Dentinogenesis imperfecta 1 with or without progressive hearing loss is associated with distinct mutations in DSPP

Dentinogenesis imperfecta 1 (DGI1, MIM 125490) is an autosomal dominant dental disease characterized by abnormal dentin production and mineralization. The DGI1 locus was recently refined to a 2-Mb interval on 4q21 (ref. 1). Here we study three Chinese families carrying DGI1. We find that the affected individuals of two families also presented with progressive sensorineural high-frequency hearing loss (gene DFNA39). We identified three disease-specific mutations within the dentin sialophosphoprotein gene (DSPP) in these three families. We detected a G-->A transition at the donor-splicing site of intron 3 in one family without DFNA39, a mutation predicted to result in the skipping of exon 3. In two other families affected with both DGI1 and DFNA39, however, we identified two independent nucleotide transversions in exons 2 and 3 of DSPP, respectively, that cause missense mutations of two adjacent amino-acid residues in the predicted transmembrane region of the protein. Moreover, transcripts of DSPP previously reported to be expressed specifically in teeth are also detected in the inner ear of mice. We have thus demonstrated for the first time that distinct mutations in DSPP are responsible for the clinical manifestations of DGI1 with or without DFNA39.

Dental aberrations in children and adolescents with osteogenesis imperfecta

The aim of this investigation was to study dental aberrations in a large sample of unrelated patients with different types and forms of osteogenesis imperfecta (OI). Sixty-eight non-related index patients aged 0.3 to 20 years (mean, 10 years) were examined clinically. Panoramic radiographs from 49 patients were analyzed. Dentinogenesis imperfecta (DI) type I was found in 27 of 65 patients and was significantly more common in OI type III than in types I and IV and in patients with a severe form of the disease. The presence or absence of DI showed almost complete accordance between affected parents and children and between affected siblings. Moreover, agenesis was found in 11 of 49 patients, apically extended pulp chambers in 20 of 48 patients, and impaction of second permanent molars in 7 of 19 patients older than 15 years. The percentage of patients with no apparent dental aberrations was approximately the same in patients with OI type I and type III and in patients with mild and severe form of the disease. The high prevalence of dental aberrations in OI stresses the importance of clinical and radiographic odontologic examination as part of the clinical investigation. In patients with mild forms of the disease, in whom the medical diagnosis is uncertain, demonstration of disturbances in dental development can be crucial for establishing the OI diagnosis. C

An overview of tooth discoloration: extrinsic, intrinsic and internalized stains

The causes of tooth discoloration are varied and complex but are usually classified as being either intrinsic, extrinsic or internalized in nature. Dietary chromogens and other external elements deposit on the tooth surface or within the pellicle layer either directly or indirectly to form extrinsic discoloration. Stains within the dentine or intrinsic discoloration often results from systemic or pulpal origin, while internalized stains are the result of extrinsic stains entering the dentine via tooth defects such as cracks on the tooth surface.

Osteogenesis imperfecta with dominant inheritance and normal sclerae

Most patients with dominantly inherited osteogenesis imperfecta have blue sclerae and relatively mild symptoms. However, in a small group of families the patients have normal sclerae and this disorder has been classified as Type 4 osteogenesis imperfecta. This paper reports the clinical and radiographical features of 48 patients from 16 families with Type 4 osteogenesis imperfecta and compares the findings with those of the classical disorder with blue sclerae (Type 1 osteogenesis imperfecta). The two types are similar in usually causing a mild disease but with a wide range of severity, and in both types the rate of fracture declines in adolescence. There are, however, some significant differences apart from the colour of the sclerae. In Type 4 the first fracture more commonly occurs at birth, dentinogenesis imperfecta is more frequent than in Type 1 and bruising and nose-bleeds are less common. As in Type 1, the radiographic appearances of the bones may be normal. It is important that Type 4 osteogenesis imperfecta should be recognised because of the need for competent genetic counselling, because the management may be different from that appropriate for Type 1 and because it may be mistaken for idiopathic juvenile osteoporosis or child abuse.

Blue sclerae and keratoglobus. Ocular signs of a systemic connective tissue disorder

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Mild forms of dentinogenesis imperfecta in association with osteogenesis imperfecta as characterized by light and transmission electron microscopy

Osteogenesis imperfecta (OI) results from various gene mutations leading to defects in type I collagen, which is the major component of both bone and dentin. Yet dentinogenesis imperfecta (DI) is found only in half of the patients with OI. Here we document patients from three families with OI and DI lacking the clinical and radiographic features of DI in permanent teeth. However, light and transmission electron microscopic studies of dentin of deciduous and permanent teeth revealed various changes in the morphology of the dentinal tubules and collagen fibers. In one family, diagnosis of DI preceded that of OI. The grade of severity of dentinal manifestations in patients with OI apparently forms a continuum from normal dentin structure to severe DI, and the marked difficulty in diagnosing mild DI may have led to underestimating its frequency. Furthermore, patients with DI should be carefully examined for the possible presence of OI.

Dentinogenesis imperfecta: endodontic implications. Case report

Dentinogenesis imperfecta is a hereditary disorder resulting in defective dentin in both the primary and secondary dentitions. The complications of dentinogenesis imperfecta are difficult to manage and provide a challenge to the dentist. This case report concerns treating an African American patient with dentinogenesis imperfecta who appeared for treatment with endodontic pathosis. It illustrates the need for appropriate and timely restorative treatment to prevent pulpal pathosis. Also demonstrated is the difficulty of endodontically treating dentinogenesis imperfecta teeth because of pulpal obliteration and abnormal dentin mineralization. Early and correct diagnosis of dentinogenesis imperfecta is imperative to enable appropriate preventive interventions and optimal dental treatment. Although pulpal pathosis is rarely reported with dentinogenesis imperfecta, endodontic treatment is occasionally necessary and has a guarded prognosis if initiated after pulp canal obliteration has occurred.

Assessment of dysplastic dentin in osteogenesis imperfecta and dentinogenesis imperfecta

Two semiquantitative scoring systems, Clinical Radiographic Score (CRS) and Dysplastic Dentin Score (DDS), were introduced for analyzing degree of dysplastic manifestations in dentin. The utility of both systems was demonstrated in a large material of teeth from patients with dentinogenesis imperfecta (DI) and osteogenesis imperfecta (OI). Twenty teeth from healthy controls, 81 teeth from 40 patients with OI, and 18 teeth with DI without OI (DI type II) were examined. The degree of dysplasia was correlated with type and form of OI and type of DI. The median DDS did not differ between DI associated with OI (DI type I) and DI type II. DDS in OI patients without clinical signs of DI was above that of control teeth. Both circumpulpal and mantle dentin showed increased DDS, although circumpulpal dentin was more severely affected. The median DDS was highest for the most severe type of non-lethal OI (type III). DDS increased significantly with form (severity) of OI. A significant association between DDS and CRS was found, although diagnosis of DI in less severe cases was not possible based on radiographic or clinical signs alone. Thus, the DDS system proved valuable when the CRS system based on radiographic/clinical manifestations failed, the most significant finding being subclinical histological manifestations of DI in patients with OI but without clinical or radiographic signs of DI. These subtle dysplastic changes are most likely an expression of genetic disturbances associated with OI and should not be diagnosed as DI, but rather be termed histologic manifestations of dysplastic dentin associated with OI.

Orthodontic and orthognathic management of a patient with osteogenesis imperfecta and dentinogenesis imperfecta: a case report

This case report describes a patient's severe Class III malocclusion, managed with a combination of orthodontic and orthognathic treatment. The medical history was complicated by osteogenesis imperfecta and dentinogenesis imperfecta. In addition the patient was a Jehovah's Witness. Patients with osteogenesis imperfecta carry an increased risk of perioperative haemorrhage, and this led to bimaxillary surgery being carried out as two discrete surgical episodes for the patient described. In addition, the risk of enamel fracture led to orthodontic bands being cemented on all teeth. In spite of the increased risks a successful outcome was achieved.

Multiple idiopathic mandibular bone cysts in a patient with osteogenesis imperfecta

Although the most common oral manifestation of osteogenesis imperfecta is dentinogenesis imperfecta, several authors have described jaw fractures and radiolucent bone lesions associated with this disease. We report a case of a 23-year-old white woman with osteogenesis imperfecta and dentinogenesis imperfecta who developed multiple unilocular, bilateral, radiolucent lesions of the mandible 5 years after presenting with a condylar fracture. This is the first documentation by surgical and histopathologic examination that the radiolucent lesions in this particular case represent multiple idiopathic bone cysts.

Dental management of severe dentinogenesis imperfecta in a mild form of osteogenesis imperfecta

Dentinogenesis Imperfecta (DI), in which the teeth are discolored, translucent and brittle, can occur in isolation as a familial trait and as a component of the skeletal dysplasia Osteogenesis Imperfecta (OI). In a Cape Town family, 20 persons in 3 generations had mild OI, with the additional manifestation of severe DI. The family was assessed at the Dental Genetic Unit of the University of the Western Cape and appropriate dental treatment was provided. In this setting, a detailed treatment plan was devised for a severely affected woman. This plan proved to be efficient and cost effective, and the final outcome was pleasing to the patient. Dentinogenesis Imperfecta is not uncommon and may well be encountered in conventional dental practice. The necessary clinical expertise is within the scope of the skills of the general dentist.

Clinical and histologic observations of opalescent dentin associated with enamel defects

The rare variant of opalescent dentin associated with enamel defect was found in a 1 1/2-year-old boy. The pulp chambers and root canals of the affected deciduous teeth were very large, with no sign of obliteration. The enamel layer of those teeth was markedly reduced in thickness, and the enamel prisms were not recognized even by scanning electron microscopy. The mantle dentin was abnormal, as were other portions of dentin.

Dentinogenesis imperfecta with dens in dente

An uncommon case of dentinogenesis imperfecta with dens in dente was studied by light microscopy, microradiography, and electron-microprobe analysis. Numerous canals and cellular inclusions were found in the coronal portion of the dentin where the tubules were sparse and irregularly distributed. In the radicular portion of the molar, large canals ran parallel to each other down to the apical region. The cementum was thinner and the Tomes granular layer greater in amount than usual. A dens in dente occurred in the radicular portion of the molar. It was located in a cavity and consisted of a mineralized cap of enamel, a spherical dentinal mass, and cellular cementum, located outside the cavity and in the "cervical" portion of the dens in dente.

Unusual dentinal changes in dentinogenesis imperfecta associated with osteogenesis imperfecta. A case report

A case is described of a boy with dentinogenesis imperfecta associated with osteogenesis imperfecta. The dentin of extracted deciduous teeth was found to show an abrupt transition to a normal tubular structure before a reversion to the more typical structure seen in dentinogenesis imperfecta. This change in the dentin appeared to have occurred in a chronologic manner. The possibilities that either a metabolic disturbance or a temporary reduced expression of the mutant gene had caused the abnormality and could account for the unusual histologic findings are discussed.

[Odontochondrodysplasia]

BACKGROUND

Dentinogenesis imperfecta is exceptionally associated to chondrodysplasia. The aim of this work is to present four cases of such an association.

CASE REPORT

These four children (three boys; one girl) suffered from growth retardation, ligamentous hyperlaxity, scoliosis. Main features were present since the first months of life. Dentinogenesis imperfecta was more marked on the first teeth. On X-rays, all patients had short tubular bones, more pronounced at the level of the middle segment of their limbs, with irregular metaphyses. Cone-shaped epiphyses were present on the hands. Iliac wings were square-shaped and vertebral bodies had a posterior wedging.

CONCLUSION

These four cases, including two previously published as Goldblatt's syndrome, share the same findings as another case described by this author. We propose the name of odontochondrodysplasia for this apparently unfortuitous association: dentinogenesis imperfecta and chondrodysplasia.

ED-A region-containing isoform of cellular fibronectin is present in dentin matrix in dentinogenesis imperfecta associated with osteogenesis imperfecta

To elucidate the defective dentin formation in osteogenesis imperfecta (OI), we analyzed the expression of selected fibronectin (FN) isoforms in the dentin matrix of a patient with dentinogenesis imperfecta (DI) associated with OI, and in normal teeth. Frozen tooth sections were immunostained with three monoclonal antibodies (MAbs). The MAb recognizing the major cell-binding region (f-33), shared by plasma FN (pFN) and cellular FN (cFN), stained the pulp of normal adult permanent teeth intensely, while no reactivity was present in predentin, (demineralized) dentin, or dental cementum. The periodontal ligament stained unevenly. The dentin matrix of the patient with OI displayed reactive zones, alternating layerwise or concentrically with non-reactive ones. Staining throughout the connective tissue of adult oral mucosa, analyzed for the form of FN present, was intense, and in dermis, which was also studied, it was moderate. Reactivities in dental tissues with the MAb specific for the ED-A region (IST-9), included in cFN but not pFN, were similar to those with MAb f-33. The mucosal connective tissue stained weakly and dermis was negative, except that nerves and endothelia of some large blood vessels stained clearly. The MAb specific for the ED-B segment (BC-1), also included in cFN only, did not stain any of the tissues analyzed. The results suggest that, unlike mucosal and dermal FNs, FNs in the dental tissues are largely cellular, and also that dentin formation in OI may be completed by successive generations of pulpal fibroblasts differentiated into hard-tissue-forming cells.

Immunoreactivity of tenascin-C in dentin matrix in dentinogenesis imperfecta associated with osteogenesis imperfecta

Osteogenesis imperfecta (OI) is a heterogeneous group of heritable connective tissue disorders, assigned to different mutations in type I collagen genes. A variety of structural abnormalities of dentin have been described in dentinogenesis imperfecta (DI) associated with OI. To clarify further the constitution of the dentin matrix in OI, we immunostained frozen and paraffin sections of deciduous teeth from four patients, each from a different family, with two monoclonal antibodies (MAbs) to the matrix glycoprotein tenascin-C (TN-C). One of the MAbs recognizes an epitope common to all TN-C isoforms (BC-4), and the other is specific for a splicing variant (BC-2). Normal teeth, oral mucosa, and skin were analyzed for comparison. Staining patterns with the two MAbs did not differ markedly. Normal dentin matrix and odontoblasts were lacking reactivity, but the pulp stained clearly. TN-C reactivity was present in the dentin matrix of all teeth obtained from two patients with different OI phenotypes and DI, and in one out of three teeth from one patient who also had DI. The reactivity was distributed in layers, but the staining patterns varied from one patient to another and from tooth to tooth. Intratubular staining seen in a tooth from the patient with clinically and histologically normal teeth was comparable with that present in normal deciduous teeth. The variation in TN-C expression suggests that, besides genetic heterogeneity, epigenetic factors could influence the composition of the dentin matrix in OI.

Uninherited dentinogenesis imperfecta

The rare hereditary disease, dentinogenesis imperfecta, is a disturbance of dentin formation in both the deciduous and permanent dentitions. It may be associated with osteogenesis imperfecta, though it is probably that the two diseases are carried by different genes. This association was recognized in a 19-year-old man. Dentinogenesis imperfecta had been diagnosed at the age of 6 and had been regarded as a mutation; 11 years later, an atypical form of osteogenesis imperfecta developed. The case is atypical because of the apparent absence of dentinogenesis imperfecta in the patient's family. The dental manifestations may have heralded the bone disease.

Dentinogenesis imperfecta: a case report

Dentinogenesis imperfecta is a rare structural anomaly that is not frequently encountered in an orthodontic office. This case report of the treatment of a patient with this condition is presented in the hope that it will add to the knowledge of this hereditary condition.

Clinical features of homozygous alpha 2(I) collagen deficient osteogenesis imperfecta

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Familial tarda type osteogenesis imperfecta with dentinogenesis imperfecta Type I. Case report

This paper presents a case of dentinogenesis imperfecta Type I occurring in a patient with familial tarda type osteogenesis imperfecta. The investigation and management of this patient is described.

Radiological features of hereditary opalescent dentin

A case of hereditary opalescent dentin is described, which showed the same clinical and radiological features as those reported previously. However, there was no evidence of osteogenesis imperfecta. While a diagnosis of type II dentinogenesis imperfecta was therefore made, this case also had features characteristic of type III dentinogenesis imperfecta. Treatment by means of an overdenture is described.

Ultrastructure of dentin matrix in heritable dentin defects

Heritable dentin defects form a group of diseases which exclusively affect dentin among the various dental tissues. While one type is associated with the generalized connective tissue disorder, osteogenesis imperfecta, other types occur as single traits. The clinical manifestations of the dentin defects vary from insignificant to severe enough to cause aesthetical and functional failure of the teeth. Scanning and transmission electron microscopic studies, reviewed in this paper, have markedly clarified the ultrastructure of the aberrant dentin matrix. Both similar and different changes seem to occur in the various forms of heritable dentin defects. Abnormalities in the appearance and organization pattern of collagen fibers in the defective dentin partly resemble those observed in skin in generalized connective tissue diseases. The similarity of ultrastructural findings in dentin defects, which are currently classified as distinct entities, and even in diseases affecting other tissues, could be related to the complicated interactions between the extracellular matrix macromolecules. Thus, many of the changes observed may be secondary in nature. Ultrastructural studies can help us to understand the pathogenesis of the different types of heritable dentin defects as well as aid in diagnostics and classification of these diseases.