This document discusses the normal radiographic appearance of teeth and surrounding structures that are important for interpreting dental radiographs. It describes how enamel appears brighter than dentine due to differences in density. The cementum, dentin, pulp chamber, root canals, lamina dura, periodontal ligament space, cancellous bone, and trabecular bone are also described in terms of their typical radiographic presentations and what variations or abnormalities may indicate pathology. Proper exposure and processing techniques are important to avoid errors in interpretation.

1. Dr MUMENA C.H

2. * Dental radiographs are used in combination with the
clinical examination to identify pathologic conditions
and anomalies
* Prerequisite for interpretation: careful exposure and
processing technique
* Reason: avoid errors that inhibit interpretation of
radiographs
* Preferred technique: Paralleling technique
* Reason: radiographs are most accurate representation of
real structure
* Prerequisite for interpretation: Understanding normal
structures before identifying anomaly or pathology

3. * Normal radiographic appearance of tooth and
surrounding anatomic structures:

4. * Rec anatomy of tooth (Enamel, dentine,
cementum, pulp)
* Enamel appears more lighter (More
radiopaque) than dentine
* Reason: it is the most dense substance in the
body
* It should appear unbroken by any radiolucency
(Dark areas)

5. * Cementum:
* Covers rooth area
* Does not appear on radiographs
* Reasons:
* It is very thin layer
* Density is similar to dentine

6. * Dentin:
* Underlies the enamel and cementum
* Dentin should appear smooth and unbroken by
radiolucency except for the pulp chamber and
root canals
* Junction between enamel and dentin is clear
* Reason:
* Different densities

7. * Pulp chamber and root canals:
* Made up of soft tissues
* Appear radiolucent
* Size of pulp chamber vary between individuals
* Root canal appearance vary
* Apical foramen and apical 2-3 mm of the canal may
or may not be visible
* In developing teeth, pulp chambers and canals are
quite large
* N.B: Pulp chambers and root canals should not
contain radiolucencies

8. * Lamina Dura
* It is the radiopaque line that follows the roots of
the teeth
* Appearance vary depending on root configuration
and angulation of the x-ray beam
* It may appear well defined or non-existent
* In areas of occlusal stress ti will appear thicker and
more dense
* An interrupted or absent lamina dura in the
absence of other signs and symptoms is not
necessarily indicative of pathology

9. * Periodontal ligament space:
* Radiolucent are between the lamina dura and
the root surface
* Extends from the alveolar crest around the
root(s) to the opposite alveolar crest
* Width of periodontal ligament space varies
* Features suggesting pathology:
* Widening adjacent to the alveolar crest
* Widening in the apical area

10. * Cancellous or trabecular bone:
* Consists of thin radiopaque plates and rods
called trabeculae surrounding the bone marrow
* It is sandwiched between the cortical plates of
maxilla and mandible
* Density and pattern of trabeculae bone vary
from individual to individual
* General presentation:
* Trabecular pattern of maxilla is denser and finer
than that of mandible

11. * END OF PART 1: FOLLOW PART 2;
RADIOGRAPHIC PRESENTATION OF DENTAL
CARIES