Principles of radiographic interpretation/ dental courses

INDIAN DENTAL ACADEMY
Leader in continuing Dental Education
www.indiandentalacademy.com

Interpretation terminology
 Interpret: to offer an explanation
 Interpretation: an explanation
 Radiographic interpretation : an explanation of what
is viewed on dental radiograph.
 Diagnosis: the identification of a disease by
examination or analysis

IMPORTANCE
 Dental radiographs are essential for diagnostic
purposes.
 All dental radiographs must be carefully reviewed
and interpreted.
 A great deal of information about the teeth and
supporting bone is obtained from radiographic
interpretation.
 It enables the dental professional to play vital role in
the detection of diseases , lesions and conditions of
the teeth and jaws that cannot be identified clinically.

CLINICAL SITUATIONS NEED
RADIOGRAPHIC EXAMINATIONS
1-Dental caries
2-periodontal diseases
3-Dental anomalies
4-Growth&development and dental malocclusion
5-occult diseases
6-Tmj disorders
7-Implants
8-paranasal sinuses
9-Trauma

Essential requirements for dental
radiographs
 Optimum viewing conditions
 Understanding the nature and limitations of the
black, white and grey radiographic image
 Knowledge of what the radiographs used in
dentistry should look like, so a critical assessment of
individual film quality can be made.

 Detailed knowledge of the range of
radiographic appearances of normal
anatomical structures
 Detailed knowledge of the radiographic
appearances of the pathological conditions
affecting the head and neck
 A systematic approach to viewing the entire
radiograph and to viewing and describing
specific lesions
 Access to previous films for comparison.

NEVER INTERPRET A FAULTY
RADIOGRAPH
Ideal radiograph:
 Visual : density & contrast
 Geometric : sharpness/detail, resolution/definition,
magnification, distortion
 Anatomical accuracy of radiographic images
 Adequate coverage of anatomical region of interest.

RADIOGRAPHIC INTERPRETATION
 CLINICAL EXAMINATION
 QUALITY OF DIAGNOSTIC IMAGE
 NUMBER &TYPE OF AVAILABLE IMAGES
 VIEWING CONDITIONS

Examples of how variations in radiographic technique
can alter the images produced of the same object. A
Correct projection. B Incorrect vertical angulation
producing an elongated image. C Incorrect vertical
angulation producing a foreshortened image. D and E
Incorrect horizontal angulations producing distorted
images.

Examples of how variations in exposure
factors can alter the image quality of the
same object
. A Overexposed. B Slightly overexposed.
C Correctly exposed.D Underexposed.

Viewing conditions
 This should be done in a quiet, darkened room
 At least two good, evenly-lit viewing boxes are required
 A bright light illuminator is required for relatively over-
exposed areas
 Mounted in holder
 Appropriate size of view box to accommodate film
 Magnifying glass-detailed examination of small regions

A, ward ray viewing box incorporating an additional incorporating
bright light source for viewing overexposed dark films
B, SDI xray reader- an extraneous light excluding intra oral film
Viewer with built in magnification

The effect of different viewing conditions on same periapical
Radiograph A, with a black surround B, with white surround
Note , increased details visible in A, particularly around molar teeth.

Image analysis
 Systematic radiographic examination -Identify
normal anatomy and examinate the entire film
 Extra oral images - panoramic films , cephalometric
views & TMJ views

First visual circuit: intraoral images
 Periapical before bitewing images
 Right maxilla to left; left mandible to right
 One anatomic structure at a time
 Eg: posterior maxilla-maxillary
sinus,tuberosity,zygomatic process
 Normal anatomy
bones, canals, foramina

Second visual circuit
 Examination of bone:
 Height of alveolar bone
 Crest relative to teeth
 Loss of height-more than 1.5 mm-periodontal
disease
 Cortication
 Lamina dura + PDL space + tooth roots
 Carcinoma-erosion of alveolar crest+ ill defined
borders.

Third visual circuit
 Examination of dentition & associated structures
 Number, Sequence, appearance, root structure
 Crowns –defective enamel, caries
 Intreproximal areas & restorations
 Pulp chambers-size, content
 Bone-radioluscent/radioopaque lesions

Aunt minny approach
 Aunt Minny represents an abnormality which
looks like one that the evaluator has seen
before, or been told about.
 It would be difficult to recognise new findings
using this approach

Analysis of intra osseous lesions
 STEP 1:LOCALIZE THE ABNORMALITY
LOCALIZED OR GENERALIZED
POSITION IN THE JAWS
SINGLE OR MULTIFOCAL
UNILATERAL OR BILATERAL
SIZE

Characteristics of lesional tissue
 Described as
miltilocular,unilocular,circumscribed or not.
 Indicates
well circumscribed –benign or cystic
poorly circumscribed-malignant.
 Radiolucent lesions without septations have three
pattern of bone destruction
geographic,moth eaten and permeative.

Geographic Pattern
 Single ,large area
 More than 1 cm
 Signifies
 large area of lysis
 Less aggressive form of
malignant lesion
 Monolocular or non septated
benign lesion

Moth Eaten Pattern
 Smaller areas of bone
destruction
 Less well defined
 3 to 5 mm
 Signifies
 Can in both benign and
malignant
 Inflammatory conditions
like osteomyelitis and
osteonecrosis
 More destructive lesion
than with geographic
pattern.

Permeative Pattern
 Much smaller and
poorly defined
 1-2 mm in size
 Signifies
 Aggressive,rapidly
destructive lesion.
 Cortex involvement
with this ,indicates
rapid destruction.

Radiolucent Lesions with Septations
 True septations
vascular lesions
 False septations
 Erosion or scalloping of endosteal surface
.eg.ameloblastoma
 Filaments of remnant host boneform locules within
lesion.eg.aneurysmal bone cyst,central giant cell
granuloma

Honeycomb Pattern
 Loculations are small
and numerous
 Represent earlier
change than soap
bubble pattern
 ameloblastoma

Soap Bubble Pattern
 Larger and less
numerous loculations.
 Signifies
 Breakdown of
honeycomb pattern
 ameloblastoma

Tennis Racket Pattern
 Septa intersect at
right angles.
 Odontogenic
myxoma

Scalloped Pattern
 Incompete septation
gives a false
impression of
multilocularity.
 Odontogenic
keratocyst

LOCATION AND EXTENT
 Location –helps in diagnosis
maxilla /mandible
unilateral/bilateral
incisor /premolar/molar
angle/ramus/body area
localized and generalized

Position in jaws
 Epicenter -coronal to tooth- odontogenic epithelium
 Epicenter of the lesion is above the mandibular
canal-odontogenic in origin
 Epicenter -below IAC-non odontogenic (likely)
 Cartilaginous lesions, osteochondromas –condylar
region.
 If the epicenter of the lesion is in the sinus, not
odontogenic in origin-alveolar process of maxilla

A ,cropped panoramic image of a lesion where epicenter
Is coronal to the mandibular first molar b,an occlusal view of
Same lesion.

A cropped panoramic image displaying a lesion
(developmental salivary gland defect) below the inferior
alveolar canal and thus unlikely to be of odontogenic
origin.

A lateral oblique view of the mandible revealing
a lesion within the inferior alveolar canal. The smooth
fusiform expansion of the canal indicates a neural lesion

The lack of a peripheral cortex on this benign cyst
indicates that it originated in the sinus and not in the alveolar
process. It therefore is unlikely to be of odontogenic origin.

STEP 2:ASSESS THE PERIPHERY &SHAPE
WELL DEFINED OR ILL DEFINED?
 Sharp margins
 Corticated margins
 Sclerotic margins
 Radiolucent band
 Blends into adjacent area
 Irregular margins

 WELL OR POORLY DEMARCATED
 Punched out-sharp- (no bony reaction)-
multiple myeloma
 Corticated-uniform-periphery- (thin opaque border)
cyst
 Sclerotic (wide, uneven opaque border)
Periapical cemental dysplasia
 Radiolucent(periphery)+ corticated
Odontoma , cementoblastoma

A cropped lateral skull view shows several punched out
Lesion of multiple myeloma

Lateral periapical cyst in mandibular premolar region
With well defined corticated periphery

Late lesions of periapical cemental dysplasia shows more
Radiopaque interior surrounded by more radiolucent margin

Note, the thin radiolucent positioned between the internal
radiopaque structure of this odontoma and radiopaque outer cortical
border.

ILL DEFINED BORDERS
 Blending border - gradual transition-normal
appearing bone & abnormal appearing trabeculae -
sclerosing osteitis
 Invasive border-bone destruction-malignancy

Periapical (A) and occlusal (B) films revealing a squamous cell carcinoma
in the anterior maxilla. Note the invasive margin that extends beyond the
lateral incisor (arrow) and the bone destruction immediately behind this
margin

Shape
 Circular
 Oval
 Scalloped
 Multilocular

Periapical film of lateral periapical cyst ,
circular or oval In shape

STEP3:ANALYZE THE INTERNAL
STRUCTURE
 Radiolucent
 Mixed
 Radiopaque
 Trabeculation
 Septa
 Calcifications
 Tooth or similar entities

lateral periapical cyst in between two
premolars shows radiolucency

Periapical cemental dysplasia showing
mixed lesion and mature radiopaque lesion

A lateral oblique view of mandibular lesion
showing an internal Septa that divides the lesion
into several compartments

A periapical film showing soft tissue mass of
shadow of polyp emanting from edentulous ridge

STEP4:ANALYSE THE EFFECTS OF THE
LESION ON SURROUNDING STrUCTURES
 Teeth , lamina dura , periodontal membrane space
 Inferior alveolar canal & mental foramen
 Maxillary antrum
 Surrounding bone density & trabecular pattern
 Outer cortical bone & periosteal reaction

A and B periapical films reveals malignant lymphoma invading
mandible.,irregular widening of pdl space is seen.

Step 5 : formulate a radiographic
interpretation
 Decision 1: Normal V/S Abnormal
 Decision2: Developmental V/S Acquired
 Decision 3: Classification
 Decision 4: Ways To Proceed

Step 5 : formulate a radiographic
interpretation

Analysis of radiographic interpretation
 Step 1: Localize the Abnormality
 Anatomic position (epicenter)
 Localized or generalized
 Unilateral or bilateral
 Single or multifocal
 Step 2: Assess the Periphery and Shape
 PERIPHERY
 Well defined
 Punched out
 Corticated
 Sclerotic
 Soft tissue capsule

 ILL defined
 Blending
 Invasive
 SHAPE
 Circular
 Scalloped
 Irregular
 Step 3: Analyze the Internal Structure
 Totally radiolucent
 Totally radiopaque
 Mixed (describe pattern)

 Surrounding Structures
 Step 4: Analyze the Effects of the Lesion on
 Teeth, lamina dura, periodontal membrane space
 Inferior alveolar nerve canal and mental foramen
 Maxillary antrum
 Surrounding bone density and trabecular pattern
 Outer cortical bone and periosteal reactions
 Step 5: Formulate a Radiographic Interpretation

A cropped panoramic image of a lesion related to the unerupted
mandibular first molar. B, An occlusal
projection providing a right-angled view of the same lesion

 Location. The abnormality is singular and
unilateral,and the epicenter lies coronal to the
mandibular firstmolar.
 Periphery and shape. The lesion has a well-
defined cortical boundary and a spherical or round
shape.
 The periphery also attaches to the cemento enamel
junction.
 Internal structure. The internal structure is totally
radiolucent.

 Effects. This lesion has displaced the first molar
in an apical direction, which reinforces the decision
that the origin was coronal to this tooth. Also, the
lesion has displaced the second molar distally and
the second premolar in an anterior direction. Apical
resorption distal root of the second deciduous molar
has occurred.
 The occlusal radiograph reveals that the buccal
cortical plate has expanded in a smooth, curved
shape, and a thin cortical boundary still exists.
 RADIOGRAPHIC DIAGNOSIS: follicular cyst

Radiographic report
 Patient & general information
 Imaging procedure
 Clinical information
 Findings
 Radiographic interpretation

Systematic viewing
 This approach ensures that all areas of the film are
observed and that the important features of the
tooth apex are examined.

 GENERAL OVERVIEW OF ENTIRE RADIOGRAPH
 1. Note the chronological and development age of
the patient
 2. Note the position, outline and density of all the
normal I superimposed anatomical shadows
including any developing teeth

 EXAMINE EACH TOOTH ON THE RADIOGRAPH
AND ASSESS
 3. THE CROWN
 Note particularly:
The presence of caries
The state of existing restorations

 THE ROOT(S)
 • The length of the root
 • The number(s)
 • The morphology
 • The size and shape of canals
 • The presence of:
a. Pulp stones
b. Root fillings
c. Internal resorption
d. External resorption
e. Root fractures www.indiandentalacademy.com

THE APICAL TISSUES
 • The integrity, continuity and thickness of:
a. The radiolucent line of the periodontal
ligament space
b. The radiopaque line of the lamina dura
 • Any associated radiolucent areas
 • Any associated radiopaque areas
 • The pattern of the trabecular bone

 Diagrams showing the
various radiographic
appearances of infection
and inflammation in the
apical tissues.
 A Normal.
 B Early apical change —
widening of the
radiolucent periodontal
ligament space (acute
apical periodontitis)
(arrowed).
 C Early apical change —
loss of the radiopaque
lamina dura (early
periapical abscess}
(arrowed).

 D Extensive destructive
acute inflammation —
diffuse, ill-defined area of
radiolucency at the apex
(periapical abscess).
 E Low grade chronic
inflammation — diffuse
radiopaque area at the
apex (sclerosing osteitis).
 F Longstanding chronic
inflammation — well-
defined area of
radiolucency surrounded
by dense sclerotic bone
(periapical granuloma or
radicular cyst).

 THE PERIODONTAL TISSUES
 • The width of the periodontal ligament
 • The level and quality of the crestal bone
 • Any vertical or horizontal bone loss
 • Any calculus deposits
 • Any furcation involvements

REFERENCES
1. Oral Radiology Principles and Interpretations –
White and Pharoah edition 5.
2. Dental radiology principles and techniques-
Joen Iannucci Haring edition 2.
3. Essentials of dental radiography and radiology
– Eric Whaites – 3rd edition.

Principles of radiographic interpretation/ dental courses

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Principles of radiographic interpretation/ dental courses