RADIOGRAPHIC INTERPRETATION OF

PERIODONTAL DISEASES

DRG. SHANTY CHAIRANI

Radiographs are used in the evaluation of periodontal disease in the following:

Determination of the condition from the affected teeth such as : clinical crown-root ration, shape and size of the crown and root, position of roots of multirooted teeth and position of a tooth in relation to adjacent teeth

Identification of predisposing factors such as calculus, the contour and status of restorations (overhangs or poor contours)

Identification of early bone changesEvaluation of the amount and location of

bone lossDetermination of the prognosis of affected

teeth through radiographic examination of the width of the periodontal ligament space and the continuity of the lamina dura

Evaluation of posttreatment results

The limitations of radiographs in the evaluation of periodontal disease

Radiographs alone cannot be used in determining periodontal status. Radiographs must be used in conjunction with the clinical exam.

Radiographs record two-dimensional images of a three-dimensional structure giving inherent difficulty for observing certain areas of the teeth and bone. Often bone changes are relatively progressed before observed radiographically.

Radiographic technique and standardized conditions are essential in diagnosis and progress or effectiveness of treatment.

The characteristic radiographic appearance of the alveolar crestal bone

The alveolar crest will appear radiopaque on a radiograph and is located 1 to 1,5 mm below the CEJ.

The alveolar crests have a variety of shapes: flat and wide; narrow and rounded; angulated. The approximate levels of adjacent CEJ's and the convexity of the proximal surfaces of the teeth are a couple of factors that may determine the shape of the alveolar crests.

Between the anterior teeth the radiopaque alveolar crest will usually appear pointed whereas between the posterior the crests are usually flat.

The alveolar crest is continuous with the lamina dura of adjacent teeth.

In the absence of disease, the bony junction between the alveolar crest and the lamina dura will be seen to form a sharp angle adjacent to the root tooth

Radiograph of normal periodontal tissue

Bone level determined

Using a probe or millimeter marked ruler place the tip of the probe or end of the ruler at the cementoenamel junction (CEJ) and note the distance between the CEJ and alveolar crest.

If the distance is more than 2 millimeters, there is bone loss.

DENTAL CONDITIONS ASSOCIATED WITH PERIODONTAL DISEASE

Occlusal trauma Traumatic occlusion does not cause gingivitis or

periodontitis, affect the epithelial attachment or cause pocket formation. But it causes some traumatic lesions

These lesions develop in response to occlusal pressures that are greater than the physiologic tolerances of the teeth’s supporting tissues.

The radiographic appearance may be seen as widening of the periodontal ligament space, decreased definition of the lamina dura, bone loss and altered trabeculation. Other signs include hypercementosis and root fractures.

Secondary occlusal traumatism in a patient with chronic periodontitis. The bone loss is particularly advanced in 2.1 with widening periodontal ligament space.

Tooth mobility Tooth mobility is not always reflected on the

radiograph, but widening of the periodontal ligament space may be an important radiographic sign of tooth mobility resulting from occlusal trauma.

Open contacts An open contact is said when the mesial and distal

surfaces of adjacent teeth are not in contact. This condition is potentially dangerous to the

periodontium because of the potential to trap food debris in this region.

Areas with open contact and early periodontal disease show more bone loss than in areas of closed contacts.

Local irritating factors Defective restorations

Overhanging or poorly contoured margins of restorations will lead to accumulation of bacterial deposits and periodontal disease.

These conditions may usualy be recognized on radiographs.

Calculus On a radiograph, calculus is usually seen as a

radiopaque projection on the proximal surface or as a radiopaque line. Calculus detection on a radiograph will depend on its degree of mineralization and on beam angulation.

Poorly contoured amalgam restoration with overhangs, an open contact and calculus are evident. Note the resorption of the crest of the interproximal septa.

An area of localised periodontitis associated with the overhanging cervical margin on the large amalgam restoration in distal 4.6. the underlying alveolar crest has a crater form radiolucency with loss of cortical outline, and a small spur of radiopaque calculus project from the mesio-cervical surface 4.7.

GINGIVITISGingivitis is not seen radiographically

because gingivitis is inflammatory changes of soft tissue.

There are no bone changes in gingivitis.

PERIODONTAL DISEASE

EARLY PERIODONTITIS Early lesion of adult periodontitis are

generally seen as areas of localized erosion of the alveolar bone crest.

In the anterior regions there will be blunting of the alveolar crest.

In the posterior regions there are loss of the normally sharp angle between the lamina dura and the alveolar crest. This angle may lose its normal cortical surface and appear rounded off with an irregular and diffuse border.

Early periodontitis

In this early stage in a 35 year old, there are loss of the cortical outline of the crest of the interdental septa of several teeth. Prominent overhanging margins are present on the amalgam restoration in mesial 4.7 and distal 4.6, the latter of which also bears a porcelain crown.

MODERATE PERIODONTITIS

If the lesions of adult periodontitis progress, the destruction of alveolar bone extends beyond the early changes in the alveolar crest and may induce a variety of bony defect.

The buccal or lingual bony plate, or both, may be lost. There may be bony defects of the interradicular or interdental bone between the buccal and lingual cortical plates.

There may be extensive vertical defect of localized or generalized horizontal bone loss.

Bone loss

Horizontal bone loss is loss in the height of the alveolar crest with the crest (bone) still in a horizontal plane parallel to a line drawn connecting the CEJ's of adjacent teeth. Horizontal bone loss may be localized or generalized. It may be mild, moderate or severe.

Vertical bone loss is uneven reduction of bone. There is greater bone loss on the proximal of one tooth than on the proximal of the adjacent tooth. The bone level is not parallel to a line connecting the adjacent CEJ's.

Horizontal bone loss Vertical bone loss

An intermediate stage, in which there is generalised irregular destruction of bone at the crest of the interdental septa, which show a loss of their cortical outline together with craterform radiolucency. The bone destruction is more advanced between the maxillary incisor and in the four molar quadrant. There is some radiolucency inter-radicular 3.6, indicating early bifurcation involvement.

ADVANCED PERIODONTITIS

Bone loss from adult periodontitis is considered advanced when the bone loss is so extensive that the remaining teeth show excessive mobility, drifting, and are in jeopardy of being lost because of inadequate support.

There may be extensive horizontal or vertical bone loss.

Progressive periodontal disease may invade the bifurcations of multirooted teeth.

An advanced stage, which is particularly marked bilaterally in the molar regions. The bone loss is so advanced that its full extent is not evident on the bitewing films, but is revealed when the film was held vertically.

An advanced lesion with bone loss reaching to the apex of the involved molar. Radiolucent areas of bone destruction are present mesially, distally and apically, there being a deep, infrabony pocket mesially which is in close proximity to the thin cortical lamina of the antral floor. Calculus are present in mesial root surface of 2.7 and disto-cervically 2.5.

There are bone destruction interdentally and bifurcation involvement in the right mandibular molar region. There are heavy deposits of calculus cervically

AGGRESSIVE PERIODONTITIS

There are two types of aggressive periodontitis :

1. Localized aggressive periodontitis (previously known as juvenile periodontitis or periodontosis)

2. Generalized aggressive periodontitis (previously known as rapid progressive periodontitis)

LOCALIZED AGGRESSIVE PERIODONTITIS

An aggressive periodontitis but uncommon form of periodontal disease.

Found in children and young adultsThe localized form is characterized by

generally severe and rapid loss of alveolar bone.

The radiographic appearance of the bone loss is typically angular (or vertical) and localized to the region of the first molar and incisors.

In this young adult, there is advanced bone destruction restricted to the incisor and first molar teeth. This distribution of lesion is typical of the disorder, although other teeth may also be involved.

GENERALIZED AGGRESSIVE PERIODONTITIS

The generalized form involves most of the dentition.

Usually between the ages of 20 and 30 years.

The generalized form is also characterized by the rapid and typically angular loss of alveolar bone that may progress to tooth loss.