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Dental radiology
Radiology in
Conservative Dentistry
II.
Size disorders on the X-ray image
o Microdontia is described as teeth
which are smaller than normal i.e.
outside the usual limits of
variation.
o Macrodontia refers to teeth that
are larger than normal.
Shape disorders on the X-ray image
Concrescence is a condition of teeth
where the cementum overlying the
roots of at least two teeth join
together. The cause can sometimes
be attributed to trauma or crowding
of teeth.
The phenomenon of gemination
arises when two teeth develop from
one tooth bud and, as a result, the
patient has an extra tooth, in contrast
to fusion, where the patient would
appear to be missing one tooth.
Fused teeth arise through union of
two normally separated tooth germs
Dilaceration refers to an angulation,
or a sharp bend or curve, in the root
or crown of a formed tooth.
Shape disorders on the X-ray image
Dens evaginatus is a condition found in
teeth where the outer surface appears to
form an extra bump or cusp. Premolars
are more likely to be affected than any
other tooth. The pulp of the tooth may
extend into the dens evaginatus.
Talon cusp is an extra cusp on an
anterior tooth located on the inside
surface of the affected tooth. Other names
for talon cusp is eagle's talon.
Dens invaginatus (dens in
dente) is a malformation of
teeth most likely resulting
from an infolding of the dental
papilla
during
tooth
development or invagination
of all layer of the enamel
organ in dental papillae.
Affected teeth show a deep
infolding of enamel and dentin
starting from the foramen
coecum or even the tip of the
cusps and which may extend
deep into the root.
Shape disorders on the X-ray image
Taurodontism is a condition found
in the molar teeth whereby the pulp
chamber is enlarged vertically at the
expense of the roots. As a result, the
floor of the pulp and the furcation
of the tooth is moved apically down
the root.
What reasons can lead to pulpitis
Pulpitis is the most common cause of dental pain and
loss of teeth.
Causes:
• bacterias penetrate through the dentin
• traumatic exposure of the pulp
• fracture of the crown or cusp
• thermal or chemical irritation
• cracked tooth syndrome
PULPITIS
UNTREATED
DEATH OF PULP
Spread of infection through
the apical foramina into the
periapical tissues
bacterias
PERIAPICAL PERIODONTITIS
caries
parodontium
Classification of the periapical lesions
http://pocketdentistry.com/1
0-diseases-of-the-pulp-andperiapical-tissues/
Periodontitis acuta on X-ray image
Acute Apical Periodontitis
Clinical features:
• Thermal changes does not induce pain.
• Slight extrusion of tooth from socket.
• Cause tenderness on mastication due to
inflammatory edema collected in PDL.
• Due to external pressure, forcing of edema fluid
against already sensitized nerve endings results
in severe pain.
Radiographic features:
• Appear normal except for widening of PDL
space.
Periodontitis chronica on X-ray image
(periapical granuloma)
Most common result of pulpitis or apical periodontitis. Periapical granuloma is localized mass of chronic granulation tissue
formed in response to infection.
Clinical features:
•
•
•
•
•
Tooth involved is non vital/ slightly tender on percussion.
Mild pain on chewing on solid food.
Tooth may be slightly elongated in socket.
Sensitivity is due to hyperaemia, edema and inflammation PDL.
In many cases, asymptomatic.
Radiographic features:
• Thickening of PDL at root apex.
• As surrounding bone resorption and proliferation of granulation tissue
appears to be radiolucent area.
• Thin radiopaque line or zone of sclerotic bone sometimes seen
outlining lesion.
• Long standing lesion may show varying degrees of root resorption.
Dental X-ray of teeth origin cysts
The radicular cyst is the most common
cystic lesion of the jaw. It is caused by pulpal
necrosis. It arises from epithelial residues in
periodontal ligament as a result of
inflammation. Types:
• Periapical cyst
• Lateral cyst
Usually, the periapical cyst is asymptomatic,
but a secondary infection can cause pain. On
radiographs, it appears a round/ovoid
radiolucency (dark area) around the apex of
the root.
These cysts may persists even after
extraction of offending tooth; such cysts are
called residual cysts.
Radiographies by root treatment
Radiographs in Endodontic Therapy
• Diagnostic Radiographs: they help for proper diagnosis of the case and help in determining the
prognosis by comparison with post operative and follow up radiographs
• Working Radiographs (with file, with master cone)
• Post operative Radiographs: they are used to evaluate the endodontic treatment.
• Follow up Radiographs: are taken to evaluate the prognosis of the endodontically treated tooth.
The parallax principle by root location
Parallax method (by Clark and Richards):
Principle:
• 2 periapical views of the same object are taken
from slightly different angles which can
provide depth to the flat 2D picture depicted
by each of the films individually.
• Useful in distinguishing the buccal or lingual
displacement of the canine.
Oral diseases as risk factors for systemic health
Focal infection: it has become increasingly clear that the oral cavity can act as
the site of origin for dissemination of pathogenic organisms to distant body
sites, especially in immunocompromised hosts such as patient suffering from
malignancies, diabetes, or rheumatoid arthritis, etc.
A number of epidemiological studies have suggested that oral infection,
especially marginal and apical periodontitis, may be a risk factor for systemic
diseases.
Potential focus in the oral cavity:
• Necrotic pulp
• Gangrenous pulp
• Periapical lesion, granuloma or cyst
• Chronic marginal gingivitis
• Chronic marginal periodontitis
• Paranasal sinuses inflammation