**5. Pattern of bone destruction**

In periodontal disease the interdental bone undergoes changes that affect the lamina dura, crestal radiodensity, size and shape of the medullary spaces, and height and contour of the bone. Height of interdental bone may be reduced, with the crest perpendicular to the long axis of the adjacent teeth horizontal bone loss; or angular or arcuate defects angular, or vertical, bone loss; could form [24–26].

Radiographs do not indicate the internal morphology or depth of craterlike defects. Also, radiographs do not reveal the extent of involvement on the facial and lingual surfaces. Bone destruction of facial and lingual surfaces is masked by the dense root structure, and bone destruction on the mesial and distal root surfaces may be partially hidden by superimposed anatomy, such as a dense mylohyoid ridge. In most cases, it can be assumed that bone losses seen interdentally continue in either the facial or the lingual aspect, creating a troughlike lesion [27].

**53**

**Figure 3.**

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

**6. Radiographic appearance of periodontal disease**

tissue destruction and include the following [29]:

Dense cortical facial and lingual plates of interdental bone obscure destruction of the intervening cancellous bone. Thus a deep craterlike defect between the facial and lingual plates might not be depicted on conventional radiographs. To record the destruction of the cancellous bone which is present interproximally and radiographically, the cortical bone must be involved. A decrease of only 0.5–1.0 mm in the thickness of the cortical plate is sufficient to permit radiographic visualization of the destruction of the inner cancellous trabeculae. Interdental bone loss may continue facially and/or lingually to form a troughlike defect that could be difficult to appreciate radiographically. These lesions may terminate on the radicular surface or may communicate with the adjacent interdental area to form one continuous lesion [28].

Radiographic changes in periodontitis follow the pathophysiology of periodontal

1.Fuzziness and disruption of lamina dura crestal cortication continuity is the earliest radiographic change in periodontitis and results from bone resorption activated by extension of gingival inflammation into the periodontal bone. Depicting these early changes depends greatly on the radiographic technique, as well as on morphological changes. No correlation was found between

*Radiographic changes in periodontitis. (A) Normal appearance of interdental bone. (B) Fuzziness and a break in the continuity of the lamina dura at the crest of the bone distal to the central incisor (*left*). There are wedgeshaped radiolucent areas at the crest of the other interdental bone. (C) Radiolucent projections from the crest* 

*into the interdental bone indicate extension of destructive processes. (D) Severe bone loss.*

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

**6.1 Periodontitis**

*Role of Radiographic Evolution: An Aid to Diagnose Periodontal Disease DOI: http://dx.doi.org/10.5772/intechopen.88035*

Dense cortical facial and lingual plates of interdental bone obscure destruction of the intervening cancellous bone. Thus a deep craterlike defect between the facial and lingual plates might not be depicted on conventional radiographs. To record the destruction of the cancellous bone which is present interproximally and radiographically, the cortical bone must be involved. A decrease of only 0.5–1.0 mm in the thickness of the cortical plate is sufficient to permit radiographic visualization of the destruction of the inner cancellous trabeculae. Interdental bone loss may continue facially and/or lingually to form a troughlike defect that could be difficult to appreciate radiographically. These lesions may terminate on the radicular surface or may communicate with the adjacent interdental area to form one continuous lesion [28].
