1. The document discusses various anatomical structures and pathologies that can appear as radiolucencies near the apex of teeth. True periapical radiolucencies contact the tooth apex, while false ones are caused by other bony lesions and may shift with angled radiographs. 2. Common true periapical lesions include granulomas, cysts, abscesses, and scars. Granulomas appear as small radiolucencies, while cysts are larger. Abscesses show diffuse radiolucency and clinical symptoms. Scars remain stable over time. 3. Management depends on the diagnosis and may include root canal treatment, surgery, antibiotics, and monitoring for regression.

1. ANATOMIC PERIAPICAL
RADIOLUCENCIES(FALSE)
TRUE PERIAPICAL
RADIOLUCENCIES
Marrow spaces and
hematopoietic defect of the
jaws
Sequelae of pulpitis
Granuloma
Dental papilla Radicular cyst
Maxillary sinus Scar
Incisive foramina and canals Chronic and acute
dentoalveolar abscess
Nasolacrimal duct Surgical defect
Naris Cholesteatoma
Greater palatine foramen Osteomyelitis
Mental foramen Dentigerous cyst
Submandibular fossa Periapical cementoma
Mandibular canal Periodontal disease
Traumatic bone cyst
Nonradicular cyst
Malignant tumors

2.  TRUE PERIAPICAL RADIOLUCENCIES represents
lesions that are truly located in contact with apex of a
tooth
 Their shadow cannot be shifted from the periapex by
taking additional radiographs at different angles
• FALSE PERIAPICAL RADIOLUCENCIES Are produced
by anatomic cavities or lytic bony lesions that donot
contact the apex of a tooth
 The radiolucent shadows may be shifted from the
periapex by taking additional radiograph at different
angles

4. INCISIVE
FORAMEN
MENTAL FORAMEN
MAXILLARY SINUS

5. SUBMANDIBULAR GLAND FOSSA
GREATER PALATINE FORAMEN

6. MANDIBULAR CANAL
NASAL FOSSA

8.  Most common type
 Result of a successful attempt by the periapical tissues to
neutralize and confine the irritating toxic
products(prostaglandins,kinins,lysosomes and endotoxins)that
are escaping from the root canal
 Low grade inflammation
 Microstructure consists of proliferating endothelial
cells,capillaries,young fibroblasts,a minimal amount of collagen and
chronic inflammatory cells
 FOUR TYPES ON BASIS OF HISTOPATHOLOGY
 Exudative
 Granulomatous
 Granulofibrous
 fibrous

9.  Radiographically,lesion is a rather well circumscribed
radiolucency somewhat rounded in shape and surrounding
the apex of the tooth
 May or may not have a thin
radiopaque(hyperostotic)border.
 Radiographs reveal presence of deep restorations,extensive
caries,fractures or a narrower pulp canal
 Periapical radiolucency of diameter less than 1.6cm is
considered as periapical granuloma
 Electrical and thermal pulp testing will usually indicate
that pulp is non-vital

10. Tooth is completely asymptomatic
Absence of sensitivity to percussion
Crown may have darker colour than of its neighbours
because of blood pigments that have diffused into
empty dentinal tubules
Swelling and expansion of cortical plate is unusual
since they rarely reach a size to produce such an effect

11. GRANULOMA
Small round or oval
radiolucency <1.6cm in
diameter surrounding apex
of tooth with or without
well-circumscribed borders

12.  Second most common
 Inflammatory cyst
 Origin from cell rest of Malassez
 Orginate in pre-existing periapical granuloma
 As the masses of proliferating epithelial nests increase in size,
the central cells start to degenerate and liquefy
 Leads to liquid-filled cavity lined with epithelium
 Cysts continues to grow because of a combination of factors
1. The products from the cell lysis are probably irritating and may
provide growth stimulus
2. Epilthelial cells discharged into the cyst lumen increase the
protein content and hence the osmotic pressure of cyst

13. fluid leading to more water diffusion into lumen
3. The pressure exerted by the enlarging cyst on the alveolar
bone induces osteoclastic action and resorption of the
periapical bone
 FEATURES
 The more pronounced the hyperostotic border of the
lesion, the more likely is the lesion to be a cyst
 Should measure atleast 1.6cm in diameter
 An untreated cyst may slowly enlarge and cause
expansion of cortical plates,observed clinically as dome
like swelling on the alveolus over the periapical region of
involved tooth

14. The swelling may develop on either the buccal or lingual side
of alveolar process and will be covered with normal-appearing
Mucosa
Initially,bony hard to palpation,but later it may demonstrate
A crackling sound(crepitus) as cortical plates become thinned
Usually,the cortical plates remain intact
Large cysts may involve a complete quadrant with some of the
Teeth occasionally mobile and some of the pulps non-vital
Root resorption is also seen
the causative tooth and the alveolar swelling are painless in
case of sterile cysts,however when infected develops pain

15. RADICULAR CYST
Round or oval well-
defined radiolucency
>1.6cm in diameter

16.  Well defined radiolucency at apex of untreated
asymptomatic tooth with nonvital or diseased pulp:90%
cases dental granuloma or radicular cyst(1.6cm or
more=radicular cyst)
 PERIAPICAL SCAR: if well sealed, persistent
asymptomatic nonenlarging radiolucency associated with
teeth which received non-surgical endodontic treatment
for granuloma and cyst
 Asymptomatic radiolucency persisting after root resection
can be either a scar or surgical defect
 PERIAPICAL CEMENTOMA: pulp is vital and mostly
involve lower teeth ,mostly incisors
 TRAUMATIC BONE CYST :pulp is vital and 90% occurs in
mandible(molar,premolar,incisor region)

17.  Extraction
 Conservative root canal therapy
 Cyst respond well to nonsurgical endodontic treatment:2
theories
1. Instrumentation beyond apex permits the cyst to drain into
canal
2. When root canal is sealed the irritating products from
gangrenous pulp are no longer present and inflammation
subsides
 Biopsy via buccal window to determine the nature of lesion
 Apical curettage or root resection procedure if 2cm or
larger(radicular cyst)
 Retrograde filling and periapical curettage if root canal is
nonnegotiable

18. For large radicular cysts with considerable bone loss
Surgical enucleation
Restoration of defect with graft,preferably autogenous
bone
Marsupialization
Decompression
Decompression with delayed enucleation
Creation of common chamber with maxillary sinus or
nasal cavity
Sequential post surgical radiographs to ensure
regression of defect

19.  Composed of dense fibrous tissue
 Situated at periapex of a pulpless tooth in which
rootcanals have been filled
 Represented by granuloma,cyst or abscess whose healing
has stopped in the formation of dense scar tissue(cicatrix)
rather than bone
 In some instances,granulation tissue during resolution
slowly organizes with production of more collagen fibers
leading to dense collagenous connective tissue scar
:permanent and radiolucent
 Microscopically : few spindle shaped fibroblasts scattered
throughout dense collagen bundles
 Scarring periapical granuloma: relatively young ,less dense
scar experiencing intermittent inflammation

20. Well circumscribed radiolucency that is more or less
round resembling granuloma and cyst radiographically
but usually smaller
Asymptomatic
Occurs mostly in anterior region of maxilla
Majority of involved teeth have been endodontically
treated
MANAGEMENT
No treatment required

21. SCAR
Well defined borders
Remain constant in size
over years
asymptomatic

22.  Primary or neoteric abscesses: associated with teeth that have
not developed apparent radiolucent lesion
• Acute apical periodontitis/acute periapical abscess
 Secondary or recrudescent abscesses: develop in a previously
existing asymptomatic periapical radiolucent lesion
PRIMARY ABSCESS:
 Radiographically normal periapical region
 Occurs due to rapid spread of virulent bacteria from canal to
periapical tissues
 Very sensitive tooth and perhaps alveolar swelling
 No resorption of bone due to sudden onset and course
 Frequent swelling of the periodontal ligament which force the
tooth out slightly from its socket leading to an increased
periodontal ligament space around entire root

23. Chronic or acute type depending on
1. Number and virulence of invading organism
2. Resistance of host
3. Type and timing of treatment
 MICROORGANISMS: Streptococci,Staphylococci,
Bacteroides, Peptococcus, Peptostreptococci,
Actinomyces, Eubacterium, Fusobacterium

24.  RADIOGRAPHIC
 periapical radiolucency is a feature of secondary abscess
 Radiolucency may vary in size
 Depending on duration ,acuteness and chronicity,margins
may be well defined with hyperostotic border to poorly
defined in chronic cases
 Sometimes present as blurred area of lessened density than
surrounding bone
 Deep restorations, caries, narrowed pulp chamber or canals
: suggestive of non-vital pulp
 Roots may show resorption of apex

25. APICAL ABSCESS
Diffuse
radiolucency in
periapical region of
affected tooth

26. MICROSCOPICALLY
Central region of necrosis with dense
accumulation of PMN leukocytes surrounded by
inflamed connective tissue wall of varying thickness
CLINICALLY
Very painful to percussion
No response to electric pulp tests
Ice application relieves pain while heat aggravates
the pain
Progression leads to penetration of cortical plates,
formation of space infection and sinus tracts
Warmth of overlying skin or mucosa
Elevation of systemic temperature

27. A small proliferation of granulomatous tissue
often forms on the surface referred to as parules
pain subsides when drainage is established
COMPLICATIONS
Osteomyelitis
Septicemia
Septic emboli
Ludwig’s angina
Cavernous sinus thrombosis

28.  Drainage established by opening pulp chamber and passing file
through canal into periapical region
 If not possible,TREPHINATION procedure done:opening made
through mucosa and bone to abscess at apex
 A THROUGH AND THROUGH DRAIN may be placed in abscess
in case of vestibular and lingual space infection along with
frequent irrigation with H2O2 solution and saline
 sample of pus for culture and sensitivity test
 Penicillin therapy(not less than 500mg qid for atleast 5
days)/erythromycin
 Antibiotics before extraction
 In case of draining sinus,exact location of the abscess can be
located by inserting a gutta-percha cone to the extent of sinus
and making radiograph of that area

29.  Occurs in patients with periapical abscess with underlying
systemic disease or who have received large doses of
radiation therapy
 Defined as an infection of bone that involves all 3
components: periosteum, cortex, and marrow
 Osteitis: localized ; Osteomyelitis: diffuse
 ACUTE OSTEOMYELITIS: Similar to acute primary
alveolar abscess, rapid onset and course, no bone
resorption, thus radiolucency may not be present
 CHRONIC OSTEOMYELITIS: low –grade infection of bone
if untreated leads to extensive bone destruction,produces
radiolucent lesion

30. Chronic osteomyelitis demonstrate 4 distinct
radiographic picture
1. Completely radiolucent
2. Mixed radiolucent and radiopaque
3. Completely radiopaque
4. Garre’s osteomyelitis
FEATURES
 Seldom observed in maxilla because of rich blood
supply
 Tooth associated: non-vital pulp,may be sensitive
to percussion and previously associated with
periapical abscess
 Periapical radiolucency somewhat rounded in
shape with poorly defined and ragged borders

31. Sequestrum present as radiopacity within a
radiolucency
Draining tract may be seen as radiolucency through
cortical plate beneath sinus opening on mucosa or
skin
Fever,malaise
Swelling on bone and mucosa around osteomyelitis

32. OSTEOMYELITIS
MOTH-EATEN
RADIOLUCENCY

33.  If area of bone destruction is large and region is not
painful:Eosinophilic granuloma:biopsy
 If only alveolar portion of jawbone is infected:Alveolar
abscess
 If tooth suspected is in fracture line or if an uncontrolled
systemic disease is present: Chronic Osteomyelitis
 Paget’s disease: several bones with classic wool appearance
MANAGEMENT
 Best treatment will be to extract the offending tooth rather
than conserving it by endodontic procedure

34. Arise from elements in periodontal ligament
Other names:
1. Periapical cemental dysplasia
2. Periapical osteofibroma
3. Periapical osteofibrosis
 Arise on a reactive basis rather than on
neoplastic basis
 3 stages in their development which are
radiographically apparent

35. 1. Early (osteolytic or fibroblastic)stage: radiolucent
2. Cellular fibroblastic stroma with small foci of
calcified material
2. Intermediate stage: radiolucent area containing
radiopaque foci
3. Final stage(mature lesion):well-defined solid
,homogeneous radiopacity surrounded in most
cases by thin radiolucent border
 Calcified material may cementum,bone or
both(differentiated using polarising microscopy)
 FEATURES
 In early stage ,they occur as radiolucencies that
are somewhat rounded,have well-defined borders
and are associated with teeth having vital pulp

36. Blacks are commonly affected
80% occur in women
90% occur in mandible
Asymptomatic
Seldom exceeds 1 cm in diameter
MANAGEMENT
Treatment required only if
radiographic changes present
If infection or expansion of
cortical plate: Surgical enucleation
If inflammation of pulp:conservative
endodontic treatment

37. 1. Hemorrhagic bone cyst
2. Extravasation cyst
3. Simple bone cyst
4. Progressive bony cyst
5. Blood cyst
 FALSE CYST(no epithelial lining)
 Localized aberration in normal bone remodeling
or metabolism

38. FEATURES
A history of trauma may or may not be present
Asymptomatic except when it reaches size sufficient to
cause expansion of jaws
Well-defined cyst-like radiolucency above the mandibular
canal either round and positioned somewhat symmetrically
about periapex of root
OR
More elongated and oriented mesiodistally extending
superiorly between premolar and molar roots producing
scalloped appearance
No aspiration results but sometimes serosanguineous fluid
or some blood may be obtained
Mandible>Maxilla
Premolar-molar region most common location

39. TREATMENT
1. open the area surgically
2. Establish a diagnosis of traumatic bone cyst
3. Remove the tissue debris present
4. Curette the walls of bony cavity to induce bleeding
5. Close the soft tissue flap securely
 Antibiotics
 ALTERNATE METHOD:injecting venous blood into
bony defect(good results but objected because
sometimes in periodic radiographic follow-up
examination, the radiolucency is found to be
expanding)

41.  WOOD AND GOAZ
 BASIC ORAL RADIOLOGY: ANIL GOVINDRAO
GHOM