All calculations were carried out at NEUCC, the Northern Europe

University Computing Centre in Copenhagen.

RESULTS

Reduction in height of the alveolar ridges

The mean reduction in anterior height of the bony alveolar ridges in Groups A

and C is shown in Table I and Fig. 3. The mean rate of reduction in the two

samples is given in Table I and is presented graphically in Figs. 4 and 5. The mean


5/13

124 Tallgren

J. Prosthet. Dent.

February, 1972

MEAN RATE OF REDUCTION OF ALVEOLAR RIDGES

mmtyear

0

EEAl’hlyr.

3yrs.

7yrs.

10yrs.

13.5yc5. 15yrs. 25yrs.

Fig. 4. The mean rate of reduction in anterior height of the maxillary and mandibular

alveolar ridges (mm/year) in Groups A and C. Based on Table I. BE = Before extraction.

AI = After insertion.

MAXILLA

El

GROUP A

GROUP C

Table I. Mean reduction and mean rate of reduction in anterior height of the bony

alveolar ridges in Group A and Group C during the total period of observation

BE, before extraction; AI, after insertion)

Reduction 1 Rate

of

reduction

Observa-

(mm.)

(mndyr.)

tion

Difference,

period

Maxilla Mandible

mand.-max.

Maxilla Mandible

(yr.) No. F 1 s

IF

s 2

jY T

Group A:

BE-AI

AIS

S-1

AI-1

1-3

3-7

AI-7

7-13.5

AI-13.5

13.5-15

11 1.27*

1.68

1.41* 1.63 0.14

11 0.50**

0.50 1.14***

0.67

0.64*

11 0.23 0.41 1.27*** 0.72 1.04**

11 0.73*(” 0.75 2.41*** 0.89 1.68”Y’

7 0.21 0.39 2.21*** 0.91 2.00X”

7 0.86” 0.85 2.71*** 1.11 1.85**

11 1.73”‘s 0.98 6.55***

2.52

4.82***

9 0.39” 0.33 1.44*** 0.58 1.05**

9 2.22*** 1.09 7.72*“* 2.88 5.50**

6 0.08

0.20

0.33”

0.26 0.25

5.08

5.64

1 .oo 2.28

0.46

2.54

0.73

2.41

0.11

1.11

0.22 0.68

0.25 0.94

0.06 0.22

0.05 0.22

Group C:

lo-25 20 0.75*** 0.53 3.00*** 1.53 2.25*** 0.05 0.20

*Denotes the 5 per cent level of significa nce.

**Denotes the 1 per cent level of significa nce.

***Denotes the 0.1 per cent level of significa nce.


6/13

Volume 27

Number 2

Reduction

of

ridges in denture

wearers 125

MEAN RATE OF REDUCTION OFALVEOLAR RIDGES

mm/ year

MANDIBLE

q

GROUP A

( J GROUP C

1

0

EEAl’hlyr.

3yrs. 7yrs. 10yrs. 13.5yrs.15yrs.

zsyrs.

Fig. 5.

See legend for Fig. 4.

changes reported below are all significant at least at the 5 per cent level if not

otherwise stated.

Regarding the previously reported reduction of the alveolar ridges in Group

A during seven years of denture wear, it should be noted that during the pre-

insertion period no significant difference between the maxillary and mandibular

reduction was found. Owing to a marked reduction of the lower ridge but only

slight reduction of the upper ridge during the subsequent years of denture wear,

the relationship between the mandibular and maxillary reduction gradually in-

creased to approximately 4: 1 at the seven-year stage.4

The present follow-up study revealed a continuing reduction of the residual

ridges. In Group A the mean decrease in anterior height of the lower ridge be-

tween the seven-year and 13.5 year controls was 1.4 mm. and that of the upper

ridge was 0.4 mm. In three of the nine subjects no further reduction of the upper

ridge was observed during this period, while the lower ridge was reduced in all

subjects. The mean decrease in mandibular height during the total period of 13.5

years was 7.7 mm. and the maxillary reduction was 2.2 mm. Of the six subjects

examined at the 15 year stage of denture wear, four subjects showed a further

reduction of the lower ridge, while only one subject displayed reduction of the

upper ridge.

In Group C the mean reduction in anterior height of the lower residual ridge

between the 10 year and 25 year stages of denture wear was 3 mm. and that of

the upper ridge was 0.8 mm. Regarding the individual results, all subjects dis-

played reduction of the lower ridge, while in three subjects no reduction of the

upper ridge was found.


7/13

126 Tdgren

J. Prosthet. Dent.

February, 1972

A 53

Q A31

Q

51

A2 A 38

A

Al7

63

32

I

5cm

I

Fig. 6. Individual tracings of the anterior bone loss of the lower ridge during 13.5 years of

complete denture wearing (Group A). The tracings show the bony contour of the anterior

residual ridge at the stage of insertion of the dentures, at the 1 year, 7 year and 13.5 year

stages of observation. Sequence according to magnitude of bone loss at the 7 year stage Sub-

jects Nos. A53 and A2 are men.

Table II. Resorption areas in the anterior region of the bony alveolar ridges in

Groups A and C AI after insertion)

Observation

Maxilla Mandible

period

(mm.l) (mm.2)

Group

(yr.)

No. Min. 1 Max. ( 5F ( s Min. ( Max. F ( s

A AI-13.5 9 10.3 47.7 27.84 12.74 20.3 120.0 58.59 36.89

C

IO-25

20

0.0 22.3 6.40 5.17 3.7 55 .3 23.93 13.61

The mean rates of reduction for the upper and for the lower ridge during the

follow-up periods were of the same magnitude in the two samples Table I, Figs.

4 and 5). As also seen in Fig. 3, the mean curves for the respective maxillary and

mandibular reduction run parallel. Judging from the mean alveolar reduction in

the two samples studied, the average reduction in anterior height of the lower

ridge during a 25 year period of complete denture wear would amount to some

9 to 10 mm. and the reduction of the upper ridge to some 2.5 to 3 mm.

Individual variation in alveolar bone loss

The magnitude of alveolar resorption showed great individual variation in both

samples of denture wearers. The means and variabilities for the resorbed areas in

the anterior region of the residual ridges are given in Table II.

The anterior bone loss of the lower ridge in the nine subjects of Group A is

shown in Fig. 6. The tracings show the bony contour of the residual ridge at the

stage of insertion of the dentures, at the one-year, the seven-year, and the 13.5 year

stages of denture wearing. The marked alveolar bone loss during the first year of

denture wearing and the gradual decrease in the rate of resorption is clearly

noticeable.


8/13

0 c

9

0 c LO

0

C23

Reduction

of


0

Cl9

a

c0

c3

c 15

0

c 33

8

C32

0 c42

c7 C6

b

4

0

Cl&

0 CL3

8 c Ll

5 cm

I

i

Fig. 7. Individual tracings of the anterior bone loss of the lower ridge between the 10 year

and 25 year stages of complete denture wear Group C, women). Sequence according to

magnitude of bone loss.

Regarding the shape of the individual resorption areas, each subject displayed

more or less the same resorption pattern throughout the period of denture wear.

In some subjects a “flat” pattern with mainly vertical bone loss was noted, while

other subjects displayed a more

“sharp” pattern with marked horizontal bone loss.

The anterior mandibular bone loss in the 20 subjects of Group C between the

10 and 25 year stages of denture wear is shown in Fig. 7. Like the findings in

Group A, the magnitude and pattern of resorption showed great individual varia-

tion. Analysis of the relationship between the anterior mandibular bone loss and

the shape of the mandible Figs. 8 and 9) revealed a marked positive correlation

with the P-angle r = 0.75”“) and a marked negative correlation -0.63”“) with

the gonial angle RL-ML) . A p renounced mandibular bone loss thus was seen

in subjects with a marked mandibular base bend a large p-angle and a small gonial

angle), while a less marked resorption was seen in subjects with a flattened man-

dibular base a small P-angle and a large gonial angle) . No association was ob-

served between the mandibular bone loss and the height of the lower ridge at the

10 year stage r = -0.01).

**Significant at the 1 per cent level.


9/13

120 Tallgren

,I. l’rosthet. Dent.

February, 1972

mm21

.

.

.

.

. l

i I

.

I

20 2L

1

.

.

.

.

.

.

.

L __

26 32 degrees

MANDIBULAR SHAPE iJ3 -ANGLE)

Fig. 8. Diagram illustrating the relationship between the mandibular shape (P-angle) and the

anterior bone loss of the lower ridge between the 10 year and 25 year sta ges of complete

denture wear (r = 0.75**).

.

.

.

.

l

.

.

.

.

.

.

. .

.

.

.

.

.

.

,i-----------LL

J

11L 116

122 126 130 13L degree t5

MANDIBULAR SHAPE (RL - ML)

Fig. 9. Diagram illustrating the relationship between the gonial angle (RL-ML) and the

anterior bone loss of the lower ridge between the 10 year and 25 year stages of complete

denture wear (r = -0.63**).


10/13

V&me 27

Number 2

Reduction

of


P-angle 23.5’

RL-ML 132.5’

p-angle 30.0’

RL-ML 116.5’

P-angle 23.0’

RL-ML 133.5’

5cm

P-angle 30.5-

I

4

RL-ML 113.5’

Fig. 10. Tracings of four complete denture wearers Group C) illustrating the relationship

between the mandibular shape and the anterior bone loss of the lower ridge. Subjects Nos.

C7 and C29 with a flattened mandibular base displayed small mandibular bone loss, while

subjects Nos. Cl2 and C41 with a marked mandibular base bend displayed large mandibular

bone loss. The marked difference between the mandibular and maxillary resorption is also seen.

The relationship observed between the mandibular resorption and the shape

of the mandible is further illustrated by the tracings Fig. 10) of two subjects with

a small mandibular resorption and of two subjects with a pronounced resorption.

The marked difference between the mandibular and the maxillary bone loss is also

seen. It may be noted that subjects Nos. 7, 29, and 12 still used their original

25-year-old dentures without any corrections having been made, while for subject

No. 41 new dentures had been made at the 14 year stage of denture wearing.

DISCUSSION

The present follow-up study of two groups of complete denture wearers to the

15 year and 25 year stages of denture wear revealed a continuing reduction of the

residual ridges, particularly marked on the lower ridge. In both samples, the mean

reduction in anterior height of the lower ridge during the follow-up periods was

about four times greater than that of the upper. The same relationship between

the mandibular and maxillary reduction was previously observed at the seven-year

stage of denture wear.3, *

The difference between the jaws in alveolar reduction increased gradually dur-


11/13

130 Tallgren

J. Prosthet. Dent.

February: 1972

ing the first years of denture wear. This would seem to indicate that the lower

ridge is more likely to respond to the various functional forces transmitted through

the dentures than the upper ridge. The most likely reason for this is in the smaller

area and less advantageous shape of the lower basal seat. In regard to the less

marked resorption of the upper ridge, the resistance offered by the hard palate

to the influence of the dentures on the alveolar ridge may play an important part.

The reduction of the residual ridges during the protracted wearing of dentures

was slight as compared to the rapid reduction during the first year of denture

wear. Thus, the mean rate of reduction for both the upper and lower ridge dur-

ing the follow-up periods was less than one tenth of that observed during the

initial year. Moreover, the rates for the maxillary and for the mandibular re-

duction were found to be of the same magnitude in the two samples. These findings

seem to indicate that during extended wearing of complete dentures. the rate of

anterior reduction for the residual ridges and the relationship between the maxillary

and mandibular reduction, on the average, remains fairly constant.

Regarding the variability in resorption, a few subjects in both samples dis-

played no further reduction of the upper ridge after the respective seven-year and

ten-year stages of observation, whereas the lower ridge showed a continued reduc-

tion in all subjects. The magnitude of alveolar bone loss, however> showed great

individual variation.

The marked correlations observed in the present follow-up study between the

shape of the mandible and the anterior bone loss of the lower ridge confirmed

previous findings from a seven-year study.16 A pronounced mandibular bone loss

was observed in subjects with a marked mandibular base bend and a less marked

resorption in subjects with a flattened mandibular base.

A pronounced resorption of the residual ridges related to the shape of the

mandible may be due to an interaction of various factors-anatomic, functional

and prosthetic. In regard to the load transmitted to the tissues underlying the

dentures, one factor especially to be considered is the muscular force. Attention is

drawn to electromyographic findings, in young individuals with natural teeth, of

a relationship between the mandibular shape and jaw muscular activi ty. In sub-

jects with a marked mandibular base bend and a small gonial angle MolleP ob-

served strong activity of the masseter and the anterior temporal muscles in the forced

closure. A similar relationship between the size of the gonial angle and the messeter

activity during chewing was observed by WitP and Ahlgren.*l A marked response

of the lower lip and mentalis muscles, observed electromyographicallyZ’ in long-

term complete denture wearers with impaired retention and stabil ity of the lower

denture, may be considered a contributing factor with regard to the anterior man-

dibular resorption.

As pointed out by Atwood, 23 the various prosthetic factors are difficult to evaluate

due to the great number of variables included. This is especially true in a long-term

investigation like the present one. However, the findings in a previous seven-year

study= of a pronounced mandibular bone loss in subjects with a more lingual

placement of the artificial lower incisors than that of the natural teeth should be

considered. Regarding rebasing or remaking of the dentures, an interesting ob-

servation in the present study was that of the seven subjects in Group C, who had


12/13

Reduction

of


been using their original dentures during 25 years without any corrections, four

subjects were among the fi ve who showed the smallest mandibular resorption in

the whole group.

With regard to the shape of the resorbed mandibular areas great variability was

observed. The individual resorption pattern, on the other band, seemed to be fairly

consistent throughout the period of denture wear.

SUMMARY AND CONCLUSIONS

This mixed-longitudinal study of edentulous individuals covering 25 years of

complete denture wearing revealed a continued reduction of the residual ridges

throughout the observation period.

The reduction of the lower ridge was particularly marked, the mean reduction

in anterior ridge height being approximately four times as great as that of the

upper ridge.

The magnitude and pattern of alveolar bone loss showed great individual

variation.

Correlations between the shape of the mandible and the anterior mandibular

bone loss indicated a pronounced resorption in subjects with a marked mandibular

base bend, and a less marked resorption in subjects with a flattened mandibular

base. These findings suggest that careful examination of the mandibular shape can

provide valuable information on the response of the residual ridges to the wearing

of dentures.

Regarding the clinical consequences of the alveolar bone loss it should be

emphasized that by regular control and prosthetic measures marked instability

of the dentures and undesirable changes in jaw and occlusal relationships can

be prevented. As the rate of resorption is most rapid during the first year of denture

wear, regular control during the first year and thereafter at least once a year is ad-

visable.

However, with the continuing resorption over years, the prosthetic replacement

of the lost tissues will give rise to increasing treatment problems and may cause

the patient extreme diff iculties in management of the dentures.

The continuing resorption,

especially of the lower ridge, therefore, constitutes

a serious prosthodontic problem.

References

1. Tallgren, A.: Changes in Adult Face Height Due to Ageing, Wear and Loss of Teeth

and Prosthetic Treatment; A Roentgen Cephalometric Study Mainly on Finnish Women,

Acta Odont. Stand. 15: Suppl. 24, l-122, 1957.

2. Tallgren, A.: The Reduction in Face Height of Edentulous and Partially Edentulous Sub-

jects During Long-Term Denture Wear;

A Longitudinal Roentgenographic Cephalo-

metric Study, Ac ta Odont. Stand. 24: 195-239, 1966.

3. Tallgren, A.: The Effect of Denture Wearing on Facial Morphology; A 7-Year Longi-

tudinal Study, Ac ta Odont. Stand. 25: 563-592, 1967.

4. Tallgren, A.: Positio nal Changes of Complete Dentures; A 7-Year Longitudinal Study,

Acta Odont. Stand. 27: 539-561, 1969.

5. Atwood, D. A,: A Cephalometric Study of the Clinic al Rest Pos ition of the Mandible.

Part I. The Variability of the Clinic al Rest Position Following the Removal of Occ lusal

Contacts, J. PROS THET. DENT . 6: 504-519, 1957.


13/13

132 Tallgren

.I. Prosthet. Dent.

Felmary, 1972

6. Duncan, E. T., and Williams, S. T.: Evaluation of Rest Position as a Guide in Prosthetic

Treatment, J.

PROSTHET. DENT.

10: 643-650, 1960.

7. Swerdlow, H.: Roentgencephalom etric Study of Vertical Dimens ion Changes in Immedi-

ate Denture Patients, J.

PROSTHET. DENT.

14: 635-650, 1964.

8. Carlsson, G. E., and Ericson , S.: Postural Face Height in Full Denture Wearers; A Longi-

tudinal X-Ray Cephalometric Study, .4cta Odont. S tand. 25: 145-162, 1967.

9. Nairn, R. I., and &tress, T. W.: Changes in Mandibular Position Following Removal of

the Remaining Teeth and Insertion of Immediate Complete Dentures, Br. Dent. J. 122:

303-306, 1967.

10. Ismail, Y. H., George, W. A., Sass ouni, V., and Scott, R. H.: Cephalometric Study of the

Changes Occurring in the Face Height Following Prosthetic Treatment. Part I. Gradual

Reduction of Both Occ lusal and Rest Face Heights, J. PROSTHET. DENT . 19: 321-330,

1968.

11. Watt, D. M.: Morphological Changes in the Denture Bearing Area Following the Ex-

traction of Maxillary Teeth, The sis, Univ. of Edinburgh, 1960.

12. Wictorin, L.: Bone Resorption in Cases With Com plete Upper Denture; A Quantitative

Roentgenographic-Photogrammetric Study,

Acta

Radiol. (Stockholm) Suppl. 228, pp. l-97,

1964.

13. Johnson, K.: A Three-Year Study of the Dimen sional Changes Occurring in the Maxilla

Following Immediate Denture Treatment, Aust. Dent. J. 12: 152-159, 1 967.

14. Car&on, G. E., Bergman, B., and HedegSrd, B.: Changes in Contour of the Maxillary

Alveolar Proces s Under Immediate Dentures; A Longitudinal Clinic al and X-Ray Ceph-

alometric Study Covering 5 Years, Acta Odont. Stand. 25: l-31, 1967.

15. Carlsson, G. E., and Persson, G.: Morphologic Changes of the Mandible After Extraction

and Wearing of Dentures; A Longitudinal, Clinica l, and X-Ray Cephalom etric Study

Covering 5 Years , Odon tol. Revy 18: 27-54, 1 967.

16. Tallgren, A.: Alveolar Bone Loss in Denture Wearers as Related to Facial Morphology,

Acta Odont. Stand. 28: 251-270, 1970.

17. Lindegard, B.: Variations in Human-Body-Build; A Somatom etric and X-Ray Cephalo-

metric Investigation on Scandinavian Adults, Acta Psychiat. (Copenhagen) Suppl. 86,

pp. I-163, 1953.

18. BjBrk, A., and Solow, B.: Measurement on Radiographs, J. Dent. Res. 41: 672-683, 1962.

19. Moller, E.: The Chewing Apparatus; An Electromyographic Study of the Action of the

Muscles of Mastication and Its Correlation to Facial Morphology, Acta Physiol. Stand.

69: Suppl. 280, pp. l-229, 1966.

20. Witt, E.: Kieferwinkel und Kaumuskulatur, Fortschr. Kieferorthop. 24: 295-300, 1963.

21. Ahlgren, J.: Mechanism of Mastication; A Quantitative Cinematographic and Electro-

myographic Study of Masticatory Movements in Children, With Spec ial Reference to

Occ lusion of the Teeth, Acta Odont. Stand. 24: Suppl. 44, I-109, 1966.

22. Tallgren, A.: An Electromyographic Study of the Behaviour of Certain Facial and Jaw

Muscles in Long-Term Complete Denture Wearers, Odontol. Tidskr. 71: 425-444, 1963.

23. Atwood, D. A.: Some Clinic al Factors Related to Rate of Resorption of Residua l Ridges,

J. PROSTHET. DENT. 12: 441-450, 1962.

INST ITUT E OF ORTHODONTICS

THE ROYAL DENTAL COLLEGE

JAGTVEJ 160

2100 COPENHAGEN, DENMARK

Date post:	07-Jul-2018
Category:	Documents
Upload:	satyendra-kumar
View:	223 times
Download:	0 times

Resor Ption

Documents