Presentation on role of radiographs in periodontal disease therapy

1. RADIOGRAPHIC AIDS IN
THE DIAGNOSIS OF
PERIODONTAL DISEASES
GROUP A

2. Course outline
1.Introduction
2. Diagnostic Requirements of
Radiographs
3. Radiographic Techniques for
Assessing Periodontal Diseases
4. Radiographic Features of Healthy
Periodontium • Alveolar Bone •
Interdental Septa • Periodontal
Ligament Space
5. Radiographic Changes in Various
Periodontal Conditions
• Osseous Defects • Chronic
Periodontitis • Aggressive
Periodontitis • Furcation Defects
• Periodontal Abscesses •
Conditions Associated with
Periodontal Diseases
• 6. Skeletal Disturbances
Manifested in the Jaws
• 7. Limitations of Conventional
Radiographs
• 8. Advanced Radiographic Aids

3. INTRODUCTION
• Radiographs are an integral component of a periodontal assessment
for those with clinical evidence of periodontal destruction
• Radiographs are considered as a valuable adjunct to the clinical
examination, because essential information is provided about the
bony tissues covered by the gingiva that cannot be diagnosed by
clinical inspection alone.
• Radiographic image formation is based on the principle of projecting
a 3-D object onto a 2-D image plane, and therefore this technique
also has limitations.

4. DIAGNOSTIC REQUIREMENTS OF
RADIOGRAPHS
1. Radiographs should only be considered following a full clinical examination.
2. A provisional diagnosis should be made with the choice of radiographs based
on the type, severity and distribution of disease.
3. Radiographs taken for reasons other than periodontal disease (e.g. horizontal
bitewings for caries diagnosis) will often provide useful information and should
be examined before further radiographs are requested
4. Prichard established the following four criteria to determine the adequate
angulation of periapical radiographs:
• The radiographs should show the tips of molar cusps with little or none of the
occlusal surface
• Enamel caps and pulp chambers should be distinct
• Interproximal spaces should be open
• Proximal contacts should not overlap unless teeth are out of line anatomically.

5. RADIOGRAPHIC TECHNIQUES
A) Panoramic radiographs:
• Panoramic radiographs provide a general view of the oral structures,
and are useful for screening bone loss patterns in general.
• They are not suitable for accurate assessment of the degree of bone
loss associated with individual teeth, as there is severe distortion and
the outline of the bone margin is often unclear due to
superimposition of intervening structures.
• Panoramic view is useful when assessing generalized periodontitis,
where large areas of jaws have to be viewed.

7. B) Periapical
radiographs
• Frequently used not only to aid the
differential diagnosis of patient’s
presenting symptoms, but also to
screen for otherwise undetected
pathological processes of the teeth
and surrounding alveolar bone.
• In the diagnosis of periodontal
diseases, periapical radiographs can
provide useful information that
cannot be obtained through
examination of the soft tissues
alone.

8. C) Bitewing Radiographs
• These are taken to show the proximal surfaces of the teeth and the crest
of the alveolar bone of both the maxilla and the mandible on the same
film.
• While they are used primarily to detect interproximal decay, they can also
provide some information on the patient’s periodontal status.
• The height of the interproximal alveolar bone margin relative to the CEJ
can be observed.
• Also, deposits of subgingival calculus may be detected.
• Limitation- Only the coronal sections of the roots of the teeth are
observed, and they are limited to the molar-premolar regions.
• The posterior bitewing projection offers both optimal geometry and the
fine detail of intraoral radiography for patients with small amounts of
uniform bone loss

10. RADIOGRAPHIC FEATURES OF HEALTHY
PERIODONTIUM
A) ALVEOLAR BONE
• The dense cortical alveolar bone forming the wall of the socket of
tooth appears radiographically as a distinct, opaque, uninterrupted,
white line parallel to the tooth root known as the lamina dura.
• The lamina dura is a continuation of the jawbone cortex, which
encases the root in a socket of cortical bone.
• The alveolar crest in a young individual is close to the CEJ. The
alveolar crests are situated approximately 2 to 3 mm apical to the CEJ
of the teeth. The shape of the alveolar crest may vary from rounded
to flat

11. Cont’d
• Between incisor teeth, the alveolar crest will usually appear pointed.
• Between premolar and molar teeth the alveolar crest will be parallel to a
line between the adjacent CEJs, where the enamel thins and disappears.
The alveolar crest will be continuous with the lamina dura of the adjacent
teeth.
• When viewing the lamina dura and the periodontal ligament, only the
interproximal portions are visible. The buccal and lingual areas are not seen
in the radiograph.
• Widening of the periodontal ligament space and loss of lamina dura can be
interpreted as resorption of the alveolar bone.
• The trabecular pattern of interdental bone is distinct and fills the inter-
radicular space

13. B) INTERDENTAL SEPTA
• The interdental septum, or septal bone, is located between the roots
of adjacent teeth.
• It is therefore more clearly visualized than bone that is located on the
buccal or lingual aspect of the tooth.
• The shape of the interdental septum is a function of the morphology
of the contiguous teeth

14. C) PDL SPACE
• The periodontal ligament is composed of
connective tissue which appears as a
fine, black, radiolucent line next to the
root surface.
• The radiolucent image between the
lamina dura and tooth is the periodontal
space and is known radiographically as
the lamina lucida.
• With disease, the periodontal ligament
space may appear at varying thicknesses.
• A widened periodontal space is
considered to be a sign of chronic
inflammation.
• However, it varies.

15. USES OF RADIOGRAPHIC ASSESSMENT
Radiographs are helpful in evaluation of the following:
1. Amount of bone present
2. Condition of the alveolar crests
3. Bone loss in the furcation areas
4. Width of the periodontal ligament

16. RADIOGRAPHIC CHANGES IN VARIOUS
PERIODONTAL CONDITIONS
• OSSEOUS DEFECTS
• Horizontal bone loss
• Clinically, horizontal bone loss is seen in suprabony pocket.
• Radiographically, horizontal bone loss appears as decreased alveolar
marginal bone around adjacent teeth. Normally, the crestal bone is
located 1-2 mm apical to the cementoenamel junction.
• With horizontal bone loss, both the buccal and lingual plates of bone,
as well as interdental bone resorbs. The remaining bone margin is
roughly perpendicular to long axis of tooth, which occurs when the
epithelial attachment is coronal to the bony defect

17. Furcation defects
• The furcation is where multiple tooth roots divide at the trunk of the tooth.
It is usually filled with bone. Furcation exposure results from intra-radicular
bone loss due to advanced periodontal disease
• In class I furcation involvement of the furcation shows that there is
decreased density of bone at the furcation area.
• In class II bone loss may or may not be seen in the furcation area.
• In class III there is complete bone loss visible in the radiograph.
• In the maxillary molars, the palatal roots’ superimposition makes the
furcation of the mesial and distal roots and is presented as arrows
radiolucency. The furcation btwn the mesial and palatal roots is clearly
seen

18. Horizontal and vertical bone loss

19. Vertical bone loss:
• Clinically, vertical bone loss is
seen in infrabony pocket which
occurs when the walls of the
pocket are within a bony
housing.
• Radiographically, vertical bone
defects are generally V shaped
and re sharply outlined.

20. Interdental craters:
• seen as irregular areas of reduced radiopacity on the alveolar bone
crests. They are generally not sharply demarcated from the rest of the
bone, with which they blend gradually.
• Radiographs do not accurately depict the morphology or depth of
interdental craters, which sometimes appear as vertical defects
• . Like the two-walled crater, this defect may be difficult to visualize on
the radiograph, because the buccal and lingual walls remain intact
and obscure the radiographic image of the defect.

21. Chronic Periodontitis
sequence of radiographic changes in
periodontitis and the tissue changes
that produce them
1. There is fuzziness and break in the
continuity of the lamina dura at the
mesial or distal aspect of the crest of
the interdental septum. These result
from the extension of gingival
inflammation into the bone causing
the widening of the vessel channels
and a reduction in calcified tissue at
the septal margin
2. Triangulation (Funnelling). Is due
to resorption of the bone along the
mesial and distal aspects causing the
widening of the pdl. The walls of the
triangles is formed along the walls of
the alveolar bone and the root
surfaces, base is towards the gingiva
and the apex towards the root.
It is an early sign of bone
degeneration and necessitate the
search for etiologic factors such as
plaque, calculus, gingivitis and food
impaction.

22. • 3. The destructive process extends
across the crest of the interdental
septum and the height is reduced.
Fingerlike radiolucent projections
extend from the crest into the
septum. The radiolucent
projections into the interdental
septum are the result of the
deeper extension of the
inflammation into the bone.
• 4. The height of the interdental
septum is progressively reduced by
the extension of inflammation and
the resorption of bone

23. Aggressive Periodontitis
• The radiographic appearance is
typically that of deep vertical bone
loss with a marked predilection for
the first molar and central incisor
regions with relative sparing of
other segments of the dentition.
• There is an arc-shaped loss of
alveolar bone extending from the
distal surface of the second
premolar to the mesial surface of
the second molar. It is usually
bilaterally symmetrical in both the
first molars of each jaw

24. Periodontal Abscesses
• The typical radiographic appearance of the periodontal abscess is that
of a discrete area of radiolucency along the lateral aspect of the root.
• However, the radiographic picture is often not typical therefore, it
cannot be relied upon for the diagnosis of a periodontal abscess

25. Conditions Associated with Periodontal
Diseases
• They include ; occlusal trauma and local irritants
• Trauma from occlusion.
• Traumatic occlusion by itself does not cause periodontitis but can
result in some traumatic lesion in response to occlusal pressures
which are greater than the physiological tolerances of the tooth’s
supporting structures
• can produce radiographically detectable changes in the lamina dura,
morphology of the alveolar crest, width of the periodontal ligament
space, and density of the surrounding cancellous bone.

26. • The injury phase of trauma from occlusion produces a loss of the
lamina dura at apices, furcations, and/or marginal areas. This loss of
lamina dura results in widening of the periodontal ligament space.
The repair phase of trauma from occlusion radiographically show
widening of the periodontal ligament space, which may be
generalized or localized
• More advanced traumatic lesions may result in deep angular bone
loss, which, when combined with marginal inflammation, may lead to
intrabony pocket formation. In terminal stages these lesions extend
around the root apex, producing a wide radiolucent periapical image

27. occlusal trauma with considerable increase in periapical bone density
(circle) and in the bone crest (green arrow).

28. Local irritating factors
• Many local factors contribute
towards periodontal disease. Some
of these factors can be visualised
on the radiographs
• These include calculus deposits
(overhanging restorations, lack of
local contact points, malposed
teeth, partial dentures, faulty
restorations and caries
• A times some of the calculus is not
visible radiographs and is not
interpreted as absence of calculus

29. SKELETAL DISTURBANCES MANIFESTED IN
THE JAWS
• Skeletal disturbances sometime produce
changes in the jaws that affect the
interpretation of radiographs from the
periodontal perspective
• In scleroderma, the periodontal ligament is
uniformly widened at the expense of the
surrounding alveolar bone.
• In Osteitis fibrosa cystica (Von
Recklinghausen’s disease of bone) there is
osteoclastic resorption of bone creating a
mass known as brown tumor. There is
generalized disappearance of the lamina dura.
• In Paget’s disease, the normal trabecular
pattern is replaced by a hazy, diffuse
meshwork of closely knit, fine trabecular
markings. The lamina dura is absent in it.
•
• In Fibrous dysplasia, there is small radiolucent
area at a root apex or an extensive
radiolucent area with irregularly arranged
trabecular markings. There may be
enlargement of the cancellous spaces, with
distortion of the normal trabecular pattern
giving a ground glass appearance and
obliteration of the lamina dura.
• In osteopetrosis, the outlines of the roots may
be obscured by diffuse radiopacity of the
jaws.

30. LIMITATIONS OF CONVENTIONAL
RADIOGRAPHS
• 1. Conventional radiographs provide a two
dimensional image of complex, three
dimensional anatomy, which may result in
following problems in periodontal
assessment:
• • Difficult to differentiate between buccal and
lingual crestal bone levels.
• • One wall defects may obscure the rest of the
defects.
• • Tooth or restoration shadows may obscure
bone defects and resorption in furcation area.
2. Due to superimposition, the details of the
bony architure may be lost
3. Radiographs do not demonstrate incipient
disease, as a minimum of 55-60%
demineralization must occur before
radiographic changes are apparent
4. Radiographs do not reliably demonstrate soft
tissue contours, and do not record changes in
the soft tissues of the periodontium.
• 5. Technique variations can affect the
appearance of the periodontal tissues.
• 6. Overexposure may lead to false
interpretations – ‘burn-out’ phenomenon.
• 7. Panoramic radiographs cannot be
completely relied upon although they do
provide a reasonable overview of periodontal
status.

32. ADVANCED RADIOGRAPHIC AIDS
• Many clinicians are adopting digital X-ray
systems to replace conventional film-
based images because;
• 30% of the bone mass at the alveolar
crest must be lost for a change in bone
height to be recognized on radiographs
• use of computerized images, which can
be stored, manipulated, and corrected for
under- and overexposures.
• This direct digital radiography obtains
real-time imaging, offering both the
clinician and the patient an improved
visualization of the periodontium by
image manipulation and comparison with
previously stored images
• Subtraction Radiography relies on
conversion of several serial radiographs
into digital images and video screen to
detect the changes in density or volume
of bone loss
• In computer assisted densitometric image
analysis system. A video camera
measures light transmitted through
radiograph and signals of the camera is
converted into gray scale images