Denture border evaluation /certified fixed orthodontic courses by Indian dental academy

“AN EFFECTIVE
TECHNIQUE FOR
DENTURE
BORDER
EVALUATION”
INDIAN
ACADEMY

DENTAL

Leader in continuing dental education
www.indiandentalacademy.com

INTRODUCTION


MAXILLARY & MANDIBULAR EDENTULOUS FOUNDATIONS:
Knowledge of oral anatomy helps the operator in understanding the
landmarks that serve as positive guides in Prosthodontic procedures
.
DEFINITION :Denture bearing areas or Denture foundation area or
Basal seat —the surface of the oral structures available to support a
denture.(GPT-8)
Denture bearing area- maxilla 24 cm2 & mandible 14 cm2 (Dr WATT
surgeon.)
The impression surface/Fitting surface1.stress-bearing/supporting areas.
2.peripheral/limiting areas.


STRESS-BEARING
AREA.
• PRIMARY.
• Hard palate.(max)
• Buccal shelf.(man)

• SECONDARY.
• Rugae .(max).
• Slopes of residual
ridge .(man).


Supporting areas.
• PRIMARY.
• Horizontal portion
of Hard palate .
(max)& Rugae
• Buccal shelf (man)

• SECONDARY.
• Crest of residual
ridge. (max)
• Slopes of residual
ridge. (man)


RELIEF AREAS.
• MAXILLA.
• Medial palatal
suture.
• Incisive foramen.
• Sharp bony
projection.
• Rugae – valley.

• MANDIBLE.
• Crest of residual
ridge.
• Sharp bony
projection.
• Mental foramen.
• Genial tubercle.
• Mylohyoid ridge.


Maxillary arch
Labial frenum:

• Fold of mucous membrane
at the median line.
• Moves with muscles of lip.
• Adequate relief for muscle
activity.
• Proper denture seal.
• Excessive relief weakens
denture base.

•A- correct
contour
•B –incorrect
contour.
•C- area
should have
been covered.


Labial notch

Buccal frenum:
 Single or double folds of
mucous membrane.
 Broad and fan shaped.
 Moves with muscles of
cheek during speech and
mastication.
 Adequate relief for muscle
activity-more clearence.
Buccal notch
•Maxillary buccal frenum area.
•Denture border contour in buccal
frenum area.


Labial vestibule
• Labial-buccal frenum.
• Muco-gingival linelimits upper border.
• Record adequate
depth/width.
• Overextension causes
instability/soreness.
•Labial flange
• Proper contouring
gives optimal
esthetics.

Buccal vestibule

• Buccal frenum to
hamular notch.
• Record adequate
depth/width.
• Improper extension
causes
Buccal flange


Maxillary tuberosity.
• Distal end of
denture must have
Coveragestability/retention.

Area of tuberosity

• Gross
enlargement(fibrou
s or bony –surgical
correction.


Hamular notch.
•Distal to maxillary
tuberosity
•Aids in locating
posterior palatal seal.
•Overextension causes
soreness.

Area of hamular notch

PPS-the seal area at the posterior border of a maxillary
removabledentalprosthesis.(GPT-8)
PPS OR POST PALATAL SEAL 0R POST DAMThe soft tissue along the junction of the hard and soft
palates on which pressure with in the physiologic limits of the
tissues can be applied by a denture to aid in the retention of
the denture. (Winkler)
•

•

•

VIBERATING LINE-an imaginary line across the posterior part of
the palate marking the division between the movable and
immovable tissues of the soft palate. this can be identified when
the movable tissues are functioning.
The anterior vibrating line is an imaginary line located at the
junction of the attached tissues overlying the hard palate and
movable tissues of the immediately adjacent soft palate.(valsalva
maneuver –method)
The posterior vibrating line is an imaginary line at junction of the
aponeurosis of the tensor veli palatini muscle and the muscular
portion of the soft palate.


Vibrating line:

• Junction of movable and
immovable part of soft
palate.
• 2mm ant to fovea palatinae.
• Aids to establish PPS.
• Distal end of denture at
least to vibrating line.
Post palatal seal area.
• From hamular notch to
hamular notch.
• Anterior to vibrating line.
• Aids in retention.

.

Fovea Palatinae.
• Bilateral indentations
near the midline of
palate.
• Formed by coalescence
of several mucous gland
ducts.
• Posterior to junction of
hard and soft palate.
• Aids in determining
vibrating line.

Hard palate
• Support for the
maxillary denture.
• Primary stress
bearing areahorizontal portion
of hard palate
lateral to midline.
• Secondary stress
bearing area –
rugae.

Alveloar ridge
• .

Alveolar groove


Incisive papilla.
• Elevation of soft
tissue over the incisive
foramen or
nasopalatine canal.
• Location : on or labial
to ridge.
• Impingement –burning
•Incisive fossa
sensation, parasthesia
and pain.
• Relief necessary.

Rugae.
• Irregular shaped
rolls of soft tissue.
• Secondary stress
bearing area.
• Should not be
distorted in the
impression.


Median palatine raphae.
• Extends from incisive
papilla to distal end of
hard palate.
• Thin mucosal covering
and non-resilient..
• Relieve adequately to
avoid trauma from
denture base.
Median palatine groove

Mandibular arch.
Labial frenum.
• Shorter and wider
than the maxillary
frenum.
• Adequate relief for
muscle activity
(mentalis).
• Proper fit around it
maintains seal’.
Labial notch.

Buccal frenum.
• Adequate relief
for muscle
activity.
• Proper denture
seal.


Buccal notch.

Labial vestibule.

• Labial-buccal frenum.
• Muscles attachment
close to the crest of
the ridge- limits the
denture flange
extension.
• Mucolabial fold limits
the depth of the
flange.
• Record adequate
depth and width.
Labial flange
• Proper contouring
gives optimal
esthetics.

Buccal vestibule.
• Buccal frenumretromolar pad.
• Record adequate
depth and width.
• Impression is
widest in this area.

Buccal flange

Buccal shelf
• .


Def..Anatomically buccal shelf is defined as the part of the basal
seat located posterior to the buccal frenum.(Boucher 10 th edition).
• The area between the mandibular buccal frenum and the anterior
edges of masseter muscle is known as buccal shelf(b12)
Boundaries:
• Anteriorly-buccal frenum.
• Posteriorly-retromolar pad.
• Medially-crest of the ridge
• Laterally-external oblique ridge.
Width-4-6 mm wide on average mandible.
• 2-3 mm or less in narrow mandible.
• The total widthof the bony foundation in this region becomes
greater as alveolar bone resorption continues.the reason is that
the inferior border of the mandible is great than the width at the
alveolar process.
Clinical implication: upper slopes of the buccal shelf adjacent to the
pad helps to resist the distal dis placement of the denture
because of the diminished available support,a narrow mandible is
usually considered the most difficult to manage.
• Clinically care should be taken to cover the area


• Interpreting the buccal shelf area:While
recording the final impression additonal load is
applied in this area,the trays comes in to direct
cotact with the mucosa.
• Preprosthetic surgery:no
• When the residual ridge becomes flat the
buccinator is often attached to the center of the
ridge.the buccinator muscle can be covered by
the denture in this area because the muscle
fibres run anterioposteriorly parallel to the bone
and the denture does not resist the contracting
forces of the muscles.the inferior part of the
buccinator is attached to the buccal shelf of the
mandible and the contraction of the muscle
doesnot lift the denture.(resorbtion
• Resisted by horizontal fibres of buccinator


Histology: mucous membrane-is more loosely
attached and less keratinised than the mucous
membrane covering the crest of the ridge.
• Submucosa:thicker,fibres of buccinator are
found running horizontally in the submucosa
immediately overlying the bone.
• The mm overlying the buccal shelf may not be
suitable histologically to provide primary support
for the denture as the mm overlying the crest of
the ridge.
• Bone:bs is covered by layer of smooth compact
boneor cortical bone(with it’s haversian
system,the bone is very dense and the trbaculae
are arranged almost at right angles to the jaw
closure) plus the fact that the bucal shelf lies at
right angles to the vertical occlusal
forces,therfore it is more suitable primary stress
bearing area for the lower denture.

• Blood supply—artery supply—buccal
artery,inferior alveolar artery,nerve supply—
buccal nerve ,inferior alveolar nerve,buccal
branch of mandibular nerve.
• Oralucousmembrane thick ness--mucous
membrane-is more loosely attached and less
keratinised than the mucous membrane covering
the crest of the ridge.
• Muscle found in this area—inferior part of the
buccinator,anterior edge of the masseter muscle.


External oblique ridge.
• A bony ridge runs
antero-posteriorly
outside the buccal
shelf.
• Denture border 1-2
mm beyond this ridge.
• Shows as Groove in
impression.


Alveolar ridge
• Residual bone with
mucous membrane.
• Crest to be
relieved.
• Buccal and lingual
slopes are
secondary stress
bearing areas.

Retromolar pad.

Retromolar fossa

• Triangular soft pad of
tissue.
• Posterior end of lower
edentulous ridge.
• Limiting landmark of distal
extension of complete
denture upto ant 2/3 rd of
retro molar pad.
• Determines height and
width of the occlusal table.
• Contents-loose connective
tissue, glandular tissue
,laterallybuccinator,posterio
rly temporalis tendon,
medially superior
constrictor and pterygo
mandibular raphe


Alveolo-Lingual sulcus.

Premylohyoid
eminence

Lingual flange

• Between lingual frenum to
retromylohyoid curtain.
• Anterior region• Premylohyoid fossapremylohyoid eminence in
impression.
• Border of Impression to make
contact with the mucosa of
the floor of the mouth when
tongue touches the upper
incisor.
soreness and instability.


Middle region.
•

From pre-mylohyoid fossa to
the distal end of the
mylohyoid ridge.

• Lingual flange extends below
the level of the mylohyoid
ridge- tongue rests on the
top of flange and aids in
stabilizing the lower denture.
• To record ask the patient to
touch the buccal mucosa on
either side of cheek with tip
of the tongue.

Posterior region.
• The flange
passes into the
retromylohyoid
fossa.
• Proper
recording gives
typical S –form
of the lingual
flange.

Retromylohyoid fossa.
• Distal end of lingual
sulcus.
• Area posterior to
the mylohyoid
muscle.
• Good seal aids in
Retromylohyoid eminence retention and
stability.
• To record –ask the
patient to protrude
the tongue

BOUNDARIES OF LATERAL THROAT FORM.

•
•
•
•
•

Anteriorly –mylohyoid muscle
Laterally –pear shaped pad
Posteriolaterally-superior constrictors and
Posteromedially –palatoglossus
The posterior limit of the mandibular
denture is determined mainly by the
palatoglossal muscle and by superior
constrictor muscle-this area is called as
retro myelohyoid curtain.


Mylohyoid ridge.
• Attachment for the
mylohyoid muscle.
• Sharp or irregular
covered by the mucous
membrane.
• Trauma from denture
base –relief necessary.


Mylohyoid muscle.
• Floor of the mouth is
formed by mylohyoid
muscle.
• Lies deep to the
sublingual gland in
the anterior regiondoes not affect the
border of denture.
• Posterior region –
affects the lingual
border in swallowing
and tongue
movements.

Genial tubercle.
• Area of muscle
attachment (Genioglossus
and Geniohyoid).
• Lies away from the crest
of the ridge.
• Prominent in Resorbed
ridges.
• Adequate relief to be
provided.

JANKELSON in 1962-Adjustments
necessary

1.DYNAMIC PHYSIOLOGY
2.FACTORS WITH MATERIALS &TECHNIQUES

PRESSURE AREAS-1.Basal surface
2.Intaglio surface
3.Denture peripheries

Common methods of border
evaluation
Visual &tactile method
Methods employing indicator paste
Disclosing wax methods


VISUAL-TACTILE
METHOD
• Experienced operators
• Selective activation of facial
musculature/tipping forces to denture
• Identify areas of over extension/under
extension
• Disadvantage-subjective& lead to over
adjustment/modification


Indicator paste
• Pressure areas on intaglio surface&
not used for border evaluations
• Low viscosity &displaced by
functional movements
• Disadv-cannot built appreciable
thickness without distortion so, not
used for under extension


Disclosing waxes
• Exhibit higher viscosities than
indicator paste , it can with stand
greater loads without complete
displacement so, they built up to
thickness
• Modification with silicone
gels/petrolatum

TECHNIQUE


CONCLUSION


Thank you
For more details please visit


Denture border evaluation /certified fixed orthodontic courses by Indian dental academy

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Viewers also liked

Viewers also liked (20)

Similar to Denture border evaluation /certified fixed orthodontic courses by Indian dental academy

Similar to Denture border evaluation /certified fixed orthodontic courses by Indian dental academy (20)

More from Indian dental academy

More from Indian dental academy (20)

Recently uploaded

Recently uploaded (20)

Denture border evaluation /certified fixed orthodontic courses by Indian dental academy

Editor's Notes