Alimentary System

Tooth - Fibrosis

Narrative
Comment:
Fibrosis within the alveolus (Figure 1, Figure 2, Figure 3, and Figure 4) may be the result of resorption affecting the incisor or molar roots. Resorption may be initiated by malocclusion, infection, or trauma (including iatrogenic fracture). Resorption may progress to complete loss of the tooth and replacement with fibrous connective tissue and/or bone. Inflammation may accompany the fibrosis (Figure 3 and Figure 4).
Recommendations:
Fibrosis should be diagnosed and graded when it is prominent in a lesion or if it has progressed to the point that fibrosis is the only lesion present. If fibrosis is a minor component of inflammation, it is not necessary to diagnose it separately, though it should be described in the pathology narrative.
References:

Long PH, Leininger JR. 1999. Teeth. In: Pathology of the Mouse (Maronpot RR, ed). Cache River Press, St Louis, MO, 13-28.

  • Image of fibrosis in the tooth from a female HSD rat in a chronic study

    Tooth - Fibrosis in a female Harlan Sprague-Dawley rat from a chronic study. There is fibrosis within the alveolar bone and a possible sequestrum of bone or osteodentin (arrow).

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<p>Tooth - Fibrosis in a female Harlan Sprague-Dawley rat from a chronic study. There is fibrosis within the alveolar bone and a possible sequestrum of bone or osteodentin (arrow).</p>

Tooth - Fibrosis in a female Harlan Sprague-Dawley rat from a chronic study. There is fibrosis within the alveolar bone and a possible sequestrum of bone or osteodentin (arrow).
<p>Tooth - Fibrosis in a female Harlan Sprague-Dawley rat from a chronic study (higher magnification of Figure 1). There is fibrosis within the alveolar bone and a possible sequestrum of bone or osteodentin (arrow).</p>

Tooth - Fibrosis in a female Harlan Sprague-Dawley rat from a chronic study (higher magnification of Figure 1). There is fibrosis within the alveolar bone and a possible sequestrum of bone or osteodentin (arrow).
<p>Tooth - Fibrosis in a female B6C3F1 mouse from a chronic study. Fibrosis has replaced much of the alveolar bone.</p>

Tooth - Fibrosis in a female B6C3F1 mouse from a chronic study. Fibrosis has replaced much of the alveolar bone.
<p>Tooth - Fibrosis in a female B6C3F1 mouse from a chronic study (higher magnification of Figure 3). Fibrosis with inflammatory cells has replaced much of the alveolar bone.</p>

Tooth - Fibrosis in a female B6C3F1 mouse from a chronic study (higher magnification of Figure 3). Fibrosis with inflammatory cells has replaced much of the alveolar bone.

Authors:

Linda H. Kooistra, DVM, PhD, DACVP
Pathologist
Charles River Laboratories, Inc.
Research Triangle Park, NC

Abraham Nyska, DVM, Diplomate ECVP, Fellow IATP
Expert in Toxicologic Pathology
Visiting Full Professor of Pathology
Sackler School of Medicine, Tel Aviv University Timrat Israel

Reviewers:

Joel R. Leininger, DVM, PhD
Senior Pathologist
MedImmune
Washington, DC

Amy Brix, DVM, PhD, DACVP
Senior Pathologist
Experimental Pathology Laboratories, Inc.
Research Triangle Park, NC