GSBS Student Publications

Title

Dental abnormalities in the osteopetrotic rat mutation microphthalmia blanc

GSBS Program

Biochemistry & Molecular Pharmacology

UMMS Affiliation

Graduate School of Biomedical Sciences; Graduate School of Biomedical Sciences; Department of Cell Biology; Department of Anatomy

Date

11-1-1994

Document Type

Article

Medical Subject Headings

Animals; Ankylosis; Autoradiography; Bone Resorption; Female; Incisor; Male; Mandible; Microphthalmos; Osteopetrosis; Rats; Rats, Mutant Strains; Time Factors; Tooth Abnormalities; Tooth Eruption

Disciplines

Life Sciences | Medicine and Health Sciences

Abstract

Dental manifestations of the mild, transient osteopetrosis in the rat mutation microphthalmia blanc (mib) were examined. Eruption of all teeth was delayed in mib rats compared to normal littermates. The delays ranged from 5 days for incisors to 3 and 2 days for the first and second molars. Normal rats had straight incisors in the sagittal plane that exhibited signs of wear, but in mib littermates the incisors were maloccluded, distorted, and showed no signs of wear. Radiographic and histological examination of the dentition of 1- and 4-week-old rats revealed that the apical end of incisors in mib rats failed to extend posteriorly to the third molar region as in normal siblings, but ended at the first molar. Histological examination of longitudinal sections of mandibles through the incisors of neonatal normal and mib rats showed that in 1-day-old mutants the incisor was closely surrounded by alveolar bone to which it was ankylosed. The incisor body in mib rats was also malformed, with an indented apical end. This ankylosis was temporary, being resolved by 3 days. These findings show that neonatal reductions in bone resorption cause incisor defects and delay the eruption of all teeth in mib rats. The malocclusion and distortion of incisors of mib rats are likely caused by temporary ankylosis of incisor matrices to alveolar bone. Taken together, these findings illustrate the concept that bone resorption is an essential and rate-limiting element of tooth eruption.

Rights and Permissions

Citation: Arch Oral Biol. 1994 Nov;39(11):985-90.

Related Resources

Link to article in PubMed

Journal Title

Archives of oral biology

PubMed ID

7695512