1999_maxillary changes under complete denture opposing mandibular implant-supported

8/2/2019 1999_Maxillary Changes Under Complete Denture Opposing Mandibular Implant-supported

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Maxillary Changes UnderComplete Dentures OpposingMandibular Implant-SupportedFixed ProsthesesSaurahb Gupta, BDS,Sybille K. Lechner, MDS , FRACDS, FPFANorton A. Duckmanton, M DS, FRACDS,

Purpose: The aim of fhis study was to determine whefher a condit ion similar toCombinafion Syndrome occurs In patients rehabiiifated with a maxil lary completedenture opposing a mandibular implant-supported f ixed prosthesis. Materials andMethods: Standardized clinic al procedures measured f it , occlusal integrity, and bone lossin the anterior m axilla in 1 f edentulous subjects meeting these requiremenfs, from thepatient pool of the Implanf Centre, Unifed Dental Hospital, Sydney, Results: A meanannual loss of 0,17 mm in tine anterior maxillary ridge height was not statisticallysignitica nt (P > 0,05). Ho wev er, Increased pressure in fhe anterior m axilla ry ridg e du rin gocclusion and loss of posterior occlusal contacts in retruded position were noted on oneor bofh sides in all subjecfs. Conclusior): Loss of posterior occlusion could nof be relafedto anferior maxillary bone loss. However, fo maintain the integrity of ttie prosfheses andtheir supporting structures, it is imporfanf fo schedule periodic recall appointments forreview of the occlusion, Inl Prosthodont 1999,12:492^97.

Osseointegrated implants are widely used inprosthodontic rehabilitation, ranging from a sin-gle-tooth replacement to implant-supported com-plete dentures; these treatments often lead to amarked improvement in chewing efficiency and al-lev ia t ion o f denture adaptat ion prob lems, ' " "^However, there may also be disadvantages in theform of bone loss in the opposing jaw.^"^'Graduate Student, Discipline of Removable Prosthodontics,Faculty of Dentistry, University o Sydney, Australia.' 'Associate Professor and Head, Discipline of Rem ovableProsthodontics, Faculty of Dentistry, University of Sydney,Australia.'Adiiini:t Associate Professor, Special Prosthodontics, UnitedDental Hospital, Sydney, Australia.Reprint requesfsi Dr Saurabh Gupta, 17 Civil Lines, NearAllahabad 8ani


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Gupta et Cliariges Under Compiete Dentures Opposing Implant Prostheses

cantilever units of the imp lant prosthesis. As a directconsequence of higher functional forces in such situ-ations, midline fracture of the maxillary denture aswell as increased incide nce of relines and remakes arereported in a few studies.^-'^- However, Zarb andSchmitt-^ did not encounter midline fractures or theneed for relining o fth e m axillary denture in 40 patientswith similar prostheses.

A difference of op inio n is also evident in 2 studiesinvestigating anterior ma xillary b one loss under com -plete dentures opposing im plant-sup ported fixed par-tial den tures, acobs et al^ reported an increased an-nual maxillary bone loss in 12 subjects with theabove men tioned prostheses, wh ile Henry et aP ' d idnot observe increased bone loss and deve lopment offlabby ridges in the anterior maxilla in a 10-year fol-low-up study of 12 subjects.The aim of this study was to determine whether acondition similar to Combination Syndrome occursin patients rehabilitated with a maxillary completedenture opposing a mandibular implant-supportedfixed prostbesis.Materials and Methods

Eleven edentulous subjects who bad been rehabili-tated witb a mandibular osseointegrated implant-supported fixed prosthesis and a maxillary completeconve ntional denture were selected from the patientpool ofthe Implant Centre, United Dental Hospital,Sydney, Australia. The sample included 4 men and7 women, their ages ranging from 53 to 74 years(mean 65.6 y). Selection criteria were that they hadbeen wearing these prostheses for at least 21 monthsand their records did not show evidence of any sys-temic factors that might affect bone loss.-""A subject information statement explaining thepurpose of the study, procedures to be carried out,and duration o fthe appointme nt was written in plainlanguage and mailed to the prospective subjects fortheir consent.Each subject was asked if he/she was satisfied w iththeir upper den ture. They were asked to grade their pre-sent chew ing ability from the time of implant treatmentas being the same, better, or poorer. Occurrences ofremakes, relines, and repairs o fth e ma xillary denturewere recorded.Ciinicai ExaminationThe m axillary denture was checked for stability andretention for each subject using conventional proce-dures for complete dentures, '" and results wererecorded as adequate or poor.

Fig 1 Height o1 Ihe biock ot the Luxatemp cast (DM G| is mea-sured to indicate the discrepancy between tootb surtaces inmaximum occiusal contact and in centric reiatian.

The fit of the maxillary denture was evaluatedusing a pressure-disclosing paste Fit-checker (GC).The amount of material was standardized by havingthe length of the bead of base paste equal to the an-teroposterior length of the denture, while the catalystpaste was half this measure. The fit was disclosedtwice in each case:1. Finger pressure; Index fingers were placed on ei-ther side, midway anteroposteriorly, to seat thedenture, and moderate finger pressure was ma in-tained until the material was set.2. Biting pressure: The subject was asked to bitewith moderate force and maintain this pressureuntil the material was set.Visual differences in thickness between the 2 dis-closing impressions, especially in the anterior p art ofthe ridge, were noted.

The discrepancy between maxillary and mandibu-lar teeth in the posterior region was determined bymeasuring the space between posterior too th surfaceson casts of the prostheses articulated in centric rela-t ion, as described by Lechner and M am me n'' (Fig 1 ).Cephalometric AnalysisLateral head cephalograms were taken w ith the den-tures in occlus ion. A set of radiographs had been takenduring the implant-supported fixed partial denturetreatment (postoperative cephalogram}. A similar ra-diograph was taken atth e study appointme nt (follow -up cephalogram). Postoperative lateral cephalograms


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Under Coniplele Denlures Opposing implanl Proslheses

Table 1 Subject Data

S u b jec t1234567891011

SexFFFMMFMFMF F

A g e(V l73747 46168705 65 96 0635 3

Cep t i a lo metric- . h . , . . ,;rr, " e r i o d

3 Oi-4 - 0 85-01

11-OQ2-053-GO3-013 - 026-05MA

Dura l ion o fde n tu r e wea r(y -mo)

6-043-114-004-0210-001-091-092-022-0215-066-03

"Time elapsed between postoperative and current cephslometric radi-ographs. No postoperaliue radiograph was available tor subject 11

Gupla et a i

Fig 2 Landmariis and points for cephalometric evaluation. ANS- antenor nasai spine; PNS = posterior nasai spine: ANS-PNS= palatai piane; C^most anterior inferior point on ma xiiia; dine= iine passing through C perpendicuiar to palatal piane; C - intersection ot palatal plane and C iine, F - point 10 mm posterioto C point aiong the paiatai plane: E line- line passing throughE' point perpendicular to palatal piane: E ^ most inferior maxiliary point aiong tine E iine: D ii ne ^ line passing through ANS perpendicuiar to paiatai piane: C-D/ine= line passing through C poinparallel to palatal piane: D= intersection of D iine and C-D line

had been taken at the time of stage 2 surgery rather thanat the time of issue of the m andibular prosthesis, w hic hin some cases had been cons iderably deiayed becauseof a variety of factors. The annual bone changes weretherefore ca lculated for the interval between the 2 setsof radiographs (observation period), which rangedfrom 2.4 to 11.0 years (mean 5.2 years), and not for theduration of denture wear, although most dentures wereworn for the majority of this period (Table 1 ).The cephalograms were a nalyzed using the systemoutlined by Scott et al-'' for vertical and horizontalmeasurements of the edentulous maxilla. Tracings forboth the postoperative radiograph and the fo llow -u pradiograph were made by the same examiner to m in-imize tracing errors, and radiographs were traced ran-domly. The relevant landmarks were identified andtraced on tracing paper for both postoperative and f ol -low-up radiographs (Fig 2). Cephalometric analysiswas carried out for only 10 subjects, as the postoper-ative cephalogram for one subject was not available.The vertical and horizontal measurement valuesobtained for the fol low-up radiograph were sub-tracted from those of the postoperative radiograph toobtain the effective a nnual change durin g the obser-vation period. Means and standard deviations werecalculated fur all measurements. The Student's ites t{2-tailed paired means comp arison) was used to sta-tistically evaluate bone loss and check tbe signifi-cance (95% co nfidence level) of the resulting valuesin this grou p. Simple regression analysis was used todetermine a linear relationship between the annualbone loss and the age of the subject and du ration ofwear of the prosthesis.

ResultsSubject Assessment of Fit of Maxillary DentureEight subjects (73%) found the fit of their maxillarydenture satisfactory, w bi le tw o co mp lained of a loosedenture. One subject observed that the denture"seems to be going up in the front and down at theback." The maxillary denture was relined for onesubject once, a pproximately 1 year before the studand the denture felt loose again at the follo w- up . Anew m axillary denture was made for another subjec5 years before the present inves tigation. The d enturehad been remade three times and relined three timesover 6 years for one subject, who reported that thepresent was the "most successful so far."Retention and Stability of Maxillary DentureThe operator assessed the re tention of the ma xillarydenture to be adequa te in 9 subjects (82 %). The stability of the denture was also found to be adequatein 9 subjects (82%). Retention and stability were observed to be poor in one subject. One subject hadpoor retention but adequate stabil ity, while anotheexhibited adequate retention but excessive laterarocking of the denture.Evaluation of Fit of Maxillary Denture

The thickness of tbe film of Fit-checker in the maxillary de nture was visually evaluated, revealing a thinner film of material in the anterior region under biting


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G up ta et I C hanges Un de r C om ple te Dentures O p po sin g Im pla nt Prostheses

pressure than w ith finger pressure (Fig 3). This was ob-served in all 11 subjects.Posterior OcclusionA loss of posterior o cclus ion was observed on one orboth sides of the denture in all subjects, ranging from0 to 2,5 mm on the left and 0 to 2.0 m m on the rightside of the prosthesis. The maximum discrepancy of2.5 m m o n the left and 2.0 mm on the right sides wasobserved in one subjecf, while the remainder were1 m m or less. The values were different o n the 2 sidesfor 10 subjects (91%).Cepbalometric Evaluation: Vertical MeasurementsC-C. Bone loss ranging from 1 to 4 mm was notedin 4 subjects (40%). No change was observed be-tween po stoperative and follo w-u p values in 3 sub-jects. A 1-mm increase was observed in 3 subjects(30%). The mean annu al bone loss was 0.17 m m, butthe difference was not found to be statistically sig-nificant (P> 0-05).E-E'. Bone loss rang ing from 1 to 4 mm was noted in6 subjects (60%), wh ile 4 subjects (40% | showed nochange. The mean annual bone loss was 0.3 mm , andthe difference was foun d to be statistically significant(P 0.05|.C-D. The measurements were the same as AN S-C forall subjects.

Fig 3 iulaxillary denture with pressure-aisclosing paste afterseating with biting force. Note heavy anterior contacts.

DiscussionPressure-disclosing paste revealed a greater am ount offorce in the anterior region on biting in all subjects, andlack ofpo sterior contacts was noted in all subjects. Byallow ing shunting of the denture in function, poor oc-clus ion o ften translates into a perceived lack of fit^^^^;the absence of posterior support could therefore wellaccount for the "looseness" of the maxillary denturedescribed by some subjects even though the operatorassessment was that the retention was adequate.Howe ver, the am ount of bone loss noted in the an-terior maxilla was equivocal, anda linear relationshipcould notbe established for annual vertical bone losswi th respect to the age and sex of the subjects or du -ration of wear of the prosthesis. Loss of posterior oc -clusion cou ld therefore not be attributed to b one lossin the anterior ma xillary region as has been suggestedin ridges opposing impiant-supported overdentures.^"''Itwo uld havebeen interestingto compare the changesin the subject who showed maximum occlusal loss,but the postoperative cephalogram was not avail-able. The radiographie evaluation indicates that thevertical measurements at the crest of the maxillaryridge (C-C) are nearly even in distribution amongbone loss, no change, and increase in height of theridge. The identification ofth e ANS point was difficultbecause ofth e thin isthmus of bone with a greater su-perim position of soft tissue and a poor-q uality radi-ograph. There seems, howev er, to be a significant re -duction in the length of the palatal plane (ANS-PNS),as well as in the height of the anterior maxilla (E-E')posterior to the crest of the ridge. The horizontalchange observed was probably a result ofth e poste-rior repositioning of the anterior nasal spine that maybe related to the age of the subject and the pressureexerted by the maxillary denture. The crest of the


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Under Complete Df tu 'es Oppo sing Implant Prostl ieses Gupta ct al

ridge is know n to move posteriorly be(-aLi...e ol ihe pat-tern ofresorp tion,-^ wh ich shifts fhe E'point along thepalatal plane because ofthe posterior repositioning ofthe C line. The paiafal contour narrows from the crestposteriorly in the supero inferior dimension, ' and thissupports the significant reduction in the E-E' dimen-sion. The posterior shift cf both the D line and the Cline possibly accounts for the insignificani changeobserved in the AN S-C dimension. The indecisive na-ture of these measurements may be a result ofthe factthat, compared with a mandibular implant-supportedoverdenture, the implant-supported fixed prosthesiswould show minimal deflection ofthe cantilever seg-ment when opposing a complete denture.It is more probable that the lost posterior supportis loss of actual tooth structure. Prostheses for allsubjects had been made by one of 2 clinicians and,at the time of issue, all posterior teeth were in con-tact in centric re lation. However, all had plastic teelh,which have been shown to be subject to wear,^'^-^'The difference in occlusal discrepancy between the2 sides may thus be caused by tbe preferred chew-ing side ofthe subject. Visual comparison of the orig-inal casts to the present prostheses showed wear insome of the cases, although as the study was retro-spective, no attempt cou ld be m ade to evaluate anydimensional change in the plastic teeth. One subjectdid observe that the denture teeth seemed to be w or n.The use of porcelain teeth in implant-supported co m-plete dentures co uld ov ercome problems associatedwith plastic teeth.Another explanation for the observed ioss of pos-terior occlusal contact could c onceivably be a tissue-directed deflection of the maxillary denture, indicat-ing a loss of posterior maxi l lary ridge height.However, this possibility was considered marginaland was not investigated.The scope of this study, being retrospective, waslimited in terms of the records available and theirquality at the time of the study. Errors in this studycoLtId aiso be attributed to the d ifficulty in identify-ing radiographie landmarks and problems associatedwith radiographie tracing.

ConclusionIn this study, the rehabilitation of the edentulousmandible with an implant-supported fixed prosthe-sis occluding w ith a maxillary com plete denture didnot appear to prom ote a co nd i t io n sim i lar toCombination Syndrome, However, loss of posteriorocclusion was observed in every case and must be an -ticipated as a sequela tc such treatment, especiallywitb opposing plastic teeth. Periodic recall appoint-ments to review the occlusion should therefore be

scheduled to maintain occlusal harmony and thehealth cf the sup porting tissues,Euture research co uld include a larger sample eto provide a clearer picture of bcn e loss and a co m -parison between tbe effects of porcelain or plasticteeth on occlusal integrity.

References1 . Lindquist LW, Car isson GE, Long-term effects on ch ew ing wit h

ma ndib ular f ixed prostfieses on osseo integrated im plants . ActaOdonto i Scand 1985;43:39-45.

2. Carlsson GE, Lindquist LW. Ten-year longitudinal study of mas-t icatory funct ion in edentulous pat ients t reated with f ised co m-plete dentures on osseointegrated implants, Int | Prosthodont] 9 9 4 ; 7 : 4 4 8 - 4 5 3 ,

3, Lindquist LW, Car lsson CE, Cfantz P-O, Rehab i l i tat ion of th eedentulou s m and ible w ith a tissue-integra led fixed prosthesis: Asix-yeai longitudina l study. Quintessence Int 19 87; IB:B 9-9 6,

4, Blomberg S, Lindquist LW , Psychological react ions to edentu-io jsness and treatment wi ih jawbone-anchored br idges. ActaPsychiatr Scand 1963:68:251-262.

5, lacobs R, van Steenberghe D, Nys M, Naert I, Ma xill ary bonersorpt ion in patients with mandibular implant-supp orted over-dent jres or fixed prostheses. | Prosthet Den t 1 9 9 3 ; 70 :13 5 - 1 40 ,

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8. Carlsson GE, Clin ical morb idity and sequelae of treatmen t withcomplete dentures. | Prosthet Dent l99B;79:I7-23,

9. Atw ood D A. Reduction of residual r idges: A major oral diseaseentity, | Prosthet Deni 1 971 26 :266 - 279 ,1 0, Wat t DM, MacCregor AR, Des ign ing Comple te Dentures .

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Problems, St Louis: Mosby, 19 74,1 2, Tal lgren A, Tryde C, Mizu tani H, Changes in jaw relat ions and

act iv i ty of mast icatory musdes in pat ients with imme diate com -plete upper dentures, J Or a i Rehab i l 1986 ; 13 :311 - 324 ,

1 3, Carlsson CE, Haraldson T, Fundamental aspects of mandibularatrophy. In: VWorthington P, Branemaik P-I (eds). AdvancedOsseointegrationSurgery, Chicago: Quintessence, 1992:109-118.

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1 7, Tal lgren A, The cont inuing reduct ion of the alveolar r idges incomplete denture wearers: A mixed- longitudinal study cover ing25 years, J Prosthe t Dent 1972;27:120-132,

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Changes Under Complete Dentures Opposing Implant Prostheses

2 0 , Falk H, Laurell L, Lundgren D, Occlusal force patferns in den-f i lic in5 wit h m andibular implanl-supporfed f ixed cant ilever pros-fheses occluded with complefe denfures, Inf ] Oral Maxi l lo facImp lan fs f 989 :4 :55-62 ,2 f . Henr>' P|, Bower RC, W al l CD, Rehabi l i tadon of fhe edenf J I O U Sman dible w i lh osseoin legrafed denia l implan ts: f 0 year to l lo w-up, Ausf DentJ f 995 ;40 : f -9 ,2 2 , Hemm ings KW , Schmi ft A, Zarb GA. Com pl ica t io n ; and ma in -tenance requirements for f ixed proitheses and overdenfures inthe edentulous ma ndible : A 5-year repor f . Inf ) Oral Maxi l lo facI m p l a n t s f 9 9 4 ; 9 : l 9 f - 1 9 6 ,2 3 , Zarb CA, Schmif f A, The longi tudinal c l in ical ef fecdveness ofQsseointegrated d ental imp lants : The T oro nio study. Part 111:Prob lems and compl ica f ions encounte red , | Pros the t Dentf 990 :64 :135- f 94 ,2 4 , M a m m e n A . C o m b i n a t i o n S y n d r o m e i n R e l a t i o n t oOsseo i r tegra ted Imp lan t Suppor ted Overden iu res [ thes is l ,Sydney. Univ of Sydney, 1992.2 5 , Scoff RF, Barber D, Masson BB, A techniquefor evaluating bonychanges in the anterior edentulous maxil la: A moditication of acephalometric analysis. Oral Surg Oral Med Oral Pathol f 99f;7 1 : 2 5 O - 2 5 f .

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Literature Abstract-

The impact of oral health on stated ability to eat certain foods; Findings fromthe National Diet afid Nutrition Survey of Older People in Great Britain.Tt i i s ex fens ive s tudy used 2 represen ta t ive samples o f peop ie aged 65 years and o lder : aSff ree- l i v ing and 275 mst i tu f iona i sub jec ts f iad a den fa l exam and were in te rv iewed about f f ie i rab i i i fy fo ea f 16 key foods The re were m ore d ie fa ry res f i i c t ions repor ted by fhe ins t i tu t ion sam -p l e , but in t f ie t ree- i i v ing pe op le , ma ny a iso had d i f t icu l f ies ea f ing severa l o t fhe toods f i lo r eo ffhe eden tu lous sub jec fs repor ted such d i t l i cu l f ies . I f was conc luded tha t the se iec t ion o t foodsin o lder peop le is subs tan t ia l l y a f feo fed by f f ie number o f fee f f i , espec ia l l y pos fe r io r occ lud ingpa i rs o f fee th , and the p resence o f comple te den tu res . T t iose c l in ica l parameters in tu rn a f fec thow peop le fee l abou t ea f ing . Th is was even more impor tan t in ins t i tu t iona l ized peop ie .D ie f i f ians and ca te re rs shou ld cons ider ca re tu i l y fhe den ta i bar r ie rs fo ea f ing essen t ia l foods .She ifiam A, Steele JG , fHarcenes W, Fincfi S, Walls AW G, GeradoTtotogy 1999:1 S:11-20. References; 26,Reprints: Prof A, Sfieiliarr, Department of Epidemiology and Public hiealth, University College, Londonfuledical School, 1-19 Tomn gfon Place, London WC IE6 BV , United Kingdom Fax: + 44 (0)20 78f 3 0242,e-mail: A,Sfisiliam(>ucl.ac,uk,flW


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1999_maxillary changes under complete denture opposing mandibular implant-supported

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