Abnormalities of Teeth qxd

Slide 32:  erosion of unknown cause

Slide 33:  bulimic erosion

Slide 34:  abrasion

Slide 28:  pathologic attrition on

occlusal surface (21y.o. male)

Slide 29:  erosion or abfractions?

Slide 30:  pathologic attrition or

erosion or both?

Slide 31:  erosion of unknown

cause

"Abnormalities of Teeth"

– 5 –

Charles Dunlap, DDS

Sept. 2004

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"Abnormalities of Teeth"

– 6 –

Charles Dunlap, DDS

Sept. 2004

Internal and External Resorption

Slides #35–39 illustrate resorption from within, internal resorption. One or many teeth may be

involved and the cause is a total mystery. (*Skeletal bone has a counterpart in which a bone or adja-

cent bones mysteriously disappear, so-called vanishing bone disease or Gorham’s syndrome.) Inter-

nal resorption may mimic dental caries as seen in Slide #36 (although you can’t see it, there was a

thin shell of  tooth structure covering the lesions). Osteoclasts (dentinoclasts?) arising in the dental

pulp inexorably resorb dentin and enamel that can be stopped only by complete removal of all pulp

tissue following early recognition and prompt endodontic treatment. Slide #40 shows dentin on the

left lined with a row of multinucleated osteoclasts occupying Howship’s lacunae. Inflamed pulp is

seen on the right.

External resorption starts on the root surface and progresses inward. Although the cause may be idio-

pathic, in some cases the cause is apparent. Slide #41 exhibits short roots on lower incisor teeth in a

person who had orthodontic treatment, a well known cause of minor external root resorption. Slide #42

exhibits resorption of the roots of a molar tooth caused by a keratocyst (the black hole) and Slide #43

shows resorption of the roots of teeth # 30 & 31 by a tumor, an ossifying fibroma. Slides # 44–46 are

examples of idiopathic external resorption. This is mysterious and frustating to patient and dentist

alike.

("Multiple Idiopathic Root Resorption." 

Oral Surg. Oral Med & Oral Path.

67:208 1989)

("Extensive Idiopathic Apical Root Resorption" 

Oral Surg. Oral Med. & Oral Path.

78:673 1994)

*Caution:  when you see short teeth, it is not always external resorption. Sometimes teeth never form

completely. Slide # 47 shows short roots, almost no roots in the maxillary teeth. This patient had radi-

ation treatment for a brain tumor at age 3. The maxillary teeth were in the field of radiation and the

formative tissue of the roots were irrepairably damaged so root development was terminated. And

sometimes roots never form and a cause cannot be found as seen in Slide #48.