rhonda f. jacob, the traditional therapeutic paradigm complete denture therapy

THE JOURNAL OF PROSTHETIC DENTISTRY JACOB

6 VOLUME 79 NUMBER 1THE JOURNAL OF PROSTHETIC DENTISTRY

Paradigm is the phraseology of the 1990s and isdefined as “example” or “model.” This article discusses“the traditional therapeutic model of complete denturetherapy.” Our challenge is to examine the “everyday rou-tines” in the prosthodontic treatment model for eden-tulous patients. Routines that include diagnoses and pro-cedures rendered quickly, skillfully, and almost reflex-ively. The experienced clinician’s diagnostic acumen hasbeen honed to note patients’ anatomic variations. Thesevariations ultimately require alterations in treatment tech-niques. Interestingly, these anatomic variations are sofrequently observed, clinicians find making alterationsin treatment techniques to be fundamental in theprosthodontic routine.

In comparison with the success of other functionalprosthetic replacements, the complete denture has hadunparalleled success, offering restoration to millions ofpeople throughout the world. Despite the fact that mostpatients continue to wear their dentures, many do not.Despite the fact that clinical techniques are meticulouslyperformed, there are patients who find their prosthesesonly marginally serviceable. Clinicians counsel their pa-tients to lower their expectations and to raise their pros-thetic awareness. When problems persist, clinicians or-der prosthetic surgery for their patients to lower theirtissue attachments and to raise their bone level. Clini-cians have pictures of the ideal ridge with the ideal tis-sue attachments etched in their experience. They haveconfidence that complete denture therapy will be suc-cessful for those persons with abundant bone quantity,

Presented at the annual meeting of the Academy of Prosthodontics,Halifax, Nova Scotia, Canada, May 1997.

aAssociate Professor, Department of Dental Oncology.

The traditional therapeutic paradigm: Complete denture therapy

Rhonda F. Jacob, DDS, MSa

University of Texas M. D. Anderson Cancer Center, Houston, Texas

The art and science of complete dentures for oral restoration has been espoused and debated forover a century. A tradition of clinical mentoring has passed this prosthodontic trust through timeto create an educational cycle where the pupil ultimately became the tutor for yet another pupil.Today’s clinical techniques and judgments are an amalgamation of these original prosthodonticphilosophies. This article will bring forward some procedures for the fabrication of completedentures for the scrutiny of their scientific bases. Scrutiny does not imply that aspects of therapynot proved in studies of rigorous scientific design are untruths. However, it is incumbent thatthose aspects of denture therapy regarded as “public domain” by the corpus of the profession beanalyzed. It is also incumbent that possible costly or harmful aspects of denture therapy be identi-fied. There is a paucity of “procedural research” in clinical investigations; research that involvesperforming an invasive or clinician-intensive procedure. This article also discusses the difficulties inperforming procedural research as a means of understanding its importance, but also realizing thereasons that this type of research is not prevalent in the dental and health professional literature.The most common types of investigations used to evaluate patient acceptance and function ofdentures will also be discussed. (J Prosthet Dent 1998;79:6-13.)

but become skeptical and have limited success in pre-dicting the therapeutic outcome for patients with se-verely resorbed residual ridges.

There is little question that the primary treatment al-ternative for edentulous patients includes complete den-ture prostheses, but whether these patients will also beadvised of the “need” for sulcoplasties, orvestibuloplasties, or whether they will “receive” boneaugmentations, visor osteotomies, or even implants, toooften depends on in whose office the patients find them-selves. Despite the fact that some of these reconstructedpatients may have successful outcomes, many continueto have functional problems and surgically related mor-bidities. There is no specific treatment modality that willensure success. Clinicians and patients are forced to ad-mit that dentures are not a substitute for teeth, ratherthey are our best solution for no teeth.

In keeping with the intent of this symposium, a num-ber of succeeding articles will examine our methods ofrestoring the edentulous patient. The articles will con-sider treatment methods, treatment successes, and theavailable scientific evidence to support diagnostic prac-tices and treatment procedures.

HOW HAVE WE ARRIVED AT THE CON-VENTIONAL DENTURE PARADIGM?

The art and science of denture therapy has been es-poused and debated for almost a century. This paradigmhas been repeatedly passed from tutor to pupil, withmodifications and amalgamations of various philoso-phies. The pupil-in-time becomes the tutor and the pro-cess continues. One cannot deny that clinical procedureshave advanced through keen observation, experience,empiricism, anecdote, artistry, and science. As the pub-

JACOB THE JOURNAL OF PROSTHETIC DENTISTRY

JANUARY 1998 7

lications and lectures from Pound, Silverman, Landa,Lytle, Wright, and Tallgren, to name a few, came on thescene and were grasped by the profession, these obser-vations and teachings became part of the clinical “pub-lic domain” of denture therapy. The observations andtechniques may have been novel at their inception, butthe observations have been repeatedly noted by clini-cians and the techniques have been performed count-less times. Through these teachings, clinicians have be-come adept at fabricating dentures that are in harmonywith patients’ variations in anatomy and variations inmandibular motion exhibited during mastication, de-glutition, and speech. Likewise, clinicians have used thesetime-honored skills to diagnose problems in existingprostheses. These prostheses are frequently in dishar-mony with the patients’ anatomy and physiology ofmandibular motion, resulting in impaired comfort andfunction.

If clinicians scrutinize the literature, they will mostlikely identify prosthodontic procedures that are notvalidated by rigid scientific methods. It may be suffi-cient to understand that some prosthodontic treatmentprocedures are empirically derived. To abandon thoseprocedures or expend more effort researching themwould be counterproductive and deter the prosthodonticcommunity from focusing on treatment questions thatwould offer more to the science of edentulous rehabili-tation.

As an overview, the multiple diagnostic and clinicalprocedures implemented in denture fabrication and di-agnosis of problem dentures are considered. Theseprosthodontic tenants were originally documented inclassic prosthodontic essays written by keen clinical ob-servers. The major arguments for the selection of tech-niques, materials, and occlusal forms were related tofunction and preservation of existing structures, prima-rily preservation of healthy mucosa and bone height.Interestingly, advocates of one treatment philosophyoften maintained an identical argument for efficacy andanatomic preservation as those clinicians espousing adiametrically opposed philosophy.

Impressions relate to the basal seat and denturebase extensions

Maximum tissue coverage is desirable with minimaldistortion of the basal tissues, without impingement onmobile frena and muscle attachments.1-3 Extension tothe hamular notch and vibrating line affords improvedmaxillary denture retention. These concepts are gener-ally accepted in the domain of prosthodontic knowledge,but a study by Kapur et al.4 failed to demonstrate a dif-ference in masticatory performance as a result of den-ture extensions in patients’ in masticatory performancetests. The concepts of making pressure, nonpressure, andselective pressure denture impressions have been de-scribed as though they are separate entities, but it is dif-

ficult to envision a clinician who can make an impres-sion “that does not embody some of the philosophies ofeach of the above.”5 Denture examination of problemprostheses includes examination for over and under ex-tension of borders, no rocking of the base when unilat-erally manipulated against the ridge, and no movementof the denture when moved in an anterior/posterior di-rection.6,7

Establishing maxillomandibular relationshiprecords considers the vertical dimension ofocclusion

Methods to establish the vertical dimension of occlu-sion include the swallowing technique,7,8 closest speak-ing space,9 ridge parallelism, and examination of facialcontours at rest position and centric occlusion posi-tion.7,10-14 When examining problem dentures, these sametechniques are used to determine whether existing den-tures are at the appropriate vertical dimension of occlu-sion.

Anterior tooth position and selection is establishedby examining facial contours, closest speaking space, Fand V position at the vermillion margin of the lip, andesthetics.7,9 Posterior tooth position can be establishedby a selection of a neutral position of the mandibularbuccal and lingual tissues or placement of the teeth overthe crest of the mandibular alveolar ridge to favor man-dibular denture stability.9,15 The plane of occlusion isoften established by an amalgamation of anatomic land-marks by using the retromolar trigone,16 lateral borderof the tongue, lip commissures,16 and ridge parallelism.These guidelines came from the examination of the natu-ral dentition, and have not necessarily been researchedas to their effect on denture function. Kapur and Soman17

studied tooth positions in 12 denture wearers, consider-ing various buccolingual and superoinferior positions andfound better masticatory performance with teeth posi-tioned over the ridge, at the height of the natural man-dibular canine position, and parallel to the ridge. Teethpositioned buccal to the ridge crest produced signifi-cant reductions in chewing efficiency.

Many tooth forms have been used throughout theyears, but they have given way to either cusp or cusplessforms. Most evaluations considered a small number ofsubjects who were asked to choose from various toothforms.18-23 The choices of the patients, their ability tomasticate test foods, and even the patients’ awareness ofthe differences in the tooth forms were varied and ofteninexplicable.

Today’s prosthodontic domain related to occlusalschemes includes cuspal teeth arranged in a balancedocclusion and cuspless teeth arranged in a “flat plane,”with simultaneous contact in centric relation occlusion,usually without any attempt to balance the denture teethin eccentric movements.7,24 There are clinicians who useanterior vertical overlap when the horizontal overlap is


8 VOLUME 79 NUMBER 1

not sufficient to prevent occlusal disharmonies in speechand mastication. Others balance this anterior verticaloverlap with a posterior protrusive contact. When ex-amining existing dentures, similar guidelines for toothposition are considered.

Centric relation occlusion position

The most common techniques for positioning the man-dible into centric relation occlusion position include theclinician exerting thumb pressure against the chin, poste-rior curling of the patient’s tongue, or use of a central-bearing-point device.7,25-27 Reproducibility of the recordhas been the primary means of judging the accuracy of atechnique. The most common recording medium is wax.Yurkstas and Kapur26 demonstrated (even in a small num-ber of study subjects) that technical differences in themanipulation of the wax recording medium and central-bearing device lead to statistically significant differencesin the three-dimensional repeatability of the various waxand central-bearing-point techniques. Michman andLanger8 examined three methods of obtaining edentu-lous centric relation occlusion records (wax medium orcentral-bearing device between wax occlusion rims, or waxmedium between maxillary teeth and mandibular wax rimwith anterior teeth) in three consecutive case series ofgroup subjects numbering between 123 and 179. Thegroups were treated by dental students and faculty, withone faculty making visual inspection of the final prosthe-ses to determine the “success” of achieving the correctcentric relation position. Within the definition of success,there was a statistically significant positive difference inthe accuracy of the record made when teeth were posi-tioned on the trial base.8 Clinicians have learned, how-ever, through continued clinical use of the various centricrelation position techniques that, barring extreme misuseof the techniques, the variations in wax manipulationsand positioning of the central-bearing-devices do notequate to a clinically significant difference. Multiple, lesscommonly used techniques have been cited with the BoosBitmeter,28 Shanahan’s29 wax cones, cephalometric radio-graphs, and so forth. Sears30 wrote, “the problem of cen-tric relation position has confused a great number of read-ers, which is not surprising, as many of the writers arealso confused.” Examination of the serviceability of ex-isting dentures usually includes a clinical assessment ofcentric relation occlusion without using a mechanicaldevice.

Final denture contours

Final denture contours should allow adequate tonguespace in the maxillary and mandibular denture31,32 andhave appropriate palatal contours to enhance speech.33-35

The buccal contours should enhance facial contours andallow the buccinator muscles to function within the con-cavity of the denture flanges.36,37

In addition to routine prosthodontic procedures, cli-

nicians have used various surgical procedures to enhancedenture stability. The most common soft tissue surgeryis the split–thickness skin graft vestibuloplasty. A 90%satisfaction rate in 152 subjects38 and 77% improvementin function in 97 subjects39 was observed aftervestibuloplasty. This latter case series described a mentalnerve sensibility complication rate from 16% to 56%,depending on the technique of nerve dissection. Theother case series described only a 10% satisfaction ratefor patients with less than 20 mm of residual mandibu-lar bone height.38 A review article examined 14 case se-ries, totaling 727 patients who received vestibuloplasty,for patient acceptance and mental nerve disturbances.Satisfaction ranged from 57% to 90% (average patientsatisfaction, 80%) and changes in lip sensation rangedfrom 5% to 39% (average disturbance, 25%).40 A 5-yearfollow-up on 30 patients who received vestibuloplastyrevealed a 1 mm resorption of bone the first year, whichcompares favorably with Tallgren’s42 data of 20postextraction patients with 6 mm of resorption the first3 years, followed by 0.3 mm of resorption over the next25 years. The conclusions from this consensus, proceed-ings based on case series of surgeries for the atrophicmandible, were that resorption of bone after procedurescan range from 40% to 50% bone loss in the first fewyears, followed by a fairly normal bone resorption pat-tern after augmentation. Variations on the visor os-teotomy (with or without interpositional bone grafts)and various onlay procedures were included.43 In a re-view article considering that complications of ridge aug-mentation, the complications related to the alveolar nervewere “unacceptably high” and were reported as beingbetween 40% and 85% in four large case series.44 Nocontrolled trials comparing various augmentation pro-cedures were performed, but the large case series re-vealed that overall bone resorption and sensory distur-bances must be considered when comparing these treat-ment modalities to other modalities that may improvedenture function.

The use of various denture techniques for the purposeof maintaining alveolar bone has not been successfullyproven in the literature. Authors45,46 have recognized forsome time that the mode of bone resorption in the max-illa and mandible is multifactorial, and has great individualvariation. Tallgren,47,48 Carlsson,49,50 and Atwood51 haveshown that bone resorption is marked immediately afterdental extractions, but the rate slows with time. A seriesof patients being treated with “complex” and “simple”denture techniques, followed with cephalometric radio-graphs for 5 years, did not reveal a difference betweenthe two groups in relation to bone loss.52

SCIENTIFIC EVIDENCE: RESEARCHDESIGN AND MEASUREMENT TOOLS

Let us consider the charge of this symposium. Asbriefly enumerated in the overview, there are a myriad


JANUARY 1998 9

of thought processes and multiple procedures involvedin making complete dentures. The multiple patient varia-tions in anatomic contours and functional movementsnecessitate alterations in clinical procedures and add tothe complexity of these procedures and the complexityof evaluating their efficacy.

What is the strength of the scientific evidence thatsupports these prosthodontic tenants in the denture para-digm? This article discusses two criteria related to thestrength of scientific evidence: (1) characteristics of theresearch design and (2) characteristics of the tools usedto measure success.

Research design

There are three means for a clinician to make deci-sions concerning a treatment process.53 The ideal deci-sion-making process is deduction: Where the clinicianexamines the facts from available studies that (1) areproperly designed prospective, randomized clinical tri-als, (2) are properly designed, large epidemiologic stud-ies that consider the efficacy of a well-accepted and well-researched treatment modality, (3) include a patientpopulation similar to that of the patient in question, (4)include the appropriate number of study subjects, and(5) reach a definitive conclusion. The concept of appro-priate numbers and definitive conclusions go hand inhand; a statistically significant, definitive conclusion can-not be reached if there are not enough study partici-pants. Even if there is a difference between the outcomesof two populations receiving two treatments, withoutenough patients in the study the results will not reveal astatistical difference. Likewise, if there are not enoughpatients in the study, one cannot be certain of the cor-rectness of a trial that finds no difference between twotreatment modalities. Deduction is the most concreteand ideal means of making treatment decisions.

The second decision-making process involves induc-tion: Where the clinician considers therapies that “oughtto work” based on his or her own clinical experience orby taking an educated “leap of faith” to extend currentconcepts of treatment beyond what has been proved.Studies considered in this realm (1) are retrospective innature, (2) may be prospective in nature but involve adifferent patient population than the patient in ques-tion, (3) may use related but not identical materials ortechniques than those being considered by the clinician,(4) have limited patient numbers such that a definitiveconclusion was not reached, but there may have been a“trend of the data” toward a difference in the two popu-lation outcomes, or (5) may have used nonrandomizedtreatment selection, with the patients being assigned orself-selecting their treatment. This latter patient selec-tion process allows biases in patient selection. When thisoccurs, there is limited possibility that the two test popu-lations will be similar.

Having discussed deduction and induction, the third

decision-making process is termed seduction: Where theclinician plans treatment based on conversations withcolleagues, manufacturers’ advertisements, testimonials,case reports, and limited case series with minimal fol-low-up and vague inclusion/exclusion criteria for pa-tient selection.

There is a paucity of deductive decision making in thehealth profession, be it in dentistry, nursing, or medicine.It is not because clinicians do not wish to deliver the bestpossible therapy, but it is primarily due to a paucity ofexcellent research. When the clinical trial requirescaregivers to perform invasive procedures to achieve aparticular outcome, as opposed to administer medication,the research design often suffers. One can imagine thatresearchers can blind the patient and a practitioner to amedication, but blinding a patient and an examiner to abone graft, vestibuloplasty, or an implant becomes im-possible. Standardizing a multiclinician, multistep clini-cal, or surgical procedure is much more difficult than stan-dardizing a drug regimen. Patients are more reluctantabout being randomized to different invasive proceduresthan they are about being randomized to different drugregimens. This is especially true when crossover drug tri-als can be designed that allow the subjects to receive bothdrugs at different time periods within the same study. Thisdesign requires fewer patient numbers, and calms patients’misgivings that they might be missing out on a particulartreatment opportunity. However, in invasive clinical tri-als, the anatomic structures may be altered with the firstprocedure, such that the second crossover procedure isnot possible. In a recent implant investigation, a cross-over trial allowed two procedures to be performed on thestudy patients.54,55 This crossover was possible as one pros-thesis used four to five implants in a totally implant-sup-ported mandibular overdenture, compared with a secondprostheses that used four to five implants to support afixed-hybrid mandibular prosthesis. This statistically sig-nificant study revealed that there are patients who are will-ing to sacrifice the concept of a fixed prostheses being a“part of me,” as opposed to a removable prostheses thatretains the stigma of being “false” to maintain ease ofcleaning their mouths. This implant overdenture designdid not have any mucosal contact in these patients, there-fore it would be an improper inductive reasoning processto extrapolate these statistically significant results to“2 implant/tissue-supported mandibular overdentures.”

When considering invasive procedural trials, patientsalso are more apt to have a preconceived notion abouttheir outcome, side effects, and morbidities when beingasked to consent to randomization. In fact, some pa-tients may want the more invasive procedure, becausethey perceive it as more “curing,” whereas others willwant the more technically advanced procedure for thesame reason. With this preconceived patient bias, it isoften difficult to accrue patients to randomized trials.

Another difficulty in designing randomized clinical



trials that involve procedures and techniques is that largepatient numbers are required to answer clinical out-comes. There are many variables within the patient popu-lation, within the complex procedures, and within theskills of the clinicians that can produce considerable varia-tion in the investigation. Also, there may be significantbut small differences between the treatments being in-vestigated. Large variations in the study and small dif-ferences between treatments equate to the need for largepatient numbers in the investigation to reach a defini-tive conclusion. In life and death medical situations, andthose situations with extreme effects on quality of life(for instance loss of eye sight or loss of hearing), clini-cians will embark on studies to prove differences of aslittle as 10% between treatments. This small differencecan require several hundreds of patients to reveal a de-finitive conclusion. When considering complete denturetherapy, it may be decided a 10% clinical difference be-tween two impression materials makes for a moot inves-tigation. This is especially true when considering thatpatient’s denture-bearing tissues are displaceable, pro-cessing changes occur in the acrylic resins, and there isthe availability of pressure indicator paste. Time andmoney for prosthodontic research may be better spentinvestigating a question with a better clinical payoff.

Given the large number of patients needed for clini-cal trials, it is often impossible for one institution, andcertainly one practitioner, to recruit enough patients tocomplete an investigation. For this reason, multi-insti-tutional studies are often required to answer a clinicalquestion. Organizing a multi-institutional trial, investi-gating a multistep procedure, and employing cliniciansof variable skill levels and biases about the test proce-dures is a monumental research task. Our internal medi-cine colleagues who prescribe medications are more aptto achieve their research goals than are we “invasive/procedural health care professionals.”

Another reason for the small patient numbers foundin investigative clinical trials of procedures and tech-niques is high research costs. Procedures that are laborintensive, require special equipment, or require specialpersonnel can escalate a research budget to nonfund-able proportions. It is also difficult to persuade patientsto agree to pay for an experimental treatment. If pa-tients must pay for treatment, they want to be assuredthat they will receive the treatment they desire. For in-stance, patients may be willing to assume the costs oftheir therapy if they can be assured that they will receiveassignment to the dental implant arm of the study. Theymay not be willing to pay if they are assigned to thecomplete denture arm of the study. However, if theycan get either treatment for free, they might be willingto take their chances with randomization. Geertman etal.56,57 randomized patients in a two-center clinical trialto implant either retained mandibular overdentures orcomplete dentures. Despite patients agreeing to the in-

vestigation and signing an informed consent that con-firmed they would receive assignment to one of the twotreatments in a randomized fashion, Geertman et al.56,57

still had subjects refuse to begin any therapy becausethey were not assigned to the group they preferred. Therewere those patients who were afraid of surgery and there-fore did not want implants, and there were those pa-tients who believed their long-standing denture prob-lems could not be cured with another denture.56-58

There are also strong clinician biases that the proce-dures we perform with arduous care are the proceduresthat offer the best cure, and those we do not (or can-not) perform are inferior. Yes, even dentists have a mi-nor deity complex. There is a very strong clinician biasagainst randomization of patients to therapies the clini-cian does not perform. Similarly, procedural cliniciansdo not like to have their therapies and outcomes criti-cally examined. They do not portray the same visceralreaction when it is a pill being scrutinized for the cure,rather than a procedure performed by their own hands.

For all the aforementioned reasons, large randomizedclinical trials have not permeated the dental or medicalliterature. What are more prevalent are some well-de-signed studies with too small a number of subjects toarrive at a definitive conclusion. Or there are studies withpatients assigned to various treatments based on the cli-nicians’ or patients’ desires, or based on the philosophyof the treating institution. These latter studies may havethe data gathered in a prospective fashion, the cliniciansmay meticulously perform the procedures, but unfortu-nately these studies are only well-documented case se-ries and cannot be used to make comparative, deductivetreatment decisions. Hence, invasive/procedural re-search is a complex issue from a social, economic, andscience aspect. This is why dentistry and a large part ofsurgical medicine has had to rely on more inductive typeof decision-making processes.

Measurement tools

The second criteria for evaluating the strength of sci-entific evidence relates to the tools used to measure suc-cess. How do we judge our success in the treatment ofthe denture patient? Certainly, the busy clinician’s suc-cess story is the patient who keeps every appointment,takes the exact allotted time in the schedule for eachappointment, requires only one try-in visit, leaves witha smile on his or her face, and returns for only onepostinsertion adjustment. This is certainly a simplifiedrepresentation, but in this scenario, most clinicians wouldthink they scored a treatment success.

Perhaps the questions should be: How do our patientsjudge treatment success, and what are the research toolsthat measure success? The most common outcome mea-surements have involved mastication of food items andpatient satisfaction questionnaires. Measuring mastica-tory performance has included assessments of swallow-


JANUARY 1998 11

ing thresholds (usually particle size assessment of knownfood volumes), number of chewing strokes, chewingtime, and electromyographic data collected during mas-tication. The use of patient questionnaires assessing vari-ables related to food eaten, comfort, esthetics, speech,retention, denture security, and overall satisfaction havebeen used. Innumerable variations on these questionsare seen in the literature and innumerable variations onthe swallowing thresholds and masticatory performanceshave been used since Manly59,60 and Kapur61 et al. firstreported these tests. The tests tend to be quite objectiveand reproducible and, in a few instances, have resultedin statistically significant differences in mastication ofdifferent foods comparing different prostheses designsand techniques, and in some studies, they have not re-sulted in any differences. These test methods have oftennot correlated with patient-based assessments of theirchewing ability of different foods, and the masticatoryperformance tests have not correlated well with the pa-tients’ overall prosthesis satisfaction. It appears there isnot a laboratory test for denture function that can pre-dict routine patient function and denture satisfaction.As clinicians, we may be placing too much emphasis oncomminution. A particular magnitude of particle sizemay not be relevant to the enjoyment of eating. Otherstudies have demonstrated that patients have altered theirfood choices when using dentures. The patients may besatisfied with their denture function because they havelowered their expectations of satisfaction, because of thetestimonials of friends and relatives in regard to the needfor altered dietary habits. Most patients have also re-ceived extensive clinical counseling from their dentists,stating that the patients should expect some changes intheir dietary choices and habits.62,63 Likewise, these mas-ticatory tests have not proven that specific denture modi-fications or techniques greatly influence masticatoryperformance.6,64-70 Despite the discrepancies in the avail-able research, there have been no discrepancies in theconclusions that (1) denture patients do not have thechewing ability or masticatory performance of personswith complete dentition, and (2) there is great individualvariation in chewing patterns and masticatory perfor-mances in complete denture patients.

There has been resurgence in the evaluation of com-plete dentures, as a control population compared withimplant-supported prostheses and preprosthetic surgeryfor the edentulous patient.56-58,71-74 Clinicians gathereddata on (a) patient-perceived satisfaction and function,and (b) investigator-designed masticatory performancetests. Some of these studies were randomized controlledtrials, and some were self- or investigator-selected pa-tient assignments. However, in all these studies, the pa-tients were categorized as having negative denture wear-ing experiences before entering any studies. In all inves-tigations, the implant-retained or implant-supportedgroups were more functionally satisfied than the com-

plete denture groups. Validated questionnaires with so-phisticated statistical analysis have been used by clini-cians in the Netherlands and England.75-77 It has beenrecognized in these studies, that there is a multifactorialinfluence of patient and treatment variables (age, gen-der, medical and mental condition, bone quality andquantity, type of restoration, number of implants, andopposing restorations). It has been recognized that thereis a multifactorial influence of patient satisfaction vari-ables (choice of food items, speech, denture security,comfort, and retention). It has been recognized thatpsychologic patient parameters are evident and must beconsidered in the complex data gathering and statisticalanalysis of these studies.75-79 What is also evident is theimperative need for studies with large numbers of sub-jects; multi-institutional, multidisciplinary, andmulticlinician involvement; and sophisticated statisticalassistance.

CONCLUSION

The charge of this symposium is to evaluate theprosthodontic literature and research related to treatingthe edentulous patient. As clinicians, we should be in-sightful and contemplate future research and treatmentopportunities. We should not be paralyzed by the presentscarcity of deduction in our daily decision-making pro-cesses, because the reality is that patients are waiting tobe treated. Treatment decisions must be made with thebest available evidence that exists. As we look to thefuture of our profession and the obligation we have todeliver the ultimate in patient care, we should bear thisin mind. As clinicians, we may be satisfied with induc-tive decision making. At least some of the time, our de-cisions will be the correct ones, even though researchhas yet to prove them correct. But if and when we be-come the patient, our point of reference might change;then perhaps we would want the treating practitioner tobe making treatment decisions based on definitive, sci-entifically sound research.

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