Hereditary opalescent dentin is a rare autosomal dominant inherited disease of dentin development. A case of hereditary opalescent dentin was reported, and the pathogenesis, family tree and restoration methods were reviewed.
Dentinogenesis Imperfecta ; Humans ; Pedigree

Hereditary dentinogenesis imperfecta is a rare autosomal dominant hereditary disease. This article reported a case of hereditary opalescent dentin and discussed the clinical features and treatment.
Dentinogenesis Imperfecta ; Humans

OBJECTIVEStudies have showed that L type calcium channel plays an important role in dentin calcification and affects tooth development and tooth reparation after injury. The objective of this article is to study the effects of nimodipine, blocking agent of L type calcium channel, on human dentinogenesis using human tooth slice organ culture in vitro.

METHODSYoung healthy human premolars were collected, and cut into 2 mm-thick transverse slices by low speed diamond saw. Agarose beads dipped in nimodipine solution and PBS weresy minetrically placed on tooth slices, and the slices were then embedded in a semisolid agarose-based medium and cultured with organ culture method for 1 week. Fluorescent band of tetracycline, Von-Kossa staining, immunohistochemical staining of the slices and transmission electron microscopy (TEM) of odontoblasts were observed to evaluate dentinogenesis changes of the slices.

RESULTSTooth slices were successfully cultured in vitro for 1 week and the odontoblasts could maintain their original morphology. After treatment with nimodipine, the fluorescent band of tetracycline was narrow and weak, and globular calcification in predentine was decreased compared with the control. TEM showed that secretory vesicles in odontoblast were somewhat increased, hut iminunohistochemical staining for collagen I showed no difference between the two groups.

CONCLUSIONNimodipine can influence the calcification of dentine, but has no obvious influence on the synthesis and secretion of dentine matrix. The results show that L type calcium channel is important in dentin calcification.

The ultimate goal of a regenerative pulp treatment strategy is to reconstitute normal tissue continuum at the pulp-dentin border, regulating tissue-specific processes of reparative dentinogenesis. However, little is known about the molecular mechanism of reparative dentinogenesis. The purpose of this study was to investigate the pulpal response after direct pulp capping and pulpotomy with mineral trioxide aggregate (MTA) by histological and immunohistochemical studies. There was continuous reparative dentin bridge formation at 2 weeks after treatment with MTA in both the pulp capping and the pulpotomy groups. The cells in the pulp capping group showed typical odontoblast characteristics, while the cells of reparative dentin in pulpotomy group were round in shape, lost their polarity, organized as a sheet of cells, and trapped in osteodentin-like mineralized tissue. In pulp capping group, upper layer of the reparative dentin showed cell lacunae indicating osteoblastic characteristics, whereas lower layer of the reparative dentin contained predentin and dentinal tubule-like structures as normal dentin. However, there was osteodentin formation in pulpotomy group. DSP protein was expressed at 4 weeks in odontoblasts of pulp capping group, while BSP was expressed at 4 weeks after pulpotomy. These results suggest that two different types of reparative dentin formation, dentin-like and bone-like dentin, may depend on the type and extent of the injury and the effect of the associated defense reaction on the structural and functional integrity at the dentin-pulp border.
Dental Pulp Capping* ; Dentin* ; Dentinogenesis ; Odontoblasts ; Osteoblasts ; Pulpotomy* ; Pemetrexed

Dentinogenesis imperfecta is a dominant autosomal hereditary disorder of dentin formation that affects the deciduous and permanent teeth. Its etiology is characterized by inadequate cell differentiation during odontogenesis. The clinical characteristics of dentinogenesis imperfecta are discolored teeth with a translucency that varies from gray to brown or amber. Radiographically, the teeth exhibit pulp obliteration, thin and short roots, bell-shaped crowns, and periapical bone rarefaction. The aim of this report was to present a case of dentinogenesis imperfecta type II that was followed up over a 17-year period. This report also presents scanning electron microscopy images of the enamel and dentin, showing that both were altered in the affected teeth. The disease characteristics and the treatments that were administered are reported in this study to guide dentists with respect to the need for early diagnosis and adequate follow-up to avoid major sequelae.
Amber ; Cell Differentiation ; Crowns ; Dental Enamel ; Dentin ; Dentinogenesis Imperfecta* ; Dentinogenesis* ; Dentists ; Early Diagnosis ; Follow-Up Studies* ; Humans ; Microscopy, Electron, Scanning ; Odontogenesis ; Tooth

The purpose of this study was to characterize functional distinction between human dental pulp cells(PC) and periodontal ligament cells(PDLC) using cDNA microarray assay and to confirm the results of the microarray assay using RT-PCR. 3 genes out of 51 genes which were found to be more expressed(>2 fold) in PC were selected, and 3 genes out of 19 genes which were found to be more expressed(>2 fold) in PDLC were selected for RT-PCR as well. According to this study, the results were as follows: 1. From the microarray assay, 51 genes were more expressed (2 fold) from PC than PDLC. 2. RT-PCR confirmed that ITGA4 and TGF beta2 were more expressed in PC than in PDLC 3. From the microarray assay, 19 genes were more expressed (2 fold) from PDLC than PC. 4. RT-PCR confirmed that LUM, WISP1, and MMP1 were more expressed in PDLC than in PC. From the present study, different expression of the genes between the PC and PDLC were characterized to show the genes which play an important role in dentinogenesis were more expressed from PC than PDLC, while the genes which were related with collagen synthesis were more expressed from PDLC than PC.
Collagen ; Dental Pulp ; Dentinogenesis ; Gene Expression ; Humans ; Oligonucleotide Array Sequence Analysis ; Periodontal Ligament

Nuclear factor I-C (NFI-C) plays a pivotal role in various cellular processes such as odontoblast and osteoblast differentiation. Nfic-deficient mice showed abnormal tooth and bone formation. The transplantation of Nfic-expressing mouse bone marrow stromal cells rescued the impaired bone formation in Nfic(-/-) mice. Studies suggest that NFI-C regulate osteogenesis and dentinogenesis in concert with several factors including transforming growth factor-β1, Krüppel-like factor 4, and β-catenin. This review will focus on the function of NFI-C during tooth and bone formation and on the relevant pathways that involve NFI-C.
Animals ; Bone Development* ; Dentinogenesis ; Mesenchymal Stromal Cells ; Mice ; NFI Transcription Factors* ; Odontoblasts ; Osteoblasts ; Osteogenesis ; Osteoporosis ; Tooth*

Neurofibromatosis type I is one of the most common autosomal dominant disorders, characterized by cafe au-lait spots, axillary freckling, Lisch nodules in the iris, multiple neurofibromas and the bone involvement with pseudoarthrosis, and the bowing of long bones. Also, osteogenesis imperfecta type I is one of the common disorders of connective tissues with autosomal dominant inheritance, characterized by osteoporosis, osseous fragility with multiple fractures, blue sclerae, deafness and imperfect dentinogenesis. Although both diseases have autosomal dominant inheritance, there have been no reports of patients with combined diseases. This case is to represent a patient of ostogenesis imperfecta type I and neurofibromatosis type I combined with familial inheritance referring to medical documents.
Connective Tissue ; Deafness ; Dentinogenesis ; Humans ; Iris ; Neurofibromatoses* ; Neurofibromatosis 1* ; Osteogenesis Imperfecta* ; Osteogenesis* ; Osteoporosis ; Pseudarthrosis ; Sclera ; Wills

Osteogenesis imperfecta has been categorized as a heritable disorder of connective tissue affecting both bone and soft tissues and is characterized by fragility of bone, blue sclera, and deafness, less frequently by dentinogenesis imperfect and laxity of ligament. The goals of orthopedic management with osteogenesis imperfecta are the treatment of acute factures and long term rehabilitation in an effort to maintain ambulation. We report a case of osteogenesis imperfecta with anterior bowing of tibia which was successfully corrected by multiple osteotomies and intramedullary fixation by Sofield method and reviewed literatures.
Connective Tissue ; Deafness ; Dentinogenesis ; Ligaments ; Methods ; Orthopedics ; Osteogenesis Imperfecta* ; Osteogenesis* ; Osteotomy ; Rehabilitation ; Sclera ; Tibia ; Walking

Dentin is the major part of tooth and formed by odontoblasts. Under the influence of the inner enamel epithelium, odontoblasts differentiate from ectomesenchymal cells of the dental papilla and secrete pre-dentin which then undergo mineralization into dentin. Transforming growth factor-beta (TGF-β)/bone morphogenetic protein (BMP) signaling is essential for dentinogenesis; however, the precise molecular mechanisms remain unclear. To understand the role of TGF-β/BMP signaling in odontoblast differentiation and dentin formation, we generated mice with conditional ablation of Smad4, a key intracellular mediator of TGF-β/BMP signaling, using Osr2 or OC-Cre mice. Here we found the molars of Osr2(Cre)Smad4 mutant mice exhibited impaired odontoblast differentiation, and normal dentin was replaced by ectopic bone-like structure. In Osr2(Cre)Smad4 mutant mice, cell polarity of odontoblast was lost, and the thickness of crown dentin was decreased in later stage compared to wild type. Moreover, the root dentin was also impaired and showed ectopic bone-like structure similar to Osr2(Cre)Smad4 mutant mice. Taken together, our results suggest that Smad4-dependent TGF-β/BMP signaling plays a critical role in odontoblast differentiation and dentin formation during tooth development.
Animals ; Cell Polarity ; Crowns ; Dental Enamel ; Dental Papilla ; Dentin* ; Dentinogenesis ; Epithelium ; Mice ; Miners ; Molar ; Odontoblasts* ; Tooth