P. 111

in veterinary patients is horizontal. This appears as generalized bone loss of a similar level across all or part of an arcade. The other pattern is angular (vertical) bone loss. The radiographic appearance of angular bone loss is one area of recession below the surrounding bone. The surrounding bone may be normal or be undergoing horizontal bone loss. Therefore it is common to have a combination of the two types in the same arcade. Bone loss does not become radiographically evident until 30- 50% of the mineralization is lost. Therefore, radiographic  ndings will always underestimate bone loss. In addition, bone loss on only on surface (i.e. lingual, palatal, or facial) may be hidden by superimposition of bone or tooth.
This may resulting in a non-diagnosed bony pocket. Always interpret radiographs in light of the complete oral examination  ndings.
Endodontic disease. Endodontic disease may be demonstrated radiographically in several ways. An individual tooth may have one, some, or all of the different changes listed below. However, only one need be present to establish a presumptive diagnosis of endodontic disease. Radiographic changes can be broken into two major classi cations: 1) changes in the surrounding bone, or 2) changes within the tooth itself.
Tooth Resorption. Physiologically, tooth resorption occurs during changing of dentition from deciduous to permanent teeth. The erupting permanent tooth causes resorption of the deciduous tooth root. Persistent deciduous dentition teeth very often undergo resorption even without permanent tooth eruption,and therefore the lifespan and time of functionality of these teeth is often very limited.
The radiographic appearance of different types of resorption does not always relate to the type of disease, however replacement resorption has some typical features. In addition, localization of the lesion also
could be linked to the speci c type. For example PIRR is often located at the cervical area of the tooth as the consequence of damaged cervical root surface and therefore was previously called a“neck lesion”.
The importance of dental radiography in TR cases cannot be overstated. Type 1 lesions typically retain
a viable root canal system, and will result in pain and endodontic infection if the roots are not completely extracted. However, the concurrent presence of a
normal periodontal ligament makes these extractions routine. With type 2 lesions, there are areas lacking
a normal periodontal ligament (ankylosis) which also demonstrate varying degrees of root resorption, which makes extraction by conventional elevation dif cult to impossible. The continued resorption in type 2 teeth is the basis for crown amputation therapy It is this authors opinion that teeth with an identi able root canal on dental radiographs MUST be extracted completely, while teeth with no discernable root canal may be treated with crown
An Urban Experience
amputation. If there is any question, always err on the side of complete extraction.
Neoplasia. Neoplasia is de ned as the abnormal growth of cells that is not responsive to normal growth control. Neoplasms can be further classi ed by their biologic behavior as benign or malignant. Benign masses:
Most benign neoplastic growths will have no boney involvement on dental radiographs. If bone involvement does occur with a benign growth it will be expansive, resulting in the bone “pulling away” from the advancing tumor leaving a decalci ed soft tissue  lled space in the tumor site. Bony margins are usually distinct. Finally, this expansive growth will typically result in tooth movement.
Malignant neoplasia: Malignant oral neoplasms typically invade bone early in the course of disease, resulting
in irregular, ragged bone destruction. Initially, the bone will have a mottled “moth eaten” appearance, but radiographs late in the disease course will reveal a complete loss of bone (the teeth will appear to  oat in space). If the cortex is involved, an irregular periosteal reaction will be seen.

   109   110   111   112   113