This document provides information on various cysts and tumors that affect the jaw bones. It begins with an introduction and outlines the topics to be covered, including odontogenic cysts, non-odontogenic cysts, and cyst-like lesions. Specific cysts discussed in detail include radicular cysts, dentigerous cysts, keratocystic odontogenic tumors, calcifying odontogenic cysts, nasopalatine duct cysts, dermoid cysts, and simple bone cysts. For each cyst, the document provides information on pathogenesis, clinical features, radiographic features, and sometimes treatment.
2. Introduction
There are variety of cysts and tumors that affect the
osseous marrow and cortex of the jaw bones, which
are uniquely derived from the tissues of developing
teeth.
4. Odontogenic Cysts
A cyst is a pathologic cavity filled with fluid, lined by
epithelium and surrounded by a definite connective
tissue wall.
The cystic fluid is either secreted by the cells lining
the cavity or derives from the surrounding tissue
fluid.
6. Odontogenic Jaw Cysts
Odontogenic cysts arise from tooth development
epithelium.
Odontogenic cysts are true cysts occurring in the
jaws. They arise from stimulation of epithelium
left over from tooth development.
7. Clinical Features
Cysts occur more often in the jaws than in any other
bone because most cysts originate from the numerous
rests of odontogenic epithelium that remain after
tooth formation.
swelling,
lack of pain (unless the cyst becomes secondarily
infected or is related to a nonvital tooth), and
missing teeth, especially third molars.
8. Radiographic features:
LOCATION:
Cysts may occur centrally (within bone) in any location
in the maxilla or mandible but are rare in the condyle and
coronoid process.
Found most often in the tooth~bearing region.
In the mandible, they originate above the inferior
alveolar nerve canal.
Odontogenic cysts n1ay grow into the maxillary antrum.
cysts also originate within the antrum.
A few cysts arise in the soft tissues of the orofacial
9. PERIPHERY
Cysts that originate in bone usually have a
periphery that is well defined and corticated
(characterized by a fairly uniform, thin,
radiopaque line).
However, a secondary infection or a chronic
state can change this appearance into a thicker,
more sclerotic boundary.
10. SHAPE
Cysts usually are round or oval, resembling a fluid-
filled balloon.
Some cysts may have a scalloped boundary.
11. INTERNAL STRUCTURE
Cysts often are totally radiolucent.
However, long-standing cysts may have dystrophic
calcification, which can give the internal aspect a sparse,
particulate appearance.
Some cysts have septa, which produce multiple
loculations separated by these bony walls or septa.
Cysts that have a scalloped periphery may appear to have
internal septa.
Occasionally the image of structures that are positioned on
either side of the cyst may overlap the internal aspect of the
cyst, giving the false impression of internal structure.
12. EFFECTS ON SURROUNDING STRUCTURES
Cysts grow slowly causing displacement and
resorption of teeth.
Cysts can expand mandible, usually in a smooth,
curved manner, and change the buccal or lingual
cortical plate into a thin cortical boundary.
Cysts may displace the inferior alveolar nerve canal
in an inferior direction or invaginate the maxillary
antrum, maintaining a thin layer of bone that
separates the internal aspect of the cyst from
maxillary
antrum.
16. Radicular cyst ( Apical Cyst , Periapical
Cyst, Apical periodontal cyst)
A radicular cyst is a cyst that
most likely results when rests
of epthielial cells in the
periodontal ligament are
stimulated by inflammatory
products from a non vital
tooth.
17. Apical Cyst (Radicular Cyst, Periapical Cyst)
Features
It develops in a preexisting
periapical granuloma.
It has similar radiographic
appearance as the periapical
granuloma:
round or oval radiolucency
well defined
well corticated if longstanding
The adjacent teeth can be displaced
but rarely resorbed.
20. Residual Cysts
It is a radicular cyst remaining
after the tooth has been
extracted.
Usually asymptomatic. Usually
small size (less than 1 cm in
diameter).
Unilocular, round or oval, well-
defined, usually well-corticated.
It can cause bone expansion and
displacement of the adjacent
teeth.
21. Dentigerous Cyst (Follicular Cyst)
A Dentigerous cyst is a
cyst that forms around
the crown of an
unerupted tooth.
22.
23. Dentigerous Cyst (Follicular Cyst)
It arises in the follicular region of
unerupted permanent tooth.
It develops after fluid accumulates
between the remnants of enamel
organ and the tooth crown.
Usually adolescents, 20-40 years old.
Most common sites: mandibular
third molar, maxillary canine,
maxillary third molar.
Unilocular radiolucency, well-
defined, often corticated, associated
with the crown of an unerupted and
displaced tooth.
Large cysts tend to expand the outer
plate (usually buccally)
26. Odontogenic Keratocyst (Keratocyst,
Keratinizing Cyst)
Features
It is lined by keratinizing
epithelium.
It is usually located in the
mandible (posterior body and
ramus region).
most develop during the
second and third decade.
It can become very large. It
extends along the body of the
mandible causing minimal
mediolateral expansion.
27. Odontogenic Keratocyst (Keratocyst,
Keratinizing Cyst)
Features
Unilocular (often with
scalloped margins) or
multilocular (more often in
larger lesions)
Smooth margins, well-defined,
often well-corticated.
Tendency for recurrence
after inadequate surgery.
Adjacent teeth: vital, rarely
resorbed.
28.
29.
30.
31. Possible factors contributing to
recurrence
Keratocyst fibrous walls are thin and fragile
satellite daughter cysts
The lining is weakly attached to the fibrous wall readily
separates from it and may not be entirely removed with it.
38. Lateral Periodontal Cyst
Lateral Periodontal
Cyst are thought to
arise from Epithelial
rests in periodontum
lateral to the tooth
root.
39. Lateral Periodontal Cyst
It is a developmental odontogenic cyst.
It arises from remnants of the dental
lamina or from the reduced enamel
epithelium.
Common site: Along the lateral surface
of the root of vital tooth. Usually in
mandibular premolar/canine region.
Usually asymptomatic.
Small size (less than 1 cm in diameter).
Unilocular, round or oval, well-defined,
usually well corticated radiolucency.
40. Calcifying odontogenic cyst
COC are uncommon, slow growing benign
lesions.
The WHO categorized COC as benign tumor.
This lesion may manufacture calcified tissue
identified as dysplastic dentin, and in some
instances the lesion is associated with an
odontoma.
This lesion also sometimes gives an appearance
of ameloblastoma although it does not behave
like one.
41. Calcifying odontogenic cyst
Clinical features:
Age: 9-90 years.
Sex: M=F
Site: Anterior part of jaws.
On inspection: Solitary swelling, anterior to molars
with the color same as adjacent gingiva, shape is
roughly oval of variable size, surface over the
swelling may be smooth.
On palpation: Non-tender, hard on palpation
(eggshell crackling or soft) buccal and lingual
expansion, perforate the cortical plate and extend
into the soft tissues.
Displacement of the teeth has been described.
42. Calcifying odontogenic cyst
Radiographic features:
Nature: Radiolucent and radiopaque.
Site: Anterior part of jaws.
Shape: Oval or round.
Number: Solitary.
Outline: May be regular in few and in few other
irregular.
Border: Well defined.
Contents: radiopacities within radiolucency.
Additional features: Resorption of adjacent roots.
When associated with an interrupted tooth
displacement of teeth is seen.
47. Nasopalatine duct cyst
Synonyms: Median anterior maxillary cyst, incisive
canal cyst.
Most common type of maxillary developmental cyst.
Develop from remnant of the Nasopalatine duct.
48. Nasopalatine duct cyst
Clinical features:
Age: 4th
to 6th
decades of life.
Sex: Male to female ratio 3:1.
Site: Maxillary anterior region. Posterior to palatine
papilla.
Symptoms:
Asymptomatic swelling (dull intermittent pain).
Burning sensation or numbness over the palatal
mucosa.
Fluid discharge form oral cavity with a salty taste (due
to mucoid secretion).
Foul taste.
49. Nasopalatine duct cyst
Sign: Solitary swelling
on anterior palate
posterior to palatine
papilla, blue in color if
the cyst is near the
surface, the deeper cyst
is covered by normal
appearing mucosa,
round or oval, margins
are considerably well
defined, surface over the
swelling may be normal
or ulcerated from
masticatory trauma.
50. Nasopalatine duct cyst
If the cyst expands, it may penetrate the labial plate
and produce a swelling below the maxillary labial
frenum.
Palpation: Tender or non-tender fluctuant swelling
and in some cases through and through fluctuation
may be elicited between labial and palatal swellings.
52. Nasopalatine duct cyst
Radiographic features:
Nature: radiolucent
site-between the central incisor,
size varies from 17 to 22 mm,
shape is heart shape because anterior nasal spine is seen
over the superior portion of the cyst as a radiopaque shadow
single in number
well defined border and regular outline.
Additional features: Divergence of roots of central
incisors, occasionally root resorption seen from lateral
respective, the cyst may expand the labial cortex as well as
palatal cortex. Floor of the nasal fossa may be displaced in a
superior direction.
54. Nasolabial cyst
Now it has been suggested that the cyst arises from the
remnants of nasolacrimal duct, or from epithelial rest
in fusion line of medial nasal, lateral nasal and
maxillary processes.
Clinical features:
Age: Wide age distribution for 12-75 years with a peak
frequency in the 4th
and 7th
decades.
Sex: Female preponderance F: M=3.7:1.
55. Nasolabial cyst
Symptom:
Most frequent symptom is swelling.
Pain.
Difficulty in nasal breathing.
Difficulty in wearing upper denture.
Infected cyst discharge from nose.
Signs: Cysts grow slowly producing a swelling of lip. They
fill out the nasolabial fold, flaring of the alae, distort the
nostril and produce a swelling of the floor of the nose.
Anteriorly they form a bulge in the labial sulcus. The
cysts are fluctuant on bimanual palpation.
56. Nasolabial cyst
Lesion is located adjacent to the
alveolar process above the
apices of incisors. Because it is
soft tissue lesion, radiograph
may not show any detectable
changes
57.
58. Dermoid cyst
Dermoid cysts are a cystic form of a teratoma
thought
to be derived from trapped embryonic cells.
The resulting cysts are lined with epidermis and filled
with keratin or sebaceous material (and in rare cases
with bone, teeth, muscle, or hair, in which case they
are properly called teratomas.
59. Dermoid cyst
Clinical features:
1) Age: Any age Mostly 15 and 35 years
2) Sex: No predilection.
Site: floor of the mouth and sub-mental areas.
Slow growing or sudden in onset.
Lie above (tongue is displaced superiorly ) or below
the mylohyoid muscle (soft tissue in the sub-mental
region is distended).
Non-tender
Size : can grow to several centimeters in diameter,
Color superficial- yellow to white, its surface is
smooth, and non ulcerated unless traumatized.
Consistency: soft to firm; it may be fluctuant and
frequently is rubbery or cheesy
60. Radiographic features:
Because dermoid cysts are soft tissue cysts, diagnostic imaging
is best accomplished by CT or MRI.
The periphery of the lesion usually is well defined by more
radiopaque soft tissue of this cyst compared with surrounding
soft tissue, as seen in CT scan.
Dermoid cysts seldom have any internal mineralized structures
when they occur in the oral cavity
If teeth or bone form in the cyst, their radiopaque images, with
characteristic shapes and densities, are apparent on the
radiograph
61.
62.
63. Simple bone cyst
Syn: Traumatic bone cyst/ extravasation cyst,
progressive bone cavities/solitary bone cyst.
Definition; SBC is a cavity within bone that is lined
by connective tissue. It may be empty or it may be
filled with fluid.
Since this cyst has no epithelial lining it is called as
false cyst.
64. Simple bone cyst
Pathogenesis: Pathogenesis is unknown. According
to Olech et al these cysts resulted from injury to and
hemorrhage within the bone of the jaw.
Hemorrhage was alleged to be followed by failure of
organization of the clot and of bony repair.
65. Simple bone cyst
A common form of treatment for simple bone cyst is
to open them and to allow bleeding within the jaw
can both cause simple bone cyst and also cause them
to resolve.
66. Simple bone cyst
Clinical features:
Age:10-20yrs mean age of 17 years.
Sex: Male to female ratio is 3:2.
Site: Posterior mandible.
Symptoms: Slowly enlarging swelling may be the complaint.
Pain or tenderness if cyst is secondarily infected.
Usually this is identified on routine radiographic
examination.
Teeth in the affected region will be vital.
There is no significant incidence of pathological
fracture.
When aspiration is productive, usually only a few
millimeters of straw colored or serosanguinous
(composed of serum and blood) fluid are obtained.
67. Simple bone cyst
Radiographic appearance:
Radiolucent lesion
Site: posterior region of mandible
Shape : round or oval, solitary
Outline: Irregular or scalloped
Border is usually ill defined.
Resorption of roots and displacement of teeth are
rare.
