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DESCRIBING ORAL SOFT TISSUE LESIONS
SITE or LOCATION
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This section will review the major soft tissue sites included in
an oral examination. The boundaries of each site and important anatomical
structures or landmarks will be emphasized.
When any abnormal change or lesion is detected, you must have a
clear understanding of its exact location. Proper recording of location
in the record will be mutually understood by any person reading
the chart.
The following descriptions lead you on a tour of the oral cavity
and its environment. Click on any underlined, blue
text to see a picture of what is being described. Practice locating
the areas described on a real person, for example a classmate.
THE ORAL CAVITY
 The oral cavity is subdivided by the alveolar processes
and the teeth
into the oral cavity proper and the oral vestibule.
The oral
cavity proper is the space enclosed within the alveolar
processes and the teeth.
The oral
vestibule is divided into a posterior and anterior section.
The anterior vestibule exists only with the lips closed.
The lips
are two highly sensitive, mobile folds composed of skin, muscle,
glands, and mucous membrane. They surround the oral orifice and
form the anterior boundary of the oral cavity.
- The upper
lip begins under the nose and extends laterally
toward the cheek to the nasolabial
sulcus. This depression begins just lateral to the nose
and passes downward lateral to the corner of the mouth or commissure.
- The lower
lip is bounded inferiorly by the prominent groove, the
labiomental sulcus
which tends to deepen with age. Laterally the lower lip may
have no distinct border, simply merging with the skin of the cheek.
- With increasing age, usually a furrow, the labiomarginal
sulcus develops at, or close to, the commissure and passes
in a convex arch toward the lower border of the mandible.
- The upper and lower lips are joined at the corners of the mouth,
the commissures
by a thin connecting fold well visible when the mouth is opened.
- The skin of the lips ends in a sharp, sometimes elevated, line.
The transitional zone between the skin and the mucous membrane
is known as the red zone or vermilion
zone or vermilion border.
- The vermilion zones end at an imaginary wet line where the lips touch
the labial surfaces of the anterior teeth when the lips are closed
lightly.
The color of the vermilion zone of the lips is
a unique human characteristic. The surface epithelium is non-keratinized,
and thus more translucent. The proximity to the surface of the
connective tissue papillae, plus the prominent, dilated, and thin
capillaries in them, accounts for the color.
The lips vary from pink to red. The more melanin
people have in their skin, the more this pigment tends to cause
the lips to take on a purple to brown color range.
The texture of the lips is normally smooth, soft, and resilient
with minimal fissuring in the young individual. With advancing age
and environmental influences, fissuring, thinning of the epithelium,
the vermilion zone color is altered and becomes more bluish to purple.
LABIAL MUCOSA
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Retraction of the lips away from the teeth and gingiva
exposes the labial mucosae.
The labial
mucosae are the rectangular areas between imaginary
lines drawn from the commissures to the distal surfaces of
the upper and lower cuspids, extending from the vermilion
border into the vestibule.
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- In the midline of the upper and lower vestibule, a fold of mucosa
extends from the mucosal surface to the alveolar mucosa. These
are the labial frenula.
- The color of the labial mucosa is normally pink to purple according
to the degree of melanin pigment present. The area is rich in
vascularity and minor salivary glands.
- Stretching of the mucosa will reveal varying degrees of prominent
vessels and ductal
orifices of the minor salivary glands. These glands can
sometimes cause the surface of the labial mucosa to be nodular
or granular.
- The texture of the labial mucosa is normally smooth, soft, and
elastic with the mucosa fixed to the underlying muscle fascia.
- We will combine the oral vestibule and buccal mucosa
since they are confluent, and many lesions involve both
sites.
- The buccal mucosa is bounded above and below by the reflection
of the mucous membrane onto the alveolar process.
- The buccal
mucosa is the entire lining mucosa of the cheeks which
is confluent anteriorly with labial mucosa and commissure
and extends posteriorly to a fold, the pterygomandibular
raphe.
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The pterygomandibular
raphe is a tendinous strip which attaches to the hamular process of the pterygoid plate
above and behind the retromolar
triangle.
BUCCAL MUCOSA AND VESTIBULE
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The buccal mucosa has one important landmark, the parotid papilla which varies considerably
from one person to another. In some people it may have a prominent
elevation or it may be just a slight indentation. This represents
the orifice of Stensen's Duct.
Although the vestibular sulcus or fornix and buccal
mucosa are confluent, the vestibular sulcus is the
horseshoe-shaped furrow formed by the reflection of the superior
and inferior borders of the buccal mucosa and labial mucosa.
This area is sometimes referred to as the mucobuccal fold,
the buccal gutter, the vestibule, and other terms like
"that place between the lips and the front teeth."
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Approximately at the middle of the buccal mucosa
in most individuals there is a longitudinal fold of tissue extending
from a point near the commissure posteriorly to close to the pterygomandibular
raphe. This is known as the linea alba buccalis or occlusal line.
The buccal mucosa contains primarily muscle,
the buccinator
and masseter. Posteriorly, it contains the parotid gland and varying amounts
of fat which from the buccal fat pad. Scattered throughout
the buccal mucosa are numerous minor salivary glands; it
may also contain sebaceous glands;
The texture of the buccal mucosa is very
similar to the labial mucosa. The mucous membrane is soft and
fixed to the inner fascia of the buccinator muscle. In some people
the numerous mucous and mixed glands in the submucosal tissue
will result in a nodular texture.
There are frequently prominent sebaceous glands or Fordyce's granules
adjacent to the commissures and extending to the molar region.
These may feel granular to touch.
The buccal
fat pad can vary considerably in the degree of prominence.
It usually decreases in prominence from childhood into adult life.
It is more easily palpated than visualized, and it lies beneath
and distal to the parotid papilla.
The vestibular
sulcus may have several folds of tissue traversing laterally
between the alveolar mucosa and the buccal mucosa. These are the
lateral frenula
or buccal frenula, usually present in the area of the
cuspids or bicuspids in both the maxilla and mandible.The mucous
membrane of the vestibular sulcus is thin, and the many small
blood vessels present are easily seen.
The submucous tissue attaching the mucous
membrane to muscles and bone is very loose, allowing for the
marked mobility of the lips and buccal mucosa. This mobility decreases
in the molar region as does the amount of this loose connective
tissue.
ALVEOLAR MUCOSA AND GINGIVA
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From the vestibular sulcus the mucous membrane continues
over the tooth-supporting bone to the cervical areas of
the teeth.This area may be subdivided into two zones. The
zone adjacent to the vestibule is the alveolar mucosa. The zone
adjacent to the teeth is the gingiva.
The alveolar mucosa and gingiva are separated
from each other by a sharp scalloped line which parallels
the free margin of the gingiva, the mucogingival
junction.
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- The gingiva is subdivided into the attached and the free gingiva. The free gingiva extends
into the interdental spaces as the gingival papilla and
ends in a knifelike edge closely adapted to the teeth circumferentially.
- The gingival sulcus is the crevice between the free marginal
gingiva and the point of attachment to the teeth at or near the
cemento-enamel junction.
HARD AND SOFT PALATE
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The roof of the oral cavity proper is formed by the
hard palate anteriorly and the soft
palate posteriorly.
The hard palate extends peripherally to
become the palatal gingiva. At the posterior
end of the hard palate, there are frequently two small depressions,
the fovea palatinae. The hard palate
terminates at an imaginary line running through, or
close to the fovea palatinae.
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In the midline there is a narrow elevated ridge,
the palatine
raphe. It extends from a small projection, the incisive papilla posteriorly over
the entire length of the hard palate.
On the anterior hard palate radiating from the
incisive papilla and anterior portions of the palatine raphe are
irregular branching ridges termed the palatine
rugae. The mucous membrane covering the anterior hard
palate is keratinized and firmly attached to the underlying
bone and therefore is not movable. The peripheral zone is firm but
more resilient toward the gingiva.
On the posterior hard palate, the lateral portions
between the palatine raphe and the gingiva contain numerous mucous
glands, nerves, and blood vessels in the submucosa. This area
may be soft to palpation due to the fat and mucous glands.
Posterior to the last molar tooth the hard palate
mucosa fuses peripherally with the vestibular gingiva and posteriorly
with the pterygomandibular raphe. This prominent ridge is the alveolar tuberosity. The concavity
distal to the tuberosity is the hamular
notch.
The soft palate begins posteriorly to the imaginary
line running laterally near the fovea palatinae. It is a thick fold
of mucous membrane which extends posteriorly and downward to end
as the uvula. This fold of mucous membrane
provides and important boundary between the oral cavity, the
nasal cavity, and the oropharynx. Laterally, the soft
palate extends downward to fuse with the pillars of the fauces.
The soft palate mucosa is thin and nonkeratinized.
The prominent vascularity gives a slightly darker red color
than the hard palate. The smooth texture may be interspersed with
prominent ductal orifices from the mucous glands.
OROPHARYNX AND PHARYNX
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The junction between the mouth and the oropharynx is a narrow passageway
bounded above by the soft palate, laterally by the anterior
and posterior pillars of the fauces, and below by the tongue. |
The pillars
of the fauces are two vertically directed projections
which descend from the soft palate. The anterior pillar is the
glossopalatine arch and the posterior pillar of the
pharyngopalatine arch. These arches form a somewhat triangular
space between them called the tonsillar niche or tonsillar
fold, which contains the palatine tonsils. The anterior
pillar ends at the lateral part of the base of the tongue.
The posterior pillar gradually flattens out on the lateral wall
of the pharynx.
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- The pharynx is a mucous-membrane lined tubular
space subdivided for descriptive purposes into three parts.
From above downward, these are the nasopharynx the
oropharynx and the laryngopharynx.
- The pharynx consists of a posterior wall and two lateral
walls all of which are continuous and fuse anteriorly
on each side with the posterior pillars of the fauces.
- The mucosal surface of the fauces and oropharynx is
normally moist. The vascularity may be very prominent
and vascular dilation can influence the degree of redness
of this area.
- The soft, smooth surface mucosa may show small elevated
aggregates of lymphoid tissue scattered randomly
over the oropharynx.
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THE TONGUE
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The tongue
is a mobile, muscular organ attached with its base and central
part of its body to the floor of the mouth. The body of
the tongue makes up the horizontal anterior two thirds
of the organ. It has two surfaces, the dorsal or dorsum being the superior
surface and the ventral
being the inferior surface.
The base and body are separated by a shallow V-shaped groove,
the terminal sulcus
which varies in prominence among individuals.
The dorsum is marked by a slight midline groove, the median
sulcus. This runs from the anterior end to a depression
near the apex of the terminal sulcus, the foramen
cecum.
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The mucosa of the dorsum forms numerous small elevations
called papillae,
giving the tongue a very characteristic, roughened surface.
There are four types of papillae, the filiform, the
fungiform, the foliate and the circumvallate.
- The filiform
papillae are the most numerous and these are slender,
conical structures, pink in color, that cover the dorsal surface.
The degree of keratinization of the many filiform papillae
and the presence of chromogenic bacteria are the major
causes of color variation on the dorsal surface.
- The fungiform
papillae are less numerous but are scattered widely along
the sides and at the apex of the tongue. They are shaped
like small mushrooms with a rounded surface and deeper red color
than the filiform papillae.
- The circumvallate
papillae are the largest, but fewest in number, and are
prominent due to their deep red color. They form a V-shaped line
just anterior and parallel to the terminal sulcus.
- At the posterior part of the lateral border, there may be irregular,
elevated folds of mucosa, the foliate
papillae. The prominence of these structures exhibit a
wide range of variation from one individual to another.
The base
or root of the tongue makes up the posterior one-third and is
the more fixed, vertical part of the organ. It is more closely
associated with the oropharynx than with the oral cavity proper.
The mucous membrane covering the base is thick and presents an irregular,
rough surface due to underlying prominences of lymphoid tissue.
The ventral surface is smooth with a thin mucous
membrane, tightly adherent to the tongue musculature. The mucosal
surface reflects onto the floor of the mouth. In the midline, there
is a distinct, elevated mucosal fold, call the lingual
frenum which attaches the free portion of the tongue to
the floor of the mouth. The normal color varies from pink to red.
There may be large, prominent veins on this surface which will cause
a bluish color.
The sides
or lateral margins of the tongue are outlined separately
because there are a relatively significant number of diagnoses that
only occur in this location. This area is approximately one centimeter
wide along the anterior two thirds of the tongue. On the lateral
borders, there is usually a sharp contrast to both texture and color
where the dorsum and ventral surface merge. There is a deeper red
as the papillae end and the smooth ventral surface begins.
FLOOR OF THE MOUTH
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The inferior boundary of the oral cavity proper is
the floor of the mouth.
When the tongue is elevated, there is a U-shaped space which
extends, laterally and anteriorly from the tongue to the alveolar
mucosa of the mandible. This represents the floor of the mouth.
- The mucosa is nonkeratinized, soft, and smooth except
for the sublingual ridges.
- The vascular network may vary in prominence.
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A number of important anatomic structures
are located beneath the surface in the lateral spaces formed
by the lingual frenulum. |
Each of these lateral spaces contains the genioglossus
and geniohyoid muscles the sublingual gland and
its ducts.
These lateral spaces also contain the upper portion
of the submandibular
glands and their ducts, nerves, lymph nodes, and abundant
fat tissue.
The underlying important structures influence the
surface features of the floor mucosa. The sublingual glands and
the ducts of the submandibular glands cause bilateral elevations
close to the lingual frenulum which are called the sublingual
folds or ridges.
Each sublingual fold ends anteriorly in a small
round papilla called the sublingual
caruncle. These caruncles contain openings for the flow
of secretions of the submandibular and sublingual glands.
This concludes the normal oral soft tissues that the dentist is
expected to include in an oral examination. This information will
help you locate and describe accurately any abnormal change found
during an examination.
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