Faculty Collaboration Database

Dental phenotype of the col1a2(oim) mutation: DI is present in both homozygotes and heterozygotes. Bone 2005 Jun;36(6):1039-46

Date

05/10/2005

Pubmed ID

15878701

DOI

10.1016/j.bone.2005.03.004

Scopus ID

2-s2.0-20444362052 (requires institutional sign-in at Scopus site)   17 Citations

Abstract

Dentinogenesis imperfecta (DI) is a common but variable feature of osteogenesis imperfecta (OI). The Col1a2(oim) mutation (oim) is a well-studied mouse model of chain deficiency OI. Heterozygous oim/+ mice have subtle skeletal fragility, while homozygous oim/oim mice have marked skeletal fragility. To further define the consequences of oim mutation, we examined teeth by light and scanning electron microscopy (SEM). The dental phenotype in Col1a2(oim) (oim) mice is more severe in incisors than in molars and includes changes in pulp chamber size, tooth shape, and dentin ultrastructure. Teeth in oim/oim animals are clinically fragile, while oim/+ teeth are grossly normal. Incisor pulp chamber areas (in mum(2)) are: upper +/+ = 358 +/- 75, lower +/+ = 671 +/- 162, upper oim/+ = 161 +/- 54, lower oim/+ = 156 +/- 19, upper oim/oim = 6900 +/- 1040, and lower oim/oim = 66 +/- 62 (P < 10(-5)). Incisor non-pulp chamber cross-sectional areas (in mum(2)), reflecting dentin areas, are: upper +/+ = 39,000 +/- 1670, lower +/+ = 35,600 +/- 1980, upper oim/+ = 47,500 +/- 2510, lower oim/+ = 26,000 +/- 1830, upper oim/oim = 29,800 + 315, and lower oim/oim = 36,800 +/- 3450 (P < 10(-5)). Ultrastructural abnormalities are more pronounced in incisors than in molars and depend on dosage of the mutant allele. These include reduction in the number and regularity of spacing of the dentinal tubules, lesser mineralization, and blurring of the boundary between peritubular and intertubular dentin. Our findings demonstrate that both oim/oim and oim/+ mice suffer from DI. The more severe incisor phenotype may reflect incisors' continuous growth.

Author List

Lopez Franco GE, Huang A, Pleshko Camacho N, Blank RD

MESH terms used to index this publication - Major topics in bold

Animals
Collagen
Collagen Type I
Dentin
Dentinogenesis Imperfecta
Female
Genotype
Heterozygote
Homozygote
Incisor
Male
Mice
Mice, Mutant Strains
Microscopy, Electron, Scanning
Molar
Mutation
Phenotype
Tooth