**3. Radiographic techniques**

In conventional radiographs, periapical and bite-wing projections offer the most diagnostic information and are most commonly used in the evaluation of periodontal disease. To properly and accurately depict periodontal bone status, proper techniques of exposure and processing are required. The bone level, pattern of bone destruction, PDL space width, as well as the radiodensity, trabecular pattern, and marginal contour of the interdental bone, vary by modifying exposure

**51**

**Figure 2.**

*Role of Radiographic Evolution: An Aid to Diagnose Periodontal Disease*

2.Enamel and pulp chambers should be seen and distinct.

accurately projects the alveolar bone level.

and development time, type of film, and X-ray angulation. Standardized, reproducible techniques are required to obtain reliable radiographs for pretreatment and posttreatment comparisons. Prichard put forward the following four criteria for the

1.The periapical radiograph should have the ability to show the cusps of molars

4.Contacts between the adjacent teeth should not overlap unless teeth are out of line. For periapical radiographs, the long-cone paralleling technique most

The bisection-of-the-angle technique elongates the projected image, making the bone margin appear closer to the crown; the level of the facial bone is distorted more than that of the lingual. Inappropriate horizontal angulation results in tooth overlap, changes the shape of the interdental bone image, alters the radiographic width of the PDL space and the appearance of the lamina dura, and may distort the

Periapical radiographs frequently do not reveal the correct relationship between the alveolar bone and the CEJ. This is particularly true in cases in which a shallow palate or floor of the mouth does not allow ideal placement of the periapical film. Bite-wing projections offer an alternative that better images periodontal bone levels. For bite-wing radiographs, the film is placed behind the crowns of the upper and lower teeth parallel to the long axis of the teeth. The X-ray beam is directed

*Comparison of long-cone paralleling and bisection-of-the-angle techniques. (A) Long-cone paralleling technique, radiograph of dried specimen. (B) Long-cone paralleling technique, same specimen as A. Smooth wire is on margin of the facial plate and knotted wire is on the lingual plate to show their relative positions. (C) Bisection-of-the angle technique, same specimen as A and B. (D) Bisection of the-angle technique, same specimen. Both bone margins are shifted toward the crown, the facial margin (smooth wire) more than the lingual margin (knotted wire), creating the illusion that the lingual bone margin has shifted apically.*

determination of adequate angulation of periapical radiographs [16–18]:

*DOI: http://dx.doi.org/10.5772/intechopen.88035*

with occlusal surface.

3.Open interproximal spaces.

extent of furcation involvement [19].

and development time, type of film, and X-ray angulation. Standardized, reproducible techniques are required to obtain reliable radiographs for pretreatment and posttreatment comparisons. Prichard put forward the following four criteria for the determination of adequate angulation of periapical radiographs [16–18]:


*Periodontal Disease - Diagnostic and Adjunctive Non-surgical Considerations*

impact of radiographs on treatment out comes.

**2. Normal interdental bone**

**3. Radiographic techniques**

produce changes in its appearance [13, 14].

angulated rather than horizontal [15] (**Figure 1**).

Periodontist need to understand the strength and weakness of diagnostic imaging and way the cost and benefits of the test before prescribing it. Prescribing the appropriate type and the number of radiographs is critical for optimizing the

The adaption of imaging which is digital as a modality of radiographic assessment of the feature, according to scientific evidence, has the potential to change the way to see the periodontal tissues. There is a little doubt that future periodontist will be using as advanced imaging modalities, either directly or indirectly [12].

Evaluation of bone changes in periodontal disease is based mainly on the appearance of the interdental bone because the relatively dense root structure obscures the facial and lingual bony plates. The bone which is present interdentally normally is seen as a radiopaque line beside the periodontal ligament (PDL) and at the bone margin, called as the lamina dura. Because this thin line represents the cortical bone which lining the socket, and change in the angulation of the beam

Crest of the interdental bone normally vary according to the convexity of the proximal tooth surfaces and the level of the cementoenamel junction (CEJ) of the approximating teeth. The faciolingual diameter of the bone is related to the width of the proximal root surface. The angulation of the crest of the interdental septum is generally parallel to a line between the CEJs of the approximating teeth. When there is a difference in the level of the CEJs, the crest of the interdental bone appears

In conventional radiographs, periapical and bite-wing projections offer the most diagnostic information and are most commonly used in the evaluation of periodontal disease. To properly and accurately depict periodontal bone status, proper techniques of exposure and processing are required. The bone level, pattern of bone destruction, PDL space width, as well as the radiodensity, trabecular pattern, and marginal contour of the interdental bone, vary by modifying exposure

*Crest of interdental bone normally parallel to a line drawn between the cementoenamel junction of adjacent* 

*teeth (arrow). Note also the radiopaque lamina dura around the roots and interdental bone.*

**50**

**Figure 1.**

4.Contacts between the adjacent teeth should not overlap unless teeth are out of line. For periapical radiographs, the long-cone paralleling technique most accurately projects the alveolar bone level.

The bisection-of-the-angle technique elongates the projected image, making the bone margin appear closer to the crown; the level of the facial bone is distorted more than that of the lingual. Inappropriate horizontal angulation results in tooth overlap, changes the shape of the interdental bone image, alters the radiographic width of the PDL space and the appearance of the lamina dura, and may distort the extent of furcation involvement [19].

Periapical radiographs frequently do not reveal the correct relationship between the alveolar bone and the CEJ. This is particularly true in cases in which a shallow palate or floor of the mouth does not allow ideal placement of the periapical film. Bite-wing projections offer an alternative that better images periodontal bone levels. For bite-wing radiographs, the film is placed behind the crowns of the upper and lower teeth parallel to the long axis of the teeth. The X-ray beam is directed

#### **Figure 2.**

*Comparison of long-cone paralleling and bisection-of-the-angle techniques. (A) Long-cone paralleling technique, radiograph of dried specimen. (B) Long-cone paralleling technique, same specimen as A. Smooth wire is on margin of the facial plate and knotted wire is on the lingual plate to show their relative positions. (C) Bisection-of-the angle technique, same specimen as A and B. (D) Bisection of the-angle technique, same specimen. Both bone margins are shifted toward the crown, the facial margin (smooth wire) more than the lingual margin (knotted wire), creating the illusion that the lingual bone margin has shifted apically.*

through the contact areas of the teeth and perpendicular to the film. Thus the projection geometry of the bite-wing films allows the evaluation of the relationship between the interproximal alveolar crest and the CEJ without distortion. If the periodontal bone loss is severe and the bone level cannot be visualized on regular bite-wing radiographs, films can be placed vertically to cover a larger area of the jaws. More than two vertical bite-wing films might be necessary to cover all the interproximal spaces of the area of interest [20] (**Figure 2**).
