biological consideration for maxillary denture bearing areas / dental courses

GOODMORNING
www.indiandentalacademy.comwww.indiandentalacademy.com

BIOLOGICAL CONSIDERATIONSBIOLOGICAL CONSIDERATIONS
FOR MAXILLARYFOR MAXILLARY
DENTURE BEARING AREADENTURE BEARING AREA

CONTENTS-CONTENTS-
 IntroductionIntroduction
 DefinitionDefinition
 Supporting structuresSupporting structures
1. Bone1. Bone
2.Mucous membrane2.Mucous membrane
 Peripheral or limiting structuresPeripheral or limiting structures

 Anatomy of limiting structures in maxillaryAnatomy of limiting structures in maxillary
regionregion
 Anatomy of supporting structures in maxillaryAnatomy of supporting structures in maxillary
regionregion
 ConclusionConclusion
 ReferencesReferences

INTRODUCTION-INTRODUCTION-
If dentures and their supporting tissues areIf dentures and their supporting tissues are
to coexist for a reasonable length of time, theto coexist for a reasonable length of time, the
prosthodontist must fully understand theprosthodontist must fully understand the
macroscopic and microscopic anatomy ofmacroscopic and microscopic anatomy of
edentulous mouth .edentulous mouth .

 Anatomic landmark-Anatomic landmark-
““ a recognizable anatomic structurea recognizable anatomic structure
used as a point of reference.”used as a point of reference.”
GPT-8GPT-8
 In both maxilla and mandible anatomicIn both maxilla and mandible anatomic
landmarks has been divided in-landmarks has been divided in-
-supporting structures-supporting structures
-peripheral or limiting structures-peripheral or limiting structures

Supporting structuresSupporting structures
 Def-Def-
““Those areas of maxillary and mandibularThose areas of maxillary and mandibular
edentulous ridges that are considered bestedentulous ridges that are considered best
suited to carry the forces of masticationsuited to carry the forces of mastication
when dentures are in function.” (GPT-8)when dentures are in function.” (GPT-8)

 Maxillary and mandibular dentures transferMaxillary and mandibular dentures transfer
occlusal loads to these so called supportingocclusal loads to these so called supporting
structures .structures .
 The ultimate support for a denture isThe ultimate support for a denture is
provided by the underlying bone which isprovided by the underlying bone which is
covered by mucous membrane. Support iscovered by mucous membrane. Support is
provided by maxillae and palatine bone inprovided by maxillae and palatine bone in
case of maxillary denture. For mandibularcase of maxillary denture. For mandibular
denture support is provided by mandible.denture support is provided by mandible.

 Each type of tissue found in oral cavity has itsEach type of tissue found in oral cavity has its
own characteristic ability to resist externalown characteristic ability to resist external
forces depending on its nature andforces depending on its nature and
histological makeup i.e type of bone andhistological makeup i.e type of bone and
mucous membrane.mucous membrane.
 Stress bearing and relief areasStress bearing and relief areas

Hard tissues-Hard tissues-
 The requirement of ideal support is theThe requirement of ideal support is the
presence of tissues that are relativelypresence of tissues that are relatively
resistant to remodeling and resorptiveresistant to remodeling and resorptive
changes.changes.
 Minimizing the pressures in those regions,Minimizing the pressures in those regions,
which are most susceptible to resorption andwhich are most susceptible to resorption and
directing the forces towards those regions,directing the forces towards those regions,
which are relatively resistant to resorptionwhich are relatively resistant to resorption
can help to maintain healthy residual ridges.can help to maintain healthy residual ridges.

 2 types of bones are seen2 types of bones are seen
-compact or cortical bone-compact or cortical bone
-cancellous or trabecular bone-cancellous or trabecular bone

Difference in ridge resorption inDifference in ridge resorption in
compact and cancellous bone-compact and cancellous bone-
 It has been suggested that bone resorption atIt has been suggested that bone resorption at
any site is a chemotactic phenomenon, that is itany site is a chemotactic phenomenon, that is it
is initiated by release of some soluble factorsis initiated by release of some soluble factors
that attract circulating monocytes to thethat attract circulating monocytes to the
target site. Osteoclasts, the cells responsibletarget site. Osteoclasts, the cells responsible
for bone resorption are nothing but modifiedfor bone resorption are nothing but modified
monocytes.monocytes.
 Degree of mineralization is less in cancellousDegree of mineralization is less in cancellous
bone, so effects of resorption are morebone, so effects of resorption are more
pronounced in cancellous bone.pronounced in cancellous bone.

Oral Mucous MembraneOral Mucous Membrane --
The bone of upper and lower edentulousThe bone of upper and lower edentulous
jaws, and the oral cavity is lined with a softjaws, and the oral cavity is lined with a soft
tissue that is known as ‘mucous membrane’.tissue that is known as ‘mucous membrane’.
Denture bases rest on the mucousDenture bases rest on the mucous
membrane, which serve as a cushion betweenmembrane, which serve as a cushion between
denture base and supporting bone.denture base and supporting bone.
The mucous membrane composed of :-The mucous membrane composed of :-
(i) Mucosa(i) Mucosa
(ii) Sub mucosa(ii) Sub mucosa

1)1) MucosaMucosa: -: -
Mucosa is formed by stratified squamousMucosa is formed by stratified squamous
epithelium cells.epithelium cells.
There is subjacent narrow layer ofThere is subjacent narrow layer of
connecting tissue to the mucosa, known asconnecting tissue to the mucosa, known as
laminalamina propriapropria..

2)2) Sub mucosaSub mucosa:: --
Sub mucosa is formed by connectiveSub mucosa is formed by connective
tissue.tissue.
Connective tissue varies in characterConnective tissue varies in character
from dense to loose alveolar tissue and alsofrom dense to loose alveolar tissue and also
varies considerably in thickness.varies considerably in thickness.
It may contain glandular, fat or muscleIt may contain glandular, fat or muscle
cells.cells.
Submucosa transmit the blood and nerveSubmucosa transmit the blood and nerve
supply to the mucosa.supply to the mucosa.
Sub mucosa attaches mucosa to theSub mucosa attaches mucosa to the
periosteal covering of the bone.periosteal covering of the bone.

 Some parts of the masticatory mucosa areSome parts of the masticatory mucosa are
without a distinct submucous layer, yet densewithout a distinct submucous layer, yet dense
connective tissue of the lamina propria firmlyconnective tissue of the lamina propria firmly
binds the mucosa to underlying periosteum.binds the mucosa to underlying periosteum.
Although not as effective in providing resiliency,Although not as effective in providing resiliency,
this connective tissue layer serves as athis connective tissue layer serves as a
protective base for the mucosa.protective base for the mucosa.

Classification of oral mucosa-Classification of oral mucosa-
Depending on its location in mouth, oralDepending on its location in mouth, oral
mucosa classified into three categories –mucosa classified into three categories –
Oral mucous membrane
Masticatory Lining Specialized

Limiting structuresLimiting structures
 The functional anatomy of mouth determines theThe functional anatomy of mouth determines the
extent of the basal surface of denture.extent of the basal surface of denture.
 The denture base should include the maximumThe denture base should include the maximum
surface, within the limits of the health andsurface, within the limits of the health and
function of the tissues it covers and contacts .function of the tissues it covers and contacts .

 Term ‘Border area’ refers to the mucosalTerm ‘Border area’ refers to the mucosal
surface area which contacts the denturesurface area which contacts the denture
borders and surrounds the spaces which areborders and surrounds the spaces which are
occupied by denture flanges.occupied by denture flanges.
 Border molding procedures are used to recordBorder molding procedures are used to record
limiting structures properly. There are 2 mainlimiting structures properly. There are 2 main
objectives of border molding in recording theobjectives of border molding in recording the
limiting structures-limiting structures-
1. to establish correct flange length and1. to establish correct flange length and
border thicknessborder thickness
2. to achieve retention through border2. to achieve retention through border
seal.seal.

BIOLOGIC CONSIDERATIONS OFBIOLOGIC CONSIDERATIONS OF
MAXILLARY IMPRESSIONSMAXILLARY IMPRESSIONS

LIMITING STRUCTURES INLIMITING STRUCTURES IN
MAXILLARY REGIONMAXILLARY REGION
 Labial frenumLabial frenum
 Labial vestibuleLabial vestibule
 Buccal frenumBuccal frenum
 Buccal vestibuleBuccal vestibule
 Hamular notchHamular notch
 Vibrating linesVibrating lines
 Fovea palatinaeFovea palatinae

1. Labial frenum1. Labial frenum
 Term frenum or frenulum refers to aTerm frenum or frenulum refers to a
connecting fold of mucous membrane servingconnecting fold of mucous membrane serving
to support or retain a part.to support or retain a part.
 labial frenum, is a fold of mucous membranelabial frenum, is a fold of mucous membrane
extends from the labial mucous membraneextends from the labial mucous membrane
reflection area to or towards the slop orreflection area to or towards the slop or
crest of residual ridge at the median line.crest of residual ridge at the median line.

 It divides the labial vestibule intoIt divides the labial vestibule into
approximately equal but asymmetrical left andapproximately equal but asymmetrical left and
right labial vestibule.right labial vestibule.
 It starts superiorly in a fan shape andIt starts superiorly in a fan shape and
converges as it descends to its terminalconverges as it descends to its terminal
attachment on the labial side of the ridge.attachment on the labial side of the ridge.
 It contains no muscle and has no action of itsIt contains no muscle and has no action of its
own.own.

 The action of the lipThe action of the lip
in this area is mainlyin this area is mainly
vertical so the labialvertical so the labial
notch in maxillarynotch in maxillary
denture must be justdenture must be just
wide and deep enoughwide and deep enough
to allow the frenum toto allow the frenum to
pass through it.pass through it.
 The denture bordersThe denture borders
should not only be cutshould not only be cut
lower but also havelower but also have
less thicknessless thickness
adjacent to labialadjacent to labial
notch.notch.

House classifiedHouse classified
frenal attachment infrenal attachment in
3 classes-3 classes-
 class1- high in maxillaclass1- high in maxilla
or low in mandibleor low in mandible
with respect to crestwith respect to crest
of ridge.of ridge.

 class 2- mediumclass 2- medium

 class 3- freniclass 3- freni
encroach onencroach on
the crest ofthe crest of
the ridge andthe ridge and
may interferemay interfere
with denturewith denture
seal, mightseal, might
requirerequire
surgicalsurgical
correction.correction.

Vertical incisiveVertical incisive
pads-pads-
 When lip is raisedWhen lip is raised
and pulledand pulled
horizontallyhorizontally
forward, a pad offorward, a pad of
submucosal softsubmucosal soft
tissue in the shapetissue in the shape
of vertical columnof vertical column
is sometimesis sometimes
observed on eachobserved on each
side of maxillaryside of maxillary
labial frenum, arelabial frenum, are
known as verticalknown as vertical
incisive pads.incisive pads.

 These are attachments of the superiorThese are attachments of the superior
incisive muscles, which course up from theirincisive muscles, which course up from their
attachments.attachments.
 The basal surface of labial flange of theThe basal surface of labial flange of the
denture should be relieved to allow for thesedenture should be relieved to allow for these
attachments.attachments.

Anterior nasal spine-Anterior nasal spine-
 It is not a limiting structure under normal
circumstances, but in instances of severe
ridge resorption, the anterior labial border of
denture should be relieved to avoid
impingement upon the mucosa overlying the
anterior nasal spine, which frequently
becomes a prominent, knife edged, limiting
structure.

Labial vestibuleLabial vestibule
 The portion of theThe portion of the
oral cavity that isoral cavity that is
bounded on one sidebounded on one side
by the teeth , gingivaby the teeth , gingiva
and alveolar ridge (orand alveolar ridge (or
residual ridge) and onresidual ridge) and on
the other by the lipsthe other by the lips
anterior to theanterior to the
buccal frenula.buccal frenula.
GPT-8GPT-8
•The labial vestibule is divided into a left and rightThe labial vestibule is divided into a left and right
labial vestibule by the labial frenum.labial vestibule by the labial frenum.

Three objectives which are apparent in theThree objectives which are apparent in the
labial vestibular region are-labial vestibular region are-
1.1. The thickness of the labial flange of theThe thickness of the labial flange of the
final impression must be developed accordingfinal impression must be developed according
to the amount of bone that has been lostto the amount of bone that has been lost
from the labial side of the ridge.from the labial side of the ridge.
2.2. The labial flange of the impression mustThe labial flange of the impression must
have sufficient height to reach thehave sufficient height to reach the
reflecting mucous membrane of thereflecting mucous membrane of the
vestibular space, but should not over extendvestibular space, but should not over extend
it.it.
3.3. There must be no interference of the labialThere must be no interference of the labial
flange with action of the lip in function.flange with action of the lip in function.

 The main muscle ofThe main muscle of
the lip, which forms thethe lip, which forms the
outer surface of the labialouter surface of the labial
vestibule, is thevestibule, is the
orbicularis oris.orbicularis oris.
 It’s tone depends onIt’s tone depends on
the support it receivesthe support it receives
from the labial flange andfrom the labial flange and
the position of the teeth.the position of the teeth.
 Because the fibersBecause the fibers
run in a horizontalrun in a horizontal
direction, the orbicularisdirection, the orbicularis
oris has only an indirectoris has only an indirect
effect on the extent ofeffect on the extent of
an impression and hencean impression and hence
on the denture base.on the denture base.www.indiandentalacademy.comwww.indiandentalacademy.com

Buccal frenumBuccal frenum
 Buccal frenum is aBuccal frenum is a
fold of mucousfold of mucous
membrane, extendsmembrane, extends
from the buccalfrom the buccal
mucous membranemucous membrane
reflection area toreflection area to
or towards the slopor towards the slop
or crest of residualor crest of residual
ridge.ridge.
• The buccal frenum forms the dividing lineThe buccal frenum forms the dividing line
between the labial and buccal vestibulesbetween the labial and buccal vestibules..

 It is sometimes aIt is sometimes a
single fold ofsingle fold of
mucousmucous
membrane,membrane,
sometimessometimes
double, and indouble, and in
some mouth,some mouth,
broad and fanbroad and fan
shaped.shaped.

muscles attachmentmuscles attachment
1.1. The levator anguli oris (caninus) muscle attachesThe levator anguli oris (caninus) muscle attaches
beneath the frenum and affects it’s position.beneath the frenum and affects it’s position.
2.2. The buccinator pulls it backward.The buccinator pulls it backward.
3.3. Orbicularis oris pulls it forward.Orbicularis oris pulls it forward.

 Because of muscle attachments, it requiresBecause of muscle attachments, it requires
more clearance for its action( in bothmore clearance for its action( in both
horizontal and vertical direction) than thehorizontal and vertical direction) than the
labial frenum does.labial frenum does.
 Inadequate provision for the buccal frenumInadequate provision for the buccal frenum
or excess thickness of the flange distal toor excess thickness of the flange distal to
the buccal notch can cause dislodgement ofthe buccal notch can cause dislodgement of
the denture when the cheeks are movedthe denture when the cheeks are moved
posteriorly as in broad smile.posteriorly as in broad smile.

 It records in the
impression as a
buccal notch
which is properly
relieved and
molded.
• It should be cresentric in form, rather thanIt should be cresentric in form, rather than
‘V’ shaped.‘V’ shaped.

Buccal vestibuleBuccal vestibule
 ItIt is defined asis defined as ““the portion of oral cavitythe portion of oral cavity
that is bounded on one side by the teeth,that is bounded on one side by the teeth,
gingiva and alveolar ridge (residual alveolargingiva and alveolar ridge (residual alveolar
ridge) and on the lateral side by the cheekridge) and on the lateral side by the cheek
posterior to the buccal frenula”.posterior to the buccal frenula”.
GPT-8GPT-8

 The buccalThe buccal
vestibule liesvestibule lies
opposite theopposite the
tuberosity andtuberosity and
extends fromextends from
the buccalthe buccal
frenum to thefrenum to the
hamular notch.hamular notch.

The size of the buccal vestibule varies withThe size of the buccal vestibule varies with
 contraction of the buccinator muscle,contraction of the buccinator muscle,
 the position of the mandible, andthe position of the mandible, and
 the amount of bone lost from the maxilla.the amount of bone lost from the maxilla.

 The extent of the buccal vestibule can beThe extent of the buccal vestibule can be
deceiving because the coronoid processdeceiving because the coronoid process
obscures it when the mouth is opened wide.obscures it when the mouth is opened wide.
Therefore it should be examined with theTherefore it should be examined with the
mouth as nearly closed as possible.mouth as nearly closed as possible.
 This space usually is higher than any otherThis space usually is higher than any other
part of the border.part of the border.

 The size and shape of the distal end of theThe size and shape of the distal end of the
buccal flange of the denture must bebuccal flange of the denture must be
adjusted according to the ramus and theadjusted according to the ramus and the
coronoid process of the mandible.coronoid process of the mandible.

 Coronomaxillary SpaceCoronomaxillary Space --
(J.Prosthet.Dent 1987:57; 186-190.(J.Prosthet.Dent 1987:57; 186-190.
N.S.Arbree, A.A.Yurkstas, and J.H.Kronman.)N.S.Arbree, A.A.Yurkstas, and J.H.Kronman.)
 Definition:- The coronomaxillary space isDefinition:- The coronomaxillary space is
that anatomic region that lies medial to thethat anatomic region that lies medial to the
coronoid process and lateral to the maxillarycoronoid process and lateral to the maxillary
tuberosity.tuberosity.

 Terms used to identify the coronomaxillaryTerms used to identify the coronomaxillary
space,are :-space,are :-
 1- Buccal space or vestibule,1- Buccal space or vestibule,
2- Buccal pocket,2- Buccal pocket,
3- Tuberosity sulcus3- Tuberosity sulcus
4- Distobuccal angle of the vestibule,4- Distobuccal angle of the vestibule,
5- Buccal sulcus,5- Buccal sulcus,
6- Buccal pouch,6- Buccal pouch,
7- Buccal mucous membrane reflection7- Buccal mucous membrane reflection
region,region,
8- Postmalar area,8- Postmalar area,
9- Retrozygomatic space.9- Retrozygomatic space.

Clinical ImplicationsClinical Implications:-:-

To get the maximum retentive qualities of theTo get the maximum retentive qualities of the
prosthesis, each patient should be evaluatedprosthesis, each patient should be evaluated
for variation in the coronomaxillary space sizefor variation in the coronomaxillary space size
during mandibular opening, as the size of theduring mandibular opening, as the size of the
space is primarily influenced by the action ofspace is primarily influenced by the action of
the coronoid process.the coronoid process.

 In someIn some
patients coronoidpatients coronoid
process appears toprocess appears to
flare laterally atflare laterally at
its height. Forits height. For
these patientsthese patients
space often remainspace often remain
same or becomessame or becomes
wider duringwider during
opening of theopening of the
mouth.mouth.

 The coronoidThe coronoid
Process may beProcess may be
relatively straight orrelatively straight or
constricting medially .constricting medially .
For these patientsFor these patients
opening of theopening of the
mandible can resultmandible can result
in narrowing of thein narrowing of the
space.space.

 If the space narrowsIf the space narrows
during opening, anyduring opening, any
horizontalhorizontal
overextension into theoverextension into the
space would result inspace would result in
denture base contactdenture base contact
and loss of retention.and loss of retention.
 In this region borderIn this region border
molding proceduremolding procedure
should include openingshould include opening
and closing, togetherand closing, together
with protrusion, andwith protrusion, and
lateral movements oflateral movements of
the jaw.the jaw.

 If coronomaxillaryIf coronomaxillary
space broadens orspace broadens or
remains of same size onremains of same size on
opening, the functionalopening, the functional
filling of this space withfilling of this space with
the denture flangethe denture flange
becomes important.becomes important.
border molding shouldborder molding should
not be done with opennot be done with open
wide, protrude, or anywide, protrude, or any
lateral movements.lateral movements.
•Here a gentle molding of the region is done byHere a gentle molding of the region is done by
pulling the cheek out, down and inwards.pulling the cheek out, down and inwards.

Microscopic features of labial and BuccalMicroscopic features of labial and Buccal
vestibulevestibule
- The mucous membrane lining vestibule isThe mucous membrane lining vestibule is
relatively thin.relatively thin.
- The submucosal layer is thick and containsThe submucosal layer is thick and contains
large amount of loose areolar tissue and elasticlarge amount of loose areolar tissue and elastic
fiber.fiber.
- Mucosa is devoid of keratinized layer and isMucosa is devoid of keratinized layer and is
freely movable with the tissue to which it isfreely movable with the tissue to which it is
attached because of the elastic nature of theattached because of the elastic nature of the
lamina propria.lamina propria.

Hamular notchHamular notch

Hamular notch is aHamular notch is a
displaceable area,displaceable area,
about 2mm wideabout 2mm wide
between thebetween the
tuberosity of thetuberosity of the
maxilla and themaxilla and the
hamular process ofhamular process of
the medialthe medial
pterygoid platepterygoid plate..
Also called as pterygomaxillary notch

Clinical SignificanceClinical Significance
 This notch is used as a boundary of theThis notch is used as a boundary of the
posterior border of the maxillary denture, back ofposterior border of the maxillary denture, back of
the tuberosity.the tuberosity.
 The impression should not end on theThe impression should not end on the
tuberosity, otherwise it will result in nonretentivetuberosity, otherwise it will result in nonretentive
denture because peripheral seal is not possible indenture because peripheral seal is not possible in
nonresilient area of tuberosity.nonresilient area of tuberosity.
 The tissue in the centre of the deep part of theThe tissue in the centre of the deep part of the
hamular notch, can be safely displaced by thehamular notch, can be safely displaced by the
posterior palatal border of the denture to help inposterior palatal border of the denture to help in
achieving a seal in this region called asachieving a seal in this region called as pterygo-pterygo-
maxillary seal.maxillary seal. www.indiandentalacademy.comwww.indiandentalacademy.com

 The tip of the pterygoid hamulus is 2-3 mmThe tip of the pterygoid hamulus is 2-3 mm
posteromedial to the distal limit of maxillaryposteromedial to the distal limit of maxillary
residual ridge. However it may be located onresidual ridge. However it may be located on
the line with crest of ridge or sometimes eventhe line with crest of ridge or sometimes even
lateral to this line.lateral to this line.
 This variation is significant in that it affectsThis variation is significant in that it affects
the length and the direction ofthe length and the direction of
pterygomaxillary seal so it becomes verypterygomaxillary seal so it becomes very
important to determine the location ofimportant to determine the location of
hamulus by palpation.hamulus by palpation.

 PterygomaxillaryPterygomaxillary
seal occupies theseal occupies the
entire width ofentire width of
hamular notch.hamular notch.
The seal beginsThe seal begins
atat
pterygomaxillarypterygomaxillary
notch and usuallynotch and usually
extends 5-7 mmextends 5-7 mm
anteromedially.anteromedially.

 Also overextensions at the hamularAlso overextensions at the hamular
notches will not be tolerated because ofnotches will not be tolerated because of
pressure on the pterygoid hamulus andpressure on the pterygoid hamulus and
interference with the pterygomandibularinterference with the pterygomandibular
raphe.raphe.


 When the mouth isWhen the mouth is
opened wide, theopened wide, the
pterygomandibularpterygomandibular
raphe is pulledraphe is pulled
forward. If theforward. If the
denture extends toodenture extends too
far into the hamularfar into the hamular
notch, the mucousnotch, the mucous
membrane coveringmembrane covering
the raphe will bethe raphe will be
traumatizedtraumatized

Palatine fovea region-Palatine fovea region-
 The fovea palatinae are indentations nearThe fovea palatinae are indentations near
the midline of the palate in posterior regionthe midline of the palate in posterior region
formed by coalescence of several mucousformed by coalescence of several mucous
membrane ducts.membrane ducts.
 They are very prominent in some individuals,They are very prominent in some individuals,
whereas in others they are barely visible orwhereas in others they are barely visible or
may be absent.may be absent.

Usually the
posterior
vibrating line is
found ,2 mm
anterior to the
foveae
palatine, but
they can be
found on or
anterior to the
vibrating line..

Review of LiteratureReview of Literature
((1) J Prosthet Dent: 1975; 33,504-510.1) J Prosthet Dent: 1975; 33,504-510.
T.L.LyeT.L.Lye conducted clinical, radiographicconducted clinical, radiographic
and histological studies of fovea palatineand histological studies of fovea palatine
and concluded that, fovea palatine wereand concluded that, fovea palatine were
positioned 1 .31 mm in front of the vibratingpositioned 1 .31 mm in front of the vibrating
line in 70% of the cases.line in 70% of the cases.
Histologically, complex nerve endingsHistologically, complex nerve endings
were found just anterior to the fovea andwere found just anterior to the fovea and
spreading to the soft palate.spreading to the soft palate.

I.J.P.1983:28; 166-70.I.J.P.1983:28; 166-70.
 A clinical study was conducted byA clinical study was conducted by S.B.KengS.B.Keng andand ROWROW
A.MA.M.,on edentulous patients to determine the distance of.,on edentulous patients to determine the distance of
the vibrating line to the fovea palatine. The resultsthe vibrating line to the fovea palatine. The results
indicated that the vibrating line is located 2.62 mm. (meanindicated that the vibrating line is located 2.62 mm. (mean
of 160 subjects) anterior to the fovea palatine.of 160 subjects) anterior to the fovea palatine.
 There was a significant correlation between theThere was a significant correlation between the
distances of vibrating line to the fovea for different typedistances of vibrating line to the fovea for different type
of soft palate contour. Soft palate with deep slope (classof soft palate contour. Soft palate with deep slope (class
III) has the vibrating line at or just in front of the fovea,III) has the vibrating line at or just in front of the fovea,
while class II medium contour was 2.3 m.m. anterior towhile class II medium contour was 2.3 m.m. anterior to
fovea, and class I flat contour of the soft palate linefovea, and class I flat contour of the soft palate line
located approximately 4 m.m. anterior to the fovealocated approximately 4 m.m. anterior to the fovea
palatine.palatine.

Fovea palatini and posterior border ofFovea palatini and posterior border of
denturedenture
 According to Boucher as fovea palatini are closeAccording to Boucher as fovea palatini are close
to vibrating line and always in soft tissues, whichto vibrating line and always in soft tissues, which
makes them an ideal guide for location ofmakes them an ideal guide for location of
posterior border of denture.posterior border of denture.
 According to Winkler fovea palatini should beAccording to Winkler fovea palatini should be
used only as guidelines to the placement ofused only as guidelines to the placement of
posterior palatal seal. The dentist who observesposterior palatal seal. The dentist who observes
the fovea and utilizes these anatomic landmarksthe fovea and utilizes these anatomic landmarks
as posterior extent of denture base can depriveas posterior extent of denture base can deprive
his patients of several millimeters up to ahis patients of several millimeters up to a
centimeter or more of tissue coverage dependingcentimeter or more of tissue coverage depending
on the palatal configuration.on the palatal configuration.


AnteriorAnterior
vibrating line-vibrating line-
 Anterior vibratingAnterior vibrating
line is an imaginaryline is an imaginary
line located at theline located at the
junction of thejunction of the
attached tissuesattached tissues
overlying the hardoverlying the hard
palate and thepalate and the
movable tissues ofmovable tissues of
the immediatelythe immediately
adjacent soft palate.adjacent soft palate.
Vibrating lines of palate-Vibrating lines of palate-

 This can be located either by valsulvaThis can be located either by valsulva
maneuver or by instructing patient to saymaneuver or by instructing patient to say
“ah” with short vigorous bursts.“ah” with short vigorous bursts.
 Due to projection of posterior nasal spineDue to projection of posterior nasal spine
anterior vibrating line is not a straightanterior vibrating line is not a straight
line between hamular processes.line between hamular processes.
 ..

 Posterior vibratingPosterior vibrating line is an imaginary line atline is an imaginary line at
the junction of the aponeurosis of tensor velithe junction of the aponeurosis of tensor veli
palatini muscle and the muscular portion ofpalatini muscle and the muscular portion of
the soft palate.the soft palate.
 It represents the demarcation between thatIt represents the demarcation between that
part of the soft palate that has limited orpart of the soft palate that has limited or
shallow movement during function and theshallow movement during function and the
remainder of soft palate that is markedlyremainder of soft palate that is markedly
displaced during function.displaced during function.
 Posterior vibrating line is visualized byPosterior vibrating line is visualized by
instructing the patient to say “ah” in a normalinstructing the patient to say “ah” in a normal
unexaggerated fashion.unexaggerated fashion.

• The distal end of the upper denture must extend atThe distal end of the upper denture must extend at
least to vibrating lines.least to vibrating lines.
 Direction of the vibrating line usually variesDirection of the vibrating line usually varies
according to the shape of palate ; the higher theaccording to the shape of palate ; the higher the
vault , the more abrupt and forward the vibratingvault , the more abrupt and forward the vibrating
line. In a mouth with flat vault , the vibrating line isline. In a mouth with flat vault , the vibrating line is
usually farther posterior and has a good curvature,usually farther posterior and has a good curvature,
affording a broader PPSA.affording a broader PPSA.
 TheThe M.M.HouseM.M.House classification is customarily usedclassification is customarily used
to designate the shape of the soft palate and itto designate the shape of the soft palate and it
describes the amount of posterior tissue that willdescribes the amount of posterior tissue that will
accept the posterior palatal seal –accept the posterior palatal seal –

Class IClass I – More than 5mm of– More than 5mm of
movable tissue availablemovable tissue available
for post damming .for post damming .
 ideal for retention.ideal for retention.
Class IIClass II – 1-5 mm of– 1-5 mm of
for post damming.for post damming.
 retention is usuallyretention is usually
possible.possible.
Class IIIClass III – Less than 1 mm– Less than 1 mm
for post damming.for post damming.
 Retention is usually poor.Retention is usually poor.

1. Irving R. Hardy and Krishan K. Kapur.1. Irving R. Hardy and Krishan K. Kapur.
Posterior border seal –Its rationale andPosterior border seal –Its rationale and
importance J Prosthet Dent.1958;8;386-397importance J Prosthet Dent.1958;8;386-397

• Due to the relative instability of theDue to the relative instability of the
denture base materials generally used, we have todenture base materials generally used, we have to
take added precaution of scoring the cast at thetake added precaution of scoring the cast at the
deepest point of the posterior palatal seal todeepest point of the posterior palatal seal to
counteract the warpage of the denture.counteract the warpage of the denture.
• If this bead causes any irritation when theIf this bead causes any irritation when the
denture is worn, it can be buffed off very easily,denture is worn, it can be buffed off very easily,
and it may make the difference betweenand it may make the difference between
excellent and merely passable retention.excellent and merely passable retention.

2.2. J prosthet.Dent.1971;25,470-488.J prosthet.Dent.1971;25,470-488.
Sidney I. Silverman-Sidney I. Silverman-
 He did a study on 500 patients whoHe did a study on 500 patients who
required complete denture. The clinicalrequired complete denture. The clinical
findings were evaluated during speechfindings were evaluated during speech
swallowing and respiratory posture.swallowing and respiratory posture.
 Silverman concluded that completeSilverman concluded that complete
maxillary denture can be extended for anmaxillary denture can be extended for an
average of 8.2 mm. dorsally to the vibratingaverage of 8.2 mm. dorsally to the vibrating
line.line.
 The extension varies from 4 to 12 mm.The extension varies from 4 to 12 mm.

3. J.Prosthet.Dent1973:23:484-93.3. J.Prosthet.Dent1973:23:484-93.
William E. AvantWilliam E. Avant did this study to dodid this study to do
comparison of different type of palatalcomparison of different type of palatal
seal in relation of complete dentureseal in relation of complete denture
retention.retention.
 Conclusions of this study were –Conclusions of this study were –
1.1. A posterior palatal seal is necessaryA posterior palatal seal is necessary
for optimum retention of maxillary completefor optimum retention of maxillary complete
dentures.dentures.
2.2. Each type of posterior palatal sealEach type of posterior palatal seal
tested in this study increased retentiontested in this study increased retention
effectively.effectively.
3.3. No one type of posterior palatal sealNo one type of posterior palatal seal
that was tested ,proved to be superior thanthat was tested ,proved to be superior than
other.other. www.indiandentalacademy.comwww.indiandentalacademy.com

4.4.Journal of prosthetic dentistry 2003;12 :265-270Journal of prosthetic dentistry 2003;12 :265-270
Behnoush RashediBehnoush Rashedi andand Vicki KVicki K PetropoulosPetropoulos, conducted a, conducted a
survey of U.S. dental schools in 2001 ,to determine thesurvey of U.S. dental schools in 2001 ,to determine the
concepts, techniques used for establishing the post palatalconcepts, techniques used for establishing the post palatal
seal Results from this survey show thatseal Results from this survey show that
 Combinations of clinical methods were mostCombinations of clinical methods were most
frequently taught for locating the vibrating line.frequently taught for locating the vibrating line.
 The phonation of the “ah” sound was the mostThe phonation of the “ah” sound was the most
popular single method taught for locating the vibrating line.popular single method taught for locating the vibrating line.
 Most dental schools (87.5%) teach students toMost dental schools (87.5%) teach students to
carve the posterior palatal seal on maxillary master cast.carve the posterior palatal seal on maxillary master cast.
 Most dental school (93.9%) take theMost dental school (93.9%) take the
compressibility of the palatal tissue into considerationcompressibility of the palatal tissue into consideration
when carving the depth of posterior palatal seal inwhen carving the depth of posterior palatal seal in
maxillary master cast.maxillary master cast.

Residual alveolar ridge-Residual alveolar ridge-
DefinitionDefinition (According to GPT-8) –(According to GPT-8) –
““The portion of the alveolar ridge and itsThe portion of the alveolar ridge and its
soft tissue covering ,which remains followingsoft tissue covering ,which remains following
the removal of teeth.”the removal of teeth.”
 ..


When the naturalWhen the natural
teeth are removed,teeth are removed,
the alveoli begin tothe alveoli begin to
fill up with the newfill up with the new
bone. At the samebone. At the same
time bone around thetime bone around the
margins of toothmargins of tooth
sockets begin tosockets begin to
shrink away.shrink away.
 This shrinkage orThis shrinkage or
resorption is rapid atresorption is rapid at
first six weeks offirst six weeks of
tooth removal, and ittooth removal, and it
continues at acontinues at a
reduced rate throughout the life and isreduced rate throughout the life and is
responsible for the formation of RARresponsible for the formation of RAR..

The alveolar ridges vary greatly in size, shapeThe alveolar ridges vary greatly in size, shape
and their ultimate form. This is dependent onand their ultimate form. This is dependent on
the following factorsthe following factors --
 Variation in bone size and its degree ofVariation in bone size and its degree of
calcification in individuals.calcification in individuals.
 Teeth show wide individual variation in size.Teeth show wide individual variation in size.
Large teeth are supported by bulky ridges andLarge teeth are supported by bulky ridges and
smaller teeth by narrow ones.smaller teeth by narrow ones.
 The amount of bone lost prior to theThe amount of bone lost prior to the
extraction of teeth.extraction of teeth.
 The amount of alveolar process removedThe amount of alveolar process removed
during extraction of teeth.during extraction of teeth.

 According to size RAR can be-According to size RAR can be-
-large-large
-medium-medium
-small-small

large medium
small

 According to shape RAR can be-According to shape RAR can be-
- smooth- smooth
- irregular- irregular
- knife edge- knife edge
- flat- flat

IrregularSmooth
Knife-edgeFlat www.indiandentalacademy.comwww.indiandentalacademy.com

Types of Alveolar ridges, palateTypes of Alveolar ridges, palate
formation and their significanceformation and their significance
Alveolar Ridge
shape
‘square to gently
rounded
Flat Palate
With
small ridge
’tapering or
V’ Shaped

square to gently
rounded
This is mostThis is most
favorable kind offavorable kind of
ridge because –ridge because –
The centre of theThe centre of the
palate presents anpalate presents an
almost flat horizontalalmost flat horizontal
area and this will aidarea and this will aid
in retention.in retention.
Flat surface
 The well developed ridges resist lateral and anteroposterior
movement of the denture..

tapering or V’
Shaped
• It is usuallyIt is usually
associated with thickassociated with thick
bulky ridges. This isbulky ridges. This is
an unfavorablean unfavorable
formation.formation.
The forces ofThe forces of
adhesion andadhesion and
cohesion are not atcohesion are not at
right angles toright angles to
surface whensurface when
counteracting thecounteracting the
normal displacingnormal displacing
forces of gravity.forces of gravity.
V’ shaped

(iii) Flat palate with small(iii) Flat palate with small
ridgesridges
This is anThis is an
unfavorable formationunfavorable formation
because –because –
 The ill developedThe ill developed
ridges do not resistridges do not resist
lateral and anterior-lateral and anterior-
posterior movementposterior movement
of the denture.of the denture.
 Shallow Sulcus doShallow Sulcus do
not form a goodnot form a good
Peripheral seal.Peripheral seal.
Shallow Flat Palate

Microscopic features of residual ridgesMicroscopic features of residual ridges
 The mucous membrane isThe mucous membrane is
attached to theattached to the
periosteum of the boneperiosteum of the bone
by the connective tissueby the connective tissue
of the sub mucosa.of the sub mucosa.
 The stratified squamousThe stratified squamous
epithelium is thicklyepithelium is thickly
keratinized.keratinized.
 The sub mucosa isThe sub mucosa is
devoid of fat ordevoid of fat or
glandular cells and it isglandular cells and it is
characterized bycharacterized by
densedensecollegenous fibers that are contiguous with lamina
propria.

 The outer surfaceThe outer surface
of bone in the regionof bone in the region
of crest of RARof crest of RAR
(most coronal portion(most coronal portion
of ridge) is usuallyof ridge) is usually
compact in nature.compact in nature.
This compact bone inThis compact bone in
combination withcombination with
tightly attachedtightly attached
keratinized mucouskeratinized mucous
membrane makesmembrane makes
crest of RARcrest of RAR
histologically besthistologically best
able to provideable to provide
primary support forprimary support for
the denture.the denture. www.indiandentalacademy.comwww.indiandentalacademy.com

RAR- a primary stress bearingRAR- a primary stress bearing
areaarea ??????
 According to Prosthodontic Treatment forAccording to Prosthodontic Treatment for
Edentulous Patients by Zarb and Bolender-Edentulous Patients by Zarb and Bolender-
““the bone in this region is subject tothe bone in this region is subject to
resorption, which limits it’s potential forresorption, which limits it’s potential for
support, unlike the palate, which is resistant tosupport, unlike the palate, which is resistant to
resorption. Because of this, ridge crest shouldresorption. Because of this, ridge crest should
be looked on as a secondary supporting area.”be looked on as a secondary supporting area.”

 They
Consider
“horizontal
portion of
hard palate
lateral to
midline” as
primary
supporting
area for
denture.


In a patientIn a patient
where toothwhere tooth
were extractedwere extracted
long time backlong time back
(years), ridge(years), ridge
becomesbecomes
smaller andsmaller and
crest of ridge increst of ridge in
many cases ismany cases is
completelycompletely
devoid ofdevoid of
smooth corticalsmooth cortical
bony surface.bony surface.

Horizontal part of palate lateral to midline should
definitely be considered a primary stress bearing area
in these patients..

Palatal region-Palatal region-
Rugae area-Rugae area-
 Rugae are the raised area of dense connectiveRugae are the raised area of dense connective
tissue radiating from the median suture in thetissue radiating from the median suture in the
anterior one third of the palate.anterior one third of the palate.
 Mucosa is keratinized and the submucosa isMucosa is keratinized and the submucosa is
fibrousfibrous
 In the area of the rugae, the palate is set atIn the area of the rugae, the palate is set at
an angle to the residual ridge and is rather thinlyan angle to the residual ridge and is rather thinly
covered by soft tissue.covered by soft tissue.

 This area contributes to the stress-bearingThis area contributes to the stress-bearing
role as well as to retention although in arole as well as to retention although in a
secondary capacity.secondary capacity.
 It resists forward movement of denture.It resists forward movement of denture.
 It should be recorded without pressure, ifIt should be recorded without pressure, if
it distorts while making impression it canit distorts while making impression it can
rebound and unseat the denture.rebound and unseat the denture.
 These folds of the mucosa play anThese folds of the mucosa play an
important role in speech so dentures shouldimportant role in speech so dentures should
reproduce this contour making it veryreproduce this contour making it very
comfortable for the patient.comfortable for the patient.www.indiandentalacademy.comwww.indiandentalacademy.com

Mid palatine raphe-Mid palatine raphe-
 This presents as slightlyThis presents as slightly
elevated bony ridge alongelevated bony ridge along
the midline of hard palate.the midline of hard palate.
 Adequate relief should beAdequate relief should be
provided in this area as-provided in this area as-
- mucosa covering the- mucosa covering the
raphe is extremely thinraphe is extremely thin
and is traumatized easily.and is traumatized easily.
-mucosa is less resilient-mucosa is less resilient
than that covering thethan that covering the
ridges so it can act asridges so it can act as
fulcrum along whichfulcrum along which
denture rocks when verticaldenture rocks when vertical
forces are applied.forces are applied.


This areaThis area
provides primaryprovides primary
support tosupport to
denture as itdenture as it
offers maximumoffers maximum
resistance toresistance to
resorption.resorption.
Horizontal portion of hard palate lateral toHorizontal portion of hard palate lateral to
midline-midline-

Lateral surface of hard palateLateral surface of hard palate
It isIt is divided individed in
 anterolateral part containing adiposeanterolateral part containing adipose
tissue in submucosatissue in submucosa
 posterolateral part containingposterolateral part containing
glandular tissue.glandular tissue.
Both of these areas are displaceable they doBoth of these areas are displaceable they do
not provide significant support to the denturenot provide significant support to the denture
but this region should be covered to providebut this region should be covered to provide
retention.retention.

Anteriolateral View Posteriolateral View

 These areas should be recorded in restingThese areas should be recorded in resting
conditioncondition because when they are displaced inbecause when they are displaced in
the final impression, they tend to return tothe final impression, they tend to return to
natural form within the completed denturenatural form within the completed denture
base, and creating an unseating force on thebase, and creating an unseating force on the
denture or causing soreness in the patientsdenture or causing soreness in the patients
mouth. For recording these tissue inmouth. For recording these tissue in
undistorted form,undistorted form, proper relief should beproper relief should be
given in the final impression tray.given in the final impression tray.

Incisive papilla-Incisive papilla-
 This coversThis covers
the incisivethe incisive
foramen andforamen and
is located inis located in
the midlinethe midline
immediatelyimmediately
behind andbehind and
betweenbetween
centralcentral
incisors.incisors.

ProsthodonticProsthodontic
significances:significances:
 It lies nearerIt lies nearer
to the crest ofto the crest of
the ridge asthe ridge as
resorptionresorption
progresses. Thusprogresses. Thus
the location ofthe location of
the incisive papillathe incisive papilla
gives an indicationgives an indication
as to the amountas to the amount
of resorption thatof resorption that
has taken place.has taken place.


 Incisive papillaIncisive papilla
acts as a guide foracts as a guide for
antero-posteriorantero-posterior
positioning of thepositioning of the
teeth, theteeth, the
labial surfaces oflabial surfaces of
the centralthe central
incisors areincisors are
usually 8-10 mmusually 8-10 mm
in front of thein front of the
papilla.papilla.

 IncisiveIncisive
papilla is usedpapilla is used
to locate theto locate the
midline of themidline of the
dental arch.dental arch.

The nasopalatine nerves and blood vessels passThe nasopalatine nerves and blood vessels pass
through the foramen, and care should be taken thatthrough the foramen, and care should be taken that
the denture base does not impinge on them.the denture base does not impinge on them.

1. Harold R. Ortman, and Ding H. Tsao1. Harold R. Ortman, and Ding H. Tsao
:Relationship of the incisive papilla to the:Relationship of the incisive papilla to the
maxillary central incisors. Jmaxillary central incisors. J
Prosthet Dent 1979;42; 492-496Prosthet Dent 1979;42; 492-496
 A study on 38 maxillary casts found thatA study on 38 maxillary casts found that
the average distance between the mostthe average distance between the most
anterior point of maxillary central incisorsanterior point of maxillary central incisors
and most posterior point of the incisive papillaand most posterior point of the incisive papilla
was 12.454 mm .was 12.454 mm .

2.J.prosthet.Dent 1981:45;592-97.2.J.prosthet.Dent 1981:45;592-97.
F.MovroskoufisF.Movroskoufis andand
G.M.RetechieG.M.Retechie did a study atdid a study at
dental school London ,UK.dental school London ,UK.
An investigation of 64 angleAn investigation of 64 angle
skeletal class I dental studentsskeletal class I dental students
showed that the incisive papillashowed that the incisive papilla
provides a stable anatomicprovides a stable anatomic
landmark for arranging the labiallandmark for arranging the labial
surface of the central incisorssurface of the central incisors
labial surface is 10.2mmlabial surface is 10.2mm
anterior to the posterior border ofanterior to the posterior border of
the papilla.the papilla.

3) Journal Indian Dent.Asso.1984:56;425-28.3) Journal Indian Dent.Asso.1984:56;425-28.
Kharat D.U. and Madan R.S. carried out a study onKharat D.U. and Madan R.S. carried out a study on
200 subjects (108 men,98 women) of different age group200 subjects (108 men,98 women) of different age group
ranging 20-65 years ,to determine the distances fromranging 20-65 years ,to determine the distances from
incisal edge of the maxillary central incisor to theincisal edge of the maxillary central incisor to the
papilla.papilla.
 The findings of the study showed that the meanThe findings of the study showed that the mean
distance of maxillary incisal edge to the incisive papilladistance of maxillary incisal edge to the incisive papilla
was 8.16was 8.16 ++ 1.26 mm for men and 7.411.26 mm for men and 7.41 ++ 0.98 mm for0.98 mm for
women.women.
 Conclusion of their study was, the distance fromConclusion of their study was, the distance from
maxillary incisal edge to the incisal papilla in dentulousmaxillary incisal edge to the incisal papilla in dentulous
men is more than the women and this distance remainsmen is more than the women and this distance remains
constant throughout the life.constant throughout the life.

((4) J.Prosthet.Dent.4) J.Prosthet.Dent.
1987:57;712-141987:57;712-14
A.M.H.graveA.M.H.grave andand
P.J.BeckerP.J.Becker compared thecompared the
position of incisive papilla,position of incisive papilla,
in between the two groupsin between the two groups
in their study. The firstin their study. The first
group consisted of existinggroup consisted of existing
complete upper dentures ofcomplete upper dentures of
67 patients(34 men,3367 patients(34 men,33
women). And anotherwomen). And another
group consisted of castgroup consisted of cast
obtained from the 60 youngobtained from the 60 young
adults.adults.

 The results of the study suggests that theThe results of the study suggests that the
labial surface of the maxillary incisorslabial surface of the maxillary incisors
should be 12-13 mm from the posteriorshould be 12-13 mm from the posterior
border of the incisive papilla. Theseborder of the incisive papilla. These
measurements was significantly smaller inmeasurements was significantly smaller in
the sample of dentures examined , whichthe sample of dentures examined , which
suggests a tendency for anterior teeth to besuggests a tendency for anterior teeth to be
placed too far posteriorly in artificial denture.placed too far posteriorly in artificial denture.

(5) J.prosthet.Dent.
1989:61;51-53. H.F.
Grove and L.Cristensen
did a study on 58 subjects
to determine the
orthographic distances
from the posterior of the
incisive papilla to the line
intersecting the distal
contact point of the
maxillary canine.
In 92% of subjects the posterior point of incisive papilla
was approximately 3mm anterior to the line between
the distal points of the canines. Neither gender, age,
nor maxillary arch form affected this distance.

6.G.C.K. Lau and R.F.K.Clark: the6.G.C.K. Lau and R.F.K.Clark: the
relationship of the incisive papilla to therelationship of the incisive papilla to the
maxillary central incisors and canine teethmaxillary central incisors and canine teeth
in southern Chinese. Prosthet Dent 1993;in southern Chinese. Prosthet Dent 1993;
70; 86-9370; 86-93
                distance of central incisor to thedistance of central incisor to the
midpoint of the incisive papilla - 9.17mmmidpoint of the incisive papilla - 9.17mm
              distance of central incisor to thedistance of central incisor to the
posterior point of the incisive papillaposterior point of the incisive papilla
-12.71mm-12.71mm


 Relationship of canine to the incisiveRelationship of canine to the incisive
papilla.papilla.
The intercanine lines in 57.3% passedThe intercanine lines in 57.3% passed
through the middle third , in 12.25% passedthrough the middle third , in 12.25% passed
through the anterior third and in 32.7% of allthrough the anterior third and in 32.7% of all
the subjects passed through the posteriorthe subjects passed through the posterior
third of incisive papilla.third of incisive papilla.
 All the similar above measurements wereAll the similar above measurements were
also made in Angle’s class1, class 2 and class 3also made in Angle’s class1, class 2 and class 3
jaws. The differences among these werejaws. The differences among these were
found statistically insignificant.found statistically insignificant.
 Results showed that there is littleResults showed that there is little
difference between various ethnic groups.difference between various ethnic groups.

 Also calledAlso called
malar process ismalar process is
located oppositelocated opposite
the first molarthe first molar
region and isregion and is
commonly seen incommonly seen in
mouth that hasmouth that has
been edentulousbeen edentulous
for long.for long.
Zygomatic process-Zygomatic process-

 SomeSome
denturesdentures
require reliefrequire relief
over the areaover the area
to aid into aid in
retention andretention and
to preventto prevent
soreness ofsoreness of
underlyingunderlying
structures.structures.

Maxillary tuberosity-Maxillary tuberosity-
 MaxillaryMaxillary
tuberositytuberosity
representsrepresents
most distalmost distal
portion ofportion of
maxillarymaxillary
alveolaralveolar
ridge.ridge.

 The tuberosityThe tuberosity
region often hangsregion often hangs
abnormally lowabnormally low
when maxillarywhen maxillary
posterior teethposterior teeth
are retained afterare retained after
mandibular molarsmandibular molars
are lost and notare lost and not
replaced, the max.replaced, the max.
teeth extrudeteeth extrude
bringing thebringing the
tuberosity withtuberosity with
them.them.
 Often the low hanging tuberosity prevents proper location
of occlusal plane. www.indiandentalacademy.comwww.indiandentalacademy.com

 Most oftenMost often
tuberositytuberosity
enlargements areenlargements are
only fibrous inonly fibrous in
nature.nature.

Review of literature-Review of literature-
1.JADA vol. 103, Dec 1981,1.JADA vol. 103, Dec 1981,
894. Ryle A. Bell, and894. Ryle A. Bell, and
Richardson.Richardson.
2.Quintessence international2.Quintessence international
1987 :18;465. Sherif E,1987 :18;465. Sherif E,
John unger and CarlJohn unger and Carl
StoneStone
 They have presentedThey have presented
techniques of non surgicaltechniques of non surgical
managemant ofmanagemant of
overhanging tuberositiesoverhanging tuberosities
for CD patients.for CD patients.
 Overhanging tuberosities in these cases reduced
intermaxillary space to less than 3 mm. This space did
not allow for the adeqate thickness of upper and lower
acrylic denture bases.www.indiandentalacademy.comwww.indiandentalacademy.com

 Before theBefore the
record bases wererecord bases were
constructed, theconstructed, the
tuberosities weretuberosities were
outlined on theoutlined on the
cast. In thesecast. In these
areas either type-areas either type-
3 gold alloy or co-3 gold alloy or co-
cr alloy was usedcr alloy was used
as denture baseas denture base
material in place ofmaterial in place of
acrylic resin.acrylic resin.

3.J.Prosthet.Dent.3.J.Prosthet.Dent.
2004;92:128-31.2004;92:128-31.
Leonard Garth LoweLeonard Garth Lowe
presented a clinical reportpresented a clinical report
for the non surgicalfor the non surgical
management ofmanagement of bilateralbilateral
undercut in tuberosityundercut in tuberosity
region. They maderegion. They made
decision to incorporatedecision to incorporate
flexible flanges in theflexible flanges in the
undercuts using resilientundercuts using resilient
silicon lining materialsilicon lining material toto
allow adequate height andallow adequate height and
thickness of the denturethickness of the denture
flangeflange..

Torus palatinusTorus palatinus
 Seen as a hard bony enlargement that occurs inSeen as a hard bony enlargement that occurs in
midline of the roof of mouth is called torusmidline of the roof of mouth is called torus
palatinus.palatinus.
 Seen in nearly 20% of populationSeen in nearly 20% of population
 2 types2 types
-almost entirely soft tissue, loose and flabby-almost entirely soft tissue, loose and flabby
- thin layer of mucosal tissue covering the bone- thin layer of mucosal tissue covering the bone
 Dentures require relief over this area to aidDentures require relief over this area to aid
retention and prevent soreness of the underlyingretention and prevent soreness of the underlying
tissues.tissues.

 A smoothA smooth
rounded smallrounded small
torus does nottorus does not
normallynormally
create muchcreate much
problem asproblem as
denture platedenture plate
may be cutmay be cut
away to avoidaway to avoid
tori or can betori or can be
extended overextended over
it with properit with proper
relief.relief.


A large,A large,
irregular,irregular,
lobbed torilobbed tori
should beshould be
treatedtreated
surgically assurgically as
cutting awaycutting away
the denturethe denture
plateplate
significantlysignificantly
reducesreduces
denturedenture
retention andretention and
also leads toalso leads to
excessive ridgeexcessive ridge www.indiandentalacademy.comwww.indiandentalacademy.com

Supporting structures
 incisive papilla
 palatal rugae
 median palatine raphe
 maxillary tuberosity
 residual alveolar ridge
 fovea palatini
Limiting structures
 Labial and buccal frena
 Labial and buccal vestibules
 pterygomaxillary notch
 Posterior palatal seal area
 Coronoid bulge

Ideal maxillary ridge:
 Abundant keratinized
attached tissue
 Square arch
 Palate U-shaped in cross-
section
 Moderate palatal vault
 Absence of undercuts
 High frenum attachments
 Well-defined hamular
notches

REFRENCES
CHARLES M.HEARTWELL, JR
ARTHUR O.RAHN
(4th
EDITION)
A ROY MACGREGOR
(3RD
EDITION)
SHEDON WINKLER
(2ND
EDITION)
ZARB.BOLENDER
(12TH
EDITION

TT
hh
aa
nn
kk
yy
oo
uu
Thank you
For more details please visit
www.indiandentalacademy.com

biological consideration for maxillary denture bearing areas / dental courses

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Similar to biological consideration for maxillary denture bearing areas / dental courses

Similar to biological consideration for maxillary denture bearing areas / dental courses (20)

More from Indian dental academy

More from Indian dental academy (20)

Recently uploaded

Recently uploaded (20)

biological consideration for maxillary denture bearing areas / dental courses