Australian Dental Journal, February, I974 17

Prosthetic management in the geriatric patient*

Sybille. K. Lechner, M.D.S., F.R.A.C.D.S. Senior Tutor, Prosthetics, University of Sydney

ABSTRACT-changes in the oral tissues of the aged edentulous patient have been described and the advantages or disadvantages of new, or remodelled dentures, or not making dentures are discussed. Stages in construction of the denture for the particular conditions are described and the value of special materials compatible with reduced tissue tolerance is assessed. Good patient reletions are essential for success in prosthetics for the geriatric patient.

Arbitrarily, geriatrics begins at age 65, but in actual fact the geriatric patient is a difficult entity to define, since chronologic age and physiologic age do not necessarily run parallel. Rather than pin- point the geriatric patient, this paper will investigate normal physiologic ageing trends in the oral cavity, typical pathologic changes in the older patient, and discuss solutions for some of the resulting prosthetic problems.

Ideally, treatment for the older patient would be group practice where a medical practitioner specializing in general geriatric medicine, a cardio- logist, a dietitian and a social worker would help ensure that the patient is at his physiologic and psyohologia best, so that the tissue limitations of each patient can he recognized. If such resources are not available, liaison with the patient’s physician is essential. It is not the prosthodontist’s place to treat the patient medically, but awareness of the general condition is vital.

Debilitated patients are usually better treated in the morning when they are at their physical best. However, if the patient suffers from chronic respiratory disease, time must be allowzd for the trachiobronchial tree to clear after the night’s accumulation of fluids, and afternoon appointments may be advisable. It is also necessary to recognize the oral symptoms of certain systemic diseases such as aniemias and those related to nutritional deficiencies. Frequently, a combination of lack of knowledge and motivation, chewing difficulties,

Lectnre, 61st Annual Session of the PDI, and the S X t h Congress of the ADA, Sydney, July, 1973.

Received for pliblication Octobsr. 19i3.

absorption defects and, very often, financial liniita- tions ensures that the geriatric patient suffers from malnutrition. Lack of knowledge we can remedy, masticatory efficiency we can try to improve, and absorption defects we must leave to the medical practitioner. Finances are unfortunately out of our control. Overall, it should be recognized that the general pattern of geriatric disorders is of chronic rather than acute disertse with a predominance of cardiovascular disorders.

Psycho I og ic changes

The normal physiologic and mental changes of old age are complicated by social influence. There may be feelings of insecurity following decreased income, change of habitat and loss of independence, or an awareness of incipient loss of health. The extraction of 8 last tooth may improve the mouth medically and dentally, hut i t may wreak havoc with the patient’s self image of youth and vitality. As the patient gets older, his reactions to other people become more child-like. He is more comfort- able and responsive in familiar surroundings and with familiar people. He reacts more to ‘‘ atmos- phere ” than to words and more can be achieved with reassuring bodily contact and a calm, friendly voice than with a logical explanation of procedure. I t can also be an enormous asset to have a younger good friend or relative as a liaison officer. Again, as with t,he young child, the familiar tone and inflexion of the friend’s voice makes understanding much easier for the patient. A cognisant younger person can reinforce at home the impressions made in the surgery and will tend to remember and supervise any instructions given as to the wearing, non-wearing or care of the dentures.

18 Australian Dental Journal, February. I974

Physical chanpes

In the face and in the oral cavity typical normal tissue changes of ageing are observed. There is an overall gradual shift of fluid from the cells to the intercellular tissues. The collagen undergoes change and the tissues become less elastic and more friable. The functional capacity of most of the body cells also decreases with age, and certain specialized cells such aa striated muscle cells and nervous tissue cells tend not. to be replaced at all.

Face The ageing face has been classically described

by Gonzalez.(l’ It is a combination of slack musculature and atrophic submucosa, and shows gradual resorption of adipose tissue, decreased thickness and elasticity of the skin, sagging of the soft tissues as the skin adheres to contracting subcutaneous layers, wrinkles a t the paths of muscular insertion and palpebral bags under the eyes.

Oral cavity

The saliva decreases in amount and often increases in viscosity. The tongue increases in size where the teeth have been lost for some time. It fills the oral cavity and lies over the crest of the lower ridge. This of course can cause great problems in lower full denture construction. Fortunately, this enlarging is at least partially reversible, so that the provision of a denture will cause the tongue to resume some- thing like its normal size. The tongue may also undergo depapillation, and a lessening of the number of taste buds can cause a lowered taste perception. A dry burning tongue may also be found in the geriatric patient. Here the etiology is uncertain, but dry burning tongue is thought to be associated with a low standard of oral hygiene, xerostoma, nutritional deficiencies and hormonal imbalance.

The goriatric mucosa on which t,he denture must rest is, a t most, an unpromising foundation. Usually the epithelium becomes thin and friable : atrophy of the submuconal tissue, fibrosis of the blood vessels and replacement of the glandular tissue hy connective tissue occurs. Very often, superinipomd on this picture of the ageing epithelium is the typically pathologic state associated with the long-term wearing of dentures.

Striated muscle cells and nervous tissue cells have a tendency not to reproduce themselves to old age, resulting in a lowered muscular co-ordination in older patients and overall postural changes. There tends to be a centric area rather than a centric

point. The mandible protrudes and the free way space becomes larger.

Alveolar bone is specifically designed to support teeth, and where the teeth are lost the bone will resorb. Masticatory pressure in a dentition is transmitted via the periodontal fibres largely as traction, and alveolar bone is, therefore, primarily constructed to withstand tensive forces. Even slight pressure, i.e. pressure normally within the physiologic limit of tolerance, will still produce resorption if it is applied to such an area. This is borne out by the apposition of bone on the tension side and the resorption of bone on the pressure side of a tooth during orthodontic movement. Therefore, resorption of alveolar bone is inevitable once the teeth are lost. It cannot he halted. Can it be decelerated by the judicious use of dentures? In the light of the foregoing i t does not seem so, and in fact Campbell,‘*’ in a study of comparative ridge resorption, found that there was a slight increase in resorption in full denture wearers. He, therefore, querie.i the concept of the use of full dentures to delay disuse atrophy of the alveolar ridge.

In the geriatric patient, gross resorption can be expected, since the teeth will probably have been lost for some time. There may be mental foramina close to the crest of the ridge. Both prominent genial tubercles and mylohyoid ridges may also be found. These areas are places of muscular insertion and s o the tension necessary for stimulation is available, resulting in prominent areas in places which obstruct, rather than aid, denture placement. There can be flabby ridges where bone has resorbed without concomitant resorption and atrophy of the overlying mucosa. This is typically seen in the upper arch, where lower incisors have pounded against an upper denture over the years. However, flabby ridges can also be seen in the lower arch.

Ageing changes such as abrasion in teeth and discoloration from fluorosis can be copied to improve denture esthetics for the older patient. The gingiva flattens and recedes, and may become peaked where the teeth are subjected to heavy wear. Unfor- tunately, mch changes of anterior tooth colour and arrangement in denture construction are often not accepted by patients, whose wishes must take precedence in matters of esthetics.

Denture construction Working with, and for, the prosthodontist making

dentures for the older patient is a certain psycho- logical tolerance if the motivation is right. Older people will submit to a great deal if their confidence is gained. Against that, there is a decreased physio-

‘ I ’ Oonzalez-Ulloa, M.. and Flores. E. S.-Senillty of the f a c e basic study to understand i t s rauses and effects. Plantic and Reconstructive Surgery, 36 : 2. 288-246 (Aug.) 1965.

l a ’ Campbell, R. L.-A coniparative study of the resorption of the alveolar ridges in denture wearers and non-denture wearern. J.A.D.A. 6 0 : 2. 143-153 (Feb.) 1960.

Australian Dental Journal, February, I974 19

l0giCd tissue tolerance and a decreased ability t.o adept to new things. As the motivation on the part of the patient is so important, it becomes very necessary to determine whether this patient really wants new d e n t m , and why, and whether we can improve his lot by providing them.

Thus, consideration must be given to adapting an old denture where possible, copying it in all its untraumatic aspects, making a new one, or leaving the patient completely edentulous.

In the light of the work done by Campb~ll '~ ' on alveolar ridge resorption, the idea of preserving tissues and preventing bone loss with a denture is no longer tenable. On the other hand esthetics and phonetics can certainly be improved, and these may be vital to the patient's self esteem. In this area the dentist must be careful not to undertake to eliminate wrinkles which really belong to the patient. I t is necessary to distinguish between those that are 8 result of tooth loss and those that are part of the natural ageing process.

Another reason for constructing dentures is obviously to improve nutrition. Masticatory efficiency will improve by possibly 30 per cent with the provision of adequate full dentures, and most patients enjoy the physical sensation of having something which enables them to chew'. However, it in quite possible to achieve an adequate diet in the tot.ally edentulous state.

Oral hygiene may be poor where the patient's age precludes him from t,he basic manipulative skills necessary for correct denture care. Unless there is a reasonable hope that the denture is to be adequately cleaned by the patient-or someone el-the wisdom of providing a denture at all should be questioned.

I t is also important to know the patient's denture history, to assess an existing denture, and t'o discover the patient's own opinion of it. Knowing how the patient feels about his denture gives us an immense advantage in planning our dental treatment.

Since t,he geriatric pat.ient finds it, difficult to adapt himself to new sensations, t,here is a need to preserve as many aspects as possible of an exist>ing denture. I f the old denture can simply be relined or its occlusion adjusted t.o increase its functional potent,ial, the patient will find the result much easier to cope with than a new. perhaps technically better, denture around which the lips and tongue must learn new pathways of action.

Mouth preparation Before beginning denture construct,ion, the Or81

tissues must be rendered as healthy as possible. This may entail denture adjustment where physical trauma exists, nutritional education where the diet is poor, and medicstion where infection is found.

An examination of the oral cavity may reveal pathological conditions typical of denture wearers. These can take the form of sore spots arising from inaccuracies of the tissue fitting surface of the denture or from overloading transmitted by the occlusion. Another common cause of trauma arises where flanges become over-extended as ridge resorption occurs. In tracking down sore spots, the use of disclosing

wax is an invaluable aid. The wax can be made extremely soft by the addition of petroleum jelly. It IS painted onto the denture in the area under investigation and the denture seated in the mouth. The wax is given time to flow ; longer in the upper than the lower, since the upper denture is more constrictive. On removal, simple irregularities of the tissue surface due to an inaccurate impression, local bone loss, or over-extension, will give a clear circumscribed area of denture material showing through t,he surrounding wax. A larger area with ill-defined margins lying over a bearing area would indicate ill-advised tissue loading, or inac- curacies in occlusal contacts causing excess loading or denture movement in function. This type of pressure area cannot be eliminated simply by the adjustment of the tissue-fitting surface of the denture. Such adjustments from the tissue side are time-consuming and unsuccessful.

Even in the absence of sore spots, i t may be necessary to mount the denture on an adjustable articulator and assess t,he occlusion. Usually, occlusal pressures will have been thrown out on to the incisors by alveolar resorption, posterior tooth wear and habitual gradual mandibular protrusion. The existing denturo may be used as a temporary bite plate by making a t,emplate of cold curing acrylic resin over the posterior teeth. This template is then adjusted until t,he occlusion can be stabilized, and thus considerably facilitate later occlusal equilibration procedures.

Papillary hyperplasia may be found in the palate caused by excess palatal relief or a suction cup in an old denture. This hyperplasia usually responds quite dramatically to the tissue conditioning materials or to the stimulation of food, saliva and tongue massage if the patient can be persuaded not t,o wear the denture for several days.

Hypertrophic folds in the sulci may also occur. Cooper'3' found t,hat such folds were a response to a sucking or vacuum situation rather than to pressure irritation as was once believed. The tissue is drawn up into the space left between normal tissue

"1 Cooper E. H.-Hyperplasia of thr oral tissue cailsecl by ill-flthng dentiires. Brit. I). J.. 116: 3, 111-114 ( F e b . l ~ 1964.

20 Australian Dental Journal. February, I974

Impressions

In dealing with the geriatric mucosa, it is usual to find a combination of atrophic submucosa and hypertrophic epithelium. There are also arew where bone rosorption and mucosal rosorption have not been a t the same rate, resultiiig in sharp spiny ridges of bone with a minimal mucosal covering, or flabby unsupported area3 of mucosal tissue and often both together in tho samo ridge. Here the selective compression improssion procedures are invaluable and the mouth can be mapped out to plan where the tissues are capablo of bearing the denture load, so areas which aro particularly fragile or unsupported can be relieved.

This technique has been doscribed by GrahamlB’ and involves the use of individual trays made of clear acrylic so that pressure areas, seen a s tissue blanching, can be checked against non-pressure areas through the tray (Fig. 1). Loading of bearing areas, pwiphoral extonsion and width and post damming c m all be controlled by the use of softened impression compound added t,o tho tray. Aress to be relieved, such as mental foramina, flabby ridges or sharp spiny bone areas, are kept well clear of tho tray, and once again impingemont can bo chocked through tho clear acrylic. Holes are then drillod in the roliof a.reas to a l l o w escapti of’ (rxcess imprwsion material. Such a procedure allows for tho nppor- tunity t.o check the cfficicncy of thcr impression in rtapes, whilst the impression is being takon.

and denture flange. He found that hypertrophic folds increased with the age of the denture, wore usually painless, and increased with the mobility of the tissues involved. Gaps between tissues and the maxillary denture are usually due to irregular resorption. Hyperplasia under the mandibular denture is less common and usually occurs where occlusal changes have caused a shunting motion of the denture, each movement drawing the tissues with it. These folds can be treated Surgically but will also very often resorb of their own accord whom the gap between denture and tissues is eliminated, or the faulty occlusion adjusted. The use of impression compound added to the shortened flange of the denture makes the task of gaining an impression inside the superfluous folds relativoly easy.

Other conditions found in the long-term denture wearer are denture sore mouth and angular cheilitis. Denture sore mouth was once considered to be an allergic reaction to acrylic resin, and angular cheilitis due to overclosure. However, a true allergy t o the donture base materials currently in use is extremely rarcr and it is now consitlorod that, denturo sore mouth and angular choilitis are related and result mainly from poor oral hygiene, bacterial growth, and nutritional deficiencies. C a ~ s o n ‘ ~ ) invctstigat,ed 35 caws of denture soro mouth antl isolatocl candida albicans in 23 patient,s, and related yoads in another 10, sometimes with candida. Ho, therefore, consitlors candida albicans to be the main cause of the inflarn- mation. He also found 19 casos of angular choilitis---- only seven of those being associated with a deep fold. He thux concluded that overclosure is not a primary fact,or in angular choilitis, and in this opinion he is supported by Lyor~,‘~’ who found that angular cheilit,is cleared of its own accord when oral canditla had heen treat,ed with a fungicido. Vitamin €3 supplements may also help. Whtrro the denturr i n to be i i i ~ . d to eliminate a’i far as possible a contributory dwp fold, the most successful method is to add bulk in the bicuspid region. Bullc in the incisal region is unxiphtly antl is of little valuo. Bulk in thr molw re,ainn may interfere with tho movoment of tho coronoitl process of the mandible. Nor docs incrraring tho vorticnl dimension com- pletely solvo tho problem, but t*tntls to lrssen thc comfort and stability of the lowcar denture and the proper functioning of tho masticatory muscles.

1‘’ Cawson. Lt. A. - Ikiiture sore inontli and siiynlar clieilitis. Brit. I). J . , 115: 11, ill-449 ( Ikr . 3) 1963.

1 ’ ’ Lynn. D. (;.,,and Chick, A . O.-I)enture sore niouth atid angular rheilitiu. A preliminary investigation into their posaiblc association with caiidlda infection. 1). Pract. and D. Record. 7 : I), 212-217 (April) 19.57.

The combination of a large tongiit~ and itlvoolar resorption will result in a (lcwvaw i n thv q)are

availabl~ for the denturr, partirnlarlv 111 the

I * ’ Graham, (’. H.-Strtw lwariiiy iirvai in fnll ( lwt i lren. S I t h Austral. (’any. Perth. W . A . , 1948.

Australian Dental Journal, February, I974 21

mandible, and thus adds to the difficulty of mandibular denture retention. Displacing forces of the muscles of lips, cheek and tongue will come into play where there is encroachment by the denture bare. However, the denture must be made a8 large as possible to achieve maximum distribution of occlusal forces and also to maintain continuous contact between denture and muscle. The problem is to achieve this compromise between a bese which is small enough not to be displaced and large enough to distribute loading adequately.

The literat,nre is quite explicit aq to the anatomic landmarks to be found a t the periphery of a denture, so that the correct extensions in terms of length are widely recognized. But where there is a grossly resorbed mandible, these extensions do not really amount to enough to give an adequate denture base. Fish"' and Brill'8' have discussed extending the denture out under the tongue. Once again they speak in terms of length, and peripheral length is limited by muscular insertion. It is, however, possible to extend in terms of width.

The natural dentition har a buccal groove in the molar region of the alveolus, and this groove is copied on donture bases to encourage the cheek to rest in i t and so aid denture retention. Investigation with both dentulous and edentulous patients, however, shows that the cheek does not rest in this groove. Patients were asked to use extremo muscular movements such as sucking, smiling, grimacing, arid swallowing, while a soft mix of alginate was in the mouth. An under-ext,ended tray was usocl to carry the olginato for the edentulous patiri.ts and no tray at, all for the dontulous ones. The only limitations of movomont were that the tongue had t,o be kept in tho oral cavity and no matorial wm to bo removed with the t,ip of the tongue. The resulting shapcs of slginate nwro remarkably uniform (Fig. 2 (a)). There is bulk in the disto-buccal ropion, bulk in the mesio-lingual region, and rxtrrmo narrowness in the labial and diat,o-lingual regionx. Similar spacaq can also bn seen in the cadaver (Fig. 2 (b)).

The purpose of those spaccs around a natural dent,ition is not certain. Probably. from thoir location near salivary duct outlets, they are storing places for saliva. However, filling the spaces witjh a denture base in the ctlentulous mandible does not seem to cause excess salivation, lack of saliva, dribbling, or calcium depouits, whereas it does enormously improve t>he stability and retention of the denture. Recording these variations in

('I FiRh, E. W-Appendirrs contribntrd by Ernest Mathrws. Principals of full dent,iire prosthesis. 8th ed. London. Staples, 1964 (p. 000).

(*I Brill, N.-Factors in the mechanism of full drnture reten- tion-a discussion of srlerted papers. Ikntal Prart., 1 8 : 1. 9-19 (Rept.) 1967.

cc31 o n

G3 Q 0 Q Q

Fig. 2a.-Cross-srrtiuns throng11 alginatc shaprs fi~riiir:d during extreme muscular movement in dentiilous and edrntuloos jaws. Note bulk in postrrior huwal and :ulterior lingnal region, and narrowness in posterior lingual and anterior labial regions.

peripheral thickness in the improssion presents no problem a t all. The spaces am them. I t is necessary only to recognize them and preserve them during denture construction.

III advanced resorption, tho improssion can encompass tho ontire polished surfacs of the denture, and oven indicate bucco-lingual tooth position. The cast is poured and fractured at the height of contour to allow removal of t,he impression and construction of the base plate, and then repositioned to act as a matrix for the final wax-up (Fig. 3). When extension in terms of width, as opposed to extension in terms of length alone, is considered, the bulk in the disto-buccal and antero-lingual regions is important, but so is the thinness in the disto-lingual and antero-labial regions if tongue movement during swallowing, or lip movement during speech, in not to he hampered.

22 Australian Dental Journal, February, I974

rig. Zh.-Section of jaw showing typical " molar area "-shaped space.

Maxillo-mandibular relationship

The combination of decreased striated muscle cells and decreased nervous tissue cells which are found in the geriatric patient will tend to lower muscular co-cirdInat,ion, so that centric relation may be difficult t,o determine. This condition is often further complicated by an habitual centric occlusion which has been acquired over the years with an old denture.

Where an habitual centric hes existed over the years with no obvious traumatic effects such as temporo-mandibular joint disturbances, or muscle spasm, it is necessary to decide whether on0 should try to change this habitual pasition to true centric when making a new denture or whethor i t can be accepted as a wd-established occlussl position.

True centric relation is a basic, reproducible position. Habitual centric occlusion comes from 8

conditioned reflex, and a conditioned reflex can break down if the conditioning impulses are missing. Where the familiar nooks and crannies of the old denture are replaced by the unfamiliar contours of a new one, the conditioned reflex of an habitual centric is very often disrupted, so that occ~usal harmony is lost. It, is, therefore, preferable to construct a new dentum to true centric. Patients very rarely have trouble accepting this relationship once it ha3 been re-established, whereas, if a new denture is built to habitual centric there is a risk of excess occlusa~ grinding or repositioning of the posterior teeth becoming necessary as the jaw relationship changes after the denture has been worn.

Another factor to be considered in maxillo- mandibu~ar relationship is that, the freeway Space

M

Fig. 3. -111 a \cry revorbed jaw the impression cau encompass must of the polished denture surface. The cast is fractured to allow removal of the impression and then repositioned to avt as a matrix for Anal dehture

ma*-up.

118tUrltlly 1nCraast.s with age, S O that tila verti081 dimension can be slightly less t,han with the younger patient.

To accommodate for weak muscular co-ordination, it is better to aim for a centric area rather than a centric point, with freedom of movement in eccentric positions and teeth which have flatter cusps or are completely cuspless. Occlusal harmony in centric and eccentric position is vitally important for the geriatric patient. Slight discrepancies in occlusal contact can cause shunting of one or both dentures, with subsequent tissue irritation and sorenes. The dentures must be remounted on an adjustable articulator a t the insertion stage and equilibrated for centric and eccentric movements.

Techniques for recording the maxillo-mandibdar relationship vary greatly. The patient must

Australian Dental Journal, February. I974 23

naturally be a t ease, and the dentist must, therefore, be a t ewe with himself and his technique when recording centric. The writer prefers to record centric with a slow relaxed closure into softened base plate wax. In this way it is possihle to sense, through the fingertips, whether the tissues are relaxed or not.

For the completely resorbed ridge, where back- ward slipping of t,he base over the ridge is suspected, wax wings can be added to the base to allow the fingers t.o Rtabilim it, while cent,ric is being recorded (Fig. 4).

Fig. 5.4b) Same base with teeth set a t the point where tongne :ind cheek meet, allowing denturr to remain in

poni t ion.

Fig. 4.-For the non-existent ridge, where backward slipping of the denture base over the tissues is suspected, wax wings can he added to the base to allow the Angers

to stabilizr it while rentrir is heing recorded.

Viy. 5.--(r) Upper teeth pet in crosshitc to accommodate disparity in size of mandible aiid niaxilla.

the moro lingual tho tooth plaocmont the more stable will be the denture. However, if lingual placement interferes with tongue position the denture will not be stable a t all (Fig. 6). Since stability is usually more difficult to achieve in the mandibular denture, the lowsr posterior teeth must be given priority and set a t the point where tongue meets cheek. The upper teeth are then set in normal relationship or in cross-bite, depending on the relative R i m of the maxilla.

Fig. 5.-(a) Base plate with teeth set over “ ridge ” had to he held in position with hall hurnishrr, as tongue size in this

patient cansed gross instability. Load distribution

Atrophy of the submucosa results in a thin friable covering over the bone. Here the soft

Bucco-lingual tooth positioning is very important lining materials which can give a cushion effect in the grossly resorbed mandible. Placing the teeth show promise ; they replace the lost, soft, and over the crest of the ridge where there is no ridge resilient submuoosa with an artificial cushion in the seems pointless to say the least. Theoretically, denture itself. Unfortunately, in practice soft

24 Australian Dental Journal. February, 1974

linings are not entirely satisfactory. The advantages are obvious. The disadvantages lie in the materials themselves : their impermanence, their poor dhesion to the denture base materials, and their tendency to encourage monilia albicans. Most important of all is the inability to adjust them and then polish the surface to a state of gloss. The meterials are being improved and will possibly have a place in the future of geriatric prosthetics.

Another method of softening the forces of meetiaation is the use of acrylic teeth rather than poroelein. Since the acrylic has a certain amount of flow end is more easily abraded, it will also tend to cushion the biting force. Of course, any advantage geined here must be weighted against the disadvantage of possible rapid wearing of the teeth and subsequent occlusal disruption. A compromise can be reached where acrylic teeth are to be used by placing amalgam restorations at the points of occlussl contact, or inserting cutter bars of stainless steel.

Other methods of dealing with an atrophic mucosa lie in an effort to reduce the actual load placed on it. This can be done both by using narrow posterior teeth to decrease the force per unit area and by using teeth with flatter cusps to decrease the horizontal forces of mastication.

The polished surface of the denture must be kept as smooth as possible, without artificial rugm or stippling, which may irritate the delicate mucosa.

Over all, when considering prosthotics for the geriatric patient, sound prosthetic principles must be observed and practised. The onus for a successful result however lies more with the dentist, since the tissue tolerance of the geriatric patient is lower. One of the most important Bspects of geriatric prosthecios is interest in the patient and his problem, and communication of this interest t,o him.

91 Bay Street, Beauty Point, N.S.W., 2008.

Music Like the oboe and other woodwinds, the brass instruments can produce sustained tones. The question arises, however, of how a bugle, which is hardly more than a loop of brass tubing with a mouthpiece at one end and a flaring bell a t the other, can produce a dozen or more distinct notes. Horns were fashioned and played for centuries before physicists were able to work out good explanations of how they worked, even though scientific attention has been directed to these questions from the earliest days. For centuries the skilled craftsman has usually been able to identify what is wrong with faulty instruments and to fix them without recourse to sophisticated knowledge of horn acoustics.-Arthur H . Benade, Scientific American, July, 1973.