A Review of Dentinogenesis Imperfecta and Primary Dentin Disorders in Dogs.

This review describes the clinical, radiographic and histologic characteristics of dentinogenesis imperfecta diagnosed in two unrelated young dogs without evidence of concurrent osteogenesis imperfecta. The dentition was noted to have generalized coronal discoloration ranging from grey-blue to golden brown. Clinical pulp exposure, coronal wear and fractures were observed as was radiographic evidence of endodontic disease, thin dentin walls or dystrophic obliteration of the pulp canal. The enamel was severely affected by attrition and abrasion despite histologically normal areas; loss was most likely due to poor adherence or support by the underlying abnormal dentin. Histologically, permanent and deciduous teeth examined showed thin, amorphous dentin without organized dentin tubules and odontoblasts had dysplastic cell morphology. Primary dentin disorders, including dentinogenesis imperfecta and dentin dysplasia, have been extensively studied and genetically characterized in humans but infrequently reported in dogs. Treatment in human patients is aimed at early recognition and multi-disciplinary intervention to restore and maintain normal occlusion, aesthetics, mastication and speech. Treatment in both humans and canine patients is discussed as is the documented genetic heritability of primary dentin disorders in humans.

Heritable bone fragility, joint laxity and dysplastic dentin in Friesian calves: a bovine syndrome of osteogenesis imperfecta.

A lethal syndrome of bone fragility, joint laxity, translucent teeth and other connective tissue defects occurred in Victoria in 37 of 84 progeny of a clinically normal, registered Friesian bull between 1978 and 1981. Test matings to unrelated cows indicated that the syndrome was transmitted as an autosomal dominant trait. Affected calves were readily recognized at birth by pink teeth and abnormal posture. At birth 14 of 19 affected calves examined had rib fractures and 4 of these calves also had fractures of long bones. Spontaneous fractures of long bones also occurred in 5 of the 11 calves which survived for more than 10 days. Hypoplasia of dentin, tendons, and ligaments were observed in all cases at necropsy. Osteopenia was only observed at necropsy in older calves. Histological lesions of bone and teeth were similar to those reported in descriptions of osteogenesis imperfecta with dentinogenesis imperfecta in man. The syndrome is provisionally designated as "bovine osteogenesis imperfecta". Semen has been collected from the progenitor bull to enable further investigations of this heritable collagenous tissue dysplasia.