Applied Anatomy / orthodontic courses by Indian dental academy
-
Upload
indian-dental-academy -
Category
Documents
-
view
227 -
download
2
Transcript of Applied Anatomy / orthodontic courses by Indian dental academy
APPLIED ANATOMY AND BEHAVIOURAL CHANGES OF ORAL MUCOSA UNDER COMPLETE DENTURE PROSTHESIS
Introduction
- Preservation of the residual structures of foundational tissues
constitute a consideration of paramount interesting prosthodontics.
- Tissues of the oral cavity are made to reveal a phenomenon of
reaction consequent to being subjected to artificial environment.
- The reaction of the tissues is universally evident from the fact that
the oral tissues will expel the irritant, big or small which enters the
oral cavity.
- Oral tissues were designed to be exposed to oral fluids and to be
stimulated by the action of tongue, cheeks and lips.
- Even in the dentulous state, the mucosa demonstrates a low
tolerance to injury or irritation. Tolerance is further depleted if
systemic disease is present.
- Oral mucosa does not appear to be suited to the role of bearing
stress and shows little or no adaptation to this altered function.
- The observations I would like to make in the following delibration
are based on the reaction of localized areas of these foundations to
the dentures which would mean the applied anatomy.
1
- Body cavities that communicate with the external surface are lined
by mucous membranes, which are coated by serous and mucous
secretions.
- The oral cavity is lined with an uninterrupted mucous membrane
which is continuous with the skin near the vermillion border of the
lips and with the pharyngeal mucosa in the region of the soft palate.
- Like skin, the oral mucosa serves to protect the underlying organs
and to receive and transmit stimuli from the environment.
Development of oral mucosa
- The primitive oral cavity develops by fusion of the embyonic /
timodeum with foregut after rupture of buccopharyngeal membrane.
This occurs at about 26 days of gestation. So the primitive oral
cavity is lived by epithelium derived from both ectiderm and
endoderm.
- The structures that develop from the brachial arches. Eg. Tongue are
covered by epithelium derived from endoderm whereas, the
epithelium covering the palate, checks and gingivae are derived
from ectoderm.
The underlying ectomesenchyme of the epithelium forms the
connective tissue of the oral mucosa.
2
Structure
- Structure of oral mucous membrane resembles the skin in many
ways. It is composed of : Epithelium, Connective tissue (Lamina
propria) and submucosa (may or may not be present).
- The 2 layers form an interface that is folded into cormgations.
Papilla of connective tissue protrude toward the epithelium carrying
blood vessels and nerves. Although the nerves actually pass into the
epithelium, it does not contain blood vessels. The epithelium inturn
is formed into ridges that protrude towards the lamna propria.
Lamina propria
Lamina popria may attach to the perosteum of the alveolar bone, or
it may overlay the submucosa which varies in different regions of the
mouth.
Submucosa
- Submucosa consists of connective tissue of varying thickness and
density. It attaches the mucous membrane to the underlying
structures. Whether this attachment is loose or firm depends on the
character of the submucosa.
3
- Glands, blood vessels, nerves and also adipose tissue are present in
the layer. It is in the submucosa that larger arteries divide into
smaller branches which then enter the lamina propria.
- Keratinizing oral epithelium has 4 layers (based on morphology) 1)
Stratum basale, 2) Stratum spinosum 3) stratum granulosum 4)
Stratum corneum.
A single cell after mitosis may remain in the basal layer and divide
again or it may become determined during which it migrates upwards.
During its migration it becomes committed to biomechanical and
morphologic changes and forms a Keratinzed lquama, a dead cell filled
with densely packed protein. After reaching the surface it desquamates.
This whole process from onset to maturation stage is called Keratinization.
Epithelium
- Epithelium of oral mucous membrane is stratified squamous
epithelium. It may be ortho keratinized, parakeratinized or
nonkeratinized depending on the location.
- A common feature of all epithelial cells is that they contain keratin
intermediate filaments as a component of their cytiskeleton.
Keratin: It is a sdeiroprotein which is principal constituent of epidermis,
hairs, nails and organic matrix of tooth enamel. It is a very insoluble
4
protein. It contains sulphur. KERATIN IS THE END RESULT OF
EPITHELIAL DEGENERATION.
The layers mentioned above are characteristic of orthokeratinization.
- The cell layers o non – keratinizing epithelium are referred to as
stratum basale, stratum intermedium, stratum superficiale (No
stratum granulosum). Surface cells are mediated and show no signs
of keratinization.
- In parakeratinization, a stratum granulosum is generally absent and
the surface cells retain a pyknotic nuclei and show some signs of
keratinzation.
Basal cells: Single layer of cuboid or high cuboidal cells. They are
separated from the connective tissue by the basement membrane.
Spinous cells: Irregularly polyhedral and larger than the basal cells of the 4
layers, this layer is most active in protein synthesis.
Granular cells: Contains flatter and wider cells. These cells are larger than
spinous cells. This layer is named for its basophilic keratohydro granules.
Cornified cells: Made up of keratinized squamae which are flatter than
granular cells. Here all the nuclei and other cell organelles have
disappeared.
5
While the term “Keratinization” is physiologic, the term keratosis is
pathologic. When keratinization occurs in a normally non keratinized
tissue, it is referred to as “keratosis”.
Classification of oral mucosa in the edentulous
Most classifications divide the oral mucosa into 3 categories, depending
on its function and location.
A) Masticatory mucosa: (Has well defined keratinized layer)
Covers the crest of the residual ridge, including the residual attached
gingival that is firmly attached to the supporting bone, and the hard palate.
B) Lining mucosa: (Devoid of keratinized layer)
It is associated with those parts of the oral cavity which are not
firmly attached to the perosteum. It covers the lips and cheeks, vestibular
spaces, the alveolingual sulcus, the soft palate, the ventral surface of the
tongue and unattached gingival found on the slopes of residual ridges.
These tissue are freely movable because of the elastic nature of underlying
lamina propria.
C) Specialized mucosa: It covers the dorsal surface of the tongue. This
mucosal covering is keratinized and includes the specialized papillae on
the upper surface of the tongue.
6
Clinical topography of the soft tissues of the oral cavity with their
microscopic anatomy and clinical importance.
- Clinical procedures used in making impressions are directly related
to gross anatomic structures of the oral cavity and their function.
- However, the response of the individual cellular components that
make up the basal seat determines the ultimate success of the
dentures in terms of preservation of the residual ridges and comfort
of the patient. Thus a constant awareness of microscopic anatomy of
the mucous membrane and bone that form the residual ridge is
essential in the development of (1) border form and (2) length and in
(3) selective placement of pressures on the basal seat during
impression procedures.
- The nature of the mucous membrane in different parts of the mouth
varies between patients and within the same patient. The keratinized
layer of the epithelium may be totally absent in some instances and
extremely thick in others.
- Although the importance of the mucosa from a health stand point
cannot be neglected, the thickness and consistency of the submucosa
are largely responsible for the support that the soft tissues afford the
dentures, since in most instances the submucosa makes up the bulk
of the mucous membrane.
7
- When the submucosal layer is thin over the bone, the soft tissues
will be non resilient and small movement of the dentures will then
to break the retentive seal.
- When the submucosal layer is loosely attached to the periosteum of
the residual ridge or is inflamed or edentulous, the tissue is easily
displaceable and the stability and support of the dentures are
adversely affected.
- Impression procedure requires modification to accommodate these
changes in the submucosa.
I. Maxilla
A. Supporting Structures
1. Crest of the residual ridge:
In healthy mouth it is firmly attached to the periosteum of the bone
of maxilla. It presents a grayish pink tissue because of its dense character
and minimal vascularity.
- Stratified sqaumous epithelium is thickly keratinized submucosa is
devoid of fat or glandular cells, but it is characterized by dense
collagenous fibres.
Though the submucosa is thin, it is still sufficiently thick to provide
adequate resiliency for primary support of upper denture.
8
2. Slopes of the residual ridge:
Here the tissues are loosely attached. This marks the end of residual
attached mucous membrane. The tissues here are non keratinized or
parakeratinized.
These loosely attached tissues will not withstand the forces of
mastication or other stresses transmitted through the denture basis.
- Mucosa of the labial vestibule between the residual alveolar ridge
and the lips and cheeks is called the valve producing area.
Less stress is placed on the movable tissues during making of the
final impression. This is because the final impression material in that
region is close to escape ways.
This fact is in accordance with the principle.
3. Hard palate:
- Mucous membrane of the hard palate is tightly fixed to the
underlying periosteum and therefore immovable. However its
thickness and consistency varies in different locations.
- Epitheliumis uniform and has a well – keratinized surface
- Various regions in the hard palate differ because of the varying
structure of the submucous layer. These zones are recognized.
a. Anterolateral area or fatty zone
9
b. Posterolateral area or glandular zone
c. Palatine raphae or median area.
a. Anterolaterally: Submucosa of the hard palate contains adipose tissue.
b. Posteriorly : Submucosa contains glandular tissue.
Importance: These tissues should be recorded in a resting condition
because when they are displaced in the final impression, they tend to return
to normal form within the completed denture base, creating an unseating
for on the denture or causing soreness in the patient’s mouth.
The secretions from the palatal glands can be an important factor in
the selection of final impression material.
c) Median palatal suture: It extends from the incisive papillae till the
posterior region on the hard palate.
- The submucosa in this region is extremely then the mucosal layer is
practically in contact with the underlying bone. So the tissue
covering the suture is non-resilient.
Importance: Little or no pressure can be placed in this region during
making of final impression or in the completed denture. Otherwise the
denture will tend to rock over the center of the palate when vertical forces
are applied to the teeth.
10
In addition this part of the mouth is highly sensitive and excessive
pressure can create excruciating pain. So proper relief in the impression
tray is required for accommodation of histologic nature of this tissue.
4. Incisive Papillae: At the anterior end of median palatal suture, there is
an elongated or oral elevation of the mucosa called incisive papillae. It
covers the incisive foramen and is located behind and between the central
incisors.
The submucosa of the nasopalatine canal would reveal the
nasopalatine nerves and vessels.
Importance: Relief should be provided for the incisive papillae in both the
final impression and completed denture to prevent pressure on the
nasopalatine vessels and nerves.
5. Palatine rugae: Rugae are irregularly shaped rolls of soft tissue in the
anterior part of the palate.
Importance: Rugae is considered to be the secondary stress bearing area
as it can resist forward movement of the denture.
B. Limiting structures
1. Vestibular spaces: It is bounded facially by the mucosa of the lips
and cheeks and orally by the mucosa of the residual ridge.
11
- The vestibule is partly divided in the median plane by the upper and
lower labial frenae and laterally by buccal frame.
- A histologic section in this region shows a relatively thin epithelium
that is non keratinized submucosal layer is thick and contains large
amounts of loose areolar tissue, and elastic fibres. So this tissue is
easily movable.
Importance: Labial or buccal flanges of the maxillary impression can be
easily overextended or underextended.
A knowledge of the size of the space in the vestibule available for
denture flanges is the key factor.
2. Vibrating line:
It is an imagninary line drawn across the soft palate that marks the
beginning of motion when the patient says “ah”.
Submucosa in this region contains glandular tissue similar to that in
the submucosa in the postero lateral part of the hard palate.
Importance: Because the soft palate does not rest directly on the bone, the
tissue for a few millimeters on either side of the vibrating line can be
repositioned in a controlled manner in the impression procedure.
This improves posterior palatal seal.
12
3. Mucous membrane in Hamular notch area:
Space between the posterior part of maxillary tuberosity and
pteregord hamulus is thick and made of loose aredor tissue.
Importance: Additional pressure can be placed on this tissue at the center
of the notch to complete the posterior palatal seal.
Spacer is provided in the find impression tray except in the region of
vibrating line and through hamular notches. Thus the tray itself contacts the
soft tissue in this region when impression is made.
These tissues can be displaced without trauma.
II. Mandibular edentulous foundations
A. Supporting structures
1. Crest of the residual ridge:
Mucous membrane covering the crest of the lower residual ridge is
similar to that of the upper ridge. In a healthy mouth it is covered by a
Keratinized layer firmly attached to the periosteum by the submucosa.
In same patients the submucosa is loosely attached to the bone over
the entire crest of the residual ridge and the soft tissue is quite movable.
Importance: when the soft tissues is movable, it must be registered
in its resting position in the final impression. Occasionally surgical
13
procedures are indicated to increase the amount of “residual attached
gingivae”.
These tissues must be in a healthy condition when the final
impression is made.
2. Buccal Shelf:
Mucous membrane covering the buccal shelf is more loosely
attached and partially keratinized and contains a thicker submucosal layer.
However the bone of the buccal shelf is covered by a layer of compact
bone composed of Haversian system.
Hence this area is suitable as a primary stress bearing area of the
mandibular edentulous foundations.
B. Limitating structures:
1. Vestibular spaces:
The mucous membrane lining these spaces is quite similar to the in
nature to that of the maxillary foundation.
The epithelium is their and non Keratinized and the submucosa is
formed of loosely arranged connective tissue fibres and elastic fibres.
Anteriorly the submucosa of the mucous membrane lining the
alveolingual sulcus contains components of the sublingual gland and is
attached to the genioglossus muscle.
14
2. Molar region: Here the submucosa attaches to the mylohyoid muscle
and mucous membrane covering the retromylohyoid certain is attached by
its submucosa to the superior constrictor muscle.
Posterior to the superior constrictor muscle fibres, when run in a
horizontal direction is found the medial pteregoid muscle running in a
vertical direction.
Importance: Length and form of the lingual flange of the lingual flange of
lower final impression tray must reflect the physiologic activity of these
structures.
3. Retromolar pad:
It has at the posterior end of the crest of lower residual ridge.
Histologically mucosa of the pad is composed of a thin, non
keratinized epithelium. Its submucosa contains glandular tissue, loose
areolar tissue, fibres of baccinator and superior constrictor muscles, the
pteregomandibular raphae and the tendon of temporalis.
Importance: because of its contents, it is recorded in a resting
position in final impression.
Behaviour of oral mucosa under stress
- Oral mucosa under compression behaves in a viscoelastic fashion
similar to skin and other biologic tissues loaded in compression.
15
- Loads imposed on the masticatory mucosa by normal mastication
and by the prosthesis consists primarily of compressive and shear
forces. However these forces will produce regions of tensile stresses
within the mucosa.
- Kydd and associates described the viscoelastic character of denture
supporting tissues.
a. There is an initial elastic compression of the soft tissue that
takes place instantly on application of load.
b. After the elastic phase there is a delayed elastic deformation
of the soft tissue that takes place slowly and continues to
diminish in rate of change as duration of load is extended.
c. An instantaneous elastic decompression occurs when the
pressure is removed.
d. This is followed by a continuing delayed elastic recovery.
- They also arranged that during function and parafunction, pressures
are applied by the dentures which will displace the soft tissues.
These pressure deform the mucoperiosteum and interferes with
circulation of blood, nutrients and metabolites.
Tissue pressure under complete maxillary dentures
16
- Cutright and associates (1976) recorded pressures under complete
maxillary dentures. They used a closed fluid system connected to a
pressure transducer and recorder to register positive and negative
pressures in 4 subjects at 4 locations.
- Each subject performed a number of controlled masticatory and non
masticatory activities.
- Pressures were recorded as positive above a base line which equaled
zero with the denture in a passive condition and negative if they
were below the base line.
- Findings indicate that a number of non masticatory activities
(swallowing, smoking and speaking) created as much or more +ve
or –ve pressures on the supporting tissues as the masticatory
activities.
Conclusion of this study
1. Stable dentures produce high pressure on the supporting tissues and
transmit these pressure from region to region varying with how the
patient uses the denture.
2. Most often, an opposite large or negative pressure immediately
followed the production of + ve pressure at the same site beneath the
denture. Thus each movement actually traumatizes the tissue twice.
17
3. Swallowing which is not associated with eating or drinking
produced very high +ve and very low –ve pressures on the tissues.
Effect of complete denture on alveolar mucosa
- Ostland studied the effect of complete dentures on the “gum tissues”
through observation of clinical changes and the examination of
histologic sections from biopsies of palatine mucosa in denture and
non denture wearers.
- He described the mucosal changes as pathologic but without frank
clinical inflammation. He demonstrated a decrease in Keratinization
of denture bearing mucosa and a decrease in mucosal thickners.
Conclusion: He concluded that a denture covering the ridge mucosa in the
absence of trauma protects underlying soft tissues from injury. So in a non
denture wearer irritation from various sources chronic inflammation
More boneloss. So because of continuous inflammation a non denture
wearer may loose more bone than a denture wearer.
- Kapur and associates conducted a study to investigate the changes
occurring in denture bearing mucosa after the use of removable
dentures. Biopsy study was performed before and after the use of
dentures. (Biopsy form crest of the ridge).
- One side of posterior edentulous ridge was stimulated with a power
driven tooth brush on week days for a period of 4 weeks. The other
18
side served as control. This was done in order know the relation
between tissue stimulation to wearing of dentures. (In a previous
study it was demonstrated that stimulation of edentulous alveolar
mucosa with an automatic tooth brush resulted in increased
keratinized).
Alveolar mucosa prior to denture insertion
Microscopic examination revealed
a) A distinct layer of keratin. This was of parakeratotic variety
with cell nuclei visible within stratum comeum.
b) Connective tissue was infiltrated with varying numbers of
lymphocytes, plasma cells – chronic inflammatory cells.
c) Edentulous mucosa that had been stimulated with automatic
tooth brush for a period of a 4 weeks showed a generalized
increase in width of stratum corneum as compared to
unstimulated mucosa.
d) Stimulated mucosa also showed greater downward extension
of rete pegs than unstimulated mucosa.
Alveolar mucosa following the wearing of dentures for 3 months
19
Microscopy showed
a) Distinct increase in width of stratum corneum in specimens taken after
dentures had been worn. It was mainly orthoKeratin (hyperortho
Keratinization) but it was mainly orthoKeratin
(hyperorthokeratinization) but zones of parakeroatosis were
occasionally in evidence.
b) The stimulated and non stimulated mucosa presented an equal amount
of keratinization indicating that the stimulation of mucosa prior to
insertion of dentures had no relationship to subsequent tissue reaction.
c) Chronic inflammatory infiltration was minimal and connective tissue
collagen appeared dense and well formed.
Conclusion: These results are in some variance with those of ostland.
Since ostlund’s biopsies were taken in posterior palatal seal areas, the
changes may have been due to continuous pressure from denture base in
this region
Biopsy specimens of the ridge (as in Kapur’s study) presents a more
accurate picture of mucosal reactions to well-adapted dentures.
It keratinization is a mechanism where by tissues gain a greater
degree of protection against local irritation or trauma, then it appears a well
adapted denture base stimulates, the underlying mucosa to produce keratin.
20
Lack of inflammation in subjacent C.T. indicates that well adapted
denture is not an irritant.
Biomechanical principles of denture construction, its relation to
keratinization
- The purpose of this study conducted by markov was to see whether
amount of keratinization of edentulous ridges had something to do
with biomechanical qualities of dentures such as occlusion, stability,
vertical dimension of occlusion, palatal relief in maxillary denture.
- Smears were made from tissues scrapings collected from mucosa
and were stained and examined microscopically.
Conclusion: Fundamental biomechanical principles of good denture
construction are of paramount importance to the health of the mouth under
complete dentures.
The principles include,
1. Good Occlusion
2. Stability
3. Establishment of correct vertical dimension of occlusion
4. Palatal relief in the midline of maxillary denture.
21
Histological changes of oral mucosa under stress.
Significant changes occurred in the epithelium and connective tissue
depending on the amount of force applied.
Epithelium: under 5g/mm2 of force epithelium showed no cytologic
changes until a 4 hour load duration was reached.
At this stage intercellular and intracellular
Changes were seen
Changes consisted of vacuolization, decreased staining of
cytoplasm, cellular swelling and increased nuclear size.
The parts of epithelium in which these changes took place were the
middle and upper layers of stratum spinosum. Cells of basal layer appeared
unaffected.
At 6 hours duration, isolated damaged cells were more frequent.
Lamina propria and submucosa:
- Length and width of papilla appeared o be decreaed. Sometimes
they were completely obliterated.
- Submucosa of mucoperiosteum that contained major blood vessel
was completely occluded under heavy loading.
22
Conclusion: with relatively small occluding forces (0.29/mm2) the denture
supporting oral mucosa can be intruded upto 20% of resting thickness.
This indicates that impression materials must flow readily with
minimal pressure when an impression is made.
Denture inflammation and associated soft tissue changes
Response of human skin to everyday wear and tear is to become
keratinized and tough. The oral mucosa does not behave in the same
manner. Even the dentulous state, the mucosa demonstrates a low tolerance
to injury or irritation. This tolerance is further reduced if systemic disease
is present. The mucosa does not appear to be suited to complete-denture
load bearing rate and demonstrates little or no ability to respond to this
altered function.
It appears that if the tolerance of the mucosal tissues is exceed (eg.
By overextended border), injury and inflammation will result and the
denture cannot be worn.
If on the other hand, initial tolerance is high and the trauma
tolerable, a fibrous response is elicited and the residual ridge is replaced
with flabby hyperplastic tissue. Dentures are frequently worn over such
tissue without discomfort.
In between these two extremes be the majority of patients, in whom
chronic mucosal irritation proceeds quietly and painlessly.
23
It may be the character of the underlying bone that determines the
tolerance and response of denture bearing mucosa.
Bergman and associates showed a causal relationship between
trauma and denture stomatitis and that stomatitis was greater in those
patients in whom the residual ridge was displaceable.
Soft tissue to long term denture wearing which are frequently
encountered are
A. Soft tissue Hyperplasia
B. Denture Stomatitis
A. Soft tissue hyperplasia:
Hyperplasia of the soft tissue under or around a complete denture is
the result of a fibroepithelial response to complete denture wearing.
It is often asymptamatic and may be limited to the tissues in the
vestibule or palatal regions or it may occur on all or part of the residual
ridge.
i) Fibrous hypoplasia on ridge crest
- It consists of rolls of hyperplastic tissue under the denture base.
- Lesion is slow to develop and painless
24
- It may be due to bone resorption, with the lesion filling the space
under the denture base caused by bone loss.
- It is most often found on anterior part of maxillary ridge.
- A single maxillary denture opposed by natural lower anterior teeth
only will usually lead to formation of this tissue.
Treatment: Early stage
- Tissue recovery period may be all that is necessary.
Advanced stage (Tissues allow excessive denture movement)
- Surgical removal
- New dentures are constructed.
ii) Epulis fissurata:
- It is the hyperplasia occurring around the border of a denture.
- It occurs in the free mucosa lining the sulcus or at the junction of
free and attached mucosa.
- It develops as a result of chronic irritation from overextended
dentures.
- Clinical examination reveals, these tissue are hyperaemic and
swollen.
25
Treatment: Incipient-stage
- Impound dentures, until healing is complete
- Dentures may be worn with tissue conditioner after removal of the
irritant.
Chronic stage
- Surgical removal, Care must be taken to avoid excising any attached
mucosa.
- Dentures can be worn as surgical dressing
- Remake the prosthesis
The flabby hyperplastic tissues found in denture wearers should be
excised to minimize progressive resorption of residual ridges.
iii) Papillary hyperplasia:
- It is a granular type of inflammation seen in the palatal regions of
maxillary arch.
- It consists of numerous closely arranged papillary projections that
give the region a warty appearance.
- Factor most likely to be involved in the formation of papillary
hyperplasia is negative pressure. A similar condition exists when
relief chambers are made in palatal regions of max, denture. When a
26
palatal relief is provided, the edge of the relief not be detectable to
the finger tip.
- This condition is not reversible.
- This lesion is not innocuous. It has been suggested that these lesions
show precancerous tendencies designated pathologically as
pseudoepitheliomatous hyperplasia. Infrequent cases show frank
carcinoma.
- Some authors agree that this lesion is entirely innocuous and
malignancy does not develop from this hyperplasia.
Treatment:
- Surgical curettage and excised tissue for microscopic examination.
- Impound the dentures until healing is complete.
- Relief or remake the prosthesis.
- Ensure 8 hours of tissue rest per day with new dentures.
B. Inflammatory process under denture bases
i) Denture stomatitis:
- It is a chronic inflammation of the denture bearing mucosa. It may
be localized or generalized in nature.
- Various causes have been suggested.
27
Trauma from illfitting dentures, parafunctional habits, nocturnal
denture wear, hypersensitivity, infection with candida albicans, and poor
and hygiene.
- there is redness of tissue under the denture base, with pain, buring of
the tissues and metallic tastes in the mouth.
- The patient may be asymptamatic also.
- It tends to occur more frequently in the maxillary arch.
Treatment:
- Impounding dentures, so that tissues return to good health
- Maticulous oral hygiene procedures.
- Use of antifungal drugs. One nystabin tablet taken 3 times a day for
10-14 days is usually sufficient to control the infection. However
antifungal drugs are used only after confirming infection with
candida albicans.
- Use of 2% solution of chlorhexidine gluconate and gingival massage
with tooth brush.
- New well fitting dentures, after the conditions has subsided.
28
ii) Denture sore mouth:
When one encounters mucosal complaints that do not fit into the
general descreption of denture stomatitis, it is diagnosed as “denture sore
mouth” syndrome.
- It is diagnosed when the treatment methods just mentioned for
denture stomatitis is unsuccessful.
- It is probably the result of an underlying abnormal metabolic or
hormonal function, a nutritional deficiency.
Eg: Diabetes
- Symptoms are bizarre spectrum of itching, painful, irritated and
tender denture bearing areas. Clinical findings are usually negative
and in such patients mucosal tolerance is very low.
- Iron deficiency, insufficient protein and incomplete intestinal
absorption have been cited as contributory factors.
Treatment:
- Patients systemic status should be investigated
- Uprage quality of dietary intake
- Impound dentures, until inflammation subsides.
29
- Slow release hydrogen chloride in achlorhydric patient, ascorbic
tablets dissolved sublingually may be helpful.
- Therapy with liver fraction tablets may rejuninate the oral mucosa.
- Refit or remake the prosthesis
iii) Stomatitis venenata: Some people react differently to certain drugs
and materials than others. Reactions found in the mouth to drugs and
materials used have been termed “stomatitis venenata”.
- Since the introduction of methyl methacrylate for dentures, some
dentists have been concerned with possible sensitization of denture
wearness to this material.
- This material of the denture base is not a factor in mouth reactions.
This opinion is supported by the clinical observation than
duplicating the denture in a different material does not relieve the
symptoms.
- Turrell (1966), has concluded that the concentration of the residual
mnomer in a properly cured acrylic resin is unlikely to elicit a
clinical response.
iv) Monitasis:
- It is a disease entity and the occurrence of disease is related to the
pathologic activity of certain monila.
30
- It is generally agreed that, moniliasis is usually found in unclean
mouths or in debilitated patients. A systemic disease such as
diabetes and all unhygienic conditions will facilitate establishment
of moniliasis.
- All dentures materials have a significant degree of porosity. This is
true whether it is acrylic or metal. Monila which are very resistant
organisms, enter the porous structures and remain there for long
periods.
- Symptoms include redness with pain, swelling of denture supporting
tissues.
- It may also occur in the form of white lesions. The affected region
may resemble a wet cigarette paper adhering the mucosa anywhere
in the mouth. It can be carefully separated, leaving a raw red area
underneath.
(While lesion chronic hyperplastic condiasis, Associated dentures
stomatitis chronic atrophic condidiasis).
Treatment:
- Discarding the existing dentures.
- Application of gentian violet 3 times a week
- Suspension of mystatin held against oral lesions
31
- New dentures after disease has been controlled.
Mechanical irritants
Decubital ulcer: They result from pressures that exceed the physiological
endurance of the tissues and may be very painful.
- It is usually associated with insertion of new dentures.
- Initially there is only slight redness at the site of the ulcer with
minimum pain. If untreated the lesion becomes white due to
necrosis.
- This calls for scheduling the first adjustment appointment for 24
hours after insertion of new dentures. Additional visits should be
scheduled as needed.
Ulcerative lesions
Angular cheilitis:
- Dentures stomatitis is occasionally accompanied by angular
stomatitis which is also known as angular cheititis or perleche.
- Bilateral lesions develop at the angles of the lips. Deep fissures or
cracks may develop which appear ulcerated and an exudative crust
may be present.
- For several years the clinical condition was though to occur due to
reduction of vertical dimension of occlusion.
32
- Bergendal (1982) has shown that this condition is usually secondary
to a denture stomatitis and the result of candida infection from
contaminated saliva.
Treatment:
Angular stomatitis responds to antifungal therapy.
- Combined treatment approach to denture stomatits and angular
stomatitis is mandatory.
Non infections local diseases affecting oral cavity
White lesions
i) Leukoplakia:
It is used to describe an oral lesion with a white, leathery plaque that is
neither painful nor tender.
- Most common sites in edentulous mucosa are the buccal mucosa
and palate. Tobacco is often a causative factor.
- Biopsy is mandatory as leukoplakia may show dyskeratosis.
- With a negative biopsy report, the palate may be safely covered with
a well fitting denture and the primary cause should be eliminated.
33
ii) Lichen planus:
Most likely to occur on the buccal surfaces of cheeks, appearing as
fine lines and forming a lacy pattern which is not painful.
- Lichen planus of erosive type is of far greater concern to the dentist.
The lesions are very painful and occur bilaterally. Ballae may
develop with painful ulcerations.
- When the ulcerations are on denture supporting tissue, wearing of a
denture is virtually impossible.
Treatment: Topically applied corticosteroids have been recommended.
- Refitting or remaking the prosthesis after healing of the lesion.
iii) Hyperkeratosis
May be observed in the regions of low grade chronic trauma, in
particular at denture border, lesions may vary from mild keratosis to
leukoedema to frank leucoplakia.
Treatment: Removal of the irritant
Malignant lesions:
- Patients who need complete dentures are usually in the age group
that is most susceptible to oral cancer.
34
- So a routine recall of denture patients at 6 months interval is very
important.
- A biopsy should be made for any lesion that cannot be identified by
other means.
- Although tobacco is involved in the history of most of the
carcinomas, patients who do not use tobacco and have illfitting
dentures are seen with carcinomas.
- Hobock reported 560 patients with direct intraoral epidermoid
carcinomas. 204 more prosthesis and in 86 there was a direct
connector between irritant by the prosthesis and development of
carcinoma.
They had these factors in common.
a) They had worn illfitting dentures for years
b) The dentures had irritated or chafed the soft tissues for a prolongued
period of time.
c) An epidermoid carcinoma was found in the region covered by the
prosthesis or was found to be in contact with the prosthesis.
Influence of systemic and nutritional factors on oral mucous
membrane
35
Evaluating the systemic and nutritional factors before starting the
fabrication of denture may prevent failure of treatment.
- One of the most important and simple ways of evaluating these
systemic factors is by taking a proper history. This should include
personal, medical and dietary information.
A. Metabolic Diseases
All tissues in the body are influenced to some extent by hormones
and oral mucosa is no exception.
Diabetes mellitus: Chronic disorder of carbohydrate metabolism.
- Cause is either a deficiency of decreased effectiveness of insulin.
- In some instances antiinsulin hormonous may be produced in excess
which counter act the effects of insulin.
- Oral lesions are non specific. There is usually a reduced resistance
to trauma and healing is poor. Condidal stomatitis is often present.
- The increased susceptibility to infection is probably due to elevated
sugar content in tissues, alteration in amino acid pool unsetting
antibody production.
Treatment: Impounding of dentures until the blood sugar comes to normal
level.
36
- It impressions have to be made in these patients, a material which
has good flow must be used since the tissue rebounding is more in a
diabetic (MINIMAL PRESSURE TECHNIQUE).
Nutritional disorders
Insufficient of essential nutrients can result from defective diet,
malabsorption from gut, factors inhibiting blood transport, increased
metabolic need etc.
Vit A: It is a well established fact that vit A is concerned primarily with
process of differentiation of epithelial cells fail to differentiate. This means
cells in basal layer loose there specificity. Thus one of the basic changes is
keratinizing metaplisa of epithelial cells.
- The epithelium of the alveolar mucosa becomes acanthotic and in
prolonged deficiencies shows keratinization.
Most changes described are reversible with administration of vit A
to deficient patients.
B Complex group
i) Vit B2 (Riboflavin):
- Deficiency is associated with malabsorption, chronic infection and
other metabolic disorders.
- Tissues of ectodermal origin are mainly affected.
37
- Non specific glossitis and Angular chelitis are the features.
Treatment: Administration of B Complex vitamin will reverse this
condition.
Blood Dyscrasias
i) Iron deficiency:
- Oral manifestations are common and many patients complain of a
burning sensation especially on the tongue.
- Dry mouth, angular chelitis and rarely difficulty in swallowing are
seen.
- Epithelial atrophy will be most evident on the tongue giving it a
smooth glazed appearance.
- Infection with candida albicans producing angular chelitis is not
uncommon because of a defect in cell mediated immunity in
anaemia.
- Histological changes show atrophy of lingual papillae and chronic
inflammatory cell infiltration in connective tissue is used an increase
in size of nuclei is also seen.
Treatment:
1. Iron therapy
38
2. High protein diet
ii) Vit B12 deficiency: Pervicious anaemia is the commonest feature.
It is caused by lack of production of intrinsic factor in the stomach.
Features are similar to iron deficiency anaemia.
Treatment: Administration of Vit B12.
Ageing and oral mucosa
- Clinical picture is that of atrophy.
- Epithelial layers are less in number and the mucosa and submucosa
show decrease in thickness.
- The depleted repair potential renders the denture bearing mucosa
and basal seat friable and easily traumatized.
- Mucosa blanches easily.
- So there is a reduction in surface area of oral mucosa.
An atrophying denture-bearing mucosa is frequently encountered
during menopause.
Etiology: Reduction in estrogen output
Treatment: Replacement therapy can be helpful.
39
A change in tissue displaceability can also be demonstrated as being
a function of age. A longer period of time is needed for the recovery of
displaced mucosa in elderly people when compared with young adults.
40