lip posi gudeline- cd

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Proshodontics

idelines to lip position in the co nstruction of com plete d entu resBrunton * /J Fraser McCord*

Avarietyo f philosophies and techniques forthe prescriptiono festheticallyand fiinctionallyacceptable complete dentures arereviewed Guidelines forthe useofanatomic landmarks arediscussed inaddition tofimctionaldeterminantsoftoothposition The value ofpre-exiraciionrecords is discussed and suggestions are made as to useful clinical aides lo more appropriateprescriptiono facceptabledentures (Ouintessence Int1994:25:121-124.

ntroduction

partial dentu res m ay be requ ired, as patients are an-pated to retain m ore of their naturaldentition. Fur-use of techniques ap pro priate to the older patient,lete dentu res, is to be expected.^ The anticipated

Clinical experience suggests that the cumulative ef-ts of biologic and chron ologic aging will result in in-

support to edentulous patients.

lipsupport ndcontour

tissue, and g lands, etc

Depa rtment of Restorative Dentistry, University Dental Hospi-tal of Manchester, Higher Cambridge Street. Manchester M156FH, England.

2. Support from underlying struc tures, such as the an-terio r teeth and associated alveolar bone '^Ricketts.'' in an attempt to quantify the pereeived ideal lip contour, studied profile photo graphs ofpopular female personalities admired for their beauty.The lips were related to the ' esthetic plane, a linedrawn from the end ofthe nose to the chin. He deter-mined that the lowerUpis approxim ately2mm and theupper lip approximately4 mm posterior to the esthetic

plane, which is used in orthodontic evaluation andtreatm ent planning.' This esthetic plane, because of itsgrea t variability,isconsidered by Ellinger^ to be a poorreference plane.Knowledge of lip positiotis in the dentate state areuseful in the transition from the dentate to the edentu-lous state, and may be used in the prescription of pros-theses for the edentulous patient. Resorptive changesin alveolar bone following the loss of maxillary teethhave been studied longitudinally.' These studies re-vealedaloss of buccal bone and an associated decreasein ridge height in the an terior region ofthemaxilla. Thenet resultisthat the maxilla decreases in size while, co-incidentally, the mandible appears to increase in widthrelative to the m axilla.'To quantify facial profile and help preserve a naturalfacial contour during the transition from a dentate toan edentulousstate.Scher' advocated the use ofaden-tofacial profilometer. This measured the nasolabial an-gle, the length of the upper lip and horizontal part ofthe nose at the pre-extractton phase of dentnre con-struction. Friedman''' recommended the use of facialmeasurements, profile patterns, and photogTaphs to

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Prosthodontics ble Clinieal indications of excessive and insufficient lip support ignsof excessivelipsupport ignsof insufficientUpsupportTensed, stretched appearance of the lipsTension lines around the moulhDistortion ofthe philtrumObhteration ofthe mentolabial, nasolabial.and labiomarginal suici

Perpetuation of the general appearance of collapsearound the mouthReduction in the size of the vermilion borders of the lipsDrooping of the corners of the moulhDeepening of the mentolabial, nasolabial, and labio-marginal sulci

Eradieation of the natural contours of the lower part Ob literation of the philtrumof the face that correlate that portion with the upperpart ofthe face

obtain an index of lip contou rs and serve as a guide topositioning the anterior teeth.Physiologic lip support is perceived to be importantnot only for a natural and pleasing appearance but alsofrom a functional poin t of view.'' The muscles of the lipsand cheeks, like al skeletal muscle, function most effi-ciently when maintained and supported at their func-tional physiologic length: esthetic considerations in theconstruction of complete dentures must therefore beassessed not only while the lips are in repose but alsowhile they are in function.''''^

The pattern of rsorption in the anterior maxilla issuch that placement of the replacement teeth over theresidual alveolar ridge will result in unphysiologic lipsupport.'" Indeed it has been observed, in some indi-viduals, that the resultant space between the upper lipand incisor teeth that oeeurs when the anterior teethare set too far palatally is responsible for phoneticproblems such as imparting a whispering quality tospeech patterns.'^While a natural tooth position on complete denturesis desirable, to further develop natural form and phys-iologic lip support, a denture must reproduee a naturalanatomy around these teeth to enhance lip support and

Tlie labial flange and associated denture base mate-rial replace the lost supporting structures of the na turalteeth: some workers'*"'" believed that physiologic lipsupport is provided by the labial flanges and the gingi-val two thirds of the anterior teeth. Contouring of thelabial flange to compensate for the loss of alveolar

bone is also important: if the replacement teeth are inan unnatu ral position , it is technically difficult to devel-op a natural contour for the labial flange."^ Further,variation in the thickness and length of the flange fromleft to right may be necessary to duplicate facial asym-metry,''The clinical signs of excessive and insufficient lipsupport, summarized in Table 1, are documented but

not quantifled."'-^ Watt and MacGregor'- stated thatthe average sagittal angle between the columella andthe lip is approximately a right angle. This angle eouldbe increased if the an terior teeth are retroclined or ifthe columellaisprom inent and at a lower levei than theala. If, however, the columella and ala in profile are atthe same level and associated with proclined anteriorteeth, an angle of more than 90 degrees is indicated. Itwas also suggested that a horizontal nasolabial anglebetween 90 and 120 degrees is appropriate. This anglewould vary according to whether the patient has a nar-row face or a broad face, the broader-faced individualrequiring a flatter angle and vice versa.Watt-'' reeommended the constrtiction and use ofbiomtrie trays to prescribe the appro priate depth andwidth of the buecal sulei and hence to facilitate the res-toration of the pre-extraction form of the lips andcheeks.

omparison ofthe edentulous and dentate statesIsmail et a P and C arisson and E ricson''' studied thesoft tissue profile of subjects prior to the extraction of

122 Quintessence International Voiume 25 N umber 2/1994


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Prosthodonticsrepo rted a dramatic ehange in the contour of the

prescribed dentur es restored the lips to the pre-ex-

h was attribu ted to the pattern of alveolar rsorp-

s and reported a more anterior position ofthe max-

the occlusai vertical dimension and an associated an-

nterior tooth position

of viewistha t of n atu ra l teeth, ' '" '^''" '' Frush ander" felt that the positioning ofth e maxillary anteri-for natu ral and pleasing lip support was an in-ion or op posing tooth position. Positioning the artifi-l incisors in positions similar to tho se of their n atural

tochange m ust be con sidered, especially in theEllinger considered th at failure to place the anterior

It has been accepted practice, by some prosthodon- to place the maxillary denture teeth over the re--'^ Long itudinal studies of post extrac tiont re presen t the original tooth positions.'-''"adenture flange is thickened, in an attemp t to plump

placed incisors, a sunken, uneosmetie oval profile withinverted lips may result,'*'A longitudinal study of upper lip length in dentateadults demonstrated that the upperliplenglh increaseswith age. ^Thus, in older patien ts, it would appear to bemore appropriate to site the maxillary incisors level

with or superior to the upper lip. This is in agreementwith Frush and Fisher,-'' who eonsidered that naturalage changes must not be disregarded when denturesare constructed. Restoration of facial contours beyondthose compatible with the patient's physiologic agemay produce the "den ture look,'""One of the most important anatomic features facili-tating positioning of the replacement central incisors isthe incisive papilla,'"-'"' The average distance from theposterior border of the papilla to the labial surface ofthe central incisors has been reported to be 12,5

mm,"**'" Other workers"'-'^''- recommendedadistanceofSto1 mm measured from the m iddle of the incisivepapilla asabiomtrie guide to anterior tooth po sition.The results uf some studies-'"'"''-^ indicated that max-illary and mandibular incisors in the "'artificial denti-tion" were set to a lower level than their natural coun-terparts: these findings appeared to confirm the per-ception that the replacement teeth had been set tomatch a longer edentulous up perlip.Hence if den turesfor the older patient are constructed so that the maxil-lary anterio r teeth are 1 to 2 mm below the verm ilionborder, they will be set to a iower level than their natu -ral counterparts when measured from the maxillaryplane.

SummaryA variety of methods have been used to study the softtissue ofthelips in an attempt to establish guidelines tofacilitate the prescription of (maxillary) complete den-tures. While no one m ethod can he said to befoolproof,the use of anatom ic guidehnes, suchasthe incisai papil-la,isto be reeommended,as isthe use of pre-extractionphotographs.

References1, Zarb GA, Bolender CL, Hictcey JC, Carlsson GE, Boucher'sProsthoduntic Trea tment for Edentutou s Patients, ed t l) . St

Louis; Mosby, t99U:3,2, McC ord JF, Gra nt AA . Quayle AA , Treatm ent options for theedentulous mandible, Eur J Prosthodont Rest Dent 1992;

t:19-23.

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Prosthodontics3, Hoad-R eddick G. Gr am A A, Gri l t iths CS, Knowledgeo den-

tal services provided: Investigations in an elderly population,J Dont 1987:15:139-146,4, Ma rtone A L, Effects of complete den tures on facial aesthetics,J Prosthet D ent 1964;14:23]-255,5, McCarlney JE, Prosthetic problems resuiling from facial and

intraoral changes in Ihe edentulous patient , J Denl 1981:9:71-83 ,

6, Ricketts RM , Planning Irealmcnl on the basis of the lacial pat-lern and an e stimate o its growtb. Pa rt 1. Cep h alom e tries andgrowtb estimation. Angle Orlbod 1957;27:14-,37,

7, Di Biase DD, Class II maloeclusion: Making the face fil. DentUpda te 1991:18:429^35 ,8, EllingerCW,Radiograph ie sludy of oral structures and Iheir re-lation to anterior tooth position, J Prosthet Dent 1968:19:36-45,9, Carlsson G E, Bergm an B, Hed cgard B, Changes in contou r oftbe maxillary alveolar process under immediate dentures, A

longitudinal clinical and x-ray cephalometric sttidy covering 5years. Acta Odontol Scand 1967:25:45-75,

10, Watt DM , Likeman PR, Morphological changes in the dentur ebearin g area following extraction of maxillary teeth, B r Denl J1974:136:225-235,11 , Likeman PR, Watt DM, Morphological changes in the maxil-lary denture bearing area: A follow up 1410 I7years afler loothextraction, Br DentJ 1974:136:500-503,

12, Wat t DM, MacGregor AR, Designing Complete Dentures , ed2, Bristol , England: W righl Sons, 1986:10,30-31,

13, Scher E, The dontofacial profilometer. Ouintes senee Int1979:10(3):6l-67,14, Friedm an S. Symposium on complete de ntures : Diagnosis andtreatment planning, Denl Chn North Am 1977:21:237-247,15, Marione AL. The phenomenon of funclion in complete den-ture prosthodontics. Anatomy of the mouth and relaled struc-tures. Part 10, Functional anatomic considerations, J ProsthetDent 1962:12:206-219.16, Mc Ge e GF, Tooth placem ent and base contour in dentur e con-struc tion. J Prosthe t D ent 1960; 10:651-657,17 , Ballard CE, Variations of posture and beha viour of the l ips andtongue which determine the position of the labial segments:The implications on orthodontics, prosthetics and spee ch. TransEu r O rthod Soc 1963:39:67-68; discussion 1963:39:89-93,18, Pound E, Modern concepts in esthetics, Itit Dent J 1960;10:154-172.19, Vig RG, The den ture look. J Prosthet D ent 96 ;11:9-15,20 , Marilato ER. Douglas JR, A positive guide to anterior toothplacem ent, J Proslh el D enl 1964; 14:848-853,21 , Krajicek DD. Natural appearance for the individual denture

patient , J Prosthet Den t 1960: 0:205-214,22 , Hooper BL. Functional factors in Ihe selection and arrange-ment of artificial leetb. J Am Dent Assoc 1934:21:603-615,23 , M arton e AL, The phenom enon of function in comp lete den-ture prostbodontics. Clinical apphcations of concepts of func-tional anatomy and speech science to complete denture pros-thodontics. Part VlILTbe final phases of denture construction,J Prostbel Dent 1963;13:204-228.

24, Watt DM, Biometrie trays for complete denture construction,J D e n t l 9 8 1 ; 9 : 1 2 6 - l 3 2 ,25 , Ismail YH , George W A, SassounI V, Scott RILCcp h a lo m eln cstudy of the changes occurring in the face hci;;litl iJIowtng pros-thetic treatment. Part L Gradual reduction of hoth occiusal andrest face heights, J Prosthet De nt 1968;19:321-330,26 , Carlsson GE, EricsonS Cha nges in the solt-t issue profile oftheface following extraction and denture treatment. A longitudi-

na ls-ray cephalom elric study, Odo ntol Tidskr 1967;75:69-98,27 , Watson R M, Bhatia SN, Tooth positions in the natura l and com-plete artificial dentitions, with special reference to the incisorteeth: An interactive on-line computer analysis, J Orai Rehabil1989; 6:139-153,

28 , Tallgren A, Lan g BR , Miller R L, Lon gitudinal slud y of soft t is-sue profile changes in patienls receiving immediate completedentures , Int J Prostho dont 1991;4:9-16,

29 , Tallgren A, Tlie effect of demure wearing on facial morpbolo-gy: A 7-year longitudinal study. Acta Odontol Scand 1967;25:563-592,

3(1. Tallgren A. Positional cbanges of complete dentures: A 7-yearlongitudinal study. Acta Odonlol Scand 1969;27:539-561.

31, Tal lgren A, Lang BR, Walker GF, Ash MM , Roentgen cephalo-melric analysis ol ridge rsorption and changes in jaw and oc-ciusal relationships in immediate complete denture wearers,J Oral R ebabil 1980:7:77-94,3 2, Tallgren A, Lang BR , Walker GF, As h MM , Chang es in jaw re-lations, hyoid position, and head posture in complete denturewearers, J Prosthet Dent 1983;50:148-156,33, Ha rton o R, The occlusai plant; in relation to facial types, JPros -thet Dent 967;]7:549-558,34 , Payne SH, Symposium on complete den tures; The t r ial den ture.Dent Clin North Am 1977;21:321-328,3 5, Anderson JN, Storer R, Imme diale and Replace ment D en-tures, cd 3. Oxford, England: Blackwell Scientific, 1981:105,36 , Wat t DM , Tootb posi t ions on complete dentures , J D ent

1978;6:147-160,37 , Frus hJP .Fish erR D, Complete dentures: The dynei thet ic inter-pretation of the dentogenic concept, J Prosthet Dent 1958;8:558-581,3 8, Forsberg CM. Facial morphology and ageing; A longitudinalcephalometric investigation of young adults, Eur J Orthod1979:1:15-23,39 , Basker RM, Davenp ort JC, Tomlin HR , Prosthet ic Treatmentof the Edentulous Palient: cd 3, New York; Macmillan,1992:175-176,40 , Ehrlich J, Gaz it E, Re lations hip of the maxillary central incisorsand eanines to the incisive papilla, J Orai Rehabil 1975;2;309-312,41 , Ortman HR, Tsao DH, Relationship of Ihe incisive papilla tothe maxillary central incisors. J Pro sthet De nt 1979,42:492-496,42 , Landa LS, Practical guidelines for complete de nture esthetics.De nt Clin Norlh Am 1977:21:285-298,43 , Nanda RS. Meng H, K api la S , Goorh uis J , Grow th changes inthe soft tissue profile. An gle O rth od I99O;6O:177-19O,

12 4 Quintessenoe International Volume25 Number 2/1994

lip posi gudeline- cd

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