Dentinogenesis imperfecta type I: A case report with literature review on nomenclature system

Progress in the pathogenic mechanism, histological characteristics of hereditary dentine disorders and clinical management strategies

Hereditary dentine disorders are autosomal dominant diseases that affect the development and structure of dentine, leading to various dental abnormalities and influencing the individual's oral health. It is generally classified as dentinogenesis imperfecta (DGI) and dentine dysplasia (DD). Specifically, DGI is characterized by the abnormal formation of dentine, resulting in teeth that are discolored, translucent, and prone to fracture or wear down easily. DD is characterized by abnormal dentine development, manifested as teeth with short roots and abnormal pulp chambers, leading to frequent tooth loss. Up to now, the pathogenesis of hereditary dentine disorders has been poorly clarified and the clinical intervention is limited. Treatment for hereditary dentine disorders focuses on managing the symptoms and preventing further dental problems. Genetic counseling and testing may also be recommended as these conditions can be passed on to future generations. In this review, we summarize the clinical features, pathogenic genes, histomorphological characteristics and therapy of hereditary dentine disorders. Due to the limited understanding of the disease at present, we hope this review could improve the recognition of the disease by clinicians, stimulate more scholars to further study the deeply detailed mechanisms of the disease and explore potential therapeutic strategies, thus achieving effective, systematic management of the disease and improving the life quality of patients.

Morphological Study of Dental Structure in Dentinogenesis Imperfecta Type I with Scanning Electron Microscopy

Background: Dentinogenesis imperfecta type I (DGI-I) is a hereditary alteration of dentin associated with osteogenesis imperfecta (OI). Aim: To describe and study the morphological characteristics of DGI-I with scanning electron microscopy (SEM). Material and methods: Twenty-five teeth from 17 individuals diagnosed with OI and 30 control samples were studied with SEM at the level of the enamel, dentin–enamel junction (DEJ) and four levels of the dentin, studying its relationship with clinical–radiographic alterations. The variables were analysed using Fisher’s exact test, with a confidence level of 95% and asymptotic significance. Results: OI teeth showed alterations in the prismatic structure in 56%, interruption of the union in the enamel and dentin in 64% and alterations in the tubular structure in all of the cases. There is a relationship between the severity of OI and the morphological alteration of the dentin in the superficial (p = 0.019) and pulpar dentin (p 0.004) regions. Conclusions: Morphological alterations of the tooth structure are found in OI samples in the enamel, DEJ and dentin in all teeth regardless of the presence of clinical–radiographic alterations. Dentin structural anomalies and clinical dental alterations were observed more frequently in samples from subjects with a more severe phenotype of OI.

Dentine disorders and adhesive treatments: A systematic review

OBJECTIVES

A better understanding of the microstructure and mechanical properties of enamel and dentine may enable practitioners to apply the current adhesive dentistry protocols to clinical cases involving dentine disorders (dentinogenesis imperfecta or dentine dysplasia).

DATA/SOURCES

Publications (up to June 2020) investigating the microstructure of dentine disorders were browsed in a systematic search using the PubMed/Medline, Embase and Cochrane Library electronic databases. Two authors independently selected the studies, extracted the data in accordance with the PRISMA statement, and assessed the risk of bias with the Critical Appraisal Checklist. A Mann-Whitney U test was computed to compare tissues damage related to the two dentine disorders of interest.

STUDY SELECTION

From an initial total of 642 studies, only 37 (n = 164 teeth) were included in the present analysis, among which 18 investigating enamel (n = 70 teeth), 15 the dentine-enamel junction (n = 62 teeth), and 35 dentine (n = 156 teeth). Dentine is damaged in cases of dentinogenesis imperfecta and osteogenesis imperfecta (p = 2.55E-21 and p = 3.99E-21, respectively). These studies highlight a reduction in mineral density, hardness, modulus of elasticity and abnormal microstructure in dentine disorders. The majority of studies report an altered dentine-enamel junction in dentinogenesis imperfecta and in osteogenesis imperfecta (p = 6.26E-09 and p = 0.001, respectively). Interestingly, enamel is also affected in cases of dentinogenesis imperfecta (p = 0.0013), unlike to osteogenesis imperfecta (p = 0.056).

CONCLUSIONS

Taking into account all these observations, only a few clinical principles may be favoured in the case of adhesive cementation: (i) to preserve the residual enamel to enhance bonding, (ii) to sandblast the tooth surfaces to increase roughness, (iii) to choose a universal adhesive and reinforce enamel and dentine by means of infiltrant resins. As these recommendations are mostly based on in vitro studies, future in vivo studies should be conducted to confirm these hypotheses.

New 3D Cone Beam CT Imaging Parameters to Assist the Dentist in Treating Patients with Osteogenesis Imperfecta

(1) Background: The aim of the work is to identify some imaging parameters in osteogenesis imperfecta to assist the dentist in the diagnosis, planning, and orthodontic treatment of Osteogenesis Imperfecta (OI) using 3D cone beam Computed Tomography (CBCT) and the Double Energy X-ray Absorptiometry (DEXA) technique. (2) Methods: 14 patients (9 males and 5 females; aged mean ± SD 15 ± 1.5) with a clinical-radiological diagnosis of OI were analyzed and divided into mild and moderate to severe forms. The patients' samples were compared with a control group of 14 patients (8 males and 6 females; aged mean ± SD 15 ± 1.7), free from osteoporotic pathologies. (3) Results: The statistical analysis allowed us to collect four datasets: in the first dataset (C1 sick population vs. C1 healthy population), the t-test showed a p-value < 0.0001; in the second dataset (C2 sick population vs. C2 healthy population), the t-test showed a p-value < 0.0001; in the third dataset (parameter X of the sick population vs. parameter X of the healthy population), the t-test showed a p-value < 0.0001; in the fourth dataset the bone mineralometry (BMD) value detected by the DEXA technique compared to the C2 value of the OI affected population only) the Welch-Satterthwaite test showed a p-value < 0.0001. (4) Conclusions: The research has produced specific imaging parameters that assist the dentist in making diagnostic decisions in OI patients. This study shows that patients with OI have a characteristic chin-bearing symphysis, thinned, and narrowed towards the center, configuring it with a constant "hourglass" appearance, not reported so far in the literature by any author.

Osteogenesis imperfecta – Pathophysiologie und aktuelle Behandlungsstrategien

Die Osteogenesis imperfecta (OI) ist eine angeborene Erkrankung des Knochens und Bindegewebes. Sie geht mit einer erhöhten Frakturneigung, Deformierung der Extremität, aber auch mit extraskelettalen Symptomen einher. Nach einer kurzen Darstellung von Klinik, Diagnostik und aktueller Therapie folgt ein umfassender Überblick über die genetischen und pathophysiologischen Grundlagen der Erkrankung und die daraus abgeleiteten zukünftigen therapeutischen Möglichkeiten.

Ungefähr 80 % der Patienten haben eine Mutation in den Kollagen-Genen COL1A1 und COL1A2. Bei diesen Patienten ist für das Kollektiv keine klare Genotyp-Phänotyp-Korrelation beschrieben. Stoppmutationen führen in der Regel zu einem quantitativen Kollagendefekt, wodurch weniger normales Kollagen gebildet wird und ein eher leichter Phänotyp entsteht. Missense-Mutationen führen zu strukturell verändertem Kollagen (qualitativer Defekt) und zu einem schwereren Phänotyp. Trotzdem gibt es Unterschiede und Vorhersagen über den individuellen Verlauf sind nur sehr eingeschränkt möglich. Neben Veränderungen in den Kollagen-Genen gibt es Mutationen, welche die Kollagenmodifikation und die Kollagensekretion betreffen. Eine eigene Gruppe bilden Gene, welche an der Osteoblastendifferenzierung beteiligt sind. Wie auch bei den weiteren, nicht näher zugeordneten Genen sind dies häufig übergeordnete Gene, deren Funktion in der Osteogenese nicht völlig verstanden ist.

Abgeleitet aus den pathophysiologischen Grundlagen, können vorhandene Medikamente zukünftig womöglich zielgerichtet eingesetzt werden. So ist der „Receptor-Activator-of-Nuclear-Factor-Kappa B-Ligand“ (RANKL)-Antikörper Denosumab spezifischer als Bisphosphonate und wird schon heute bei OI-Typ VI (SERPINF1) verwendet. Weitere Medikamente wie Anti-Sklerostin oder Stammzelltherapien werden unter Berücksichtigung der Pathophysiologie aktuell entwickelt.

Phenotypic Properties of Collagen in Dentinogenesis Imperfecta Associated with Osteogenesis Imperfecta

Introduction

Dentinogenesis imperfecta type 1 (OIDI) is considered a relatively rare genetic disorder (1:5000 to 1:45,000) associated with osteogenesis imperfecta. OIDI impacts the formation of collagen fibrils in dentin, leading to morphological and structural changes that affect the strength and appearance of teeth. However, there is still a lack of understanding regarding the nanoscale characterization of the disease, in terms of collagen ultrastructure and mechanical properties. Therefore, this research presents a qualitative and quantitative report into the phenotype and characterization of OIDI in dentin, by using a combination of imaging, nanomechanical approaches.

Methods

For this study, 8 primary molars from OIDI patients and 8 primary control molars were collected, embedded in acrylic resin and cut into longitudinal sections. Sections were then demineralized in 37% phosphoric acid using a protocol developed in-house. Initial experiments demonstrated the effectiveness of the demineralization protocol, as the ATR-FTIR spectral fingerprints showed an increase in the amide bands together with a decrease in phosphate content. Structural and mechanical analyses were performed directly on both the mineralized and demineralized samples using a combination of scanning electron microscopy, atomic force microscopy, and Wallace indentation.

Results

Mesoscale imaging showed alterations in dentinal tubule morphology in OIDI patients, with a reduced number of tubules and a decreased tubule diameter compared to healthy controls. Nanoscale collagen ultrastructure presented a similar D-banding periodicity between OIDI and controls. Reduced collagen fibrils diameter was also recorded for the OIDI group. The hardness of the (mineralized) control dentin was found to be significantly higher (p<0.05) than that of the OIDI (mineralized) dentine. Both the exposed peri- and intratubular dentinal collagen presented bimodal elastic behaviors (Young’s moduli). The control samples presented a stiffening of the intratubular collagen when compared to the peritubular collagen. In case of the OIDI, this stiffening in the collagen between peri- and intratubular dentinal collagen was not observed and the exposed collagen presented overall a lower elasticity than the control samples.

Conclusion

This study presents a systematic approach to the characterization of collagen structure and properties in OIDI as diagnosed in dentin. Structural markers for OIDI at the mesoscale and nanoscale were found and correlated with an observed lack of increased elastic moduli of the collagen fibrils in the intratubular OIDI dentin. These findings offer an explanation of how structural changes in the dentin could be responsible for the failure of some adhesive restorative materials as observed in patients affected by OIDI.

Dentinogenesis imperfecta in Osteogenesis imperfecta type XI in South Africa: a genotype-phenotype correlation

BACKGROUND

The maxillofacial and dental manifestations of Osteogenesis imperfecta (OI) have significant implications in terms of management. Although the occurrence of abnormal dentine in some forms of OI is well documented, there is scant information on the association of abnormal dentine in the Black African persons with phenotypic OI III and genotypic OI XI in South Africa.

METHODS

This was a cross-sectional analytic study. A series of 64 Black South African individuals with a confirmed phenotypic diagnosis of OI III, ages ranging from 3 months to 29 years, were assessed clinically, radiographically, and at a molecular level.

RESULTS

A total number of 64 saliva samples were analyzed and 3 DNA variations were identified in exon 5 of the FKBP10 gene. The homozygous mutation, c.[831dupC]; [831dupC], was identified in 23 affected persons who had no clinically obvious features of DI in their primary and secondary teeth. Radiologically, mild features of DI were evident in 10 persons in whom radiographic images were obtained and were given a Clinical-radiological score of 2. A compound heterozygous mutation, c. [831delC]; [831dupC], was identified in three siblings. An intraoral examination of these affected persons revealed no clinically apparent features of DI in their primary and secondary teeth. Due to the lack of radiological facilities, the presence or absence of DI could not be confirmed or negated. A second compound heterozygous mutation, c.[831dupC]; [1400-4C>G], was identified in a female of 29 years belonging to the Xhosa linguistic group. Her teeth appeared clinically normal but it was not possible to obtain radiographs. In 37 affected individuals, no disease-causing mutations were identified.

CONCLUSION

Black African individuals in SA with the homozygous mutation in the FKBP10 gene have clinically unaffected teeth yet exhibited radiographic features of DI to varying degrees. This characterization is suggestive of a relationship between the genetic abnormality and the clinical manifestations of DI. The authors suggest that this diagnosis must include teeth that are clinically and/or radiologically aberrant, and should not exclude the presence of other, milder, dentinal aberrations associated with OI. There was no correlation between severity of OI and DI in this cohort of individuals.

Hereditary dentine dysplasias: terminology in the context of osteogenesis imperfecta

Hereditary dentine dysplasias (HDD) such as dentinogenesis imperfecta (DI) and dentine dysplasia (DD) are a group of genetic conditions characterised by an abnormal dentine structure due to disturbances in the formation, composition, or organisation of the dentine matrix. Either the primary or both primary and secondary dentition are affected to varying degrees. These disorders result from mutations in the genes encoding the major protein constituents of dentine, notably collagens and phosphoproteins. The clinical and radiological features of the hereditary dentine dysplasias (HDD) are relevant to clinical dentistry, in particular osteogenesis imperfecta (OI) which is a well-known heterogeneous genetic disorder. OI is currently the focus of considerable academic attention and involvement of the teeth is a frequent and variable manifestation. In this analysis, the literature related to the classification, clinical features, and molecular pathogenesis of heritable structural tooth diseases affecting dentine formation is reviewed. The definition, history of the terminology and the development of the current classification is outlined and discussed in detail with the aim to address semantic confusion that has arisen in the literature on HDD and to provide clarity on the use of appropriate terminology in the context of OI.

Dentinogenesis imperfecta type II: A case report with 17 years of follow-up

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.

Minimally invasive orthodontics: elastodontic therapy in a growing patient affected by Dentinogenesis Imperfecta

AIM

The aim of the study was to report the use of an elastodontic therapy in a growing patient affected by Dentinogenesis Imperfecta, second class malocclusion, deep bite and lower arch crowding from the deciduous dentition to permanent one.

CASE REPORT

At first, the 5-year-old patient was treated with an elastodontic device known as "Nite-Guide". When the patient was 7 years old, during her first permanent molars and incisors eruption and after optimal house-practices, an Occlus-o-Guide Series G was placed at night and on daylight (two hours a day) performing exercises aimed to activate facial muscles and facilitate the deep bite reopening. At 9 years of age, with totally deep bite resolution, she used the Occluso-Guide only at night to hold down previous results and follow patient's dental growth. At 11 years of age, after successful teeth switching, we prescribed an Occlus-o-Guide Series N, which is functional for permanent dentition and guaranteed an eruptive guide for last dental elements.

CONCLUSIONS

This clinic case could be considered an example of approach for all those patients with systemic and/or dental diseases that do not allow adequate dental retention, which is necessary for most orthodontic appliances; elastodontic devices do not require adequate dental retention and define a minimum intervention on the surfaces of the teeth.

Prevalence of Dentinogenesis Imperfecta in a French Population

BACKGROUND

Dentinogenesis imperfecta is a genetic disorder of the dentin occurring during the tooth development. It leads to many structural changes that can be identified clinically (brownish colored teeth, cracked enamel) and radiologically (globular crown, cervical constriction, short roots, and obliterated pulp chamber and/or root canals). The aim of this study was to determine by panoramic radiographs assessment the incidence of dentinogenesis imperfecta in a group of patients attending a specialized maxillofacial imaging center in Paris, France.

MATERIAL AND METHODS

A retrospective observational study was conducted using panoramic radiographs of 8830 patients (3723 males and 5107 females), which were used to search the radiological criteria of dentinogenesis imperfecta.

RESULTS

In our sample, the prevalence of dentinogenesis imperfecta was 0.057%. Out of the 8830 subjects, 0.080% of the males presented the radiological signs of the dentinogenesis imperfecta against 0.039% of the females.

CONCLUSION

In our study, we found that dentinogenesis imperfecta is a relatively rare dental anomaly in France, with a rate different from the rates reported in other studies and with no disparity in prevalence among genders.

Dental Management of a Child with Dentinogenesis Imperfecta: A Case Report

Dentinogenesis imperfecta (DI) is a hereditary dentin defect caused by an autosomal dominant mutation in dentin sialophosphoprotein gene. Defective dentin development results in discolored teeth that are prone to wear and fracture. Early diagnosis and proper treatment are necessary to achieve better functional and esthetic results and minimize nutritional deficiencies and psychosocial distress. In order to prevent excessive loss of tooth structure, placement of stainless steel crowns (SSCs) on deciduous and young permanent posterior teeth is recommended as soon as such teeth erupt. This clinical report presents the clinical manifestations and management of a 3.5-year-old child diagnosed with DI type II.

Osteogenesis imperfecta: pathophysiology and treatment

Osteogenesis imperfecta is a rare hereditary disease mostly caused by mutations impairing collagen synthesis and modification. Recently recessive forms have been described influencing differentiation and activity of osteoblasts and osteoclasts. Most prominent signs are fractures due to low traumata and deformities of long bones and vertebrae. Additional patients can be affected by dwarfism, scoliosis Dentinogenesis imperfecta, deafness and a blueish discoloration of the sclera. During childhood state of the art medical treatment are i.v. bisphosphonates to increase bone mass and to reduce fracture rate. Surgical interventions are needed to treat fractures, to correct deformities and should always be accompanied by physiotherapeutic and rehabilitative interventions.