The document discusses the anatomy of edentulous ridges in the maxilla and mandible, which is important for complete denture design. The mandible provides significantly less total support area (14cm2) than the maxilla (24cm2), making it less capable of resisting occlusal forces. The consistency of the mucosa and underlying bone varies in different parts of the ridge, with some areas able to withstand more force than others. A thorough understanding of the anatomical landmarks and structures that limit, support, and require relief in complete dentures is necessary for optimal denture fit and function.

1. PRESENTED BY:
Dr. BRAJENDRA SINGH TOMAR
PG 1ST YEAR
DEPT. OF PROSTHODONTICS
GUIDED BY:
Dr. G. S. CHANDU

2. • THE ANATOMY OF EDENTULOUS RIDGES IN THE MAXILLA
AND MANDIBLE IS VERY IMPORTANT FOR THE DESIGN OF
THE COMPLETE DENTURE
• THE TOTAL AREA OF SUPPORT FROM THE MANDIBLE IS
SIGNIFICANTLY LESS THAN FROM THE MAXILLA.
• THE AVERAGE AVAILABLE DENTURE BEARING AREA FOR AN
EDENTULOUS MANDIBLE IS 14cm2 , WHEREAS FOR
EDENTULOS MAXILLA IT IS 24cm2. THEREFORE THE
MANDIBLE IS LESS CAPABLE OF RESISTING OCCLUSAL
FORCES THAN THE MAXILLA.
INTRODUCTION
• THE CONSISTENCY OF THE MUCOSA AND THE UNDERLYING
BONE IS DIFFERENT IN VARIOUS PARTS OF THE EDENTULOUS
RIDGE
• SOME PARTS OF THE RIDGE ARE CAPABLE OF
WITHSTANDING MORE FORCE THAN OTHER AREARS

3.  SERVES AS A CUSHION
BETWEEN THE DENTURE
BASE AND THE
SUPPORTING BONE.
 MUCOUS MEMBRANE IS
COMPOSED OF MUCOSA
AND SUB MUCOSA.
 SUBMUCOSA IS FORMED
BY CONNECTIVE TISSUE
THAT VARIES FROM DENSE
TO LOOSE AREOLAR
TISSUE
 MUCOSA COVERING THE
HARD PALATE AND THE
CREST OF THE RIDGE IS
CLASSIFIED AS
MASTICATORY MUCOSA
 CHARECTERIZED BY ITS
WELL –DEFINED
KERATINIZED EPITHELIUM
AND LACK OF TISSUE

4.  LIMITING STRUCTURES
 SUPPORTING STRUCTURES
 RELIEF AREAS

5.  LABIAL FRENUM
 LABIAL VESTIBULE
 BUCCAL FRENUM
 BUCCAL VESTIBULE
 HAMULAR NOTCH
 POSTERIOR PALATAL SEAL AREA

6.  FOLD OF MUCOUS
MEMBRANE
 NO MUSCLE
 NO ACTION OF ITS OWN
 A “V” SHAPED NOTCH
SHOULD BE RECORDED
DURING IMPRESSION
MAKING
 LABIAL NOTCH OF THE
LABIAL FLANGE OF THE
DENTURE MUST BE JUST
WIDE ENOUGH AND JUST
DEEP ENOUGH TO
ACCOMMODATE THE
LABIAL FRENUM

7.  IT IS DIVIDED LEFT AND
RIGHT BY THE LABIAL
FRENUM
 ORBICULARIS ORIS IS THE
MAIN MUSCLE WHICH
FORMS THE OUTER
SURFACE OF THE LABIAL
VESTIBULE
 ORBICULARIS ORIS
MUSCLE HAS ONLY AN
INDIRECT EFFECT ON THE
LABIAL VESTIBULE
BECAUSE ITS FIBERS RUN
IN HORIZONTAL
DIRECTION

8.  DIVIDING LINE BETWEEN
THE LABIAL AND BUCCAL
VESTIBULE.
 FRENUM MAY BE SINGLE
OR DOUBLE.
 LEVETOR ANGULI ORIS
MUSCLE ATTACHES
BENEATH THE FRENUM.
 ORBICULARIS MUSCLE
PULLS THE FRENUM
FORWARD.
 BUCCINATOR MUSCLE
PULLS IT BACKWARD.
 REQUIRE MORE
CLEARENCE FOR ITS
ACTION

9.  EXTEND FROM BUCCAL
FRENUM TO HAMULAR
NOTCH
 BOUNDED LATERALLY BY
THE CHEEKS AND
MEDIALLY BY THE RIDGE.
 SIZE OF THE VESTIBULE
VARIES WITH THE
CNTRACTION OF
BUCCINATOR MUSCLE,
POSITION OF THE
MANDIBLE, AND AMOUNT
OF BONE LOST FROM
MAXILLA.
 ADEQUATE DEPTH/WIDTH
SHOULD BE RECORDED

10.  DISTAL LIMIT OF THE
BUCCAL VESTINULE.
 SITUATED BETWEEN THE
TUBROSITY AND
HAMULUS OF THE MEDIAL
PTERYGOID BONE.
 TENSOR VELI PALATINI
MUSCLE RUNS
HORIZONTALLY
THROUGH THIS NOTCH.
 AIDS IN ACHIEVING
POSTERIOR PALATAL
SEAL.

11.  “THE SOFT TISSUE AT OR ALONG THE JUNCTION OF THE HARD
AND SOFT PALATE ON WHICH PRESSURE WITHIN THE
PHYSIOLOGICAL LIMITS OF THE TISSUE S CAN BE APPLIED BY A
DENTURE TO AID IN THE RETENSION OF THE DENTURE” -GPT.
PARTS:
•POSTPALATAL SEAL
•PTERYGOMAXILLARY SEAL
EXTENSIONS:
•ANTERIORLY- ANTERIOR VIBRATING LINE
•POSTERIORLY- POSTERIOR VIBRATING LINE
•LATERALLY- 3-4 MM ANTERIOLATERAL TO
HAMULAR NOTCH

12.  “THE IMAGINARY LINE ACROSS THE POSTERIOR PART OF
THE PALATE MAKING THE DIVISION BETWEEN THE
MOVABLE AND IMMOVABLE TISSUES OF THE SOFT PALATE
WHICH CAN BE IDENTIFIED WHEN THE MOVABLE TISSUES
ARE MOVING”-GPT
Anterior &Posterior
Vibrating line

13. PRIMARY STRESS
BEARING AREA
SECONDRY STRESS
BEARING AREA
 HARD PALATE
 MAXILLARY
TUBEROSITY
 RESIDUAL
ALVEOLAR RIDGE

14.  COVERED BY KERATINIZED SQUAMOUS
EPITHELIUM.
 ANTERIOLATERALLY, THE SUBMUCOSA
CONTAINS ADIPOSE TISSUE.
 POSTEROLATERALLY IT CONTAINS
GLANDULAR TISSUE.
 THE HORIZONTAL PORTION OF THE
HARD PALATE PROVIDES THE PRIMARY
STRESS-BEARING AREA

15.  IT IS THE POSTERIOR
CONVEXITY OF THE
MAXILLARY BODY.
 THE MEDIAL AND
LATERAL WALLS RESIST
THE HORIZONTAL AND
TORQUING FORCES
WHICH WOULD MOVE
THE DENTURE BASE IN
LATERAL OR PALATAL
DIRECTION.
 THEREFORE MAXILLARY
DENTURE BASE SHOULD
COVER THE TUBEROSITY
AND FILL THE HAMULAR
NOTCHES.

16.  COVERED BY KERATINIZED SRATIFIED
SQUAMOUS EPITHELIUM.
 THE SUB MUCOSA IS CHARECTERIZED BY DENSE
COLLAGENOUS FIBERS THAT ARE CONTIGUOUS
WITH LAMINA PROPRIA
 CONSIDERED AS A SECONDRY STRESS BEARING
AREA BECAUSE IT IS SUBJECTED TO RESORPTION
TO HORIZONTAL PORTION OF HARD PALATE

17.  INCISIVE PAPILLA
 MEDIAN PALATAL RAPHE
 FOVEA PALATINE

18.  SITUATED ON A LINE
IMMEDIATELY BEHIND
AND BETWEEN THE
CENTRAL INCISORS
 THE INCISIVE FORAMEN IS
LOCATED BENEATH THE
INCISIVE PAPILLA.
 LOCATION OF THE INCISIVE
PAPILLA GIVES AN
INDICATION AS TO THE
AMOUNT OF RESORPTION
THAT HAS TAKEN PLACE.
 THE NASOPALATINE
NERVES AND VESSELS PASS
THROUGH THE INCISIVE
FORAMEN.

19.  THE SUBMUCOSA IS
EXTREMELY THIN IN THE
REGION OF MEDIAL
PALATAL SUTURE, SO THE
MUCOSAL LAYER IS IN
CLOSE CONTACT WITH THE
UNDERLYING BONE.
 FOR THIS REGION, THE SOFT
TISSUE COVERING THE
MEDIAN PALATAL TISSUE IS
NONRESILIENT IN NATURE
& MAY NEED TO BE
RELIEVED.

20.  BILATERAL INDENTATION
NEAR THE MIDLINE OF
PALATE
 FORMED BY COALESCENCE
OF SEVERAL MUCOSAL
GLAND DUCT
 POSTERIOR TO JUNCTION OF
HARD AND SOFT PALATE
 ALWAYS ON SOFT PALATE

21.  LIMITING STRUCTURES
 SUPPORTING STRUCTURES
 RELIEF AREAS

22.  Labial frenum
 Labial vestibule
 Buccal frenum
 Buccal vestibule
 Lingual frenum
 Alveolingual sulcus
 Retromolar pad
 Pterygomandibular raphe

23.  It is a fold of mucous
membrane at the median
line.
 It divids the labial
vestibule into left and
right labial vestibule
 Recorded as a notch in
the impression made

24.  Frenum contains
fiber of Orbicularis
oris and Mentalis
muscle
 Therefore the
frenum is quite
sensitive and active,
and the denture
must be fitted
carefully around it
to maintain a seal
without causing
soreness

25.  The labial vestibule
extend from the
labial frenum to the
buccal frenum
 Muscle attachment
close to the crest of
the ridge –limits the
denture flange
extension

26.  The buccal frenum
forms the dividing
line between the
labial and buccal
vestibule.
 It overlies the
depressor anguli oris
muscle.
 Fibers of buccinator
muscle attached to
the frenum.

27.  Frenum may be
single or double,
broad U shaped or
sharp V shaped.
 It should be relieved
to prevent
displacement of the
denture during
function.

28.  Extend from buccal
frenum to retromolar
pad
 The extent of buccal
vestibule is influenced
by the buccinator
muscle,
which extends from the
modiolus anteriorly to
the pterygomandibular
raphe posteriorly
 The impression is widest
in this region.

29.  Fold of mucous
membrane.
 •Base of tongue to
supragenial tubercle.
 The anterior region of
the lingual flange is
called sub-lingual
crescent area
 A high frenum is
called as Tongue tie.it
should be corrected if
it affects the stability
of the denture.

30. Space between the
residual ridge & tongue .
Extends from lingual
frenum to retromylohyoid
curtain .
3 regions (anterior,
middle & posterior)
The anterior region
extends from the lingual f.
back to where mylohyoid
muscle curves above the
level of the sulcus
(premylohyoid fossa) .

31. The middle region extends from
premylohyoid fossa to the distal
end of the mylohyoid ridge,
curving medially from the body
of the mandible. This curvature is
caused by the prominance of
mylohyoid ridge & the action of
mylohyoid muscle.
The posterior region: here the
flange passes into the
retromylohyoid fossa &
completes the typical S form of
the correctly shaped lingual
flange.

32. The retromylohyoid
space lies at the distal
end of the
alveololingual sulcus.
Bounded by
Anterior tonsillar
pillar,posteriorly by the
retromylohyoid
curtain.

33.  Formed
 posteriorly by the
superior constrictor
muscle,
 Laterally by the
mandible &
pterygomandibular
raphe,
 Anteriorly by lingual
tuberosity, and
 Inferiorly by the
mylohyoid muscle.

34.  The retromolar pad is a
pear shaped area
containing glandular
tissue, loose areolar
connective tissue,the
lower margin of the
pterygomandibular
raphe,fibers of
buccinator and superior
constrictor, along with
the fibers of temporal
tendon.
 The retromolar papilla is a pear shaped area just
anterior to the retromolar pad, it is dense, fibrous
connective tissue.

35.  Buccal shelf area
 Residual alveolar ridge

36.  Extend from the buccal
frenum to the anterior
edge of the masseter
muscle.
 Boundries :
Medially- crest of the ridge
Laterally- external oblique
ridge.
Distally –retromolar pad

37. The mucous membrane
covering the buccal
shelf area is loosely
attached, less
keratinized & contains
thick submucosal layer.
Considered as a
primary stress-bearing
area because it is
covered by a layer of
cortical bone, & it lies at
right angles to vertical
occlusal forces

38.  The crest of the
residual alveolar
ridge is covered by
fibrous connective
tissue,
 But in many mouths
the underlying bone
is cancellous and
without a good
cortical bony plate
covering it.

39.  The mucous membrane covering the crest of the
residual ridge is covered by keratinized layer
and is attached by its submucosa to the
periosteum of the mandible.
 The extent of this attachment varies
considerably. In some people, the submucosa is
loosely attached to the bone over the entire
crest of the residual ridge, and the soft tissue is
quite movable.

40.  In others, the submucosa is firmly attached to
the bone on both the crest and the slopes of the
lower residual ridge.
 However, because underlying bone is often
cancellous (bony spicules and nutrient canals),
the crest of the residual ridge may not be
favorable as the primary stress-bearing area for
a lower denture.

41.  Mental foramen
 Genial tubercle
 Mylohyoid ridge
 Mandibular tori.

42.  As resorption takes place,
the mental foramen will
come to lie closer to the
crest of ridge.
 In these circumstances, the
mental nerve and blood
vessels may be compressed
by denture base unless relief
is provided.
 Pressure on mental nerve
can cause numbness of
lower lip.

43.  The genial tubercle are a
pair of dense
prominences at the
inferior border of the
mandible at the lingual
midline.
 They represents the
muscle attachment of
the genioglossus and
geniohyoid muscle.
 They only become
relevant in the denture
when there is excessive
resorption of the
residual ridge.

44.  The mylohyoid ridge is a boney
prominence along the lingual
aspect of the mandible
 Soft tissue usually hides the
sharpness of mylohyoid ridge.
 Anteriorly, this ridge with
mylohyoid muscle is close to
inferior surface of mandible.
 Posteriorly, after resorption, it
often flushes with the residual
ridge.
 The mucous membrane
overlying the sharp or irregular
mylohyoid ridge needs to be
relieved.

45.  Mandibular tori are
lingual bilateral
prominences of
cortical bone in the
premolar area.but they
may extend
posteriorly to the
molar area.
 small tori may only
require relief in the
denture.
 Large tori reguire
removal before a
denture can be
fabricated

46.  Boucher's Prosthodontics Treatment for
Edentulous Patients. 13th Edition.
Chapter 8.
 Winkler’s –Essentials of Complete Denture
Prosthodontics.
Chapter-7.
 Heartwell’s syllabus of complete
denture.4th edition.
Chapter 6.

48.  THESE ARE THE
MUCOSAL FOLDS IN THE
ANTERIOR REGION OF
THE HARD PALATE.
 IN THE AREA OF THE
RUGAE , THE PALATE IS
SET AT AN ANGLE TO
THE RESIDUAL RIDGE &
COVERED BY THIN SOFT
TISSUE.
 PALY AN IMPORTANT
ROLE IN SPEECH